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Sample records for two-lane rural roadway

  1. Development of adjustment functions to assess combined safety effects of multiple treatments on rural two-lane roadways.

    Science.gov (United States)

    Park, Juneyoung; Abdel-Aty, Mohamed

    2015-02-01

    Numerous studies have attempted to evaluate the safety effectiveness of specific single treatment on roadways by estimating crash modification factors (CMFs). However, there is a need to also assess safety effects of multiple treatments since multiple treatments are usually simultaneously applied to roadways. Due to the lack of sufficient CMFs of multiple treatments, the Highway Safety Manual (HSM) provides combining method for multiple CMFs. However, it is cautioned in the HSM and related sources that combined safety effect of multiple CMFs may be over or under estimated. Moreover, the literature did not evaluate the accuracy of the combining method using CMFs obtained from the same study area. Thus, the main objectives of this research are: (1) to estimate CMFs and crash modification functions (CM Functions) for two single treatments (shoulder rumble strips, widening (1-9ft) shoulder width) and combination (installing shoulder rumble strips+widening shoulder width) using the observational before-after with empirical Bayes (EB) method and (2) to develop adjustment factors and functions to assess combined safety effects of multiple treatments based on the accuracy of the combined CMFs for multiple treatments estimated by the existing combining method. Data was collected for rural two-lane roadways in Florida and Florida-specific safety performance functions (SPFs) were estimated for different crash types and severities. The CM Functions and adjustment functions were developed using linear and nonlinear regression models. The results of before-after with EB method show that the two single treatments and combination are effective in reducing total and SVROR (single vehicle run-off roadway) crashes. The results indicate that the treatments were more safety effective for the roadway segments with narrower original shoulder width in the before period. It was found that although the CMFs for multiple treatments (i.e., combination of two single treatments) were generally

  2. Evaluating the safety risk of roadside features for rural two-lane roads using reliability analysis.

    Science.gov (United States)

    Jalayer, Mohammad; Zhou, Huaguo

    2016-08-01

    The severity of roadway departure crashes mainly depends on the roadside features, including the sideslope, fixed-object density, offset from fixed objects, and shoulder width. Common engineering countermeasures to improve roadside safety include: cross section improvements, hazard removal or modification, and delineation. It is not always feasible to maintain an object-free and smooth roadside clear zone as recommended in design guidelines. Currently, clear zone width and sideslope are used to determine roadside hazard ratings (RHRs) to quantify the roadside safety of rural two-lane roadways on a seven-point pictorial scale. Since these two variables are continuous and can be treated as random, probabilistic analysis can be applied as an alternative method to address existing uncertainties. Specifically, using reliability analysis, it is possible to quantify roadside safety levels by treating the clear zone width and sideslope as two continuous, rather than discrete, variables. The objective of this manuscript is to present a new approach for defining the reliability index for measuring roadside safety on rural two-lane roads. To evaluate the proposed approach, we gathered five years (2009-2013) of Illinois run-off-road (ROR) crash data and identified the roadside features (i.e., clear zone widths and sideslopes) of 4500 300ft roadway segments. Based on the obtained results, we confirm that reliability indices can serve as indicators to gauge safety levels, such that the greater the reliability index value, the lower the ROR crash rate.

  3. Assisted overtaking: an assessment of overtaking on two-lane rural roads

    NARCIS (Netherlands)

    Hegeman, G.

    2008-01-01

    At the start of the 21st century overtaking on two-lane rural roads is a major traffic safety problem. However, this dissertation research demonstrates that most drivers are perfectly able to safely perform these manoeuvres. Their time spent in the left lane is about eight seconds. Preparing subtask

  4. Assisted overtaking: an assessment of overtaking on two-lane rural roads

    NARCIS (Netherlands)

    Hegeman, G.

    2008-01-01

    At the start of the 21st century overtaking on two-lane rural roads is a major traffic safety problem. However, this dissertation research demonstrates that most drivers are perfectly able to safely perform these manoeuvres. Their time spent in the left lane is about eight seconds. Preparing

  5. Influence of deficiencies in traffic control devices in crashes on two-lane rural roads.

    Science.gov (United States)

    López, Griselda; de Oña, Juan; Garach, Laura; Baena, Leticia

    2016-11-01

    One of the main objectives of all public administrations is reducing traffic crashes. To this end, Road Safety Inspections (RSI) stand out as a key measure. Signaling roads is one of the foremost tasks of RSI. A road that is improperly or poorly signaled can lead to incorrect placement or maneuvers of vehicles and ambiguous situations that can increase the risk of crashes. This paper analyses the relationship between road crashes in two-lane rural highways and certain deficiencies in signaling. The results show that deficiencies such as "incomplete removal of road works markings" or "no guide sign or in incorrect position" are the ones associated with a higher probability of crashes in two-lane rural highways. In view of these results, governmental agencies should verify that the original conditions of a highway are re-established after any construction work is completed. They should also continuously follow up on the signaling of this type of highway in order to maintain optimal conditions.

  6. Development of safety performance functions for Spanish two-lane rural highways on flat terrain.

    Science.gov (United States)

    Garach, Laura; de Oña, Juan; López, Griselda; Baena, Leticia

    2016-10-01

    Over decades safety performance functions (SPF) have been developed as a tool for traffic safety in order to estimate the number of crashes in a specific road section. Despite the steady progression of methodological innovations in the crash analysis field, many fundamental issues have not been completely addressed. For instance: Is it better to use parsimonious or fully specified models? How should the goodness-of-fit of the models be assessed? Is it better to use a general model for the entire sample or specific models based on sample stratifications? This paper investigates the above issues by means of several SPFs developed using negative binomial regression models for two-lane rural highways in Spain. The models were based on crash data gathered over a 5-year period, using a broad number of explanatory variables related to exposure, geometry, design consistency and roadside features. Results show that the principle of parsimony could be too restrictive and that it provided simplistic models. Most previous studies apply conventional measurements (i.e., R(2), BIC, AIC, etc.) to assess the goodness-of-fit of models. Seldom do studies apply cumulative residual (CURE) analysis as a tool for model evaluation. This paper shows that CURE plots are essential tools for calibrating SPF, while also providing information for possible sample stratification. Previous authors suggest that sample segmentation increases the model accuracy. The results presented here confirm that finding, and show that the number of significant variables in the final models increases with sample stratification. This paper point out that fully models based on sample segmentation and on CURE may provide more useful insights about traffic crashes than general parsimonious models when developing SPF.

  7. When do drivers abort an overtaking maneuver 5 on two-lane rural roads

    NARCIS (Netherlands)

    Farah, H.

    2016-01-01

    Overtaking on two-lane roads is a complex driving maneuver. Drivers who desire to overtake a lead vehicle need to evaluate the available gaps in the opposite direction and accept a sufficient gap to successfully complete the overtaking maneuver. However, often drivers realize that the gap they acce

  8. Crash prediction model for two-lane rural highways in the Ashanti region of Ghana

    Directory of Open Access Journals (Sweden)

    Williams Ackaah

    2011-07-01

    Full Text Available Crash Prediction Models (CPMs have been used elsewhere as a useful tool by road Engineers and Planners. There is however no study on the prediction of road traffic crashes on rural highways in Ghana. The main objective of the study was to develop a prediction model for road traffic crashes occurring on the rural sections of the highways in the Ashanti Region of Ghana. The model was developed for all injury crashes occurring on selected rural highways in the Region over the three (3 year period 2005–2007. Data was collected from 76 rural highway sections and each section varied between 0.8 km and 6.7 km. Data collected for each section comprised injury crash data, traffic flow and speed data, and roadway characteristics and road geometry data. The Generalised Linear Model (GLM with Negative Binomial (NB error structure was used to estimate the model parameters. Two types of models, the ‘core’ model which included key exposure variables only and the ‘full’ model which included a wider range of variables were developed. The results show that traffic flow, highway segment length, junction density, terrain type and presence of a village settlement within road segments were found to be statistically significant explanatory variables (p<0.05 for crash involvement. Adding one junction to a 1 km section of road segment was found to increase injury crashes by 32.0% and sections which had a village settlement within them were found to increase injury crashes by 60.3% compared with segments with no settlements. The model explained 61.2% of the systematic variation in the data. Road and Traffic Engineers and Planners can apply the crash prediction model as a tool in safety improvement works and in the design of safer roads. It is recommended that to improve safety, highways should be designed to by-pass village settlements and that the number of junctions on a highway should be limited to carefully designed ones.

  9. Development of comprehensive accident models for two-lane rural highways using exposure, geometry, consistency and context variables.

    Science.gov (United States)

    Cafiso, Salvatore; Di Graziano, Alessandro; Di Silvestro, Giacomo; La Cava, Grazia; Persaud, Bhagwant

    2010-07-01

    In Europe, approximately 60% of road accident fatalities occur on two-lane rural roads. Thus, research to develop and enhance explanatory and predictive models for this road type continues to be of interest in mitigating these accidents. To this end, this paper describes a novel and extensive data collection and modeling effort to define accident models for two-lane road sections based on a unique combination of exposure, geometry, consistency and context variables directly related to the safety performance. The first part of the paper documents how these were identified for the segmentation of highways into homogeneous sections. Next, is a description of the extensive data collection effort that utilized differential cinematic GPS surveys to define the horizontal alignment variables, and road safety inspections (RSIs) to quantify the other road characteristics related to safety. The final part of the paper focuses on the calibration of models for estimating the expected number of accidents on homogeneous sections that can be characterized by constant values of the explanatory variables. Several candidate models were considered for calibration using the Generalized Linear Modeling (GLM) approach. After considering the statistical significance of the parameters related to exposure, geometry, consistency and context factors, and goodness of fit statistics, 19 models were ranked and three were selected as the recommended models. The first of the three is a base model, with length and traffic as the only predictor variables; since these variables are the only ones likely to be available network-wide, this base model can be used in an empirical Bayesian calculation to conduct network screening for ranking "sites with promise" of safety improvement. The other two models represent the best statistical fits with different combinations of significant variables related to exposure, geometry, consistency and context factors. These multiple variable models can be used, with

  10. Speed Distribution on Two-Lane Rural Highways with Mixed Traffic: A Case Study in North East India

    Science.gov (United States)

    Saha, Pritam; Roy, Nabanita; Sarkar, Ashoke Kumar; Pal, Manish

    2017-06-01

    This work focuses on minimising inaccuracies in distributional assumptions of speed data on two-lane roads with heterogeneous traffic to improve accuracy in capacity and level of service analysis. Accordingly, field study was conducted on a two-lane highway in India that exhibits heterogeneity in its traffic composition. Two distribution functions, namely, normal and logistic were examined for the observed speed data. The appropriate function was chosen using a methodology based on K-S test and field validation. Logistic distribution function was found to exhibit its aptness in describing speed under such traffic and was, thereby, considered in estimating the limiting speed of slower vehicles that tends to obstruct the flow of traffic. Vehicles that move at or below this speed cause delay to the faster ones resulting in formation of platoons at moderate and heavy flow when passing is restricted. Since the percent time-spent-following, a performance measure to assess level-of-service of two-lane highways, considers proportion of vehicles that are trapped inside platoons, it is imperative to estimate the limiting speed of slower vehicles correctly to approximate the delayed vehicles.

  11. Factors associated with crash severity on rural roadways in Wyoming

    Directory of Open Access Journals (Sweden)

    Debbie S. Shinstine

    2016-08-01

    Full Text Available The ability to identify risk factors associated with crashes is critical to determine appropriate countermeasures for improving roadway safety. Many studies have identified risk factors for urban systems and intersections, but few have addressed crashes on rural roadways, and none have analyzed crashes on Indian Reservations. This study analyzes crash severity for rural highway systems in Wyoming. These rural systems include interstates, state highways, rural county local roads, and the roadway system on the Wind River Indian Reservation (WRIR. In alignment with the Wyoming strategic highway safety goal of reducing critical crashes (fatal and serious injury, crash severity was treated as a binary response in which crashes were classified as severe or not severe. Multiple logistic regression models were developed for each of the highway systems. Five effects were prevalent on all systems including animals, driver impairment, motorcycles, mean speed, and safety equipment use. With the exception of animal crashes, all of these effects increased the probability that a crash would be severe. Based upon these results, DOTs can pursue effective policies and targeted design decisions to reduce the severity of crashes on rural highways.

  12. Studying the effect of spiral curves and intersection angle, on the accident ratios in two-lane rural highways in Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Hossain Jalal Kamali

    2013-07-01

    Full Text Available Safety in highways is one of the most important subjects in Transportation Engineering. Increasing rate of vehicles and the needs to design or geometrically modifying the highways, emphasized on the safe-designing of the roadways more than before. Between the constructive components of the highway, horizontal curves due to the more occurrences of accidents are of great importance. The American ministry of highway and transportation introduced the software IHSDM, with variant capabilities, to predict accidents. In this research, five types of curves (simple circle curve and clothoid-circle-clothoid at different intersection angles were designed, and accident rates based on the standard specifications on each curve was predicted by using the IHSDM, and the results are compared with each other. Finally, by processing the curves of accident rates versus the curves types and intersection angle, and comparing them with each other, the necessity of using spiral curves in the highway design is emphasized.

  13. Traffic states and jamming transitions induced by a bus in two-lane traffic flow

    Science.gov (United States)

    Nagai, Ryoichi; Nagatani, Takashi; Taniguchi, Naoki

    2005-05-01

    We study the traffic states and jamming transitions induced by a bus (slow car) in a two-lane traffic of cars. We use the dynamic model which is an extended one of the optimal velocity model to take into account the lane changing. The fundamental (flow-density) diagram is presented. The fundamental diagram changes highly by introducing a bus on a two-lane roadway. It is found that there are the six distinct states for the two-lane traffic flow including a bus. The spatio-temporal patterns are presented for the distinct traffic states. The dynamical state of traffic changes with density of cars. It is shown that the dynamical transitions among the distinct traffic states occur at some values of density. The phase diagram (region map) is shown for the two-lane traffic flow including a bus.

  14. Rural roadway safety perceptions among rural teen drivers living in and outside of towns.

    Science.gov (United States)

    Ramirez, Marizen; Roth, Lisa; Young, Tracy; Peek-Asa, Corinne

    2013-01-01

    To compare perceptions about rural road and general driving behaviors between teens who live in- and out-of-town from rural communities in Iowa. A cross-sectional survey was conducted with 160 teens anticipating their Intermediate License within 3 months upon enrollment into this study. Self-administered surveys were used to collect demographics and driving exposures (eg, frequency of driving, age when first drove unsupervised). Two Likert scales were included to measure agreement with safe driving behaviors on rural roads and general safe driving behaviors (eg, speeding, seat belt use). T-tests were calculated comparing mean composite scores between in- and out-of-town teens, and between mean rural road and general driving safety attitude scores. A linear regression multivariable model was constructed to identify predictors of the rural road score. While the majority of teens endorsed rural road and general safe driving behaviors, up to 40% did not. Thirty-two percent did not believe the dangers of animals on rural roads, and 40% disagreed that exceeding the speed limit is dangerous. In-town teens were less safety conscious about rural road hazards with a significantly lower mean composite score (4.4) than out-of-town teens (4.6); mean scores for general driving behaviors were similar. Living out-of-town and owning one's own car were significant predictors of increased rural road safety scores. Rural, in-town teens have poorer safety attitudes about rural roadway hazards compared with out-of-town teens. Interventions that involve education, parental supervision, and practice on rural roads are critical for preventing teen crashes on rural roads. No claim to original US government works.

  15. Capacity of two-lane roads

    CSIR Research Space (South Africa)

    Kennedy, DA

    1991-01-01

    Full Text Available Relationships of speed vs density, volume and percentage loop occupation are investigated. The effect of differing directional splits in traffic volumes is also examined. A method of determining the Level-of Service of two-lane roads in terms...

  16. Continuum modeling for two-lane traffic flow

    Institute of Scientific and Technical Information of China (English)

    Haijun Huang; Tieqiao Tang; Ziyou Gao

    2006-01-01

    In this paper,we study the continuum modeling of traffic dynamics for two-lane freeways.A new dynamics model is proposed, which contains the speed gradient-based momentum equations derived from a car-following theory suited to two-lane traffic flow.The conditions for securing the linear stability of the new model are presented.Numerical tests are carried out and some nonequilibrium phenomena are observed, such as small disturbance instability,stop-andgo waves,local clusters and phase transition.

  17. Lane changing analysis for two-lane traffic flow

    Institute of Scientific and Technical Information of China (English)

    Tieqiao Tang; Haijun Huang; S.C.Wong; Rui Jiang

    2007-01-01

    In this paper,the two-lane traffic are studiedby using the lane-changing rules in the car-followingmodels.The simulation show that the frequent lanechanging occurs when the lateral distance in car fol-lowing activities is considered and it gives rise to oscil-lating waves.In contrast,if the lateral distance is notconsidered (or considered occasionally),the lane chang-ing appears infrequently and soliton waves occurs.Thisimplies that the stabilization mechanism no longer func-tions when the lane changing is permitted.Since theoscillating and soliton waves correspond to the unsta-ble and metastable flow regimes,respectively,our studyverifies that a phase transition may occur as a result ofthe lane changing.

  18. A modified two-lane traffic model considering drivers' personality

    Science.gov (United States)

    Zhu, H. B.; Zhang, N. X.; Wu, W. J.

    2015-06-01

    Based on the two-lane traffic model proposed by Chowdhury et al., a modified traffic model (R-STCA model, for short) is presented, in which the new symmetric lane changing rules are introduced by considering driving behavioral difference and dynamic headway. After the numerical simulation, a broad scattering of simulated points is exhibited in the moderate density region on the flow-density plane. The synchronized flow phase accompanied with the wide moving jam phase is reproduced. The spatial-temporal profiles indicate that the vehicles move according to the R-STCA model can change lane more easily and more realistically. Then vehicles are convenient to get rid of the slow vehicles that turn into plugs ahead, and hence the capacity increases. Furthermore the phenomenon of the high speed car-following is discovered by using the R-STCA model, which has been already observed in the traffic measured data. All these results indicate that the presented model is reasonable and more realistic.

  19. The effect of interruption probability in lattice model of two-lane traffic flow with passing

    Science.gov (United States)

    Peng, Guanghan

    2016-11-01

    A new lattice model is proposed by taking into account the interruption probability with passing for two-lane freeway. The effect of interruption probability with passing is investigated about the linear stability condition and the mKdV equation through linear stability analysis and nonlinear analysis, respectively. Furthermore, numerical simulation is carried out to study traffic phenomena resulted from the interruption probability with passing in two-lane system. The results show that the interruption probability with passing can improve the stability of traffic flow for low reaction coefficient while the interruption probability with passing can destroy the stability of traffic flow for high reaction coefficient on two-lane highway.

  20. A new traffic model with the consideration of coupling effect with two lanes

    Institute of Scientific and Technical Information of China (English)

    Peng Guang-Han; Sun Di-Hua; He Heng-Pan

    2009-01-01

    This paper introduces a new two-lane high-order continuum model by embedding the two delay time scales con-tinuum traffic model presented by Xue (2003 Phys. Rev. E 68 066123) into the multi-lane model proposed by Daganzo (1997 Transpn. Res. B 31 83) with the consideration of the coupling effect between the vehicles of two lanes in instan-taneous traffic situation and lane-change effect. In the novel model, the coupling effect of two lanes and phenomena of lane change, which were not discussed in Daganzo's model and Xue's model, are taken into account. Numerical simulation shows that it is in accordance with real traffic flow. This obviously indicates that the new phenomenon and behaviour are analogous results as single lane presented by Xue, and the proposed model is more reasonable on two lanes. Furthermore, the generation rate between two lanes is also investigated. The results show that the formation and diffusion of traffic shock wave can be better simulated on two lanes.

  1. Influence of lane change on stability analysis for two-lane traffic flow

    Institute of Scientific and Technical Information of China (English)

    Zheng Liang; Ma Shou-Feng; Zhong Shi-Quan

    2011-01-01

    This paper deals mainly with the influence of lane changing behaviours on the stability of two-lane traffic flow under a periodic boundary condition.Following the description of an optimal velocity model for two vehicle groups and the derivation of their stability conditions,the feedback signals,which involve information about vehicles from both lanes acting on the two-lane traffic system,are introduced into the optimal velocity model.The control signals play a role in alleviating the traffic jam only if the traffic state is in congestion,and their role will vanish if the traffic state is in the steady state.The numerical simulations show that lane changing behaviours can break the steady state of two-lane traffic flow and aggravate the traffic disturbance,but the control method would successfully suppress the traffic jam eventually,which implies that the conclusions obtained here have certain theoretical and practical significance.

  2. Feedback control for car following model based on two-lane traffic flow

    Science.gov (United States)

    Ge, Hong-xia; Meng, Xiang-pei; Zhu, Hui-bing; Li, Zhi-Peng

    2014-08-01

    In the paper, two-lane traffic flow considering lane changing behaviors has been discussed based on the control theory, and the friction interference which is from the neighbor lane has been taken into account. By using the control method, the stability condition is derived. The feedback signals, which include vehicular information from both lanes, acting on the two-lane traffic system have been introduced into the Full Velocity Difference car-following model. In the end, simulations are conducted to examine the validity and reasonability of the control method. It is proven that lane changing behaviors can aggravate the traffic perturbation. The traffic flow congestion could be suppressed by using the control method and the simulation results are in good agreement with the theoretical analysis.

  3. A Two-Lane Cellular Automata Model with Influence of Next-Nearest Neighbor Vehicle

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, we propose a new two-lane cellular automata model in which the influence of the next-nearest neighbor vehicle is considered. The attributes of the traffic system composed of fast-lane and slow-lane are investigated by the new traffic model. The simulation results show that the proposed two-lane traffic model can reproduce some traffic phenomena observed in real traffic, and that maximum flux and critical density are close to the field measurements.Moreover, the initial density distribution of the fast-lane and slow-lane has much influence on the traffic flow states.With the ratio between the densities of slow lane and fast lane increasing the lane changing frequency increases, but maximum flux decreases. Finally, the influence of the sensitivity coefficients is discussed.

  4. Analysis of average density difference effect in a new two-lane lattice model

    Science.gov (United States)

    Zhang, Geng; Sun, Di-Hua; Zhao, Min; Liu, Wei-Ning; Cheng, Sen-Lin

    2015-11-01

    A new lattice model is proposed by taking the average density difference effect into account for two-lane traffic system according to Transportation Cyber-physical Systems. The influence of average density difference effect on the stability of traffic flow is investigated through linear stability theory and nonlinear reductive perturbation method. The linear analysis results reveal that the unstable region would be reduced by considering the average density difference effect. The nonlinear kink-antikink soliton solution derived from the mKdV equation is analyzed to describe the properties of traffic jamming transition near the critical point. Numerical simulations confirm the analytical results showing that traffic jam can be suppressed efficiently by considering the average density difference effect for two-lane traffic system.

  5. Flow difference effect in the two-lane lattice hydrodynamic model

    Institute of Scientific and Technical Information of China (English)

    Wang Tao; Gao Zi-You; Zhao Xiao-Mei; Tian Jun-Fang; Zhang Wen-Yi

    2012-01-01

    By introducing a flow difference effect,a modified lattice two-lane traffic flow model is proposed,which is proved to be capable of improving the stability of traffic flow.Both the linear stability condition and the kink-antikink solution derived from the modified Korteweg-de Vries (mKdV) equation are analyzed.Numerical simulations verify the theoretical analysis.Furthermore,the evolution laws under different disturbances in the metastable region are studied.

  6. Controlling traffic jams on a two-lane road using delayed-feedback signals

    Institute of Scientific and Technical Information of China (English)

    Liang ZHENG; Shi-quan ZHONG; Shou-feng MA

    2012-01-01

    This paper focuses mainly on the stability analysis of two-lane traffic flow with lateral friction,which may be caused by irregular driving behavior or poorly visible road markings,and also attempts to reveal the formation mechanism of traffic jams.Firstly,a two-lane optimal velocity (OV) model without control signals is proposed and its stability condition is obtained from the viewpoint of control theory.Then delayed-feedback control signals composed of distance headway information from both lanes are added to each vehicle and a vehicular control system is designed to suppress the traffic jams.Lane change behaviors are also incorporated into the two-lane OV model and the corresponding information about distance headway and feedback signals is revised.Finally,the results of numerical experiments are shown to verify that when the stability condition is not met,the position disturbances and resulting lane change behaviors do indeed deteriorate traffic performance and cause serious traffic jams.However,once the proper delayed-feedback control signals are implemented,the traffic jams can be suppressed efficiently.

  7. Two-lane traffic-flow model with an exact steady-state solution.

    Science.gov (United States)

    Kanai, Masahiro

    2010-12-01

    We propose a stochastic cellular-automaton model for two-lane traffic flow based on the misanthrope process in one dimension. The misanthrope process is a stochastic process allowing for an exact steady-state solution; hence, we have an exact flow-density diagram for two-lane traffic. In addition, we introduce two parameters that indicate, respectively, driver's driving-lane preference and passing-lane priority. Due to the additional parameters, the model shows a deviation of the density ratio for driving-lane use and a biased lane efficiency in flow. Then, a mean-field approach explicitly describes the asymmetric flow by the hop rates, the driving-lane preference, and the passing-lane priority. Meanwhile, the simulation results are in good agreement with an observational data, and we thus estimate these parameters. We conclude that the proposed model successfully produces two-lane traffic flow particularly with the driving-lane preference and the passing-lane priority.

  8. Overtaking Safety Evaluation and Setting of Auxiliary Lane on Two-Lane Highway in China

    Directory of Open Access Journals (Sweden)

    Guozhu Cheng

    2016-01-01

    Full Text Available Overtaking experiments on four two-lane highways were conducted. The data of overtaking conflict time (the time difference between the time of driving back to the original lane and the time of meeting with the first opposing vehicle and experimental drivers’ risk feeling were observed. Membership was adopted to denote the experimental drivers’ risk feelings which also denote the severity of traffic conflict. Membership ranges from 0 to 1 and corresponding risk becomes higher; that is, traffic conflict becomes more serious. According to the observed relationship between overtaking conflict time, and drivers’ risk feeling membership, Cauchy distribution function was adopted as membership function. The thresholds of the severity of traffic conflict were determined through Delphi method. The relationship model among traffic volume, overtaking conflict time and design speed was established according to experimental data. Then the idea of setting auxiliary lane on two-lane highway in China was presented. And the traffic volume values that need setting auxiliary lane corresponding to different design speed and traffic conflict degree were given according to the established model. It is expected to improve the traffic safety level of two-lane highway in China through setting auxiliary lane.

  9. Comparison of consistency assessment models for isolated horizontal curves in two-lane rural highways

    Directory of Open Access Journals (Sweden)

    Danilo Cárdenas-Aguilar

    2015-01-01

    Full Text Available El análisis de consistencia del diseño geométrico de carreteras tiene por objetivo contar con carreteras más seguras. Para analizar consistencia existen dos tipos de modelos: agregados y desagregados. Los primeros consideran diferencias de velocidades de diseño y operación en la mitad de la curva. Los segundos consideran la variación espacial del perfil de velocidad de operación. Este trabajo comparó los dos métodos usando datos empíricos de velocidad de operación obtenidos con un GPS de 10 Hz en 34 curvas horizontales simples de carreteras de dos carriles en Chile. Los resultados permitieron concluir que solo en 19 casos los métodos resultaron equivalentes entre sí. Esta compatibilidad sólo se da cuando el perfil de velocidad de operación posee poca varianza especial. Si el perfil de velocidad de operación es muy variable espacialmente, el nivel de consistencia obtenido usando los 2 métodos es diferente, caso en el cual resulta más conveniente combinarlos.

  10. Contribution to Accident Prediction Models Development for Rural Two-Lane Roads in Serbia

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    Draženko Glavić

    2016-08-01

    Full Text Available Over the last three decades numerous research efforts have been conducted worldwide to determine the relationship between traffic accidents and traffic and road characteristics. So far, the mentioned studies have not been carried out in Serbia and in the region. This paper represents one of the first attempts to develop accident prediction models in Serbia. The paper provides a comprehensive literature review, describes procedures for collection and analysis of the traffic accident data, as well as the methodology used to develop the accident prediction models. The paper presents models obtained by both univariate and multivariate regression analyses. The obtained results are compared to the results of other studies and comparisons are discussed. Finally, the paper presents conclusions and important points for future research. The results of this research can find theoretical as well as practical application.

  11. Shape-dependence of the barrier for skyrmions on a two-lane racetrack

    Science.gov (United States)

    Müller, Jan

    2016-10-01

    Single magnetic skyrmions are localized whirls in the magnetization with an integer winding number. They have been observed on nano-meter scales up to room temperature in multilayer structures. Due to their small size, topological winding number, and their ability to be manipulated by extremely tiny forces, they are often called interesting candidates for future memory devices. The two-lane racetrack has to exhibit two lanes that are separated by an energy barrier. The information is then encoded in the position of a skyrmion which is located in one of these close-by lanes. The artificial barrier between the lanes can be created by an additional nanostrip on top of the track. Here we study the dependence of the potential barrier on the shape of the additional nanostrip, calculating the potentials for a rectangular, triangular, and parabolic cross section, as well as interpolations between the first two. We find that a narrow barrier is always repulsive and that the height of the potential strongly depends on the shape of the nanostrip, whereas the shape of the potential is more universal. We finally show that the shape-dependence is redundant for possible applications.

  12. Two-lane traffic rules for cellular automata: A systematic approach

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, K. [Los Alamos National Lab., NM (United States)]|[Forschungszentrum Juelich (Germany). Hoechsteleistungsrechenzentrum HLRZ; Wolf, D.E. [Forschungszentrum Juelich (Germany). Hoechstleistungsrechenzentrum HLRZ]|[Gerhard-Mercator-Univ., Duisburg (Germany). Theoretische Physik; Wagner, P. [Univ. zu Koeln (Germany). Zentrum Fuer Paralleles Rechnen]|[Deutsche Forschungsanstalt fuer Luft- und Raumfahrt, Koeln (Germany); Simon, P. [Los Alamos National Lab., NM (United States)

    1997-11-05

    Microscopic modeling of multi-lane traffic is usually done by applying heuristic lane changing rules, and often with unsatisfying results. Recently, a cellular automation model for two-lane traffic was able to overcome some of these problems and to produce a correct density inversion at densities somewhat below the maximum flow density. In this paper, the authors summarize different approaches to lane changing and their results, and propose a general scheme, according to which realistic lane changing rules can be developed. They test this scheme by applying it to several different lane changing rules, which, in spite of their differences, generate similar and realistic results. The authors thus conclude that, for producing realistic results, the logical structure of the lane changing rules, as proposed here, is at least as important as the microscopic details of the rules.

  13. Event-Based Modeling of Driver Yielding Behavior to Pedestrians at Two-Lane Roundabout Approaches.

    Science.gov (United States)

    Salamati, Katayoun; Schroeder, Bastian J; Geruschat, Duane R; Rouphail, Nagui M

    2014-01-01

    Unlike other types of controlled intersections, drivers do not always comply with the "yield to pedestrian" sign at the roundabouts. This paper aims to identify the contributing factors affecting the likelihood of driver yielding to pedestrians at two-lane roundabouts. It further models the likelihood of driver yielding based on these factors using logistic regression. The models have been applied to 1150 controlled pedestrian crossings at entry and exit legs of two-lane approaches of six roundabouts across the country. The logistic regression models developed support prior research that the likelihood of driver yielding at the entry leg of roundabouts is higher than at the exit. Drivers tend to yield to pedestrians carrying a white cane more often than to sighted pedestrians. Drivers traveling in the far lane, relative to pedestrian location, have a lower probability of yielding to a pedestrian. As the speed increases the probability of driver yielding decreases. At the exit leg of the roundabout, drivers turning right from the adjacent lane have a lower propensity of yielding than drivers coming from other directions. The findings of this paper further suggest that although there has been much debate on pedestrian right-of-way laws and distinction between pedestrian waiting positions (in the street versus at the curb), this factor does not have a significant impact on driver yielding rate. The logistic regression models also quantify the effect of each of these factors on propensity of driver yielding. The models include variables which are specific to each study location and explain the impact size of each study location on probability of yielding. The models generated in this research will be useful to transportation professionals and researchers interested in understanding the factors that impact driver yielding at modern roundabouts. The results of the research can be used to isolate factors that may increase yielding (such as lower roundabout approach speeds

  14. Examining the effect of speed, roadside features, and roadway geometry on crash experience along a rural corridor

    Institute of Scientific and Technical Information of China (English)

    Donald C.Watson Jr.; Ahmed Al-Kaisy; Nathan D.Anderson

    2014-01-01

    This paper presents a current investigation into crash experience along a 15.7-mile rural corridor in southwest Montana with the aim of better understanding crash causal factors along the corridor. The study utilized ten years of crash data, geometric data, and observed free-flow speed data along the corridor. A systematic approach was used where every tenth of a mile was described in term of the crash experience, speed, alignment, and roadside features. Using bivariate and multivariate statistical anal-yses, the study investigated the crash experience along the corridor as well as some of the underlying relationships which could explain some of the crash causal factors. Results show a strong association between crash rates and horizontal curvatures even for flat curves that can be negotiated at speeds above the posted speed limit, per the highway design equations. Higher crash rates were also found to be associated with the difference between the observed free-flow speeds and the speed dictated by the curve radius or sight distance as per the design equations. Further, results strongly support the safety benefits of guardrails as evidenced by the lower crash rates and severities. The presence of fixed objects and the steepness of side slopes were also found to have an effect on crash rates and severities.

  15. Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle across Two Lanes of Opposing Traffic

    Science.gov (United States)

    Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.

    2013-01-01

    This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications--bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous…

  16. Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle across Two Lanes of Opposing Traffic

    Science.gov (United States)

    Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.

    2013-01-01

    This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications--bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous…

  17. Two-lane traffic simulations with a blockage induced by an accident car

    Science.gov (United States)

    Zhu, H. B.; Lei, L.; Dai, S. Q.

    2009-07-01

    Based on the two-lane traffic model proposed by Chowdhury et al., a highway traffic model with a blockage induced by an accident car is proposed, in which both symmetric lane changing rules and asymmetric lane changing rules are adopted. The fundamental diagrams and spatial-temporal profiles are presented after the numerical simulation and the jam transition is studied. It is shown that the accident car not only causes a local jam behind the accident car, but also causes vehicles to cluster in the bypass lane. The asymmetric lane changing rules are more advantageous in reducing the local jam than the symmetric lane changing rules when the accident car is in the right lane, and the symmetric lane changing rules are superior when the accident car is in the left lane. Furthermore the curves of lane-changing frequency against the total density are given. It is found that the vehicles will change lane more frequently when traffic is inhomogeneous with different types of vehicle or with an accident car.

  18. Motion of Skyrmions in Well-Separated Two-Lane Racetracks

    Science.gov (United States)

    Lai, P.; Zhao, G. P.; Morvan, F. J.; Wu, S. Q.; Ran, N.

    Magnetic skyrmions are topological structures which can be used to store information as data bits in metallic racetrack memories. Their good properties, such as their stability, small size and low currents needed to drive them make them better candidates than traditional magnetic domain walls for the building of the next generation data storage. A skyrmion racetrack memory has been suggested, with the binary data encoded in the distance between skyrmions when the racetrack is a single lane. Here, we propose a new skyrmion-based two-lane racetrack structure separated by a high-K (high magnetocrystalline anisotropy) middle lane, which confines the skyrmions in their respective lanes. This design gives a new data presentation for the skyrmions on the racetrack. Phase diagrams for the skyrmion motion on the proposed racetrack as functions of the current density, middle lane anisotropy, middle lane width and DMI constant have been calculated and given, demonstrating that skyrmions can be driven in different lanes of the racetrack. This design offers the possibility of building an ultrafast and energy-efficient skyrmion transport device.

  19. Modeling mechanical restriction differences between car and heavy truck in two-lane cellular automata traffic flow model

    Science.gov (United States)

    Li, Xin; Li, Xingang; Xiao, Yao; Jia, Bin

    2016-06-01

    Real traffic is heterogeneous with car and truck. Due to mechanical restrictions, the car and the truck have different limited deceleration capabilities, which are important factors in safety driving. This paper extends the single lane safety driving (SD) model with limited deceleration capability to two-lane SD model, in which car-truck heterogeneous traffic is considered. A car has a larger limited deceleration capability while a heavy truck has a smaller limited deceleration capability as a result of loaded goods. Then the safety driving conditions are different as the types of the following and the leading vehicles vary. In order to eliminate the well-known plug in heterogeneous two-lane traffic, it is assumed that heavy truck has active deceleration behavior when the heavy truck perceives the forming plug. The lane-changing decisions are also determined by the safety driving conditions. The fundamental diagram, spatiotemporal diagram, and lane-changing frequency were investigated to show the effect of mechanical restriction on heterogeneous traffic flow. It was shown that there would be still three traffic phases in heterogeneous traffic condition; the active deceleration of the heavy truck could well eliminate the plug; the lane-changing frequency was low in synchronized flow; the flow and velocity would decrease as the proportion of heavy truck grows or the limited deceleration capability of heavy truck drops; and the flow could be improved with lane control measures.

  20. A two-lane cellular automaton traffic flow model with the influence of driver, vehicle and road

    Science.gov (United States)

    Zhao, Han-Tao; Nie, Cen; Li, Jing-Ru; Wei, Yu-Ao

    2016-07-01

    On the basis of one-lane comfortable driving model, this paper established a two-lane traffic cellular automata model, which improves the slow randomization effected by brake light. Considering the driver psychological characteristics and mixed traffic, we studied the lateral influence between vehicles on adjacent lanes. Through computer simulation, the space-time diagram and the fundamental figure under different conditions are obtained. The study found that aggressive driver makes a slight congestion in low-density traffic and improves the capacity of high-density traffic, when the density exceeds 20pcu/km the more aggressive drivers the greater the flow, when the density below 40pcu/km driver character makes an effect, the more cautious driver, the lower the flow. The ratio of big cars has the same effect as the ratio of aggressive drivers. Brake lights have the greatest impact on traffic flow and when the density exceeds 10pcu/km the traffic flow fluctuates. Under periodic boundary conditions, the disturbance of road length on traffic is minimal. The lateral influence only play a limited role in the medium-density conditions, and only affect the average speed of traffic at low density.

  1. Analysis of a novel two-lane lattice model on a gradient road with the consideration of relative current

    Science.gov (United States)

    Cao, Jin-Liang; Shi, Zhong-Ke

    2016-04-01

    In this paper, a novel hydrodynamic lattice model is proposed by considering of relative current for two-lane gradient road system. The stability condition is obtained by using linear stability theory and shown that the stability of traffic flow varies with three parameters, that is, the slope, the sensitivity of response to the relative current and the rate of lane changing. The stable region increases with the increasing of one of them when another two parameters are constant. By using nonlinear analysis, the Burgers, Korteweg-de Vries, and modified Korteweg-de Vries equations are derived to describe the phase transition of traffic flow. Their solutions present the density wave as the triangular shock wave, soliton wave, and kink-antikink wave in the stable, metastable, and unstable region, respectively, which can explain the phase transitions from free traffic to stop-and-go traffic, and finally to congested traffic. To verify the theoretical results, a series of numerical simulations are carried out. The numerical results are consistent with the analytical results. To check the novel model, calibration are taken based on the empirical traffic flow data. The theoretical results and numerical results show that the traffic flow on the gradient road becomes more stable and the traffic congestion can be efficiently suppressed by considering the relative current and lane changing, and the empirical analysis shows that the novel lattice model is reasonable.

  2. A viscous continuum traffic flow model with consideration of the coupling effect for two-lane freeways

    Institute of Scientific and Technical Information of China (English)

    Sun Di-Hua; Peng Guang-Han

    2009-01-01

    In this paper,the viscous continuum traffic flow model for a single lane is extended to the traffic flow for two-lane freeways. The proposed model is a higher-order continuum model considering the coupling and lane changing effects of the vehicles on two adjacent lanes. It results from integrating the Taylor series expansion of the viscous continuum traffic flow model proposed by Ge (2006 Physics A 371 667) into the multi-lane model presented by Daganzo (1997Transpn. Res. B 31 83). Our proposed model may be used to describe non-anisotropic behaviour because of lane changing in multi-lane traffic. A linear stability analysis is given and the neutral stability condition is obtained. Also,issues related to lane changing,shock waves and rarefaction waves,local clustering and phase transition are investigated through a simulation experiment. The simulation results show that the proposed model is capable of explaining some particular traffic phenomena commonly observable in real world traffic flow.

  3. Rapid roadway development

    Energy Technology Data Exchange (ETDEWEB)

    David Hainsworth [CSIRO Exploration & Mining (Australia)

    2009-06-15

    A new mining machine, the ACBM, has been developed, which will demonstrate new technologies and will act as a platform for further research and development. With the advent of the ACARP Roadway Development Task Group and the CM2010 project, an ACARP initiative to develop a new mining machine that can operate for 20 hours per day at 10m per hour development rate, it is believed that the Autonomous Conveyor Bolter Module (ACBM) will remain a key potential building block to meet certain CM2010 project targets. The bolt storage and delivery system has been found to be appropriate for further investigation and development as part of ongoing CM2010 studies. This final project reports and discusses the successes of the project; examines the reasons for failure to achieve the initial project objectives; shows how reduced scope objectives were defined; and describes the learnings from this project which will provide a positive influence to the direction of future work.

  4. 考虑交通障碍的双车道扩展交通流模型%Extend Two-lane Traffic Flow Model with a Blockage

    Institute of Scientific and Technical Information of China (English)

    李建锋; 赵靖

    2012-01-01

    借助智能交通系统(ITS),把扩展的车辆跟驰模型应用于双车道,建立根据确定规则进行换道的扩展交通流跟驰模型.通过改变发车车头间距,在开放边界条件下左车道有交通事故发生时,重现实际交通中的交通流现象.数值模拟发现:双车道交通流模型能够有效地抑制交通流阻塞,提高交通流量.%The extended car-following model is applied into two-lane system based on intelligent transportation system application (ITS). Then, an extended model of two-lane traffic in which vehicles change the lane by a deterministic rule is presented. The typical traffic induced by a car accident on the left lane under the open boundary is investigated. The simulation results suggest that the two-lane traffic model can suppress the traffic jam and enhance the traffic flow effectively.

  5. 30 CFR 56.9313 - Roadway maintenance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Roadway maintenance. 56.9313 Section 56.9313 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... § 56.9313 Roadway maintenance. Water, debris, or spilled material on roadways which creates hazards...

  6. 30 CFR 57.9313 - Roadway maintenance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Roadway maintenance. 57.9313 Section 57.9313 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... § 57.9313 Roadway maintenance. Water, debris, or spilled material on roadways which creates hazards...

  7. Experimental Study of Drivers' Overtaking Behavior on Two-lane Highways%双车道公路驾驶员超车行为试验研究

    Institute of Scientific and Technical Information of China (English)

    刘江

    2013-01-01

    By high-accuracy GPS dynamic data acquisition instrument,the author designed the experimental plan of drivers' overtaking on the two-lane highways with the drivers' perceive to measure the overtakable gap and the returnable gap.The experimental results could be used as the basis for the study of two-lane highways' capacity,drivers' overtaking behavior,the design of overtaking sight distance and intelligent transportation system.%通过利用高精度全球定位系统(global positioning system,GPS)动态数据采集仪,结合驾驶员超车过程的感受度,设计了双车道公路上测量可回车车头时距和可超车车头时距的试验方案,获得的实验数据可为研究双车道公路通行能力、驾驶员超车行为、设计超车视距以及构建智能交通系统提供实测数据依据.

  8. Study on traffic states and jamming transitions for two-lane highway including a bus by using a model with calibrated optimal velocity function

    Science.gov (United States)

    Li, Zhipeng; Yi, Yi

    2014-07-01

    In this paper, traffic states and jamming transitions on two-lane highway including a bus are studied by using a car following model with a calibrated optimal velocity function. We derive a new flow-density diagram with four distinctly separated traffic states, which is different from that of the earlier study obtained by applying the OVM with theoretical optimal velocity function. The spatio-temporal diagrams are presented to illustrate phase characteristics of each traffic state. It is found that the phase characteristic features of two of four states are different from any state of the earlier result, and traffic flow of state 2 and state 3 can reproduce some characteristics observed from empirical investigations such as centralized lane-changing, hanging tail of cluster, and synchronized flow. In addition, we have clarified the lane-changing behaviors and their effects on two-lane traffic flow including a bus. It is shown that the velocity oscillations behind the bus can help the lane-changing in state 2 and the behaviors of lane-changing are the important reason of forming of the synchronized flow in state 3. It is also concluded that lane-changing can only improve the current in the region of middle density.

  9. Study on the effects of driver's lane-changing aggressiveness on traffic stability from an extended two-lane lattice model

    Science.gov (United States)

    Li, Zhipeng; Zhang, Run; Xu, Shangzhi; Qian, Yeqing

    2015-07-01

    In this paper, the effects of driver's lane-changing aggressiveness on the stability of traffic flow of two-lane are studied by using a generalized lattice hydrodynamic model with consideration of lane-changing aggressiveness of each individual. The effect of lane-changing aggressiveness parameter on traffic stability is derived through employing linear stability analysis with finding that the driver's lane-changing aggressiveness has an important impact on the stability of the traffic flow in a two-lane system. To describe the phase transition, the mKdV equation near the critical point is derived by using the reductive perturbation method, with obtaining the dependence of the propagation kink solution for traffic jams on the lane-changing aggressiveness. It can be concluded from the phase diagram of stability criterion that the higher lane-changing aggressiveness leads to a more stable traffic flow. In addition, the stabilizing effect of the optimal current difference weakens gradually with the increasing of the lane-changing aggressiveness adjusting coefficient, even vanishes when the value of lane-changing aggressiveness adjusting coefficient is greater than a critical value. Theoretical conclusions are also confirmed by the numerical simulations.

  10. Piezoelectric Energy Harvesting for Roadways

    OpenAIRE

    Xiong, Haocheng

    2015-01-01

    Energy harvesting technologies have drawn much attention as an alternative power source of roadway accessories in different scales. Piezoelectric energy harvesting consisting of PZT piezoceramic disks sealed in a protective package is developed in this work to harness the deformation energy of pavement induced by traveling vehicles and generate electrical energy. Six energy harvesters are fabricated and installed at the weigh station on I-81 at Troutville, VA to perform on-site evaluation. T...

  11. Apparatus, System, And Method For Roadway Monitoring

    KAUST Repository

    Claudel, Christian G.

    2015-06-02

    An apparatus, system, and method for monitoring traffic and roadway water conditions. Traffic flow and roadway flooding is monitored concurrently through a wireless sensor network. The apparatus and system comprises ultrasound rangefinders monitoring traffic flow, flood water conditions, or both. Routing information may be calculated from the traffic conditions, such that routes are calculated to avoid roadways that are impassable or are slow due to traffic conditions.

  12. Roadway Automobile Stability. A Numerical Study

    OpenAIRE

    Nikolov, Svetoslav; Nedev, Valentin; Bachvarov, Stefan

    2008-01-01

    A mathematical model of the roadway automobile motion is numerically analyzed. This model is intended to describe the roadway automobile stability. A previous paper [6] described the model in detail and the general method of qualitative analysis. In the present paper, we continue the discussion of stability by numerical simulations and the specific question we attempted to answer is: which parameter(s) of automobile geometry and quality of the roadway can serve as a reliable predictor(s) for ...

  13. Cost effectiveness of new roadway lighting systems

    Directory of Open Access Journals (Sweden)

    Yi Jiang

    2015-06-01

    Full Text Available Appropriate and adequate lighting at select locations on roadways is essential for roadway safety. As the lighting technologies advance, many types of new lighting devices have been developed for roadway lightings. The most promising new lighting technologies for roadway lighting include light emitting diode, induction, plasma, and metal halide lighting systems. A study was conducted to compare the new systems with the conventional high pressure sodium systems that are currently used on the Indiana roadway systems. In this study, the engineering issues, were analyzed such as illuminance, color rendering, power usage, cost effectiveness, and approval procedures for new roadway lighting systems. This paper, however, presents only the study findings related to cost effectiveness of the evaluated roadway lighting systems. Illustrated in this paper are the main features of the roadway lighting systems under evaluations, installations of the new lighting systems, measurements of power consumptions, and life cycle cost analyses of the lighting systems. Through this study, experience and knowledge have been obtained on the installations, power measurements, and cost effectiveness of the new types of the roadway lighting devices. The actual power values of various luminaires were obtained by measuring the electric current with a multi-meter. It was found that the differences between the rated and measured power values could be significant. The results of the life cycle cost analysis indicate that the lower life cycle costs of some of the alternative lighting devices are attributed to their relatively lower electricity usages and longer lamp/emitter replacement cycles.

  14. 双车道公路设置附加车道交通量条件研究%Traffic Volume Conditions of Setting Auxiliary Lane on Two-lane Highway

    Institute of Scientific and Technical Information of China (English)

    程国柱; 翟露露; 秦丽辉; 王玉霞

    2015-01-01

    In order to reduce traffic accidents and improve operating efficiency on two-lane highway, the concept of setting auxiliary lane on two-lane highway is proposed, and the traffic volume conditions of setting up auxiliary lane on two-lane highway are studied. Data is obtained through vehicle experiment on two-lane highway, and the relational model among the traffic conflict time, the traffic volume and the design speed on two-lane highway is established. Based on the established model, the different conditions of traffic volume of setting auxiliary lane on two-lane highway are obtained. It shows that auxiliary lane should be set when traffic volume is more than 495 veh/h/ln and 454 veh/h/ln respectively on two-lane highway with the design speed of 80 km/h and 60km/h. It isn't recommend to set auxiliary lane on two-lane highway with the design speed of 40 km/h because the benefit is not obvious.%为了减少双车道公路交通事故数量、提高运行效率,提出了双车道公路设置附加车道的理念,基于试验数据开展了双车道公路设置附加车道的交通量条件研究.通过双车道公路实车实验获得的基础数据,建立了双车道公路交通冲突时间与交通量、设计速度的关系模型.依据构建的模型,给出了对应不同设计速度的双车道公路设置附加车道的交通量条件.基于样本数据的研究结果表明:设计速度为80 km/h的双车道公路,单向交通量大于495 veh/h/ln时,应设置附加车道;设计速度为60 km/h的双车道公路,单向交通量大于454 veh/h/ln,应设置附加车道;设计速度为40 km/h及以下的双车道公路,设置附加车道效益不明显,不建议设置.

  15. STUDY OF DESTRESSING METHODS IN ROADWAY CORNERS

    Institute of Scientific and Technical Information of China (English)

    KANGHongpu

    1995-01-01

    The destressing mechanism, rational parameters and adaptability of various kinds of destressing methods in roadway comers are analyzed in detail in this paper. A new kind of destressing method by driving openings is proposed. The crux that destressing openings control the deformation of surrounding rock of roadways, the affect to the destressing effect by the location and size of the destressing openings are analyzed by means of FEM. The results point out that the destressing openings can effectively reduce the floor heave and side-to-side convergence of the roadway. protected. It has high destressing capacity and very extensive adaptability compared with the destressing methods near roadway contour, and it can be used to support the roadways in high-stress zone.

  16. 49 CFR 236.24 - Spacing of roadway signals.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Spacing of roadway signals. 236.24 Section 236.24..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems Roadway Signals and Cab Signals § 236.24 Spacing of roadway signals. Each roadway signal...

  17. 49 CFR 236.21 - Location of roadway signals.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Location of roadway signals. 236.21 Section 236.21..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems Roadway Signals and Cab Signals § 236.21 Location of roadway signals. Each roadway signal...

  18. Autodesk Roadway Design for Infraworks 360 essentials

    CERN Document Server

    Chappell, Eric

    2015-01-01

    Quickly master InfraWorks Roadway Design with hands-on tutorials Autodesk Roadway Design for InfraWorks 360 Essentials, 2nd Edition allows you to begin designing immediately as you learn the ins and outs of the roadway-specific InfraWorks module. Detailed explanations coupled with hands-on exercises help you get up to speed and quickly and become productive with the module's core features and functions. Compelling screenshots illustrate step-by-step tutorials, and the companion website provides downloadable starting and ending files so you can jump in at any point and compare your work to the

  19. Roadway dynamic response analysis under mining rockburst condition

    Institute of Scientific and Technical Information of China (English)

    LI Chun-rui; QI Qing-xin; PAN Jun-feng; LAN Hang

    2009-01-01

    In order to determine how a roadway withstands a momentum wave and de-termine the extent of damage to rock surrounding the roadway under different force wave peak impacts, the roadway dynamic response state was analysed using numerical simula-tion method. The roadway's critical peak force wave and fracture region under dynamic wave action were put forward. It is concluded that the method has practical value to road-way support and rockburst prevention.

  20. Roadway Design Guidelines and Project Acknowledgements

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Design guidelines and recommendations for planning and delivering surface transportation projects on Service lands. The main holding (Roadway Design Guidelines) is a...

  1. The effects of roadway characteristics on farm equipment crashes: A GIS approach

    Science.gov (United States)

    Greenan, Mitchell Joseph

    for every 5 foot increase in shoulder width, the odds of a crash decreased by 8 percent. (CI: 0.86-0.98). Although not statically significant, unpaved roads increased the odds of a crash by 17 percent. (CI: 0.91-1.50) Lastly, it was found that Farm to Market routes increased the odds of a crash by two fold compared to local roads (which make up roughly 67 percent of Iowa public roads). (CI: 1.72-2.43) When the same model was stratified by rurality (urban/rural), it was found that high traffic density leads to a higher risk of a crash in rural areas. Iowa routes and Farm to Market routes had a greater odds of a crash in urban than rural areas, and road and shoulder width were more protective in rural than urban areas. When only using roads with a crash involving an injury versus all other roads as the outcome, Iowa routes and roads with increased speed limits had higher odds for an injury-involved crash, while increased road width were more protective against crashes involving injuries. Findings from the study suggest that several roadway characteristics were associated with farm-equipment crashes. Through administrative and engineering controls, the six static explanatory variables used in this study may be modified to decrease the risk of a farm equipment crash. Speed limit can be modified through administrative controls while traffic density, road and shoulder width, road type, and surface type can be modified through engineering controls. Results from this study provide information that will aid policy-makers in developing safer roads for farm equipment.

  2. Influencing factors of infrared surveying in roadway

    Institute of Scientific and Technical Information of China (English)

    CAI Kang-xu; GUO Da

    2006-01-01

    The main factors that affect infrared surveying in roadway include that property of rock, electromechanical equipments running, environmental temperature, hydrogeology and support material etc. This paper sums up the expression features of these disturbing factor through theoretical analysis and actual measurement contrasts and considers that some tunnel section does not suit to go on infrared survey, for instance, soft rock meets water to expanse, and surround rock has obviously pouring water. The basic methods had made evading disturbing of electromechanical equipments, environmental temperature and protect material etc to become possible. It is helpful that offers infrared surveying technical service for production safety better in roadway.

  3. Use of reflective surfaces on roadway embankment

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Doré, Guy

    2007-01-01

    adherence characteristics for roadway use. In Kangerlussuaq Airport, western Greenland, ground-penetrating radar (GPR) has been used to compare the variation of the frost table underneath a normal black asphalt surface and a more reflective surface (white paint). The GPR results have shown a clear...

  4. Roadway dynamic response analysis under mining rockburst condition

    Energy Technology Data Exchange (ETDEWEB)

    Chun-rui Li; Qing-xin Qi; Jun-feng Pan; Hang Lan [China Coal Research Institute, Beijing (China). Mining Design and Research Institute

    2009-09-15

    In order to determine how a roadway withstands a momentum wave and determine the extent of damage to rock surrounding the roadway under different force wave peak impacts, the roadway dynamic response state was analysed using numerical simulation method. The roadway's critical peak force wave and fracture region under dynamic wave action were put forward. It is concluded that the method has practical value to roadway support and rockburst prevention.The article is based on the anaysis of Xinwen Mining Group's geologic condition of Xiezhuang 4-2 mine. 4 refs., 4 figs., 1 tab.

  5. Numerical simulation of seismic survey in coal mine roadway

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, G.; Li, G.; Cheng, J. [Chang' an University, Xi' an (China). College of Geological Engineering and Geomatics

    2008-11-15

    With the staggered-grid high order finite difference wave field simulation method, the elastic wave field caused by explosives with a point source in a coal mine roadway was simulated and different type of waves in the wave field were distinguished. Comparing all three spatial components of the propagation of the waves caused by explosives on or under the roadway at different depths, this indicates that: on the roadway base, the reverberation caused by the top and bottom of the roadway (multiple reflection on the top and bottom of the roadway) is the main disturbing wave in the roadway seismic survey which will seriously disturb the reflection of the deep place coal bed underneath the roadway; at a depth of several metres under the roadway basal bottom boundary, the reverberation disturbing wave is greatly reduced and the reflection caused by deeper coal bed can be clearly detected; high signal-to-noise ratio data can be found with the Y component detector because of the propagation of SH waves; high resolution of seismic data is possible in a roadway. In the model, a cavity 3 metres high and 4 metres wide can be detected underneath the roadway. 5 refs., 7 figs.

  6. Soil Stabilization for Roadways and Airfields

    Science.gov (United States)

    1987-07-01

    Tyndall AFB FL 32403-6001 ELEMENT NO. NO. NO. ACCESSION NO 11 TITLE (Include Security Classification) Soil Stabilization For Roadways and Airfields...Application) .................. ... 165 62 Transit Mixing of Lime Slurry on City . Street Project, Using Recirculating Pump at Rear. Pressure and...produced by pul- verizing clinker c6nsisting essentially of hydraulic calcium silicates, and usually containing one or more of the forms of calcium

  7. Coal Mine Roadway Stability in Soft Rock: A Case Study

    Science.gov (United States)

    Shen, Baotang

    2014-11-01

    Roadway instability has always been a major concern in deep underground coal mines where the surrounding rock strata and coal seams are weak and the in situ stresses are high. Under the high overburden and tectonic stresses, roadways could collapse or experience excessive deformation, which not only endangers mining personnel but could also reduce the functionality of the roadway and halt production. This paper describes a case study on the stability of roadways in an underground coal mine in Shanxi Province, China. The mine was using a longwall method to extract coal at a depth of approximately 350 m. Both the coal seam and surrounding rock strata were extremely weak and vulnerable to weathering. Large roadway deformation and severe roadway instabilities had been experienced in the past, hence, an investigation of the roadway failure mechanism and new support designs were needed. This study started with an in situ stress measurement programme to determine the stress orientation and magnitude in the mine. It was found that the major horizontal stress was more than twice the vertical stress in the East-West direction, perpendicular to the gateroads of the longwall panel. The high horizontal stresses and low strength of coal and surrounding rock strata were the main causes of roadway instabilities. Detailed numerical modeling was conducted to evaluate the roadway stability and deformation under different roof support scenarios. Based on the modeling results, a new roadway support design was proposed, which included an optimal cable/bolt arrangement, full length grouting, and high pre-tensioning of bolts and cables. It was expected the new design could reduce the roadway deformation by 50 %. A field experiment using the new support design was carried out by the mine in a 100 m long roadway section. Detailed extensometry and stress monitorings were conducted in the experimental roadway section as well as sections using the old support design. The experimental section

  8. Quantifying the total cost of infrastructure to enable environmentally preferable decisions: the case of urban roadway design

    Science.gov (United States)

    Gosse, Conrad A.; Clarens, Andres F.

    2013-03-01

    Efforts to reduce the environmental impacts of transportation infrastructure have generally overlooked many of the efficiencies that can be obtained by considering the relevant engineering and economic aspects as a system. Here, we present a framework for quantifying the burdens of ground transportation in urban settings that incorporates travel time, vehicle fuel and pavement maintenance costs. A Pareto set of bi-directional lane configurations for two-lane roadways yields non-dominated combinations of lane width, bicycle lanes and curb parking. Probabilistic analysis and microsimulation both show dramatic mobility reductions on road segments of insufficient width for heavy vehicles to pass bicycles without encroaching on oncoming traffic. This delay is positively correlated with uphill grades and increasing traffic volumes and inversely proportional to total pavement width. The response is nonlinear with grade and yields mixed uphill/downhill optimal lane configurations. Increasing bicycle mode share is negatively correlated with total costs and emissions for lane configurations allowing motor vehicles to safely pass bicycles, while the opposite is true for configurations that fail to facilitate passing. Spatial impacts on mobility also dictate that curb parking exhibits significant spatial opportunity costs related to the total cost Pareto curve. The proposed framework provides a means to evaluate relatively inexpensive lane reconfiguration options in response to changing modal share and priorities. These results provide quantitative evidence that efforts to reallocate limited pavement space to bicycles, like those being adopted in several US cities, could appreciably reduce costs for all users.

  9. Research on Relationship of Traffic Condition and Traffic Safety of Two-Lane Highway in Plane Areas%平原区双车道公路交通条件与交通安全的关系研究

    Institute of Scientific and Technical Information of China (English)

    李强; 王蓉蓉; 路维; 胡江碧

    2012-01-01

    On the bais of traffic accident data of the two-lane highway in plane areas, the influence of vertical-section, cross-section and intersection with the traffic accidents, and contrasting the analysis with conclusion abroad are discussed , then a conclusion on the relationship of the traffic condition and the traffic safety of two-lane highway in plane areas is got, a traffic safety prediction model is established,so it has important significance on the upgrading the highway safety.%以平原区双车道公路交通事故资料为基础,分析了道路平曲线和纵断面线形及交叉口等因素与交通事故的关系,将分析结论和国外研究结果相对比,得出我国平原区双车道公路交通条件与交通安全的关系,并建立交通安全性预测模型,对提升我国双车道公路安全性具有重要的意义.

  10. Analysis of soft rock roadway deformation mechanism in Zhangshuanglou Mine

    Institute of Scientific and Technical Information of China (English)

    顾士亮

    2003-01-01

    On basis of ground stress surveying and analysis of physical nature and mechanics character of rock, the deformation mechanism of west main roadway in Zhangshuanglou Mine is studied. It is put forward that engineering mechanics nature, infiltration of water and concentrated stress on pillar are the main factors to affect stability of the west main roadway. The overall thinking used to restore the roadway is raised.

  11. 49 CFR 214.353 - Training and qualification of roadway workers who provide on-track safety for roadway work groups.

    Science.gov (United States)

    2010-10-01

    ... provide on-track safety for roadway work groups. 214.353 Section 214.353 Transportation Other Regulations... who provide on-track safety for roadway work groups. (a) The training and qualification of roadway workers who provide for the on-track safety of groups of roadway workers through establishment of...

  12. Support structure for the linings of roadways

    Energy Technology Data Exchange (ETDEWEB)

    Lerchbaum, K.

    1989-02-08

    In a support structure for the lining of roadways, said structure having a plurality of frames divided into frame parts in the peripheral direction and having lagging arranged between the frames, a frame part is clampable to an adjacent frame part by a pre-assembled locking member undetachably fixed to one of the frame parts. The locking members are formed by bolts fixed so as to be pivotable round an axis tangential or parallel to the periphery of the frame, and can be clamped with adjacent frame parts.

  13. Sustainable development of roadways in Africa

    Directory of Open Access Journals (Sweden)

    Akindeji-Oladeji, O.

    2012-12-01

    Full Text Available Dallas Roadway Products (DRP soil stabilization technology can effectively improve road foundation construction and with it the strength of roadway sub-grades and sub-bases. Soil samples were collected from roads in Nigeria’s six geo-political regions. DRP LS-40 (lignate sulfonate and DRP SA-44 (sulfuric acid were added to the soil materials. The mixture precipitated a non-reversible chemical reaction that involved a permanent change in the soil structure. The chemicals reacted with the clay content, increasing the soil material plasticity. In non-plastic soils, clay materials were added to the soil, which was then pulverised. The study showed that DRP soil stabilisation chemicals can render poor, unsuitable or marginally deficient soils apt for use as a sub-base or base in roadway construction.

    La tecnología de Dallas Roadway Products (DRP constituye una metodología eficaz para mejorar la construcción de las capas inferiores del firme de calzadas y con ella la resistencia de las bases y sub-bases de las carreteras. En esta investigación se recogen muestras del terreno que constituye las carreteras existentes en las seis regiones geopolíticas nigerianas. Al incorporar a las muestras el DRP LS-40 (lignosulfonato y el DRP SA-44 (ácido sulfúrico, la mezcla acelera una reacción química no reversible que produce una modificación permanente del entramado del suelo. La reacción de las sustancias químicas con la arcilla del suelo aumenta su plasticidad. A los suelos sin plasticidad se agregan materiales arcillosos, procediéndose a continuación a la pulverización del material resultante. Según los resultados obtenidos, las sustancias químicas de estabilización de suelos de DRP pueden transformar los suelos pobres, inapropiados o deficientes en materiales adecuados para servir como bases o sub-bases de las carreteras.

  14. 49 CFR 236.527 - Roadway element insulation resistance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Roadway element insulation resistance. 236.527 Section 236.527 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... element insulation resistance. Insulation resistance between roadway inductor and ground shall...

  15. Analysis of soft rock mineral components and roadway failure mechanism

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie

    2001-01-01

    The mineral components and microstructure of soft rock sampled from ro adway floor in Xiagou pit are determined by X-ray diffraction and scanning elec t ron microscope. Combined with the test of expansion and water softening prop erty of the soft rock, the roadway failure mechanism is analyzed, and the reason able repair supporting principle of roadway is put forward.

  16. THEORETICAL ANALYSIS OF THE STABILITY OF A DEEP ROADWAY

    Institute of Scientific and Technical Information of China (English)

    付国彬

    1995-01-01

    In this paper the thickness of a broken zone, a state parameter of roadway surrounding rock, is used as the index to evaluate the stability of surrounding rock of a deep roadway. The paper gives a theoretic formula for calculating the thickness of the broken zone. The author points out that not only the ultimate strength of rockmass but its residual strength and strain-softening level all have a great influence on the stability of surrounding rock of a deep roadway. The peper′s results show that to reinforce surrounding rock, raise its residual strength and lower its strain-softening level should be taken as a basic requirement for supports of a deep roadway. In addition, the research also indicates that it is impossible for roadway supports to change surrounding rock states of a deep roadway, so it is certain for them to work in a broken state. For this reason, a sufficient yieldable quantity is necessary for roadway supports used in deep mining.

  17. 49 CFR 236.529 - Roadway element inductor; height and distance from rail.

    Science.gov (United States)

    2010-10-01

    ...; Roadway § 236.529 Roadway element inductor; height and distance from rail. Inductor of the inert roadway element type shall be maintained with the inductor pole faces at a height above the plane of the tops of... 49 Transportation 4 2010-10-01 2010-10-01 false Roadway element inductor; height and distance from...

  18. 49 CFR 214.335 - On-track safety procedures for roadway work groups.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false On-track safety procedures for roadway work groups... Protection § 214.335 On-track safety procedures for roadway work groups. (a) No employer subject to the provisions of this part shall require or permit a roadway worker who is a member of a roadway work group...

  19. Theory and technology of preventing water from flooding roadways

    Institute of Scientific and Technical Information of China (English)

    CAO Sheng-gen; HOU Shi-song; LI Zhong-hua

    2008-01-01

    According to the principle of effective stress action of rock and soil, we established a mechanical model of water flooding into roadways, analyzed the constitutive relation of hydrodynamic pressure and contact pressure of rock and soil and discovered that the process of pre-grouting of a roadway curtain is a dynamically balancing process in which effective stress keeps gradually increasing and pore water pressure gradually declines. In such a grouting process, the initial water plugging effect is realized when the effective stress and total stress reaches equilibrium. A rigid-flexible packing layer is designed behind the brickwork to increase the effective stress and reduce pore water pressure in order to have a permanent water proof performance. This provides a theoretical basis for roadway driving and permanent water prevention. The monitoring and application results show that the initial and permanent waterproof theory has provided an effective method for roadway driving and making it waterproof.

  20. A New Roadway Danger: Drivers Chasing 'Pokemon Go'

    Science.gov (United States)

    ... gov/news/fullstory_161005.html A New Roadway Danger: Drivers Chasing 'Pokemon Go' At least 14 crashes ... it remains imperative for people to understand the dangers of driving with that level of distraction. "This ...

  1. Fast roadway detection using car cabin video camera

    Science.gov (United States)

    Krokhina, Daria; Blinov, Veniamin; Gladilin, Sergey; Tarhanov, Ivan; Postnikov, Vassili

    2015-12-01

    We describe a fast method for road detection in images from a vehicle cabin camera. Straight section of roadway is detected using Fast Hough Transform and the method of dynamic programming. We assume that location of horizon line in the image and the road pattern are known. The developed method is fast enough to detect the roadway on each frame of the video stream in real time and may be further accelerated by the use of tracking.

  2. Roadway deformation during riding mining in soft rock

    Institute of Scientific and Technical Information of China (English)

    Zhao Guozhen; Ma Zhanguo; Zhu Qinghua; Mao Xianbiao; Feng Meimei

    2012-01-01

    "Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.

  3. TWO-LANE BLACKTOP: REFUGEES & TORTURE

    Directory of Open Access Journals (Sweden)

    JESÚS GARCÍA CÍVICO

    2017-06-01

    Full Text Available The right not to be subjected to torture or to cruel, inhuman or degrading treatment or punishment, and the right of asylum have, individually considered, an extensive field of application", but it is possible to point out some traits in common. Firsty, in both rights undelie the moral spirit of the Universal Declaration of Human Rights. At the same time, according to the recent reports of the main human rights organisations, both rights are in deep political crisis. Furthermore, is possible to see that sometimes they cross each other: there is a triple «zone of intersection between the right of asylum and the right not to suffer torture, inhuman or degrading treatment: one of the reasons for escaping from a country is to avoid suffering torture ("refuge after torture" secondly, sometimes inhuman and degrading treatment occur precisely in the process of seeking asylum ("inhuman treatment in the refuge", finally, there are countries with strong deficiencies in their immigration policies and this can produce a perverse effect: the transfer of potential asylum seekers to countries where they are at risk of torture or inhuman treatment again ("torture or inhuman and degrading treatment after asylum".

  4. SELECTION OF HORIZONTAL DISTANCE X BETWEEN ROADWAY AND THE EDGE OF ITS UPPER PILLAR

    Institute of Scientific and Technical Information of China (English)

    陆士良; 孙永联; 姜耀东

    1994-01-01

    The horizontal distance X between roadway and the edge of its upper pillar is considered as an important parameter for layout of roadway in floor strata or in the adjacent coal seam. Based on the research achievements of rockstrata pressure, this paper illustrates the quantitative relationship among the mining situation of upper seam, the roekstrata properties around roadway, the vertical distance Z (between roadway and its upper pillar), and the horizontal distance X (between roadway and the edge of its upper pillar), and provides a main basis for the selection of value X and the relative location between roadway and its upper seam.

  5. The Complex Function Method Roadway Section Design of the Soft Coal Seam

    Directory of Open Access Journals (Sweden)

    Shihao Tu

    2016-01-01

    Full Text Available As for the sophisticated advanced support technique of vertical wall semicircle arch roadway in the three-soft coal seam, a design of flat top U-shape roadway section was put forward. Based on the complex function method, the surrounding rock displacement and stress distribution laws both of vertical wall semicircle arch roadway and of flat top U-shape roadway were obtained. The results showed that the displacement distribution laws in the edge of roadway surrounding rock were similar between the two different roadways and the area of plasticity proportion of flat top U-shape roadway approximately equals that of vertical wall semicircle arch roadway. Based on finite element method, the bearing behaviors of the U-type steel support under the interaction of surrounding rock in vertical wall semicircle arch roadway and flat top U-shape roadway were analyzed. The results showed that, from a mechanics perspective, U-type steel support can fulfill the requirement of surrounding rock supporting in flat top U-shape roadway and vertical wall semicircle arch roadway. The field measurement of mining roadway surrounding rock displacement in Zouzhuang coal mine working face 3204 verified the accuracy of theoretical analysis and numerical simulation.

  6. Rock roadway complementary support technology in Fengfeng mining district

    Institute of Scientific and Technical Information of China (English)

    Zeng Xiantao; Jiang Yaodong; Jiang Cong; Ma Zhenqian; Zhan Shaojian; Zhang Kexue; He Changhai

    2014-01-01

    This paper takes No. 52 return uphill roadway of Yangquhe coal mine as a research project. Based on the research, especially its geological condition, indoor experiments, numerical simulation and theoretical analysis were employed to determine the difficult coefficients of Yangquhe project. By using these means, the difficult coefficients of the deep rock engineering were determined. From a study of the effects of crustal stress and the roof mechanism on roadway stability, the transformation mechanism in Yangquhe coal mine has been determined. As a result of this research, the interactive support technology of pre-stressed cable mesh was developed and the technology tested in mining engineering, which proved to be feasible.

  7. 公交车停靠诱发交通瓶颈的元胞自动机模拟%Investigation on traffic bottleneck induce by bus stopping with a two-lane cellular automaton model

    Institute of Scientific and Technical Information of China (English)

    李庆定; 董力耘; 戴世强

    2009-01-01

    利用双车道元胞自动机模型,研究公交车停靠对道路混合交通流的影响.针对港湾式和非港湾式两种不同公交车站设置,在开放边界下模拟了公交车停靠所产生的交通瓶颈问题,给出了车辆入流概率.公交车比例相平面上的相图,区分了自由流相和拥挤相,研究了相图各区中公交车站附近的平均密度和速度分布图,比较了两种公交车站情况下的道路交通流的动力学特征.研究发现,当公交车比例较小时,与非港湾式车站相比,港湾式车站可以显著改善车站处的交通状况.%In this paper, the influence of typical bus stops on traffic flow is investigated with the cellular automaton traffic model. For on-line and off-line bus stops, a two-lane cellular automaton model is proposed to simulate the traffic bottleneck induced by bus stopping under the open boundary condition. The phase diagram in the phase plane of injection probability and bus fraction is provided and two phases, i.e., the free flow phase and congested flow phase, are distinguished. The distributions of the mean density and velocity near the bus stop in different traffic phases are given and the comparison of dynamical characteristics of traffic flows is made for different types of bus stops. It is found that using the off-line bus stop can significandy improve the traffic flow in its neighboring region, compared with the on-line bus stop in the case of small fraction of buses.

  8. THE CLASSIFICATION OF THE SURROUNDINGS OF COAL MINING ROADWAYS

    Institute of Scientific and Technical Information of China (English)

    邹喜正; 侯朝炯; 李华祥

    1996-01-01

    This introduces the calculation of opaper the deformationg .the Surroundings of coaowaysand the divisi of surroundings into 5 levels by means or !fuzzy integral assess mairrx, wnlcnserves-asthe scientific basis for selecting supporting pattern of roadways and determining the, pa-rameters of support.

  9. Optimal formulations of some asphalt concrete roadway protective impregnation compositions

    Directory of Open Access Journals (Sweden)

    Yulia A. Ubas’kina

    2016-03-01

    Full Text Available The current paper describes optimization of the formulations of asphalt concrete roadway protective impregnation compositions based on BND 60/90 bitumen modified with petroleum resin. Physicochemical, technological and operating parameters of the prepared samples of the compositions are investigated.

  10. Louisiana Speaks Transportation Option C Roadway Improvements, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_c_roadway_improvements

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional roadways included in the Louisiana Speaks community growth option of compact development (Option C). This network...

  11. Louisiana Speaks Transportation Option B Roadway Improvements, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_b_roadway_improvements

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional roadways included in the Louisiana Speaks community growth option of compact and dispersed development (Option B)....

  12. Louisiana Speaks Transportation Option A Roadway Improvements, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_a_roadway_improvements

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional roadways included in the Louisiana Speaks Regional Plan community growth option of dispersed development (Option A)....

  13. Modeling the chemical evolution of nitrogen oxides near roadways

    Science.gov (United States)

    Wang, Yan Jason; DenBleyker, Allison; McDonald-Buller, Elena; Allen, David; Zhang, K. Max

    2011-01-01

    The chemical evolution of nitrogen dioxide (NO 2) and nitrogen monoxide (NO) in the vicinity of roadways is numerically investigated using a computational fluid dynamics model, CFD-VIT-RIT and a Gaussian-based model, CALINE4. CFD-VIT-RIT couples a standard k- ɛ turbulence model for turbulent mixing and the Finite-Rate model for chemical reactions. CALINE4 employs a discrete parcel method, assuming that chemical reactions are independent of the dilution process. The modeling results are compared to the field measurement data collected near two roadways in Austin, Texas, State Highway 71 (SH-71) and Farm to Market Road 973 (FM-973), under parallel and perpendicular wind conditions during the summer of 2007. In addition to ozone (O 3), other oxidants and reactive species including hydroperoxyl radical (HO 2), organic peroxyl radical (RO 2), formaldehyde (HCHO) and acetaldehyde (CH 3CHO) are considered in the transformation from NO to NO 2. CFD-VIT-RIT is shown to be capable of predicting both NO x and NO 2 profiles downwind. CALINE4 is able to capture the NO x profiles, but underpredicts NO 2 concentrations under high wind velocity. Our study suggests that the initial NO 2/NO x ratios have to be carefully selected based on traffic conditions in order to assess NO 2 concentrations near roadways. The commonly assumed NO 2/NO x ratio by volume of 5% may not be suitable for most roadways, especially those with a high fraction of heavy-duty truck traffic. In addition, high O 3 concentrations and high traffic volumes would lead to the peak NO 2 concentration occurring near roadways with elevated concentrations persistent over a long distance downwind.

  14. Catastrophe mechanism and disaster countermeasure for soft rock roadway surrounding rock in Meihe mine

    Institute of Scientific and Technical Information of China (English)

    Yu Yang⇑; Zhu Caikun; Chong Deyu; Liu Yang; Li Sichao

    2015-01-01

    The soft rock’s heterogeneity and nonlinear mechanical behavior cause extremely difficult maintenance on the soft rock roadway. Aiming at the asymmetric deformation and destruction phenomenon appearing after excavating and supporting the 7101 air return way in Meihe mine, this paper comprehensively adopted a variety of methods to analyze the roadway surrounding rock deformation rule, obtaining the roadway surrounding rock stress and plastic zone distribution rule under no supporting condition and the roadway surrounding rock deformation features under original symmetric supporting condition. Furthermore, this paper revealed the catastrophe mechanism, and proposed the concept of‘weak struc-ture’ and the disaster countermeasure of‘overall stabilizing the roadway and strengthening the support of weak structure’ . The industrial test shows that the disaster control technology can realize the coordination deformation of the supporting structure and roadway surrounding rock, thus significantly controlling the deformation of roadway surrounding rock.

  15. Coal mining with Triple-section extraction process in stagger arrangement roadway layout method

    Science.gov (United States)

    Cui, Zimo; Liu, Baozhu; Zhao, Jingli; Chanda, Emmanuel

    2017-03-01

    This paper introduces the Triple-section extraction process in the three-dimensional roadway layout of stagger arrangement method for longwall top-coal caving mining. This 3-D roadway layout of stagger arrangement method without coal pillars, which arranged the air intake roadway and air return roadway in different horizons, realizing the design theory transformation of roadway layout from 2D system to 3D system. And the paper makes systematic analysis to the geological, technical and economic factors, applies this new mining roadway layout technology for raising coal recovery ratio and solving the problems about full-seam mining in thick coal seam synthetically according to theoretical study and mining practice. Furthermore, the paper presents a physical simulation about inner staggered roadway layout of this particular longwall top-coal caving method.

  16. Residential Proximity to Major Roadways and Lung Cancer Mortality. Italy, 1990–2010: An Observational Study

    Directory of Open Access Journals (Sweden)

    Ettore Bidoli

    2016-02-01

    Full Text Available Background: Air pollution from road traffic has been associated to an increased risk of lung cancer. Herein, we investigated the association between lung cancer mortality and residence near Italian highways or national major roads. Methods: Information on deaths for lung cancer registered from 1990 to 2010 and stratified by age, gender, and urban or rural municipality of residence at death were obtained from the National Institute of Statistics. Distance between the centroid of the municipality of residence and closest major roadways was considered as a proxy of pollution exposure. Relative Risks (RR and 95% confidence intervals (CI were computed using Poisson log-linear models adjusted for age, calendar period, deprivation index, North/South gradient, and urban/rural status. Results: A gradient in risk for lung cancer mortality was seen for residents within 50 meters (m of national major roads. In particular, in rural municipalities a statistically significant increased risk for lung cancer death was observed in both sexes (RR = 1.27 for distance <25 m vs. 500–1999 m, 95% CI 1.17–1.42, in men; RR = 1.97, 95% CI 1.64–2.39, in women. In urban municipalities, weak risks of borderline significance were documented in both sexes (RR = 1.06, 95% CI 0.99–1.15 in men; and RR = 1.09, 95% CI 0.97–1.22 in women. No statistically significant association emerged between residence within 100 to 500 m from highways and RRs of death for lung cancer. Conclusions: In Italy, residing near national major roads, in particular in rural municipalities, was related to elevated risks of death for lung cancer.

  17. Filtration effectiveness of HVAC systems at near-roadway schools.

    Science.gov (United States)

    McCarthy, M C; Ludwig, J F; Brown, S G; Vaughn, D L; Roberts, P T

    2013-06-01

    Concern for the exposure of children attending schools located near busy roadways to toxic, traffic-related air pollutants has raised questions regarding the environmental benefits of advanced heating, ventilation, and air-conditioning (HVAC) filtration systems for near-road pollution. Levels of black carbon and gaseous pollutants were measured at three indoor classroom sites and at seven outdoor monitoring sites at Las Vegas schools. Initial HVAC filtration systems effected a 31-66% reduction in black carbon particle concentrations inside three schools compared with ambient air concentrations. After improved filtration systems were installed, black carbon particle concentrations were reduced by 74-97% inside three classrooms relative to ambient air concentrations. Average black carbon particle concentrations inside the schools with improved filtration systems were lower than typical ambient Las Vegas concentrations by 49-96%. Gaseous pollutants were higher indoors than outdoors. The higher indoor concentrations most likely originated at least partially from indoor sources, which were not targeted as part of this intervention. Recent literature has demonstrated adverse health effects in subjects exposed to ambient air near major roadways. Current smart growth planning and infill development often require that buildings such as schools are built near major roadways. Improving the filtration systems of a school's HVAC system was shown to decrease children's exposure to near-roadway diesel particulate matter. However, reducing exposure to the gas-phase air toxics, which primarily originated from indoor sources, may require multiple filter passes on recirculated air. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  18. Rapid roadway development - interim reports June 2001 & 2002

    Energy Technology Data Exchange (ETDEWEB)

    Michael Kelly; David Hainsworth; Ron McPhee; Baotang Shen; C. Wesner; Barry Wright; Rao Balusu; D. Adhikary; Huo Guo; Michael Wendt; Sheng Xue [CSIRO Exploration & Mining (Australia)

    2002-06-15

    Three reports are available on this five year project: Rapid roadway development final report ACARP C8014, May 2000; Rapid roadway development project progress report ACARP C9017, June 2001; Roadway span stability study - field monitoring at Moranbah north mine and numerical analyses, ACARP C9017, June 2002. The project is based on the design and construction of an automatic bolting/bridge conveyor unit that can sit behind a variety of cutting machines and interface with a variety of coal haulage options. Under the project agreement between JCOAL and CSIRO, JCOAL has funded $5.335 million over the five-year period. The scope of the overall project includes five main components: Automatic Roofbolting System; Platform for Automatic Bolter; Strata Control and Risk Assessment; Remote and Automatic Control Systems; and Systems Engineering and Field Trials. The first two reports are status reports describing progress in all five components of the project. The third report details a specific strata control investigation that was undertaken as part of the project. Because the system requires a limited support for the initial 12 metres of driveage, the strata control component requires new assessment tools to be developed to ascertain the application of the system in differing geotechnical environments. The report details assessment of mechanisms in coal roof left unsupported during place change operations. The results are significant as they provide new information about initial stress conditions and stress change during mining.

  19. Effect of bolting on roadway support in extremely weak rock.

    Science.gov (United States)

    Li, Qinghai; Shi, Weiping; Qin, Zhongcheng

    2016-01-01

    In mine roadway support operations, floor bolting not only played a role in floor heave control, but also in reinforcing roof and its two sides. Correspondingly, bolting of roof and two sides also played a part in floor heave control. To quantify the effect of such bolting, based on roadway support in extremely weak rock, three physical models were produced and tested in laboratory. Through comparison of their displacements in three physical simulation experiments, the reinforcing effect of bolting in extremely weak rock roadways was quantified. Reinforcing coefficients was defined as displacement ratio between original support and new support regime. Results indicated that the reinforcing coefficients, for bolting of roof and its two sides, on floor, two sides, and roof reached 2.18, 3.56, and 1.81 respectively. The reinforcing coefficients for floor bolting on floor, two sides, and roof reached 3.06, 2.34, and 1.39 respectively. So in this extremely weak rock, the surrounding rock should be considered as an integral structure in any support operation: this allows for better local strength improvement, and provided future design guidance.

  20. Study of dynamic pressure roadway supporting scheme under condition of thick composite roof

    Institute of Scientific and Technical Information of China (English)

    Wei-Jun WANG; Li-Qiang LUO; Wei-Jian YU; Hai WU; Yan-Si QU

    2013-01-01

    This paper analyzed the strata behaviors of solid-coal roadway,gob-side entry driving and deformation law of surrounding rock in depth under high stress and thick composite roof based on the dynamic pressure roadway as engineering background in Fengcheng mining area,Jiangxi province.The results,both field measurement andnumerical simulation show that gob-side entry driving results the deformation of coal roadway main wall,however,entity-coal roadway driving results deformation of main roof and floor.The maintenance state of gob-side entry driving is better than entity-coal roadway,this situation is relevant to thick composite roof layered and easy collapse characteristics.At the same time,this paper put forward and proved proper dynamic pressure roadway supporting scheme under the surrounding rock condition and stress environment.

  1. The establishment of the 3D landscape of the mine underground roadway

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kai-xuan; WU Wen-bo; HAN Zhao-tao

    2008-01-01

    Because of the complexity and variability of the mine underground roadway, roadway is required to be dynamically generated in 3-1) display, viewpoint can be trans-formed to achieve the 3-D roaming effect, and can do interactive inquiries and positioning for the roadway. In terms of the requirements above, gave the comparatively detailed elaboration of the solution, using the open graphics library (OpenGL) and relying on VC++ 6.0 combined with Database Programming. Mainly establish the 31) model landscape of the underground roadway using OpenGL based on VC programming environment and MFC programming, elaborated the powerful 3D graphics library, i.e. OpenGL in detail, gave the algorithm which can realize the relative positioning and of arbitrary point and the roaming and so on in the mine roadway, and also solves illumination, turning, and other issues of the roadway model.

  2. The establishment of the 3D landscape of the mine underground roadway

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kai-xuan; WU Wen-bo; HAN Zhao-tao

    2008-01-01

    Because of the complexity and variability of the mine underground roadway,roadway is required to be dynamically generated in 3-D display,viewpoint can be transformed to achieve the 3-D roaming effect,and can do interactive inquiries and positioning for the roadway.In terms of the requirements above,gave the comparatively detailed elaboration of the solution,using the open graphics library (OpenGL) and relying on VC++6.0 combined with Database Programming.Mainly establish the 3D model landscape of the underground roadway using OpenGL based on VC programming environment and MFC programming,elaborated the powerful 3D graphics library,i.e.OpenGL in detail,gave the algorithm which can realize the relative positioning and of arbitrary point and the roaming and so on in the mine roadway,and also solves illumination,turning,and other issues of the roadway model.

  3. Research on Length of Blocked Road Section for Maintenance of Two-lane Highway in Mountain Area Based on Vissim%基于Vissim的山区双车道公路养护作业封闭段长度研究

    Institute of Scientific and Technical Information of China (English)

    孙文亮; 刘振清; 贺玉龙; 高发亮

    2012-01-01

    建立山区双车道公路养护作业区Vissim仿真模型,通过信号灯控制通行时间,模拟在不同封闭段长度下车辆的运行状态,对行程延误、排队长度、停车次数和停驶车辆百分比等参数进行分析,得出山区双车道公路单车道封闭,短期养护作业封闭段长度不宜大于200 m,长期养护作业封闭段长度不宜大于2500 m,这为山区双车道公路养护作业区设置和交通组织提供理论依据.%The simulation model of maintenance area for two-lane highway in mountain area was established based on Vissim. The model can simulate vehicles' running state with different lengths of blocked road section through signal lamp controlling time, and can analyze parameters such as trip delay, queuing length, number of stops and the percentage of suspended vehicles. The result shows that the blocked single-lane section length for short-term maintenance of two-lane highway in mountain area should be less than 200 m and that for long-term maintenance should be less than 2500 m. It provided a theoretical basis of setting maintenance area and transportation organizations for two-lane highway in mountain area.

  4. Support technologies for deep and complex roadways in underground coal mines:a review

    Institute of Scientific and Technical Information of China (English)

    Hongpu Kang

    2014-01-01

    Based on geological and mining characteristics, coal mine roadways under complex conditions were divided into five types, for each type the deformation and damage characteristics of rocks surrounding roadways were analyzed. The recent developments of roadway support technologies were introduced abroad, based on the experiences of supports for deep and complex roadways from Germany, the United States and Australia. The history and achievements of roadway support technologies in China were detailed, including rock bolting, steel supports, grouting reinforcement and combined supports. Four typical support and reinforcement case studies were analyzed, including a high stressed roadway 1,000 m below the surface, a roadway surrounded by severely weak and broken rocks, a chamber surrounded by weak and broken rocks, and a roadway with very soft and swelling rocks. Based on studies and practices in many years, rock bolting has become the mainstream roadway support form in China coal mines, and steel supports, grouting reinforcement and combined supports have also been applied at proper occasions, which have provided reliable technical measures for the safe and high effective construction and mining of underground coal mines.

  5. Analyzing Potential Grid Impacts from Future In-Motion Roadway Wireless Power Transfer Scenarios: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Meintz, Andrew; Gonder, Jeffrey; Jorgenson, Jennie; Brooker, Aaron

    2016-08-01

    This work examines the grid impact of in-motion roadway wireless power transfer through the examination of the electrification of high-capacity roadways inside a metropolitan area. The work uses data from a regional travel study and the Federal Highway Administration's Highway Performance Monitoring System to estimate the electrified roadway's hourly power use throughout a week. The data are then combined with hourly grid load estimates for the same metropolitan area to determine the overlay of traditional grid load with additional load from a future electrified roadway.

  6. Analyzing Potential Grid Impacts from Future In-Motion Roadway Wireless Power Transfer Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Meintz, Andrew; Gonder, Jeffrey; Jorgenson, Jennie; Brooker, Aaron

    2017-01-01

    This work examines the grid impact of in-motion roadway wireless power transfer through the examination of the electrification of high-capacity roadways inside a metropolitan area. The work uses data from a regional travel study and the Federal Highway Administration's Highway Performance Monitoring System to estimate the electrified roadway's hourly power use throughout a week. The data are then combined with hourly grid load estimates for the same metropolitan area to determine the overlay of traditional grid load with additional load from a future electrified roadway.

  7. Quantity and quality of runoff from selected guttered and unguttered roadways in northeastern Ramsey County, Minnesota

    Science.gov (United States)

    Mitton, G.B.; Payne, G.A.

    1997-01-01

    Five roadway sections in northeastern Ramsey County, Minnesota were monitored during 1993-95, to evaluate water quality and loading of constituents from roadway runoff. Two snowmelt-runoff and five rainfall-runoff events were monitored per year at each site. Additional samples of rainfall were analyzed to determine if rainfall was a direct source of constituent loading to roadway runoff. Roadway-runoff samples were analyzed for selected physical properties, dissolved solids, nutrients, dissolved ions, selected metals, and semi-volatile compounds.

  8. Louisiana Speaks Regional Plan Vision New or Improved Roadways, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_roadway_improvements

    Data.gov (United States)

    Louisiana Geographic Information Center — This GIS shapefile data illustrates new or improved roadways included in the Louisiana Speaks Regional Plan Vision. This network accommodates a land use pattern that...

  9. Plastic zone distribution laws and its types of surrounding rock in large-span roadway

    Institute of Scientific and Technical Information of China (English)

    Li Chong; Xu Jinhai; Pan Jianzhong; Ma Chao

    2012-01-01

    In order to study the distribution laws and types of plastic zone of surrounding rock in large-span roadway,we analyzed the distribution laws with different spans and lateral pressures using FLAC3D numerical calculation software.Based on the roadway support difficulty and distribution laws of the plastic zone of surrounding rock,we defined the large-span roadway and classified the types of large-span rectangular roadways.As a result,the distribution laws of the plastic zone on surrounding rock in a rectangular roadway with different spans and lateral pressures were obtained.The results show that the area of the plastic zone on surrounding rock increased with the increase of the spans and lateral pressures,and the plastic zone was symmetrical to the center line of roadway.At λ =0.5,1.0,1.5,and 2.0,the plastic zone presented "addleshape" distribution,"ellipse" distribution."thin and high" distribution and "inverse trapezium" distribution,respectively.In addition,we classified the roadways into four types according to the different lateral pressures and spans,including small-span,moderate-span,large-span and extreme-large-span roadways.

  10. Experimental study on stability control technology of surrounding rock of deep roadways in coal mine

    Institute of Scientific and Technical Information of China (English)

    Luo Yong; Yuan Liang; Yang Yang

    2014-01-01

    In order to solve effectively the problems of deep mining with safety and high efficiency,the multi-ple factors influencing the stability of deep rock roadway and technical problems are analyzed in the light of the severe situation of effective mining for deep coal resource,and the stability control methods for deep rock road-way are provided,which are based on the idea of combined support with separated steps and integral control of surrounding rock of deep rock roadway. The suggested methods were applied to a deep rock roadway with-648 m depth in Gubei coal mine of Huainan area. The field test was carried out and the in-situ monitoring was imple-mented,and the support scheme was optimized and adjusted to improve the stability of the surrounding rock of the roadway based on the feedback analysis. The results showed that the stability can be improved greatly by the provided control methods for deep roadway. The present methods for stability control of deep rock roadway can be used to other deep rock roadways with the similar conditions.

  11. 49 CFR 236.505 - Proper operative relation between parts along roadway and parts on locomotive.

    Science.gov (United States)

    2010-10-01

    ... roadway and parts on locomotive. 236.505 Section 236.505 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.505 Proper operative relation between parts along roadway and parts on locomotive....

  12. NOAA EPA Near-Roadway Sound Barrier Atmospheric Tracer Study 2008

    Science.gov (United States)

    A roadway toxics dispersion study was conducted at the Idaho National Laboratory to document the effects on concentrations of roadway emissions behind a roadside sound barrier in various conditions of atmospheric stability. The key finding was that reduced concentrations were me...

  13. 49 CFR 236.514 - Interconnection of cab signal system with roadway signal system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Interconnection of cab signal system with roadway signal system. 236.514 Section 236.514 Transportation Other Regulations Relating to Transportation... Interconnection of cab signal system with roadway signal system. The automatic cab signal system shall...

  14. 76 FR 74585 - Railroad Workplace Safety; Adjacent-Track On-Track Safety for Roadway Workers

    Science.gov (United States)

    2011-11-30

    ... fouling a track, and flagmen and watchmen/ lookouts * * *.'' See Sec. 214.7, ``Roadway worker.'' \\4\\ The... another common method of establishing on- track safety in which a trained and qualified watchman/lookout... location of the roadway worker. See Sec. Sec. 214.329 and 214.7 ``Watchman/ ] lookout.'' Train approach...

  15. State of roadway supports in the mines of RAG Deutsche Steinkohle; Stand des Streckenausbaus bei der RAG Deutsche Steinkohle

    Energy Technology Data Exchange (ETDEWEB)

    Opolony, Klaus [RAG Deutsche Steinkohle AG, Herne (Germany). Servicebereich Technik und Logistikdienste

    2011-03-15

    The drivage of roadways in the mines of RAG Deutsche Steinkohle poses a new major economic challenge every year. In 2009 about 500 Mio. Euro were invested in the preparatory work for development and gate roads. The roadway supports in gate road drivages are described in the contribution. These roadways and their support concepts are the basic prerequisite to ensure efficient coal extraction. About 90% of the total roadway drivages are undertaken in the seam horizon as spine and gate roads. (orig.)

  16. Roadway failure and support in a coal seam underlying a previously mined coal seam

    Institute of Scientific and Technical Information of China (English)

    Lu Yinlong; Wang Lianguo; Zhang Bei

    2012-01-01

    The influence of an upper,mined coal seam on the stability of rock surrounding a roadway in a lower coal seam is examined.The technical problems of roadway control are discussed based on the geological conditions existing in the Liyazhuang Mine No.2 coal seam.The stress distribution and floor failure in the lower works after mining the upper coal is studied through numerical simulations.The failure mechanism of the roof and walls of a roadway located in the lower coal seam is described.The predicted deformation and failure of the roadway for different distances between the two coal seams are used to design two ways of supporting the lower structure.One is a combined support consisting of anchors with a joist steel tent and a combined anchor truss.A field test of the design was performed to good effect.The results have significance for the design of supports for roadways located in similar conditions.

  17. Characteristics of stress distribution in floor strata and control of roadway stability under coal pillars

    Institute of Scientific and Technical Information of China (English)

    Tongqiang Xiao; Bai Jianbiao; Xu Lei; Zhang Xuebin

    2011-01-01

    Given the difficulties encountered in roadway support under coal pillars, we studied the characteristics of stress distribution and their effect on roadway stability, using theoretical analysis and numerical simulation. The results show that, under a coal pillar, vertical stress in a floor stratum increases while horizontal stress decreases. We conclude that the increased difference between vertical and horizontal stress is an important reason for deformation of the surrounding rock and failures of roadways under coal pillars. Based on this, we propose control technologies of the surrounding rock of a roadway under a coal pillar, such as high strength and high pre-stressed bolt support, cable reinforcement support,single hydraulic prop with beam support and reinforcement by grouting of the surrounding rock, which have been successfully applied in a stability control project of a roadway under a coal pillar.

  18. Failure mechanism and stability control technology of rock surrounding a roadway in complex stress conditions

    Institute of Scientific and Technical Information of China (English)

    Yu Yang; Bai Jianbiao; Chen Ke; Wang Xiangyu; Xiao Tongqiang; Chen Yong

    2011-01-01

    To solve the problem of supporting three downhill coal structures in the Yongan Coal Mine of Shanxi Jincheng,we studied the regular development of stress and plastic zones and characteristics of deformation of rock surrounding roadway groups after a period of roadway driving,mining one side as well as mining both sides,we used FLAC3D for our numerical and theoretical analyses.Field test were carried out,where we revealed the deformation mechanism of roadways and its coal pillars in complex stress conditions.We proposed a roadway stability control technology using backwall grouting with high-water rapid hardening material and combined support with bolt and cable anchoring after mining both sides.Our field practices showed that deformation of rock surrounding roadways can be controlled with this technology.

  19. Plastic zone analysis and support optimization of shallow roadway with weakly cemented soft strata

    Institute of Scientific and Technical Information of China (English)

    Zhang Jihua; Wang Lianguo; Li Qinghai; Zhu Shuangshuang

    2015-01-01

    Based on a shallow roadway with weakly cemented soft strata in western China, this paper studies the range and degree of plastic zones in soft strata roadways with weak cementation. Geological radars were used to monitor the loose range and level of surrounding rocks. A mechanical model of weakly cemented roadway was established, including granular material based on the measured results. The model was then used to determine the plastic zone radium. The predicted results agree well with measured results which provide valuable theoretical references for the analysis of surrounding rock stability and support reinforcing design of weakly cemented roadways. Finally, a combined supporting scheme of whole sec-tion bolting and grouting was proposed based on the original supporting scheme. It is proved that this support plan can effectively control the deformation and plastic zone expansion of the roadway sur-rounding rock and thus ensure the long-term stable and safe mining.

  20. Review of roadway control in soft surrounding rock under dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    侯朝炯

    2003-01-01

    The basic characteristics of the soft rock roadway under the dynamic pressure are analyzed. At the same time, the three fundamental approaches for controlling the surrounding rock are proposed, which are improving the surrounding rock strength, lowering the rock mass stress and selecting the reasonable supporting technology. The research results are elucidated, including the distribution of the surrounding rock plastic zone, the movement and damage of the surrounding rock under the dynamic pressure, controlling the floor heave through reinforcing the roadway walls and corners, the new route to develop the roadway metal supporting technique, the key theory and technique for the bolt supporting in the coal roadway, the performance and prospect of the ZKD high-water-content quick-setting material, and so on. Finally, some personally views are put forward about the roadway metal supporting, bolt supporting, new material and the stress-relief under the high stress condition.

  1. Investigation into the deformation of a large span roadway in soft seams and its support technology

    Institute of Scientific and Technical Information of China (English)

    Fu Jianqiu; Feng Chao; Shi Jianjun

    2011-01-01

    We investigated the deformation failure mechanism of surrounding rock from the aspect of engineering support for a roadway in seams with soft roofs and soft floors and observed the large displacement of the roadway in these soft seams.The result shows that the deformation area is quite large,and settlement of the roof is evident and displacement of the side walls is also obvious.We considered rock bolt-cable coupling for roadway support in seams with soft roofs and floors,in which the cable should be fixed at key positions.As well,we designed an optimal scheme to support a roadway in soft seams of the Shizuishan Second Mine in Ningxia,China.Field monitoring results show that bolt-cable coupling support has achieved the aims of roadway stability control and minimizes deformation.

  2. 49 CFR 214.521 - Flagging equipment for on-track roadway maintenance machines and hi-rail vehicles.

    Science.gov (United States)

    2010-10-01

    ... maintenance machines and hi-rail vehicles. 214.521 Section 214.521 Transportation Other Regulations Relating... WORKPLACE SAFETY On-Track Roadway Maintenance Machines and Hi-Rail Vehicles § 214.521 Flagging equipment for on-track roadway maintenance machines and hi-rail vehicles. Each on-track roadway maintenance...

  3. Experimental Study on Shear Performance of Bolt in Roadway Supporting

    Directory of Open Access Journals (Sweden)

    D.J. Li

    2014-09-01

    Full Text Available The corner bolt is proved to be effective in the control of floor deformation of roadway, and the relevant studies on bolting mechanisms are of great significance in improving roadway stability. In this paper, two types of shear tests on six forms of bolts are performed by using self-designed shear test device, the electro-hydraulic servo triaxial testing system. The shear characteristics of different types of bolts are obtained. The results show that different bolt rods or different internal filling conditions result in large differences in shear resistance and different deformation adaptability. We find that the filling materials added can improve the shear performance of bolt significantly, and the bolt with steel not only can improve the strength of bolt body, but also has the bimodal characteristic that makes the bolt have the secondary bearing capacity and withstand larger deformation range during the process of shear, and shows a better support performance. Hoping to provide the experiment basis for support design and field application in the future.

  4. QUADRATIC REPRESENTATION FOR ROADWAY PROFILE THAT MINIMIZES EARTHWORK COST

    Institute of Scientific and Technical Information of China (English)

    Ahmad A.MOREB; Mohammad S.ALJOHANI

    2004-01-01

    Roadway design usually involves choices regarding grade selection and earthwork (transportation) that can be solved using linear programming. Previous work considered the road profile as series of interconnected linear segments. In these models, constraints are included in the linear programming formulation to insure continuity of the road, which cause sharp connectivity points at the intersection of the linear segments. This sharp connectivity needs to be smoothed out after the linear programming solution is found and the earth in the smoothed portion of the roadway has to be moved to the landfill.In previous research, the smoothing issue is dealt with after an optimal solution is found. This increases the work required by the design engineer and consequently increases the construction cost;furthermore, the optimal solution is violated by this smoothing operation. In this paper, the issue of sharp connectivity points is resolved by representing the road profile by a quadratic function. The continuity constraints are dropped (unneeded) and global optimality is guaranteed. Moreover, no violation is incurred to implement the optimum results. Although a quadratic function is used to represent the road profile, the mathematical model is purely linear in nature.

  5. Support technology for mine roadways in extreme weakly cemented strata and its application

    Institute of Scientific and Technical Information of China (English)

    Meng Qingbin; Han Lijun; Qiao Weiguo; Lin Dengge; Fan Jiadong

    2014-01-01

    For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surround-ing rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sec-tions, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, I-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic sta-bility of surrounding rock and support structure.

  6. Water Inrush Mode and Its Evolution Characteristics with Roadway Excavation Approaching to the Fault

    Directory of Open Access Journals (Sweden)

    Hu Wang

    2012-07-01

    Full Text Available Water inrush disaster is an important factor in restricting safe production of the coal mine. Taking the roadway in seam in Danhou Coal Mine, as the engineering background, according to the spatial relationship of the roadway, the impermeable layer, the fault and the loading conditions, the fault activation mechanical model under the roadway excavation disturbance was built, and the fault activation conditions, roadway water inrush criterion and water inrush three modes were put forward. A three-dimensional numerical calculation models were built by using FLAC3D. Through fluid-solid coupling calculation, the surrounding rock damage and failure, the water inrush channel formation, and the evolution process of water inrush of the roadway excavation approaching the fault were analyzed, moreover, the displacement field, the stress field and the surrounding rock plastic failure characteristics of the roadway were revealed. Furthermore, under the conditions of different water pressure, impermeable rock thickness, fault displacement, and fault dip angles, the roadway water inrush modes and their evolution characteristics were comparatively analyzed.  

  7. Simulation of the relationship between roadway dynamic destruction and hypocenter parameters

    Institute of Scientific and Technical Information of China (English)

    GAO Ming-shi; DOU Lin-ming; ZHANG Nong; XIE Yao-she; ZHENG Bai-sheng

    2008-01-01

    Many factors can induce rock burst. Shock energy and shock distance are two key factors affecting rock burst. The 32101 roadway of the Xingcun coal mine, which has a tendency for rock burst, was used as an example. The dynamic module of Itasca's FLAC (Fast Lagrangian Analysis of Continua) 2D explicit finite-difference software was used to simulate the roadway's destruction. The vibration velocity and displacements of the rock surrounding the roadway were modeled for different shock energies and hypo-center distances. The simulation results indicate that the vibration velocity and displacement of rock surrounding the roadway have a quadratic relationship to the shock energy and a power law relationship to the distance of the hypocenter from the roadway. A dynamic view of the process was obtained from a series of "snap-shots" collected at 100 different time steps. This shows an isolat-ing "river" is first formed at the hypocenter. The region above the "river" is a low stress zone while below the "river" a high stress zone exists. This high stress zone surrounds the ribs of the roadway in a "double ear" pattern. Continuous and repeated action of the high stress in the "double ear" shaped zone destroys the roadway.

  8. Characterization of Source Signatures of Fine Roadway Particles by Pyrolysis-GC-MS

    Science.gov (United States)

    van Bergen, S. K.; Holmén, B. A.

    2001-12-01

    Fine particulate matter, defined as particles with an aerodynamic diameter less than 2.5 μ m (PM2.5), is of growing concern due to its detrimental effects on human health and the environment. Roadway traffic generates a significant fraction of PM2.5 in urban areas. Since exposure to fine particles derived from mobile sources commonly occurs, understanding the physicochemical processes that contribute to the generation, transport and atmospheric reactivity of roadway PM is important. Factors that influence the properties of roadway PM include: the mass, number and size distribution of the particles as well as their chemical composition. These factors are partially determined by the sources of the roadway particles. The focus of this effort is to identify unique organic chemical profiles of known roadway sources of PM using a new rapid characterization technique. A pyrolysis GC-MS analytical method is being developed to uniquely characterize the sources of roadway PM2.5 such as brake dust, tire wear, and direct emissions from diesel and gasoline engines. The source profiles will be used in conjunction with measurements of the composition of ambient roadway PM to determine the importance of the various roadway sources. The advantages of this technique over conventional solvent extractions include: smaller (mg) sample mass requirements, short extraction times and minimal sample handing. Preliminary two-step pyrolysis results will be presented for PM samples from individual sources and an ambient roadway. Specific analytical issues that will be discussed include: modifications of commercial pyrolysis hardware to improve reproducibility; desorption versus pyrolysis; developing appropriate pyrolysis programs for heterogenous sample materials; and method detection limits.

  9. Landscaping of highway medians and roadway safety at unsignalized intersections.

    Science.gov (United States)

    Chen, Hongyun; Fabregas, Aldo; Lin, Pei-Sung

    2016-05-01

    Well-planted and maintained landscaping can help reduce driving stress, provide better visual quality, and decrease over speeding, thus improving roadway safety. Florida Department of Transportation (FDOT) Standard Index (SI-546) is one of the more demanding standards in the U.S. for landscaping design criteria at highway medians near intersections. The purposes of this study were to (1) empirically evaluate the safety results of SI-546 at unsignalized intersections and (2) quantify the impacts of geometrics, traffic, and landscaping design features on total crashes and injury plus fatal crashes. The studied unsignalized intersections were divided into (1) those without median trees near intersections, (2) those with median trees near intersections that were compliant with SI-546, and (3) those with median trees near intersections that were non-compliant with SI-546. A total of 72 intersections were selected, for which five-year crash data from 2006-2010 were collected. The sites that were compliant with SI-546 showed the best safety performance in terms of the lowest crash counts and crash rates. Four crash predictive models-two for total crashes and two for injury crashes-were developed. The results indicated that improperly planted and maintained median trees near highway intersections can increase the total number of crashes and injury plus fatal crashes at a 90% confidence level; no significant difference could be found in crash rates between sites that were compliant with SI-546 and sites without trees. All other conditions remaining the same, an intersection with trees that was not compliant with SI-546 had 63% more crashes and almost doubled injury plus fatal crashes than those at intersections without trees. The study indicates that appropriate landscaping in highway medians near intersections can be an engineering technology that not only improves roadway environmental quality but also maintains intersection safety.

  10. Study on mechanism and practice of surrounding rock control of high stress coal roadway

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-jun; YANG Lei; OUYANG Guang-bin

    2006-01-01

    The mechanical principle and surrounding rock deformation feature of high stress coal roadway was analyzed. The condition of stress balance of the kind of the roadway was put forward. The surrounding rock control principle and supporting technique of high stress coal roadway were discussed. It was very important to control early days deformation of coal sides. The supporting strength is should increased, so the strength loss of coal sides is decreased. The range of plastic fluid zone is reduced. The above mention-ned principle is applied in industrial test, and the new supporting technique is applied successfully.

  11. Stability analysis for main roof of roadway driving along next goaf

    Institute of Scientific and Technical Information of China (English)

    柏建彪

    2003-01-01

    Focusing on the stability of surrounding rock around the roadway driving along next goaf with a narrow coal pillar, a mechanics model of the triangle block structure of main roof above the roadway is established, and the sliding stability coefficient K1 and the rotation stability coefficient K2 are proposed to describe the stability of the triangle block structure quantitatively. The structure can keep a self stability before and after the roadway excavation, at the stage of mining-induced effect, the stability of the structure is lowered, and the structure may become instability with decreasing the coal strength, increasing the mining height of working face and the mining depth.

  12. Arrangement of anchor reinforcement in roadway for fully mechanized sublevel caving

    Institute of Scientific and Technical Information of China (English)

    勾攀峰; 陈启永; 芦付松

    2003-01-01

    Bolting of mining roadway for fully mechanized sublevel caving has been practised successfully in Hebi mining area.It provides a new method for roadway support and settles the problem of support difficulty radically for sublevel caving in Hebi mining area.Where anchor reinforcement holds an important station in roadway support.This article brings forward the arrangement project of anchor based on theoretic analysis.Compared with arranged in the middle of the entry, anchor arranged in the vertex of the entry can reduces the length of anchor,shortens the anchor installation time,and heightens the reliability of anchor installation.

  13. Dynamic distribution of gas pressure and emission around a driving roadway

    Energy Technology Data Exchange (ETDEWEB)

    Gao Jian-liang; Hou San-zhong [Henan Polytechnic University, Jiaozuo (China). School of Safety Science and Engineering

    2007-11-15

    The finite difference method was applied to simulate the dynamic variation of gas pressure in coal seams around a developing roadway and the gas emission rate on the airway surface. The gas pressure distribution advances with the advancement of the working face. The rate of emission of gas from the roadway surface decreases with the elapse of exposure time of the roadway surface. When the new working face is first exposed the emission of methane is highest and it then decreases sharply. 11 refs., 7 figs., 1 tab.

  14. Numerical simulation of distribution regularities of dust concentration during the ventilation process of coal roadway driving

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Jiang, Z.; Wang, S.; Liu, Y. [University of Science and Technology Beijing, Beijing (China)

    2007-04-15

    The paper examined the distribution regularities of dust, based on the theory of two-phase flow of gas and solid, and the characteristics of the coal mine driving working face, using the discrete phase models of computational fluid mechanics to simulate the dust concentration during the ventilation process of coal roadway driving with forced ventilation. In a coal roadway driving with forced ventilation, the concentration of whole dust and respirable dust is higher in the area close to the working face, the concentration will decrease towards the exit of the roadway. It was found that exhaust ventilation is better than forced ventilation for dust removal. 7 refs., 5 figs., 1 tab.

  15. Carbon monoxide levels measured in major commuting corridors covering different landuse and roadway microenvironments in Hong Kong

    Science.gov (United States)

    Chan, L. Y.; Liu, Y. M.; Lee, S. C.; Chan, C. Y.

    Vehicle exhaust is the major source of pollutant in modern cities. About half of Hong Kong residents are living in suburban or rural areas. They need to traverse through tunnels, highways, urban street canyons and other road conditions in different landuse areas when they traverse to work in urban centres or new towns. Also, there is increasing traffic, especially trucks across the border between Hong Kong and mainland China via several border highways. This study helps us in assessing the exposure level of suburban and cross border commuters. Carbon monoxide (CO) is used as a tracer for traffic emission. An experimental vehicle traversing major commuting corridors were used to measure CO levels in different landuse and roadway microenvironments including tunnels and highways. The air samples were taken simultaneously at the outside and inside of a travelling vehicle. Result indicates that the pattern of fluctuation of the out-vehicle and in-vehicle CO level vary with different landuse areas. The variation pattern of in-vehicle CO level is closely related to that of out-vehicle level. The effects of the out-vehicle CO concentration on the in-vehicle CO concentration under different roadway conditions in various landuse categories are examined. There is an indication that external air pollutants penetrated into the in-vehicle compartment through car body cracks, ventilation system. From our observation, the exhaust of a nearby petrol vehicle contributed significantly to the in-vehicle CO level. The use of low standard of diesel fuel from Shenzhen in mainland China leads to higher CO level near border area.

  16. Engineering study on roadway support in high-stress composite soft rock

    Institute of Scientific and Technical Information of China (English)

    贾明魁; 程东泉

    2003-01-01

    The present study is focused on the roadway support in high-stress composite soft rock. This paper expounds the two main features of roadway in soft rock, i.e., great deformation of surrounding rock and remarkable rheological deformation. Furthermore, on the basis of analyzing physico-chemical component of surrounding rock and the situation of the damaged roadway, the method of adopting strong bolting and shotcreting mesh for the primary support, bolting and grouting for the secondary support is put forward in light of the on-the-spot investigation of stress tension, mechanical parameter and engineering geology. The application reveals the method facilitates the continuation of west main roadway and the restoration of shaft station and chambers. Consequently, better techno-economic results have been achieved.

  17. High prestress truss cable support principle and its application in large cross section coal roadway

    Institute of Scientific and Technical Information of China (English)

    YAO Jing-ming; HE Fu-lian; XIAO Xiao

    2007-01-01

    With the enlarge of cross section of roadway,the radius of plastic area and broken area increase.and the tensile stress and shear stress distributing in roof coal-rock layers relevantly increase,which induce support effect not obvious for ordinary bolt(cable).While bounding point and support structure of the truss cable is in vertex angle of roadway,and supplies coal-rock layers in bounding area with the horizontal and vertical pressure,SO it settles the support problems in large cross section coal roadway.From the point of view of mechanics,gave emphasis on the invalid mechanics of ordinary bolt(cable)in large cross section coal roadway and supported mechanics of prestress truss cable.The author successfully used this technique in Wuyang Mine.and had the huge economic efficiency and the social benefit.

  18. Mechanics model and numerical analysis of floor heave in soft rock roadway

    Institute of Scientific and Technical Information of China (English)

    ZHU Chuan-qu; WANG Yong; CHEN Miao-ming; CHEN Zhi; WANG Hong-ming

    2011-01-01

    The mechanism of floor heave was analyzed by establishing mechanics models and solving differential equations.The amount of floor heave is proportional to the abutment pressure of surrounding rock,roadway width,and the distance of support pressure peak to the roadway and is inversely proportional to the elastic modulus of floor rock.Using FLAC2D to simulate floor rock grouting in soft rock roadway verifies the active role of floor rock grouting in the floor controlling of soft rock roadway; floor rock grouting and grouting range directly impact on the stability scope of surrounding rock,namely,with the increase of grouting range,the subsidence of roof,the approach of both sides,and the amount of floor heave decreased gradually,the stability of surrounding rock is enhanced.

  19. Numerical Simulation of Squeezing Failure in a Coal Mine Roadway due to Mining-Induced Stresses

    Science.gov (United States)

    Gao, Fuqiang; Stead, Doug; Kang, Hongpu

    2015-07-01

    Squeezing failure is a common failure mechanism experienced in underground coal mine roadways due mainly to mining-induced stresses, which are much higher than the strength of rock mass surrounding an entry. In this study, numerical simulation was carried out to investigate the mechanisms of roadway squeezing using a novel UDEC Trigon approach. A numerical roadway model was created based on a case study at the Zhangcun coal mine in China. Coal extraction using the longwall mining method was simulated in the model with calculation of the mining-induced stresses. The process of roadway squeezing under severe mining-induced stresses was realistically captured in the model. Deformation phenomena observed in field, including roof sag, wall convexity and failed rock bolts are realistically produced in the UDEC Trigon model.

  20. Calculation of the Chilling Requirement for Air Conditioning in the Excavation Roadway

    Directory of Open Access Journals (Sweden)

    Yueping Qin

    2015-10-01

    Full Text Available To effectively improve the climate conditions of the excavation roadway in coal mine, the calculation of the chilling requirement taking air conditioning measures is extremely necessary. The temperature field of the surrounding rock with moving boundary in the excavation roadway was numerically simulated by using finite volume method. The unstable heat transfer coefficient between the surrounding rock and air flow was obtained via the previous calculation. According to the coupling effects of the air flow inside and outside air duct, the differential calculation mathematical model of air flow temperature in the excavation roadway was established. The chilling requirement was calculated with the selfdeveloped computer program for forecasting the required cooling capacity of the excavation roadway. A good air conditioning effect had been observed after applying the calculated results to field trial, which indicated that the prediction method and calculation procedure were reliable.

  1. APPLICATION OF NEURAL NETWORK TO SUPPORT OF ROADWAY IN SOFT ROCK

    Institute of Scientific and Technical Information of China (English)

    Han Fengshan; Kang Lixun

    2000-01-01

    It is well known that artificial neural network which has marvelous ability to gain knowledge has been widely used in various engineering field.In this paper, support of roadway in soft rock has been researched based on neural network.

  2. Analysis of factors associated with traffic injury severity on rural roads in Iran

    Directory of Open Access Journals (Sweden)

    Andishe Ranjbari

    2012-01-01

    Full Text Available BACKGROUND: Iran is a country with one of the highest rates of traffic crash fatality and injury, and seventy percent of these fatalities happen on rural roads. The objective of this study is to identify the significant factors influencing injury severity among drivers involved in crashes on two kinds of major rural roads in Iran: two-lane, two-way roads and freeways. METHODS: According to the dataset, 213569 drivers were involved in rural road crashes in Iran, over the 3 years from 2006 to 2008. The Classification And Regression Tree method (CART was applied for 13 independent variables, and one target variable of injury severity with 3 classes of no-injury, injury and fatality. Some of the independent variables were cause of crash, collision type, weather conditions, road surface conditions, driver's age and gender and seat belt usage. The CART model was trained by 70% of these data, and tested with the rest. RESULTS: It was indicated that seat belt use is the most important safety factor for two-lane, two-way rural roads, but on freeways, the importance of this variable is less. Cause of crash, also turned out to be the next most important variable. The results showed that for two-lane, two-way rural roads, "improper overtaking" and "speeding", and for rural freeways, "inattention to traffic ahead", "vehicle defect", and "movement of pedestrians, livestock and unauthorized vehicles on freeways" are the most serious causes of increasing injury severity. CONCLUSIONS: The analysis results revealed seat belt use, cause of crash and collision type as the most important variables influencing the injury severity of traffic crashes. To deal with these problems, intensifying police enforcement by means of mobile patrol vehicles, constructing overtaking lanes where necessary, and prohibiting the crossing of pedestrians and livestock and the driving of unauthorized vehicles on freeways are necessary. Moreover, creating a rumble strip on the two edges of

  3. Analysis of factors associated with traffic injury severity on rural roads in Iran.

    Science.gov (United States)

    Kashani, Ali Tavakoli; Shariat-Mohaymany, Afshin; Ranjbari, Andishe

    2012-01-01

    Iran is a country with one of the highest rates of traffic crash fatality and injury, and seventy percent of these fatalities happen on rural roads. The objective of this study is to identify the significant factors influencing injury severity among drivers involved in crashes on two kinds of major rural roads in Iran: two-lane, two-way roads and freeways. According to the dataset, 213569 drivers were involved in rural road crashes in Iran, over the 3 years from 2006 to 2008. The Classification And Regression Tree method (CART) was applied for 13 independent variables, and one target variable of injury severity with 3 classes of no-injury, injury and fatality. Some of the independent variables were cause of crash, collision type, weather conditions, road surface conditions, driver's age and gender and seat belt usage. The CART model was trained by 70% of these data, and tested with the rest. It was indicated that seat belt use is the most important safety factor for two-lane, two-way rural roads, but on freeways, the importance of this variable is less. Cause of crash, also turned out to be the next most important variable. The results showed that for two-lane, two-way rural roads, "improper overtaking" and "speeding", and for rural freeways, "inattention to traffic ahead", "vehicle defect", and "movement of pedestrians, livestock and unauthorized vehicles on freeways" are the most serious causes of increasing injury severity. The analysis results revealed seat belt use, cause of crash and collision type as the most important variables influencing the injury severity of traffic crashes. To deal with these problems, intensifying police enforcement by means of mobile patrol vehicles, constructing overtaking lanes where necessary, and prohibiting the crossing of pedestrians and livestock and the driving of unauthorized vehicles on freeways are necessary. Moreover, creating a rumble strip on the two edges of roads, and paying attention to the design consistency of

  4. Air pollutant concentrations near three Texas roadways, Part I: Ultrafine particles

    Science.gov (United States)

    Zhu, Yifang; Pudota, Jayanth; Collins, Donald; Allen, David; Clements, Andrea; DenBleyker, Allison; Fraser, Matt; Jia, Yuling; McDonald-Buller, Elena; Michel, Edward

    Vehicular emitted air pollutant concentrations were studied near three types of roadways in Austin, Texas: (1) State Highway 71 (SH-71), a heavily traveled arterial highway dominated by passenger vehicles; (2) Interstate 35 (I-35), a limited access highway north of Austin in Georgetown; and (3) Farm to Market Road 973 (FM-973), a heavily traveled surface roadway dominated by truck traffic. Air pollutants examined include carbon monoxide (CO), oxides of nitrogen (NO x), and carbonyl species in the gas-phase. In the particle phase, ultrafine particle (UFP) concentrations (diameter duty traffic, wind speed, and proximity to the road were found to be the most important factors determining UFP concentrations near the roadways. Since wind directions were not consistent during the sampling periods, distances along wind trajectories from the roadway to the sampling points were used to study the decay characteristics of UFPs. Under perpendicular wind conditions, for all studied roadway types, particle number concentrations increased dramatically moving from the upwind side to the downwind side. The elevated particle number concentrations decay exponentially with increasing distances from the roadway with sharp concentration gradients observed within 100-150 m, similar to previously reported studies. A single exponential decay curve was found to fit the data collected from all three roadways very well under perpendicular wind conditions. No consistent pattern was observed for UFPs under parallel wind conditions. However, regardless of wind conditions, particle concentrations returned to background levels within a few hundred meters of the roadway. Within measured UFP size ranges, smaller particles (6-25 nm) decayed faster than larger ones (100-300 nm). Similar decay rates were observed among UFP number, surface, and volume.

  5. Residential proximity to a major roadway is associated with features of asthma control in children.

    Directory of Open Access Journals (Sweden)

    Meredith S Brown

    Full Text Available BACKGROUND: While several studies suggest that traffic-related air pollutants are detrimental for respiratory health, few studies have examined relationships between residential proximity to a major roadway and asthma control in children. Furthermore, a major limitation of existing research is reliance on self-reported outcomes. We therefore determined the spatial relationship between the distance from a major roadway and clinical, physiologic and inflammatory features of asthma in a highly characterized sample of asthmatic children 6-17 years of age across a wide range of severities. We hypothesized that a closer residential proximity to a major roadway would be associated with increased respiratory symptoms, altered pulmonary function and a greater magnitude of airway and systemic inflammation. METHODOLOGY/PRINCIPAL FINDINGS: 224 children 6-17 years with confirmed asthma completed questionnaires and underwent spirometry, plethysmography, exhaled nitric oxide determination, exhaled breath condensate collection and venipuncture. Residential distance from a major roadway was determined by mapping the geographic coordinates of the residential address in Geographic Information System software. The distance between the home address and the nearest major roadway was calculated according to the shortest distance between the two points (i.e., "as the crow flies". Asthmatic children living in closer proximity to a major roadway had an increased frequency of wheezing associated with increased medication requirements and more hospitalizations even after controlling for potential confounders. These children also had increased airway resistance, increased airway inflammation reflected by a lower breath condensate pH, and higher plasma EGF concentrations. CONCLUSIONS/SIGNIFICANCE: These findings suggest that closer residential proximity to a major roadway is associated with poorer asthma control in school-age children. Assessment of residential proximity to

  6. RESEARCH ON REPAIR SUPPORT FOR FLOOR HEAVE IN SOFT ROCK ROADWAY

    Institute of Scientific and Technical Information of China (English)

    黄庆享; 杨忠民

    1997-01-01

    The run-around of Xiagou subincline bottom is a soft rock roadway, its floor has heaved over 1 m. In this paper, by electronic microscope scanning and X-ray diffraction analysis, the components of the soft rock are determined and the breaking mechanism of roadway is analyzed as well. Through finite element calculation and simulation model test, the reasonable repair support method is put forward.

  7. Guidance manual on the estimation of airborne asbestos concentrations as a function of distance from a contaminated roadway for roadway screening

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, R.D.; Droppo, J.G.; Peloquin, R.A.; Bienert, R.W.; VanHouten, N.C.

    1990-04-01

    This Guidance Manual provides a quantitative approach for estimating, for the purpose of screening/ranking, the airborne concentrations of asbestos from roads surfaced with asbestos-bearing serpentine rock. This manual identifies the procedures necessary for estimating screening-level airborne concentrations of asbestos in disturbed soils associated with roadways whose surfacing material contains asbestos fibers. The manual is to be used in conjunction with the Airborne Asbestos Concentration Estimator System-Roadway Screening (AACES-RS) computer code. 12 refs., 11 figs., 4 tabs.

  8. Fracture characteristics of a soft rock roadway: staged and zoned control

    Energy Technology Data Exchange (ETDEWEB)

    Li Xue-hua; Yao Qiang-ling; Zhang Nong [China University of Mining & Technology, Xuzhou (China). State Key Laboratory of Coal Resource and Mine Safety

    2009-05-15

    An accurate understanding of fracture and cracking in surrounding rock is the key to solving the problem of maintaining a soft-rock roadway. Experimental studies have been done within a typical soft-rock roadway in a coal mine. The components and micro-structural features of the surrounding rock were investigated. The properties of the rocks around the roadway and the process of fracture expansion were tested on site. The results show that crack propagation and run-through are non-uniform and occur in several stages. Key technologies for supporting the roadway by stages in different regions were put forward after considering time effects, local breakdown characteristics and fracture development. Staged concrete spraying, intensive support from anchor bolting (cabling) and control of the grouting process in the surrounding rock are the main parts of strengthened support technology. Practice shows that rock cracking in soft rock surrounding a roadway can be effectively controlled by this support technology. Stability of the rock surrounding the roadway can be achieved. 12 refs., 13 figs., 1 tab.

  9. Deformation and Failure Mechanism of Roadway Sensitive to Stress Disturbance and Its Zonal Support Technology

    Directory of Open Access Journals (Sweden)

    Qiangling Yao

    2016-01-01

    Full Text Available The 6163 haulage roadway in the Qidong coal mine passes through a fault zone, which causes severe deformation in the surrounding rock, requiring repeated roadway repairs. Based on geological features in the fault area, we analyze the factors affecting roadway deformation and failure and propose the concept of roadway sensitive to stress disturbance (RSSD. We investigate the deformation and failure mechanism of the surrounding rocks of RSSD using field monitoring, theoretical analysis, and numerical simulation. The deformation of the surrounding rocks involves dilatation of shallow rocks and separation of deep rocks. Horizontal and longitudinal fissures evolve to bed separation and fracture zones; alternatively, fissures can evolve into fracture zones with new fissures extending to deeper rock. The fault affects the stress field of the surrounding rock to ~27 m radius. Its maximum impact is on the vertical stress of the rib rock mass and its minimum impact is on the vertical stress of the floor rock mass. Based on our results, we propose a zonal support system for a roadway passing through a fault. Engineering practice shows that the deformation of the surrounding rocks of the roadway can be effectively controlled to ensure normal and safe production in the mine.

  10. Deformation mechanisms in a coal mine roadway in extremely swelling soft rock.

    Science.gov (United States)

    Li, Qinghai; Shi, Weiping; Yang, Renshu

    2016-01-01

    The problem of roadway support in swelling soft rock was one of the challenging problems during mining. For most geological conditions, combinations of two or more supporting approaches could meet the requirements of most roadways; however, in extremely swelling soft rock, combined approaches even could not control large deformations. The purpose of this work was to probe the roadway deformation mechanisms in extremely swelling soft rock. Based on the main return air-way in a coal mine, deformation monitoring and geomechanical analysis were conducted, as well as plastic zone mechanical model was analysed. Results indicated that this soft rock was potentially very swelling. When the ground stress acted alone, the support strength needed in situ was not too large and combined supporting approaches could meet this requirement; however, when this potential released, the roadway would undergo permanent deformation. When the loose zone reached 3 m within surrounding rock, remote stress p ∞ and supporting stress P presented a linear relationship. Namely, the greater the swelling stress, the more difficult it would be in roadway supporting. So in this extremely swelling soft rock, a better way to control roadway deformation was to control the releasing of surrounding rock's swelling potential.

  11. Distribution of lead in urban roadway grit and its association with elevated steel structures.

    Science.gov (United States)

    Weiss, Arlene L; Caravanos, Jack; Blaise, Marc J; Jaeger, Rudolph J

    2006-12-01

    In an effort to determine the source of exterior lead contamination, we investigated the concentration of lead in roadway grit along major thoroughfares in New York City and in certain areas under elevated steel structures supporting elevated rails. Such structures represent only one source of lead in roadway grit. While data revealed that the median lead concentration in roadway grit did not exceed the standard for a lead hazard in bare residential soil in any borough, the limit of 400 microg/g was exceeded 22%, 18%, 10.5%, and 7.7% of the time in Manhattan, Brooklyn, The Bronx, and Queens, respectively. The second part of the study revealed the presence of high concentrations of lead in roadway grit directly under elevated steel structures. The differences in the concentration of lead in roadway grit under steel structures in comparison to areas in NYC not near elevated rails was statistically significant. Of the eight sites studied from 225 total samples, the median roadway grit lead level was 340 ppm, while the level under steel structures was 1480 ppm. Preliminary efforts to determine particle size distribution revealed that 84% of the particles were in the range of 125-500 microm, but the highest concentration of lead was in the smallest fraction analyzed (steel structures is a public health problem as these lead particulates get re-suspended in the ambient environment and are wafted and tracked into residences.

  12. ATMOSPHERIC MODELING IN SUPPORT OF A ROADWAY ACCIDENT

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.; Hunter, C.

    2010-10-21

    The United States Forest Service-Savannah River (USFS) routinely performs prescribed fires at the Savannah River Site (SRS), a Department of Energy (DOE) facility located in southwest South Carolina. This facility covers {approx}800 square kilometers and is mainly wooded except for scattered industrial areas containing facilities used in managing nuclear materials for national defense and waste processing. Prescribed fires of forest undergrowth are necessary to reduce the risk of inadvertent wild fires which have the potential to destroy large areas and threaten nuclear facility operations. This paper discusses meteorological observations and numerical model simulations from a period in early 2002 of an incident involving an early-morning multicar accident caused by poor visibility along a major roadway on the northern border of the SRS. At the time of the accident, it was not clear if the limited visibility was due solely to fog or whether smoke from a prescribed burn conducted the previous day just to the northwest of the crash site had contributed to the visibility. Through use of available meteorological information and detailed modeling, it was determined that the primary reason for the low visibility on this night was fog induced by meteorological conditions.

  13. Extended Visual Glances Away from the Roadway are Associated with ADHD- and Texting-Related Driving Performance Deficits in Adolescents.

    Science.gov (United States)

    Kingery, Kathleen M; Narad, Megan; Garner, Annie A; Antonini, Tanya N; Tamm, Leanne; Epstein, Jeffery N

    2015-08-01

    The purpose of the research study was to determine whether ADHD- and texting-related driving impairments are mediated by extended visual glances away from the roadway. Sixty-one adolescents (ADHD =28, non-ADHD =33; 62% male; 11% minority) aged 16-17 with a valid driver's license were videotaped while engaging in a driving simulation that included a No Distraction, Hands-Free Phone Conversation, and Texting condition. Two indicators of visual inattention were coded: 1) percentage of time with eyes diverted from the roadway; and 2) number of extended (greater than 2 s) visual glances away from the roadway. Adolescents with ADHD displayed significantly more visual inattention to the roadway on both visual inattention measures. Increased lane position variability among adolescents with ADHD compared to those without ADHD during the Hands-Free Phone Conversation and Texting conditions was mediated by an increased number of extended glances away from the roadway. Similarly, texting resulted in decreased visual attention to the roadway. Finally, increased lane position variability during texting was also mediated by the number of extended glances away from the roadway. Both ADHD and texting impair visual attention to the roadway and the consequence of this visual inattention is increased lane position variability. Visual inattention is implicated as a possible mechanism for ADHD- and texting-related deficits and suggests that driving interventions designed to address ADHD- or texting-related deficits in adolescents need to focus on decreasing extended glances away from the roadway.

  14. Application of full-length anchor support technology in a large-section roadway under complicated geological conditions

    Institute of Scientific and Technical Information of China (English)

    DONG Yun-fei; WANG Yun-gang

    2012-01-01

    Coal roadway support is the foundation and strong guarantee of safe coal production.With the FLAC3D numerical simulation,the roadway full-length anchor support mechanism was studied,and the full-length anchor force-transferring mechanism and stress-field distribution formed by roadway surrounding rocks were analyzed,which will provide a scientific basis for a support technology in large-section roadways under complicated geological conditions and lay a foundation for the popularization and application of a full-length anchor support system under special geological conditions.

  15. A new cable truss support system for coal roadways affected by dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    Hong Yan; Fulian He

    2012-01-01

    The support of coal roadways is seriously affected by intense dynamic pressures.This can lead to problems with large deformation of the roof and the two side walls of coal roadways.Rapid convergence of the walls and roof,a high damage rate to the bolts and cables,or even abrupt roof collapse or rib spalling can occur during the service period of these coal roadways.Analyzing the main support measures used in China leads to a proposed new cable truss supporting system.Thorough study of the entire structure shows the superiority of this design for roadways suffering under dynamic pressure.A corresponding mechanical model of the rock surrounding the cable truss system is described in this paper and formulas for calculating pre-tightening forces of the truss cable,and the minimum anchoring forces,were deduced.The new support system was applied to a typical roadway affected by intensive dynamic pressure that is located in the Xinyuan Coal Mine.The results show that the largest subsidence of the roof was 97 mm,the convergence of the two sides was less than 248 mm,and the average depth of the loose,fractured layer was only 6.12 mm.This proves that the new support system is feasible and effective.

  16. Floor heave characteristics and control technology of the roadway driven in deep inclined-strata

    Institute of Scientific and Technical Information of China (English)

    Wang Meng; Guo Guanlong; Wang Xiangyu; Guo Yu; Dao Vietdoan

    2015-01-01

    Based on in-mine instrumentation and theoretical analysis of the unsymmetrical large-deformation that occurred in the roadway after excavation, Differential Floor Heave (DFH) was found to be the main reason for roadway failure. It needs to be pointed out that the specific roadway was driven in inclined rock strata. In addition, the factors that contribute to the occurrence of DFH are discussed in detail. It is believed that DFH is triggered by the unsymmetrical stress distribution in the floor and the different rock types encountered near the two floor corners. Hence, DFH control should be focused on the left floor corner where shearing failure occurs initially and the left floor surface where tensile failure is more severe. The proposed DFH control strategies include unsymmetrical grouting for the whole roadway, re-design of the roof and ribs support, reinforcement of the weak zones, and release of the concentrated stress in the earlier stage. Meanwhile, it is recommended that in the later stage, both bolts and cable bolts with higher strength and the backfilling technique using the coal measure rocks and concrete should be employed in the reversed-arch floor. The field instrumentation results, after using the proposed control strategies, indicate that large deformation in a DFH roadway has been successfully controlled.

  17. Deformation mechanism and stability control of roadway along a fault subjected to mining

    Institute of Scientific and Technical Information of China (English)

    Yan Shuai; Bai Jianbiao; Li Wenfeng; Chen Jigang; Li Lei

    2012-01-01

    It is difficult to maintain the roadway around a fault because of the fractured surroundings,complex stress environment,and large and intense deformation in the mining process.Based on a tailgate of panel S2205 in Tunliu colliery,in Shanxi province,China,we investigated the evolution of stress and displacement of rocks surrounding the roadway during the drivage and mining period using theoretical analysis,numerical simulation and field trial methods.We analyzed the deformation and failure mechanisms of the tailgate near a fault.The deformation of surrounding rock caused by unloading in the drivage period is large and asymmetric,the roadway convergence increases with activation of the fault and secondary fracture develops in the mining period.Therefore,we proposed a specific control technique of the roadway along a fault as follows:(1) High-strength yielding bolt not only supports the shallow rock to loadbearing structures,but also releases primary deformation energy by use of a pressure release device in order to achieve high resistance to the pressure retained; (2) Grouting of near-fault ribside after initial stabilization of the rock deformation is used to reinforce the broken rock,and to improve the integral load-bearing capacity of the roadway.The research results were successfully applied to a field trial.

  18. Development of fractures in soft rock surrounding a roadway and their control

    Institute of Scientific and Technical Information of China (English)

    Li Xuehua; Yao Qiangling; Man Jiankang; Chen Chaoqun; He Lihui

    2011-01-01

    As the excavation of roadway,new fractures will be formed and the pre-existing fractures extend with the redistribution of stress in surrounding rocks.Eventually,fracture zone and bed separation are formed in rocks because of the developed fractures.Therefore,mastering the fracture evolution of surrounding rocks is very important to maintain the stability of roadway.The surrounding rocks of main haulage roadway in a certain coal mine is so broken and loose that the supporting is very difficult.Based on comprehensive analysis of the engineering geological conditions,a sight instrument was used to observe the fractures of internal surrounding rocks.Four indices,i.e.,the width of fracture zone W,the number of fractures n,the width of fractures d and rock fracture designation RFD,are put forward to evaluate the fracture development.According to the evolution rules of the soft rock roadway from this paper,control principles by stages and by regions are presented through the research.At the same time,the best time of grouting reinforcement is determined on the basis of fracture saturation.Field practice shows that the roadway can satisfy normal production during service periods by suitable first support and grouting reinforcement.

  19. Support technology of deep roadway under high stress and its application

    Institute of Scientific and Technical Information of China (English)

    Cao Rihong; Cao Ping; Lin Hang

    2016-01-01

    Roadway instability has been a major concern in the fields of mining engineering. This paper aims to pro-vide practical and efficient strategy to support the roadways under high in-situ stress. A case study on the stability of deep roadways was carried out in an underground mine in Gansu province, China. Currently, the surrounding rock strata is extremely fractured, which results in a series of engineering disasters, such as side wall collapse and severe floor heave in the past decades. Aiming to solve these problems, an improved support method was proposed, which includes optimal bolt parameters and arrangement, floor beam layout by grooving, and full length grouting. Based on the modeling results by FLAC3D, the new support method is much better than the current one in terms of preventing the large deformation of sur-rounding rock and restricting the development of plastic zones. For implementation and verification, field experiments, along with deformation monitoring, were conducted in the 958 level roadway of Mining II areas. The results show that the improved support can significantly reduce surrounding rock deforma-tion, avoid frequent repair, and maintain the long-term stability of the roadway. Compared to the original support, the new support method can greatly save investment of mines, and has good application value and popularization value.

  20. Deformation mechanism of roadways in deep soft rock at Hegang Xing'an Coal Mine

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaojie; Pang Jiewen; Liu Dongming; Liu Yang; Tian Yihong; Ma Jiao; Li Shaohua

    2013-01-01

    Engineering geomechanics characteristics of roadways in deep soft rock at Hegang Xing'an Coal Mine were studied and the nature of clay minerals of roadway surrounding rock was analyzed.This paper is to solve the technical problems of high stress and the difficulty in supporting the coal mine,and provide a rule for the support design.Results show that mechanical deformation mechanisms of deep soft rock roadway at Xing'an Coal Mine is of ⅠABⅡABcⅢABCD type,consisting of molecular water absorption (the ⅠAB-type),the tectonic stress type + gravity deformation type + hydraulic type (the ⅡABC-type),and the ⅢABCD-type with fault,weak intercalation and bedding formation.According to the compound mechanical deformation mechanisms,the corresponding mechanical control measures and conversion technologies were proposed,and these technologies have been successfully applied in roadway supporting practice in deep soft rock at Xing'an Coal Mine with good effect.Xing'an Coal Mine has the deepest burial depth in China,with its overburden ranging from Mesozoic Jurassic coal-forming to now.The results of the research can be used as guidance in the design of roadway support in soft rock.

  1. Sustainability assessment of roadway projects under uncertainty using Green Proforma: An index-based approach

    Directory of Open Access Journals (Sweden)

    Adil Umer

    2016-12-01

    Full Text Available Growing environmental and socioeconomic concerns due to rapid urbanization, population growth and climate change impacts have motivated decision-makers to incorporate sustainable best practices for transportation infrastructure development and management. A “sustainable” transportation infrastructure implies that all the sustainability objectives (i.e., mobility, safety, resource efficiency, economy, ecological protection, environmental quality are adequately met during the infrastructure life cycle. State-of-the-art sustainability rating tools contain the best practices for the sustainability assessment of infrastructure projects. Generally, the existing rating tools are not well equipped to handle uncertainties associated with data limitations and expert opinion and cannot effectively adapt to site specific constraints for reliable sustainability assessment. This paper presents the development of a customizable tool, called “Green Proforma” for the sustainability assessment of roadway projects under uncertainties. For evaluating how well the project meets sustainability objectives, a hierarchical framework is used to develop the sustainability objective indices by aggregating the selected indicators with the help of fuzzy synthetic evaluation technique. These indices are further aggregated to attain an overall sustainability index for a roadway project. To facilitate the decision makers, a “Roadway Project Sustainometer” has been developed to illustrate how well the roadway project is meeting its sustainability objectives. By linking the sustainability objectives to measurable indicators, the “Green Proforma” paves the way for a practical approach in sustainable planning and management of roadway projects.

  2. Study of mechanical principle of floor heave of roadway driving along next goaf in fully mechanized sub-level caving face

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-jun; HOU Chao-jiong

    2001-01-01

    On the basis of analyzing floor strata mechanical circumstance of the roadway, the mechanical model was established. The relative displacement of roadway floor, narrow pillar floor coal mass and floor strata was calculated, the results showed that the high abutment pressure on coal mass beside the roadway was the main reason to lead to relative displacement of floor stra ta. And the roadway floor heave come mainly from three aspects. Firstly, the roadway floor strata is easily fractured by the stretch stress. Secondly, because the high abutment pressure is greater than the uniaxial compressive strength of floor strata, when the roadway floor strata are fractured, the coal mass floor strata at the same depth will be fractured, and broken rock will fluid into the open roadway. Thirdly, comparing with the coal mass floor, the roadway floor is relative ascending

  3. Stability analysis for main roof of roadway driving along next goaf

    Energy Technology Data Exchange (ETDEWEB)

    Bai, J. [China University of Mining and Technology, Xuzhou (China). School of Energy Science and Engineering

    2003-06-01

    Focusing on the stability of surrounding rock around the roadway driving along next goaf with a narrow coal pillar, a mechanics model of the triangle block structure of main roof above the roadway is established, and the sliding stability coefficient K{sub 1} and the rotation stability coefficient K{sub 2} are proposed to describe the stability of the triangle block structure quantitatively. The structure can keep self stable before and after the roadway excavation, at the stage of mining-induced effect, the stability of the structure is lowered, and the structure may become unstable with decreasing the coal strength, increasing the mining height of working face and the mining depth. 8 refs., 3 figs., 2 tabs.

  4. Theory and application of infrared surveying gas gushing technology in coal-rock roadway

    Institute of Scientific and Technical Information of China (English)

    蔡康旭

    2002-01-01

    Geological structure and gas expansion when gas pressure was released can affect the distribution of infrared radiation energy or temperature at coal-rock surface. From this, the foundation of roadway infrared surveying technical was formed. According to the thermodynamic principle of ideal gas and the law of energy conservation, the relation was established between gas gushing amount from coal-rock and air temperature to fall in roadway. At the same time, this paper has analyzed coal-rock density change that geological structure aroused and the change exerted influences on infrared radiation power at surface, as well as, has analyzed the infrared radiation feature of gas gushing at geological structure district. Application results show that infrared survey technology can be used to analyze and forecast the change of coal-rock gas gushing effectively, and to guide the enforcement of the roadway gas project of prevention and handling economically.

  5. Numerical Simulation for Roadways in Swelling Rock Under Coupling Function of Water and Ground Pressure

    Institute of Scientific and Technical Information of China (English)

    缪协兴; 卢爱红; 茅献彪; 张东升

    2002-01-01

    According to the analogical relation in the governing differential equations of the humidity stress field theory and the temperature stress field theory, the problem of solving the humidity stress field was transformed into that of solving the temperature stress field by the change of parameters. As a result, th e problem of roadways in swelling rock under the coupling function of water and ground pressure can be solved by the analytical module of temperature stress fie ld in software ANSYS. In the numerical simulation mentioned above, three kinds of supporting, I.e. Steel support, bolting support and non-support, were taken I nto account, the pressure distribution and deformation state of roadways with a swelling rock floor under the coupling function of water and ground pressure were analyzed and compared with those in the action of only ground pressure. The rese arch results provides a scientific basis for the deformation control of roadways in swelling rock.

  6. Roadway backfill method to prevent geohazards induced by room and pillar mining: a case study in Changxing coal mine, China

    Science.gov (United States)

    Zhou, Nan; Li, Meng; Zhang, Jixiong; Gao, Rui

    2016-11-01

    Coal mines in the western areas of China experience low mining rates and induce many geohazards when using the room and pillar mining method. In this research, we proposed a roadway backfill method during longwall mining to target these problems. We tested the mechanical properties of the backfill materials to determine a reasonable ratio of backfill materials for the driving roadway during longwall mining. We also introduced the roadway layout and the backfill mining technique required for this method. Based on the effects of the abutment stress from a single roadway driving task, we designed the distance between roadways and a driving and filling sequence for multiple-roadway driving. By doing so, we found the movement characteristics of the strata with quadratic stabilization for backfill mining during roadway driving. Based on this research, the driving and filling sequence of the 3101 working face in Changxing coal mine was optimized to avoid the superimposed influence of mining-induced stress. According to the analysis of the surface monitoring data, the accumulated maximum subsidence is 15 mm and the maximum horizontal deformation is 0.8 mm m-1, which indicated that the ground basically had no obvious deformation after the implementation of the roadway backfill method at 3101 working face.

  7. 49 CFR 214.525 - Towing with on-track roadway maintenance machines or hi-rail vehicles.

    Science.gov (United States)

    2010-10-01

    ... or hi-rail vehicles. 214.525 Section 214.525 Transportation Other Regulations Relating to... SAFETY On-Track Roadway Maintenance Machines and Hi-Rail Vehicles § 214.525 Towing with on-track roadway maintenance machines or hi-rail vehicles. (a) When used to tow pushcars or other maintenance-of-way...

  8. 49 CFR 214.509 - Required visual illumination and reflective devices for new on-track roadway maintenance machines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Required visual illumination and reflective... Required visual illumination and reflective devices for new on-track roadway maintenance machines. Each new on-track roadway maintenance machine shall be equipped with the following visual illumination...

  9. Mechanical properties of abandoned and closed roadways in the Kushiro Coal Mine, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Y.; Ishijima, Y.; Ichihara, Y.; Kiyama, T.; Kumakura, S.; Takada, M.; Sugawara, T.; Narita, T.; Kodama, J.; Sawada, M.; Nakata, E. [Hokkaido University, Hokkaido (Japan)

    2011-06-15

    The objective of this research is to clarify the mechanical properties and self-healing ability of the Excavation Damaged Zone (EDZ) around rock caverns in clastic-rock. Observations of nearly one hundred closed roadways up to fifty years old, which can be regarded as very severe EDZs with no initial sealability and are up to 300 m deep in clastic-rock, were made at the Kushiro Coal Mine, Japan, to accomplish the objective. Most old roadways were closed, though a few remain open. Closure of old roadways was mainly due to roof deflection and/or floor heave. Large plastic deformations dominated; however, severe fractures were seldom observed in closed old roadways. Rayleigh wave velocity and hydraulic conductivity in the closed old roadways were in the range of 0.3-1.2 km/s and 5 x 10{sup -7}-1 x 10{sup -7} m/s, respectively, and those in EDZ and EdZ (Excavation disturbed Zone) around recently excavated roadways were 1.1-1.8 km/s and 1 x 10{sup -8}-5 x 10{sup -8} m/s, respectively. The extent of EDZ around the present tailgate was in the range of 1-5 m. Mechanical excavation and prevention from water are suggested as the key points for long-term maintenance of rock repositories. Pressurization from inside the cavern to decrease the permeability of EDZ is proposed for maintenance of rock repositories in medium-hard clastic-rock masses at similar depths for long periods.

  10. Residential Proximity to Major Roadways and Risk of Type 2 Diabetes Mellitus: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Zhiqing Zhao

    2016-12-01

    Full Text Available Research indicates that higher levels of traffic-related pollution exposure increase the risk of diabetes, but the association between road proximity and diabetes risk remains unclear. To assess and quantify the association between residential proximity to major roadways and type 2 diabetes, a systematic review and meta-analysis was performed. Embase, Medline, and Web of Science were searched for eligible studies. Using a random-effects meta-analysis, the summary relative risks (RRs were calculated. Bayesian meta-analysis was also performed. Eight studies (6 cohort and 2 cross-sectional with 158,576 participants were finally included. The summary unadjusted RR for type 2 diabetes associated with residential proximity to major roadways was 1.24 (95% confidence interval [CI]: 1.07–1.44, p = 0.001, I2 = 48.1%. The summary adjusted RR of type 2 diabetes associated with residential proximity to major roadways was 1.12 (95% CI: 1.03–1.22, p = 0.01, I2 = 17.9%. After excluding two cross-sectional studies, the summary results suggested that residential proximity to major roadways could increase type 2 diabetes risk (Adjusted RR = 1.13; 95% CI: 1.02–1.27, p = 0.025, I2 = 36.6%. Bayesian meta-analysis showed that the unadjusted RR and adjusted RR of type 2 diabetes associated with residential proximity to major roadways were 1.22 (95% credibility interval: 1.06–1.55 and 1.13 (95% credibility interval: 1.01–1.31, respectively. The meta-analysis suggested that residential proximity to major roadways could significantly increase risk of type 2 diabetes, and it is an independent risk factor of type 2 diabetes. More well-designed studies are needed to further strengthen the evidence.

  11. A Bandwidth-Efficient Service for Local Information Dissemination in Sparse to Dense Roadways

    Directory of Open Access Journals (Sweden)

    Patricia Noriega-Vivas

    2013-07-01

    Full Text Available Thanks to the research on Vehicular Ad Hoc Networks (VANETs, we will be able to deploy applications on roadways that will contribute to energy efficiency through a better planning of long trips. With this goal in mind, we have designed a gas/charging station advertising system, which takes advantage of the broadcast nature of the network. We have found that reducing the number of total sent packets is important, as it allows for a better use of the available bandwidth. We have designed improvements for a distance-based flooding scheme, so that it can support the advertising application with good results in sparse to dense roadway scenarios.

  12. A Bandwidth-Efficient Service for Local Information Dissemination in Sparse to Dense Roadways

    Science.gov (United States)

    Garcia-Lozano, Estrella; Campo, Celeste; Garcia-Rubio, Carlos; Cortes-Martin, Alberto; Rodriguez-Carrion, Alicia; Noriega-Vivas, Patricia

    2013-01-01

    Thanks to the research on Vehicular Ad Hoc Networks (VANETs), we will be able to deploy applications on roadways that will contribute to energy efficiency through a better planning of long trips. With this goal in mind, we have designed a gas/charging station advertising system, which takes advantage of the broadcast nature of the network. We have found that reducing the number of total sent packets is important, as it allows for a better use of the available bandwidth. We have designed improvements for a distance-based flooding scheme, so that it can support the advertising application with good results in sparse to dense roadway scenarios. PMID:23881130

  13. Analysis on mechanism and key factors of surrounding rock instability in deeply inclined roadway affected by argillation and water seepage

    Institute of Scientific and Technical Information of China (English)

    Ma Rui; Li Guichen; Zhang Nong; Liu Cong; Wei Yinghao; Zhang Ming

    2015-01-01

    Based on the characteristics of surrounding rocks for deeply inclined roadway affected by argillation and water seepage, a structure model of layer crack plate was established to analyze the shear sliding insta-bility mechanism. Through solid mechanics analysis of anchored surrounding rock with defect from water seepage, combined with numerical analysis for instability mechanism under water seepage in deeply inclined roadway, key factors were proposed. Results show that with increasing height of layer crack plate, lateral buckling critical load value for high wall of the roadway decreases;there is a multi-stage distribution for tensile stress along the anchor bolt with defect under pulling state condition;groundwater seepage seriously affects the strength of surrounding rock of the roadway, to some extent the plastic zone of the high side rises up to 8 m. Finally some support strategies were proposed for the inclined roadway and successfully applied to Haoyuan coal mine in Tiela mining area, western China.

  14. Interaction driver-bicyclist on rural roads: Effects of cross-sections and road geometric elements.

    Science.gov (United States)

    Bella, Francesco; Silvestri, Manuel

    2017-03-17

    The interaction of motorists and bicyclists, particularly during passing maneuvers, is cited as one of the primary causes of bicyclist fatalities. This paper reports the results of a driving simulator study, which sought to analyze the effects that three cross-section configurations of a two-lane rural road and four geometric elements of the road have on driver behavior, during the interaction with a cyclist. A two-lane rural road, about 11km long, was designed and implemented in an advanced-interactive driving simulator. Three different cross-sections (all with same width, but with and without a bicycle lane and for different widths of bicycle lane) were tested. Forty participants carried out three driving sessions (one for each road alignment with different cross-section) and were exposed to the condition of bicycle traffic along four geometric elements of the alignment (2 tangents with different lengths, right curve and left curve). The driving simulator experiments were designed in such a way that, along the sections where the driver-cyclist interactions occurred, the oncoming traffic was absent. Overall, 468 speed profiles and 468 lateral position profiles were plotted to obtain the descriptive variables of the driver behavior during the interaction with the cyclist. The influences of cross-sections, geometric elements and bicycle traffic conditions on driver behavior were evaluated by a multivariate variance analysis. The presence of the cyclist determined different levels of influence on driver's trajectory for the three cross-sections. A wider bicycle lane ensured a higher later clearance distance between driver and cyclist, allowing safer overtaking maneuver. The interferences of the cyclist on driver's behavior depended on the geometric elements. On tangents, the lowest lateral clearances were recorded and no speed reduction was observed, compared to the cyclist absence condition. On the left curve, the higher lateral clearance was recorded, due to the

  15. Instability mechanism and control technology of soft rock roadway affected by mining and high confined water

    Institute of Scientific and Technical Information of China (English)

    Li Guichen; Jiang Zuohan; Lv Chuangxin; Huang Chao; Chen Gui; Li Mingyuan

    2015-01-01

    Based on deformation and failure characteristics of the second belt conveyor roadway at level II of Zhuxianzhuang coal mine, laboratory experiments, numerical calculation and field test were adopted to analyze the composition and microstructure of mudstone, the law of mudstone hydration and its strength weakening induced by water, the characteristics of surrounding rock deformation and failure under the action of confined water. Results showed that montmorillonite clay minerals accounted for as much as 76% of mudstone, with a large number of pores existing in the microstructure. Besides, as the molecular structure of montmorillonite changed, mudstone microstructure damage occurred with the macroscopic manifestation of its rheological instability. Weakening degree of confined water on residual strength of mudstone was almost 50%. The instability mechanism of soft rock roadway caused by high confined water is that surrounding rock circulates the process of ‘fracture-seepage-mud ding-closed’ twice, which weakens its strength and leads to roadway instability. A combined support technology, namely the, ‘high-toughness sealing layer+hollow grouting cables+full-length anchoring bolts with deep borehole’ was proposed. Based on field observation, the soft rock roadway was controlled effectively, which also verified the effectiveness of new control technology for surrounding rock.

  16. Deformation effect of lateral roof roadway in close coal seams after repeated mining

    Institute of Scientific and Technical Information of China (English)

    Xie Jianlin; Xu Jialin; Wang Feng; Guo Jiekai; Liu Donglin

    2014-01-01

    This paper analyzed the deformation mechanism in lateral roof roadway of the Ding Wu-3 roadway which was disturbed by repeated mining of close coal seams Wu-8 and Wu-10 in Pingdingshan No. 1 Mine. To determine the strata disturbance scope, the strata displacement angle was used to calculate the protection pillar width. A numerical model was built considering the field geological conditions. In simulation, the mining stress borderline was defined as the contour where the induced stress is 1.5 times of the original stress. Simulation results show the mining stress borderline of the lateral roadway extended 91.7 m outward after repeated mining. Then the original stress increased, deforming the road-way of interest. This deformation agreed with the in situ observations. Moreover, the strata displacement angle changed due to repeated mining. Therefore, reselection of the displacement angle was required to design the protective pillar width. Since a constant strata displacement angle was used in traditional design, the proposed method was beneficial in field cases.

  17. Auxiliary ventilation in mining roadways driven with roadheaders: Validated CFD modelling of dust behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Torano, J.; Torno, S.; Menendez, M.; Gent, M. [University of Oviedo, Asturias (Spain)

    2010-01-15

    The production of dust when driving mining roadways can affect workers health. In addition, there is a decrease in productivity since Mine Safety regulations establish a reduction in the working time depending on the quartz content and dust concentration in the atmosphere. One of the gate roadways of the longwall named E4-S, belonging to the underground coal mine Carbonar SA located in Northern Spain, is being driven by an AM50 roadheader machine. The mined coal has a high coal dust content. This paper presents a study of dust behaviour in two auxiliary ventilation systems by Computational Fluid Dynamics (CFD) models, taking into account the influence of time. The accuracy of these CFD models was assessed by airflow velocity and respirable dust concentration measurements taken in six points of six roadway cross-sections of the mentioned operating coal mine. It is concluded that these models predicted the airflow and dust behaviour at the working face, where the dust source is located, and in different roadways cross-sections behind the working face. As a result, CFD models allow optimization of the auxiliary ventilation system used, avoiding the important deficiencies when it is calculated by conventional methods.

  18. Influence of dynamic pressure on deep underground soft rock roadway support and its application

    Institute of Scientific and Technical Information of China (English)

    Meng Qingbin; Han Lijun; Chen Yanlong; Fan Jiadong; Wen Shengyong; Yu Liyuan; Li Hao

    2016-01-01

    Due to high ground stress and mining disturbance, the deformation and failure of deep soft rock roadway is serious, and invalidation of the anchor net-anchor cable supporting structure occurs. The failure char-acteristics of roadways revealed with the help of the ground pressure monitoring. Theoretical analysis was adopted to analyze the influence of mining disturbance on stress distribution in surrounding rock, and the change of stress was also calculated. Considering the change of stress in surrounding rock of bot-tom extraction roadway, the displacement, plastic zone and distribution law of principal stress difference under different support schemes were studied by means of FLAC3D. The supporting scheme of U-shaped steel was proposed for bottom extraction roadway that underwent mining disturbance. We carried out a similarity model test to verify the effect of support in dynamic pressure. Monitoring results demonstrated the change rules of deformation and stress of surrounding rock in different supporting schemes. The supporting scheme of U-shaped steel had an effective control on deformation of surrounding rock. The scheme was successfully applied in underground engineering practice, and achieved good technical and economic benefits.

  19. Deformation control of asymmetric floor heave in a deep rock roadway:A case study

    Institute of Scientific and Technical Information of China (English)

    Sun Xiaoming; Wang Dong; Feng Jili; Zhang Chun; Chen Yanwei

    2014-01-01

    In order to control asymmetric floor heave in deep rock roadways and deformation around the surrounding rock mass after excavation, in this paper we discuss the failure mechanism and coupling control countermeasures using the finite difference method (FLAC3D) combined with comparative analysis and typical engineering application at Xingcun coal mine. It is indicated by the analysis that the simple symmetric support systems used in the past led to destruction of the deep rock roadway from the key zone and resulted in the deformation of asymmetric floor heave in the roadway. Suitable rein-forced support countermeasures are proposed to reduce the deformation of the floor heave and the potential risk during mining. The application shows that the present support technology can be used to better environmental conditions. The countermeasures of asymmetric coupling support can not only effectively reduce the discrepancy deformation at the key area of the surrounding rock mass, but also effectively control floor heave, which helps realize the integration of support and maintain the stability of the deep rock roadways at Xingcun coal mine.

  20. Dust captures effectiveness of scrubber systems on mechanical miners operating in larger roadways.

    CSIR Research Space (South Africa)

    Hole, BJ

    1998-03-01

    Full Text Available The project was directed towards bord and pillar working by mechanised miners operating in larger section roadways, where the problem of scrubber capture tends to be greatest owing to the limited size of the zone of influence around exhaust...

  1. High-resistance controlled yielding supporting technique in deep-well oil shale roadways

    Institute of Scientific and Technical Information of China (English)

    Yu Yang; Bai Jianbiao; Wang Xiangyu; Wang Junde; Xue Shizhi; Xu Ke

    2014-01-01

    In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed roadway and revealed its failure mechanism by taking comprehensively the methods of field geological investigation, displacement monitoring of surrounding rock, rock properties and hydration properties experiments and field application tests. Based on this work, the high-resistance controlled yielding supporting principle is proposed, which is:to‘resist’ by high pre-tightening force and high stiff-ness in the early stage, to‘yield’ by making use of the controlled deformation of a yielding tube in the middle stage, and to‘fix’ by applying total-section Gunite in the later stage. A high-resistance controlled yielding supporting technique of‘high pre-tightening force yielding anchor bolt+small-bore pre-tight-ening force anchor cable+rebar ladder beam+rhombic metal mesh+lagging gunite’ has been estab-lished, and industrial on site testing implemented. The practical results show that the high-resistance controlled yielding supporting technique can effectively control the large deformation and long-time rhe-ology of deep-well oil shale roadways and can provide beneficial references for the maintenance of other con-generic roadways.

  2. Distribution of Side Abutment Stress in Roadway Subjected to Dynamic Pressure and Its Engineering Application

    Directory of Open Access Journals (Sweden)

    Yao Qiangling

    2015-01-01

    Full Text Available The borehole stress-meter was employed in this study to investigate the distribution of the side abutment stress in roadway subjected to dynamic pressure. The results demonstrate that the side abutment stress of the mining roadway reaches a peak value when the distance to the gob is 8 m and the distribution curve of the side abutment stress can be divided into three zones: stress rising zone, stress stabilizing zone, and stress decreasing zone. Further numerical investigation was carried out to study the effect of the coal mass strength, coal seam depth, immediate roof strength, and thickness on the distribution of the side abutment stress. Based on the research results, we determined the reasonable position of the mining roadway and the optimal width of the barrier pillar. The engineering application demonstrates that the retention of the barrier pillar with a width of 5 m along the gob as the haulage roadway for the next panel is feasible, which delivers favorable technological and economic benefits.

  3. Risk analysis for roadways subjected to multiple landslide-related hazards

    Science.gov (United States)

    Corominas, Jordi; Mavrouli, Olga

    2014-05-01

    Roadways through mountainous terrain often involve cuts and landslide areas whose stability is precarious and require protection and stabilization works. To optimize the allocation of resources, government and technical offices are increasingly interested in both the risk analysis and assessment. Risk analysis has to consider the hazard occurrence and the consequences. The consequences can be both direct and indirect. The former include the costs regarding the repair of the roadway, the damage of vehicles and the potential fatalities, while the latter refer to the costs related to the diversion of vehicles, the excess of distance travelled, the time differences, and tolls. The type of slope instabilities that may affect a roadway may vary and its effects as well. Most current approaches either consider a single hazardous phenomenon each time, or if applied at small (for example national) scale, they do not take into account local conditions at each section of the roadway. The objective of this work is the development of a simple and comprehensive methodology for the assessment of the risk due to multiple hazards along roadways, integrating different landslide types that include rockfalls, debris flows and considering as well the potential failure of retaining walls. To quantify risk, all hazards are expressed with a common term: their probability of occurrence. The methodology takes into consideration the specific local conditions along the roadway. For rockfalls and debris flow a variety of methods for assessing the probability of occurrence exists. To assess the annual probability of failure of retaining walls we use an indicator-based model that provides a hazard index. The model parameters consist in the design safety factor, and further anchorage design and construction parameters. The probability of failure is evaluated in function of the hazard index and next corrected (in terms of order of magnitude) according to in situ observations for increase of two

  4. Sensitivity Analysis of Mechanical Parameters of Different Rock Layers to the Stability of Coal Roadway in Soft Rock Strata

    Directory of Open Access Journals (Sweden)

    Zeng-hui Zhao

    2013-01-01

    Full Text Available According to the geological characteristics of Xinjiang Ili mine in western area of China, a physical model of interstratified strata composed of soft rock and hard coal seam was established. Selecting the tunnel position, deformation modulus, and strength parameters of each layer as influencing factors, the sensitivity coefficient of roadway deformation to each parameter was firstly analyzed based on a Mohr-Columb strain softening model and nonlinear elastic-plastic finite element analysis. Then the effect laws of influencing factors which showed high sensitivity were further discussed. Finally, a regression model for the relationship between roadway displacements and multifactors was obtained by equivalent linear regression under multiple factors. The results show that the roadway deformation is highly sensitive to the depth of coal seam under the floor which should be considered in the layout of coal roadway; deformation modulus and strength of coal seam and floor have a great influence on the global stability of tunnel; on the contrary, roadway deformation is not sensitive to the mechanical parameters of soft roof; roadway deformation under random combinations of multi-factors can be deduced by the regression model. These conclusions provide theoretical significance to the arrangement and stability maintenance of coal roadway.

  5. Sensitivity analysis of mechanical parameters of different rock layers to the stability of coal roadway in soft rock strata.

    Science.gov (United States)

    Zhao, Zeng-hui; Wang, Wei-ming; Gao, Xin; Yan, Ji-xing

    2013-01-01

    According to the geological characteristics of Xinjiang Ili mine in western area of China, a physical model of interstratified strata composed of soft rock and hard coal seam was established. Selecting the tunnel position, deformation modulus, and strength parameters of each layer as influencing factors, the sensitivity coefficient of roadway deformation to each parameter was firstly analyzed based on a Mohr-Columb strain softening model and nonlinear elastic-plastic finite element analysis. Then the effect laws of influencing factors which showed high sensitivity were further discussed. Finally, a regression model for the relationship between roadway displacements and multifactors was obtained by equivalent linear regression under multiple factors. The results show that the roadway deformation is highly sensitive to the depth of coal seam under the floor which should be considered in the layout of coal roadway; deformation modulus and strength of coal seam and floor have a great influence on the global stability of tunnel; on the contrary, roadway deformation is not sensitive to the mechanical parameters of soft roof; roadway deformation under random combinations of multi-factors can be deduced by the regression model. These conclusions provide theoretical significance to the arrangement and stability maintenance of coal roadway.

  6. Stability control of surrounding rocks for a coal roadway in a deep tectonic region

    Institute of Scientific and Technical Information of China (English)

    Xiao Tongqiang; Wang Xiangyu; Zhang Zhigao

    2014-01-01

    In order to effectively control the deformation and failure of surrounding rocks in a coal roadway in a deep tectonic region, the deformation and failure mechanism and stability control mechanism were stud-ied. With such methods as numerical simulation and field testing, the distribution law of the displace-ment, stress and plastic zone in the surrounding rocks was analyzed. The deformation and failure mechanisms of coal roadways in deep tectonic areas were revealed:under high tectonic stress, two sides will slide along the roof or floor;while the plastic zone of the two sides will extend along the roof or floor, leading to more serious deformation and failure in the corner of two sides and the bolt supporting the corners is readily cut off by the shear force or tension force. Aimed at controlling the large slippage defor-mation of the two sides, serious deformation and failure in the corners of the two sides and massive bolt breakage, a ‘controlling and yielding coupling support’ control technology is proposed. Firstly, bolts which do not pass through the bedding plane should be used in the corners of the roadway, allowing the two sides to have some degree of sliding to achieve the purpose of ‘yielding’ support, and which avoid breakage of the bolts in the corner. After yielding support, bolts in the corner of the roadway and which pass through the bedding plane should be used to control the deformation and failure of the coal in the corner. ‘Controlling and yielding coupling support’ technology has been successfully applied in engineering practice, and the stability of deep coal roadway has been greatly improved.

  7. Study on destressing technology for a roadway driven along goaf in a fully mechanized top-coal caving face

    Institute of Scientific and Technical Information of China (English)

    瞿群迪

    2003-01-01

    Based on the deformation characteristics of the roadways driven along goaf in fully mechanized top-coal caving faces, the author considers that it is the key to ensure the stability of surrounding rocks of roadway driven along goaf to control the deformation during the period affected by mining. Considering the characteristics of the roadway layout in fully mechanized top-coal caving faces, a technical scheme of destressing is put forward and the destressing effect is analyzed by using the software of Universal Distinct Element Code 3.0(UDEC 3.0).

  8. Impacts of Roadway Emissions on Urban Fine Particle Exposures: the Nairobi Area Traffic Contribution to Air Pollution (NATCAP) Study

    Science.gov (United States)

    Gatari, Michael; Ngo, Nicole; Ndiba, Peter; Kinney, Patrick

    2010-05-01

    Air quality is a serious and worsening problem in the rapidly growing cities of sub-Saharan Africa (SSA), due to rapid urbanization, growing vehicle fleets, changing life styles, limited road infrastructure and land use planning, and high per-vehicle emissions. However, the absence of ambient monitoring data, and particularly urban roadside concentrations of particulate matter in SSA cities, severely limits our ability to assess the real extent of air quality problems. Emitted fine particles by on-road vehicles may be particularly important in SSA cities because large concentrations of poorly maintained vehicles operate in close proximity to commercial and other activities of low-income urban residents. This scenario provokes major air quality concerns and its investigation should be of priority interest to policy makers, city planners and managers, and the affected population. As part of collaboration between Columbia University and the University of Nairobi, a PM2.5 air monitoring study was carried out over two weeks in July 2009. The objectives of the study were 1) to assess average daytime PM2.5 concentrations on a range of Nairobi streets that represent important hot-spots in terms of the joint distribution of traffic, commercial, and resident pedestrian activities, 2) to relate those concentrations to motor vehicle counts, 3) to compare urban street concentrations to urban and rural background levels, and 4) to assess vertical and horizontal dispersion of PM2.5 near roadways. Portable, battery-operated PM2.5 samplers were carried by field teams at each of the five sites (three urban, one commuter highway, and one rural site), each of which operated from 7 AM to 7 PM during 10 weekdays in July 2009. Urban background monitoring took place on a rooftop at the University of Nairobi. Preliminary findings suggest highly elevated PM2.5 concentrations at the urban sites where the greatest pedestrian traffic was observed. These findings underscore the need for air

  9. Applied on bolting-cable anchor support of full-seam roadway in weaker thick coal seam

    Institute of Scientific and Technical Information of China (English)

    赵庆彪; 张生华; 郭励生

    2003-01-01

    The designing method and the supporting mechanism of both bolt and small cable anchor for full-seam roadway in the weaker thick coal seam are systematically analyzed, and the construction technology and the supporting results are briefly summarized.

  10. 49 CFR 214.517 - Retrofitting of existing on-track roadway maintenance machines manufactured on or after January 1...

    Science.gov (United States)

    2010-10-01

    ... TRANSPORTATION RAILROAD WORKPLACE SAFETY On-Track Roadway Maintenance Machines and Hi-Rail Vehicles § 214.517... maintenance machine manufactured on or after January 1, 1991, shall have the following: (a) A change-of...

  11. Association of Roadway Proximity with Indoor Air Pollution in a Peri-Urban Community in Lima, Peru

    National Research Council Canada - National Science Library

    Underhill, Lindsay J; Bose, Sonali; Williams, D'Ann L; Romero, Karina M; Malpartida, Gary; Breysse, Patrick N; Klasen, Elizabeth M; Combe, Juan M; Checkley, William; Hansel, Nadia N

    2015-01-01

    .... Additionally, domestic allergen exposure is unknown in such populations. We conducted a pilot study of 25 homes in peri-urban Lima, Peru to estimate the effects of roadway proximity and season on residential concentrations...

  12. Rural Aging

    Science.gov (United States)

    ... Rural Health Topics & States Topics View more Rural Aging The nation's population is aging, and with that change comes increased healthcare needs. ... Disease Control and Prevention report, The State of Aging and Health in America 2013 , the population 65 ...

  13. Failure Mechanism Analysis and Support Design for Deep Composite Soft Rock Roadway: A Case Study of the Yangcheng Coal Mine in China

    Directory of Open Access Journals (Sweden)

    Bangyou Jiang

    2015-01-01

    Full Text Available This paper presented a case study of the failure mechanisms and support design for deep composite soft rock roadway in the Yangcheng Coal Mine of China. Many experiments and field tests were performed to reveal the failure mechanisms of the roadway. It was found that the surrounding rock of the roadway was HJS complex soft rock that was characterized by poor rock quality, widespread development of joint fissures, and an unstable creep property. The major horizontal stress, which was almost perpendicular to the roadway, was 1.59 times larger than the vertical stress. The weak surrounding rock and high tectonic stress were the main internal causes of roadway instabilities, and the inadequate support was the external cause. Based on the failure mechanism, a new support design was proposed that consisted of bolting, cable, metal mesh, shotcrete, and grouting. A field experiment using the new design was performed in a roadway section approximately 100 m long. Detailed deformation monitoring was conducted in the experimental roadway sections and sections of the previous roadway. The monitoring results showed that deformations of the roadway with the new support design were reduced by 85–90% compared with those of the old design. This successful case provides an important reference for similar soft rock roadway projects.

  14. The principle of stability control of surrounding rock-bearing struc-tures in high stress soft rock roadways

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-jun; ZHU Yong-jian; LI Shu-qing; ZHANG Peng

    2009-01-01

    Through the description of the deformational features of the surrounding rock around high stress engineering soft rock roadways,the coupling stabilization principle of inner and outer structures in surrounding rock was put forward.The supporting principles of high stress engineering soft rock roadway (high resistance and yielding support,timely support,high strength and high stiffness supports) were proposed,which were applied in engineering practices,and obtained better achievements.

  15. The principle of stability control of surrounding rock-bearing structures in high stress soft rock roadways

    Energy Technology Data Exchange (ETDEWEB)

    Wei-jun Wang; Yong-jian Zhu; Shu-qing Li; Peng Zhang [Hunan Key Laboratory of Safe Mining Techniques of Coal Mines, Xiangtan (China)

    2009-03-15

    Through the description of the deformational features of the surrounding rock around high stress engineering soft rock roadways, the coupling stabilization principle of inner and outer structures in surrounding rock was put forward. The supporting principles of high stress engineering soft rock roadway (high resistance and yielding support, timely support, high strength and high stiffness supports) were proposed, which were applied in engineering practices in Shuijingtou colliery, and obtained better achievements. 5 refs., 4 figs.

  16. The Impact of the Low Throw Fault on the Stability of Roadways in a Hard Coal Mine

    Directory of Open Access Journals (Sweden)

    Małkowski Piotr

    2017-03-01

    Full Text Available Ensuring roadways stability in hard coal mines is one of the main challenges faced by engineers. A changeable geological structure have caused the roadway’s conditions to vary, thus influencing its stability. One of the causes of those changes is the presence of a previously undiscovered fault zone (small faults crossed the roadway within which a significant convergence or support deformation may occur.

  17. Experimental Study on Roof Structure Characteristics and Its Failure Pattern in Coal Roadway

    Institute of Scientific and Technical Information of China (English)

    薛亚东; 康天合; 黄宏伟

    2004-01-01

    Based on the investigation and statistics of logs of 211 bole holes and strata data from 79 roadways in 13 coal mines located in Xishan, Jincheng, Lu'an, Fenxi, and Huozhou in China, the roadways' roof structures were classified as multi-thin-layer, thin-thick combined layer, integrated thick layer, thick-coal layer, and cracked layer according to the geometric features and spatial strength distribution of surrounding rock. Then eight sub-categories were defined as different situations. And seven simulation modeling tests were carried out. The strata structures of these models were different from each other. At last, the relationship between roof structure and its failure pattern was discussed.

  18. Mechanics analysis on the conditions of rock burst occurrence in the coal mass of roadway rib

    Institute of Scientific and Technical Information of China (English)

    CHEN Xue-hua; DENG Xiao-lin; LI Zhong-hua

    2008-01-01

    According to the rock burst features occurred in the coal mass of roadway rib in one mine, the mechanics model of coal mass and roof structure system along the edge of goaf was founded to analyze the stress of roof rock layer, so the subside curve of roof rock layer was deduced. Furthermore, the stability of coal and rock system were analyzed, the critical load and critical resistance zone were used to judge the danger degree of rock burst occurrence. The influence of coal mass strength, brittleness degree, coal seam thickness, roof thickness, suspending length, equivalent shear module on the critical load,critical resistance zone was confirmed. So the rock burst occurrence conditions of coal mass in roadway rib mainly depend on mining depth, coal seam thickness and hard roof and floor, which are decided by the above studies, and successfully applied in prediction and prevention of rock burst in this mine.

  19. Selecting basic parameters for turnouts when driving mine roadways with a single track

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, V.E.; Zayats, I.E.; Ignatova, E.M.

    1982-12-01

    The paper discusses methods for optimizing mine haulage during drivage of roadways in underground coal mines. Locomotive haulage with a single track is used. Site selection for the turnout point is analyzed. Analyses show that from 35 to 70% of loading time is spent on mine car exchange. Time necessary for exchange depends on method of moving mine cars (by locomotives or by miners) and on position of turnout point in relation to the face. When the distance between the face and turnout point is excessive loading time increases. A method for optimizing position of a turnout point in relation to the face during mine drivage is discussed. The following factors are considered: advance rate of roadway drivage, method of mine car changing, parameters of a turnout. Examples of practical use of the equations are given. Comparative evaluations show that optimizing position of a turnout in relation to the face permits cost of mine drivage to be reduced by about 15%.

  20. Simulation and analysis of airflow stability during fire in mine belt roadway

    Institute of Scientific and Technical Information of China (English)

    ZHANG Sheng-zhu; CHENG Wei-min; LI Qiu-jin; ZHANG Rui; LUO Chuan-long

    2010-01-01

    According to fluid dynamics analysis during the fire, the criteria k-ε two-equation model for solving three-dimensional turbulence was determined, the pollutants generated in the fire disaster were set by adopting Mixture multiphase flow, and the SIMPLE algorithm was used for solving on the basis of comprehensive consideration on the heat radiation and components transmission during fire. By simulating the airflow flowing state inside the tunnel during fire disaster of downward ventilation, drift ventilation, and ascensional ventilation, respectively, with regard to the actual situation of No.1, No.3, and No.5 belt roadway in Kongzhuang Coal Mine, the velocity vector distributions of pollutants under different inlet air volumes were obtained, and the damage degree and influential factors of disaster were also clear, which is helpful to control and avoid disaster during belt roadway fire.

  1. Study on the collision detection method between the 2-arm drill rig arms and the roadway

    Directory of Open Access Journals (Sweden)

    Fuxiang ZHANG

    2015-12-01

    Full Text Available In order to achieve the automation drilling of the improved CMJ2-27 drill, kinematic analysis of the drill rig is conducted aiming the collision between the arms and the roadway during the operation process. By suing the Denavit-Hartenberg (D-H method, the transformation matrix of coordinate system is obtained, then the coordinates of each joint and the ends are derived. The collision detection approach between the arm and the roadway is given. Theoretical calculation and the motion simulation experiment are conducted by using the detection method for a 88-hole drilling program for a mine. The research results show that the method is feasible and has the characteristics of simple procedures and high efficiency.

  2. A new technology for coal and gas control based on the in situ stress distribution and the roadway layout

    Institute of Scientific and Technical Information of China (English)

    Yang Wei; Lin Baiquan; Zhai Cheng; Li Xianzhong; Sun Xin; Zhang Chao

    2012-01-01

    An auxiliary gas control technology is described that can reduce coal and gas outburst accidents when there is no existing protective coal seam and gas pre-draining is not effective.Numerical simulation methods were used to study the Stress distribution ahead of the roadway face for different in situ stresses.The results from the simulation can then provide a new gas control technology.The results show that a high stress concentration,high stresses,and high displacement gradients appear ahead of the roadway face when the maximum in situ stress is aligned perpendicular to the roadway axis.The risk of gas outburst is higher when the stresses decrease rapidly over distance and when the release of more energy occurs immediately after driving the roadway.The gas outburst risk is much smaller when the in situ stress is aligned parallel to the roadway axis.During design of the coal mine most of the coal roadways should be arranged to parallel the maximum in situ stress.This will decrease the outburst risk in general and may be considered a new gas outburst prevention method.

  3. Numerical simulation study of the failure evolution process and failure mode of surrounding rock in deep soft rock roadways

    Institute of Scientific and Technical Information of China (English)

    Meng Qingbin; Han Lijun; Xiao Yu; Li Hao; Wen Shengyong; Zhang Jian

    2016-01-01

    Based on the safety coefficient method, which assigns rock failure criteria to calculate the rock mass unit, the safety coefficient contour of surrounding rock is plotted to judge the distribution form of the frac-tured zone in the roadway. This will provide the basis numerical simulation to calculate the surrounding rock fractured zone in a roadway. Using the single factor and multi-factor orthogonal test method, the evolution law of roadway surrounding rock displacements, plastic zone and stress distribution under different conditions is studied. It reveals the roadway surrounding rock burst evolution process, and obtains five kinds of failure modes in deep soft rock roadway. Using the fuzzy mathematics clustering analysis method, the deep soft surrounding rock failure model in Zhujixi mine can be classified and pat-terns recognized. Compared to the identification results and the results detected by geological radar of surrounding rock loose circle, the reliability of the results of the pattern recognition is verified and lays the foundations for the support design of deep soft rock roadways.

  4. Prediction model of gas explosion overpressure in full-scale coal mine blind roadway

    Energy Technology Data Exchange (ETDEWEB)

    Yun-Feng Liang; Xin-Quan Zhou; Jiu-Ling Zhang; Shao Shao [China University of Mining and Technology (Beijing), Beijing (China). State Key Laboratory of Coal Resources and Safe Mining

    2009-01-15

    On the basis of the TNT equivalency method and by analysing data from gas explosion experiments, a new prediction method was put forward to estimate the attenuation of explosion overpressure in a full-scale coal mine blind roadway and its validity was testified in three cases. The results show that there is good agreement between the calculated and experimental data. 8 refs., 2 figs.

  5. Research and application of coal and gas outburst control measure based on hydraulic extrusion in roadway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, M.; Pan, H.; Li, Y.; Hu, B.; Chen, W. [Henan Polytechnic University, Jiaozuo (China)

    2007-02-15

    The technology system and equipment of hydraulic extrusion were presented. Based on the actual conditions of Liyi Coal Mine, reasonable parameters of injecting water were studied. The measure caused the stress concentration region of the coal seam to move forward, the pressure relief region was widened, and gas was released efficiently. The remarkable effect of coal and gas outburst prevention was achieved and the roadway driving speed was increased by 1.5 times. 7 refs., 5 figs.

  6. Determination of rational support parameters of bolting and shotcreting with wire mesh in soft roadway

    Institute of Scientific and Technical Information of China (English)

    LIU She-yu; MA Nian-jie; LIU Shao-wei

    2005-01-01

    Based on a great number of measured data, the author put forward zonal compressive and tensile deformation mechanism of soft rock around roadway. By using self-supporting capacity of compressive zone and controlling rock deformation of tensile zone, the long bolt or short bolt group supporting form was given for different size of rock compressive zone and tensile zone. Finally, studied on the determining method of rational support parameters of bolting and shotcreting with wire mesh in different support technology.

  7. Residential proximity to major roadways is associated with increased prevalence of allergic respiratory symptoms in children

    Directory of Open Access Journals (Sweden)

    Gregor Porebski

    2014-11-01

    Full Text Available [b]introduction and objective[/b]. Numerous epidemiologic studies have reported increased risk of allergic rhinitis and asthma in relation to ‘western life-style’, which represents diversity of factors. We hypothesized that residential proximity to major roadways, reflecting an exposure to traffic-related air pollution, is associated with prevalence of allergic respiratory symptoms in children. [b]materials and methods[/b]. A total of 8290 individuals of two age groups: 16 year olds and 7 year olds from Krakow, Poland were included. We used the Polish version of the International Study of Asthma and Allergy in Childhood supplemented with a question concerning the distance between a responder’s house and a high traffic density road: below 200 m, from 200–500 m, or more than 500 m. [b]results[/b]. Children and adolescents with a residential proximity closer to a major roadway had more frequent asthma-related symptoms in the last 12 months and at any time in the past. Consistent with the increased frequency of asthmatic symptoms, responders residing within 200 meters complained more often of sneezing, runny or blocked nose accompanied by itchy-watery eyes and hay fever in comparison to responders who resided 200–500 meters from a major roadway. The lowest rate of nasal symptoms was observed in residents living in the distance to major roads (> 500 meters. The rate of positive answers decreased in a distant-dependent manner. [b]conclusions[/b]. Our findings suggest an important spatial relationship between the distance from a major roadway and the evaluated respiratory symptoms. The results emphasize the need for more comprehensive air quality policies within urban areas with increased motor vehicle density.

  8. Theory and application of infrared surveying gas gushing technology in coal-rock roadway

    Energy Technology Data Exchange (ETDEWEB)

    Cai, K. [Xiangtan Polytechnic University, Xiangtan (China). Dept. of Mineral Resources Engineering

    2002-12-01

    Gas expansion when the gas pressure is released can change the coal-rock surface infrared radiation. Results discussed in this paper show that infrared survey technology can be used to effectively analyze and forecast the changes of coal-rock gas gushing, and to guide the enforcement of the roadway gas project for preventing gas gushing and handling the gas. 5 refs., 4 figs.

  9. Numerical simulation of grooving method for floor heave control in soft rock roadway

    Institute of Scientific and Technical Information of China (English)

    Sun Jin; Wang Lianguo

    2011-01-01

    Grooving method can restrain the deformation and destruction of surrounding rock by transferring the maximum stress to deep rock, bringing about the effective control for floor heave in soft rock roadway.Based on this important effect, and to discuss the relationship between cutting parameters and pressurerelief effect, this paper carried out a numerical simulation of grooving along bottom slab and two sides of gateway with finite difference software FLAC2D. The results show that the control effect on floor heave in soft rock tunnel can be improved by selecting appropriate cutting parameters. Appropriately increasing the crevice depth in the middle of the floor can improve the stress state of bottom slab by stress transfer.So the floor heave can be more effectively controlled. To lengthen the crevice in the comers of roadway can simultaneously transfer the maximum stresses of bottom slab and two sides to deep rock, And promote the pressure-relief effect. Extending the crevice length and crevice width on both sides within a certain range can decrease the stress concentration in the corners of roadway, and reduce the deformation of two sides. The cutting position beneficial to restrain the floor heave is close to the bottom slab.

  10. Research on U-steel yieldable support with backfill technology in rock roadway

    Institute of Scientific and Technical Information of China (English)

    LUO Yong; CHANG Ju-cai

    2009-01-01

    The loading on U-steel yieldable support cannot be organically combined with the law of strata behaviors from the surrounding rocks of roadway. In order to effectively solve the problem, U-steel yieldable support with backfill material and the performance requirements of backfill material were analyzed on the basis of structural mechanics. The mechanical properties of backfill material selected were tested in the laboratory, and the test results show that the ratio of the backfill material complies with the requirements of backfill technology; it can effectively optimize the relationship between the support and the surrounding rock, and the filling layer can avoid the partial stress concentration and fully improve the support performance. Compared with U-steel yieldable support with gangue filling, the filed application shows that the supporting result of U-steel yieldable support with backfill technology is satisfactory, the stress on U-steel yieldable support with backfill technology decreases greatly and distributes uniformly, convergence of the surrounding rock of roadway is decreased by more than 50%, and the surrounding rocks of roadway are controlled effectively.

  11. Research on U-steel yieldable support with backfill technology in rock roadway

    Energy Technology Data Exchange (ETDEWEB)

    Yong Luo; Ju-cai Chang [Huainan Mining Group Co. Ltd., Huainan (China). Postdoctoral Scientific Research Station

    2009-12-15

    The loading on U-steel yieldable support cannot be organically combined with the law of strata behaviors from the surrounding rocks of roadway. In order to effectively solve the problem, U-steel yieldable support with backfill material and the performance requirements of backfill material were analyzed on the basis of structural mechanics. The mechanical properties of backfill material selected were tested in the laboratory, and the test results show that the ratio of the backfill material complies with the requirements of backfill technology; it can effectively optimize the relationship between the support and the surrounding rock, and the filling layer can avoid the partial stress concentration and fully improve the support performance. Compared with U-steel yieldable support with gangue filling, the filed application shows that the supporting result of U-steel yieldable support with backfill technology is satisfactory, the stress on U-steel yieldable support with backfill technology decreases greatly and distributes uniformly, convergence of the surrounding rock of roadway is decreased by more than 50%, and the surrounding rocks of roadway are controlled effectively.

  12. A Geometric Computational Model for Calculation of Longwall Face Effect on Gate Roadways

    Science.gov (United States)

    Mohammadi, Hamid; Ebrahimi Farsangi, Mohammad Ali; Jalalifar, Hossein; Ahmadi, Ali Reza

    2016-01-01

    In this paper a geometric computational model (GCM) has been developed for calculating the effect of longwall face on the extension of excavation-damaged zone (EDZ) above the gate roadways (main and tail gates), considering the advance longwall mining method. In this model, the stability of gate roadways are investigated based on loading effects due to EDZ and caving zone (CZ) above the longwall face, which can extend the EDZ size. The structure of GCM depends on four important factors: (1) geomechanical properties of hanging wall, (2) dip and thickness of coal seam, (3) CZ characteristics, and (4) pillar width. The investigations demonstrated that the extension of EDZ is a function of pillar width. Considering the effect of pillar width, new mathematical relationships were presented to calculate the face influence coefficient and characteristics of extended EDZ. Furthermore, taking GCM into account, a computational algorithm for stability analysis of gate roadways was suggested. Validation was carried out through instrumentation and monitoring results of a longwall face at Parvade-2 coal mine in Tabas, Iran, demonstrating good agreement between the new model and measured results. Finally, a sensitivity analysis was carried out on the effect of pillar width, bearing capacity of support system and coal seam dip.

  13. Study on ascending mining roadway layout of close distance coal seams in deep mine

    Institute of Scientific and Technical Information of China (English)

    SHI Yong-kui; MO Ji

    2007-01-01

    To solve the problems appeared in mining process of No.2 seam, the ascending stress-releasing mining method was adopted. Studying on the reasonable layout of actual mining roadway in upper coal seams is the precondition of successful ascending mining.By using "device of leak measuring by blocking up double ends", it detected the height of overburden water flowing fractured zone originated from sub-coal seams mining. Thus it proved that the actual mining roadway of No.2 upper ascending seam was located in the smooth sagging zone. On the basis of analyzing the stress-releasing effect of sub-coal seams mining to upper coal seams by using RFPA software, it analyzed the stability of up-face coal seams and the reasonable location of starting cut in up-face coal seams. It also analyzed the reasonable gateway location in upper coal seams, which ensured the crossheading in upper coal seams out of the effect of sub-coal work face mining by using theory of underground pressure. Meanwhile, the reasonable pillars dimensions in upper coal seams by building the structure mechanics model of stope were researched. It can make the roadway driven along next goaf to be located in low stress zone, and be beneficial to keeping roads stable owing to less stress of surrounding rock. Finally, it tested the rationality of the layout method of roads in upper coal seams by engineering field measurement in 3221 working face.

  14. Wide pillar roadway retained in the deep high gas coal seam

    Institute of Scientific and Technical Information of China (English)

    Pan; Liyou; Feng; Enhu; Zhao; Qingshou; Chen; Liqiang; Kong; Fanpeng

    2012-01-01

    According to the geological and mining conditions of deep high gas coal seam,this paper established the mechanical model of stope surrounding rock,and analyzed the stress distribution and deformation failure mechanism of working face and coal pillar.The research determined the arrangement mode that adjacent working faces retain wide pillar,and the reasonable support method of roadway that the combined support of roof and grouting combined together.The reasonable time of reinforced roadway was determined.Through analyzing the mechanical model of the ways of roadway supporting,this research drew the conclusions as follows:the combined support of roof and working slope improved the support strength and range of surrounding rock,optimized the support by adjusting the angle of anchor,and reached the support requirements by using cement grouting in working slope and chemical grout in roof.The technology was applied in 15104 working face of Baoan Mine,and obtained good results.

  15. Minimising the fire hazard from the use of belt conveyors in intake roadways

    Energy Technology Data Exchange (ETDEWEB)

    Leeming, J.R. [Health and Safety Executive, Sheffield, S. Yorkshire (United Kingdom)

    2010-07-01

    The fire that occurred a the Creswell underground coal mine in Derbyshire in 1950 in which 90 miners lost their lives was caused by a damaged rubber conveyor belt that ignited after being friction heated. The fire propagated along the intake trunk roadway by the burning belt itself, which ignited the timber roadway supports and hampered fire-fighting efforts. This paper demonstrated that operating conveyors in intake trunk roadways presents a risk that products of combustion can be carried to the working areas of a mine via ventilation pathways, thus creating a hazard to the underground miners. In North America, the use of belt air is not commonly used to ventilate working areas. However, these arrangements are common in the United Kingdom. As such, installation, inspection and maintenance standards have been created to minimize the risk of fire in underground, remotely operated belt conveyors in underground mines. Monitoring systems are also in place for early detection of any fire. A review of recent underground fires in the United Kingdom has shown that the measures adopted have been successful in avoiding uncontrollable fires. 13 refs., 5 figs.

  16. On 3D Geo-visualization of a Mine Surface Plant and Mine Roadway

    Institute of Scientific and Technical Information of China (English)

    WANG Yunjia; FU Yongming; FU Erjiang

    2007-01-01

    Constructing the 3D virtual scene of a coal mine is the objective requirement for modernizing and processing information on coal mining production. It is also the key technology to establish a "digital mine". By exploring current worldwide research, software and hardware tools and application demands, combined with the case study site (the Dazhuang mine of Pingdingshan coal group), an approach for 3D geo-visualization of a mine surface plant and mine roadway is deeply discussed. In this study, the rapid modeling method for a large range virtual scene based on Arc/Info and SiteBuilder3D is studied, and automatic generation of a 3D scene from a 2D scene is realized. Such an automatic method which can convert mine roadway systems from 2D to 3D is realized for the Dazhuang mine. Some relevant application questions are studied, including attribute query, coordinate query, distance measure, collision detection and the dynamic interaction between 2D and 3D virtual scenes in the virtual scene of a mine surface plant and mine roadway. A prototype system is designed and developed.

  17. [Performance of Grass Swales for Controlling Pollution of Roadway Runoff in Field Experiments].

    Science.gov (United States)

    Huang, Jun-jie; Shen, Qing-ran; Li, Tian

    2015-06-01

    Two different styles of grass swales were built in new Binhu region of Hefei city to monitor the flux and quality of the influent and effluent water under actual precipitation conditions, in order to evaluate the performance of water quality purification and pollution load control for roadway runoff. The results showed that both of the grass swales could effectively remove the pollutants such as TSS, COD, Pb, Cu, Cd, Zn in roadway runoff; the median EMC removal efficiencies of TSS and COD were 67.1%, 46.7% respectively,for facility I, and the median EMC removal efficiencies of TSS and COD were 78.6%, 58.6% respectively, for facility II; the concentrations of Pb, Cu, Zn in the effluent of facility II could meet the requirements of the surface water quality class V; release of nitrogen and phosphorus occurred in both facilities I and I[ in several rainfall events, mainly in heavy storms; the removal efficiencies of TP in the two grass swales were improved with the increase of influent concentration; the mean removal efficiencies of TP in facilities I and II were 14.7% and 45.4%, respectively; the load control performance of facility II for pollutants such as TSS, COD, TP, TN, NH4+ -N and NO3- -N was better than that of facility I; in the district with poor soil permeability and low ground slope, application of dry swale could achieve better performance in water quality control and pollution load reduction of roadway runoff.

  18. To illuminate or not to illuminate: roadway lighting as it affects traffic safety at intersections.

    Science.gov (United States)

    Bullough, John D; Donnell, Eric T; Rea, Mark S

    2013-04-01

    A two-pronged effort to quantify the impact of lighting on traffic safety is presented. In the statistical approach, the effects of lighting on crash frequency for different intersection types in Minnesota were assessed using count regression models. The models included many geometric and traffic control variables to estimate the association between lighting and nighttime and daytime crashes and the resulting night-to-day crash ratios. Overall, the presence of roadway intersection lighting was found to be associated with an approximately 12% lower night-to-day crash ratio than unlighted intersections. In the parallel analytical approach, visual performance analyses based on roadway intersection lighting practices in Minnesota were made for the same intersection types investigated in the statistical approach. The results of both approaches were convergent, suggesting that visual performance improvements from roadway lighting could serve as input for predicting improvements in crash frequency. A provisional transfer function allows transportation engineers to evaluate alternative lighting systems in the design phase so selections based on expected benefits and costs can be made.

  19. Deformation failure and countermeasures of deep tertiary extremely soft rock roadway in Liuhai coal mine

    Institute of Scientific and Technical Information of China (English)

    Yang Jun; Wang Dong; Shi Haiyang; Xu Huichen

    2015-01-01

    In view of failure phenomena with nonlinear large deformation including extensive damage, whole sec-tion destruction in short time, high rate of repair, most destruction forms occurred in the tertiary road-way of soft rocks engineering in Liuhai mine, according to the methods of geological survey, theoretical analysis, numerical calculation and in-situ test, the composite failure mechanism of molecular expansion, tectonic stress, gravity stress and engineering deviatoric stress, faults and random joint in this area is ana-lyzed deeply, then an coupling support of double-layer-truss is proposed. The research results show that the first wave of deformation energy was released by bolt-mesh-cable fixed into the roof, floor and two sides of the roadway. While the second wave of deformation energy was released through the interface function between double-layer-truss and the surrounding rock. The double-layer-truss that characterized by high strength, good integrity can absorb high deformation energy of surrounding rocks, which led to the uniform distribution of the stress. Engineering practice shows this technology has been successfully applied to control the deformation failure of the tertiary extremely soft rock roadway.

  20. Layout and support design of a coal roadway in ultra-close multiple-seams

    Institute of Scientific and Technical Information of China (English)

    严红; 翁明月; 冯锐敏; 李伟康

    2015-01-01

    A roadway within ultra-close multiple-seams(RUCMSs) is one of the most difficult supported coal roadways to deal with in underground coal mines. This is usually due to the unknown stress distributions, improper roadway layout, and unreasonable support parameters. In order to solve this support problem and effectively save RUCMSs from frequent and abrupt disasters(such as serious deformation of the surrounding rock, roof cave ins, and coal side collapse), a comprehensive method is adopted here which includes theoretical analysis, numerical simulation, and field monitoring. A mechanical model was constructed to determine the stress distribution in the coal pillar after two sides of a longwall panel had been mined. Based on this model, the horizontal, vertical, and tangential stress equations for the plane below the floor of the upper-left coal pillar were deduced. In addition, a typical coal mine(the Jinggonger colliery, located in Shuozhou city, Shanxi province, China) with an average distance between its 9# and 11# coal seams of less than 8.0 was chosen to conduct research on the proper layout and reasonable support required for a typical coal roadway located within coal seam 11#. Using FLAC3D(Fast Lagrangian Analysis of Continua in 3-Dimensions) numerical software, eight schemes were designed with different horizontal distances(d) between the center lines of the coal pillar and the roadway in the lower coal seam(RLCS). The simulations and detailed analysis indicate that the proper distances required are between 22.5 and 27.5 m. A total of 20 simulation schemes were used to investigate the factors influencing the support provided by the key bolts(bolt length, spacing, distance between two rows, installation angle, and pre-tightening force). The results were analyzed and used to determine reasonable values for the support parameters. Field results show that the stability and strength of the RLCS can be effectively safeguarded using a combination of researched stress

  1. Layout and support design of a coal roadway in ultra-close multiple-seams

    Institute of Scientific and Technical Information of China (English)

    严红; 翁明月; 冯锐敏; 李伟康

    2015-01-01

    A roadway within ultra-close multiple-seams (RUCMSs) is one of the most difficult supported coal roadways to deal with in underground coal mines. This is usually due to the unknown stress distributions, improper roadway layout, and unreasonable support parameters. In order to solve this support problem and effectively save RUCMSs from frequent and abrupt disasters (such as serious deformation of the surrounding rock, roof cave ins, and coal side collapse), a comprehensive method is adopted here which includes theoretical analysis, numerical simulation, and field monitoring. A mechanical model was constructed to determine the stress distribution in the coal pillar after two sides of a longwall panel had been mined. Based on this model, the horizontal, vertical, and tangential stress equations for the plane below the floor of the upper-left coal pillar were deduced. In addition, a typical coal mine (the Jinggonger colliery, located in Shuozhou city, Shanxi province, China) with an average distance between its 9# and 11# coal seams of less than 8.0 was chosen to conduct research on the proper layout and reasonable support required for a typical coal roadway located within coal seam 11#. Using FLAC3D (Fast Lagrangian Analysis of Continua in 3-Dimensions) numerical software, eight schemes were designed with different horizontal distances (d) between the center lines of the coal pillar and the roadway in the lower coal seam (RLCS). The simulations and detailed analysis indicate that the proper distances required are between 22.5 and 27.5 m. A total of 20 simulation schemes were used to investigate the factors influencing the support provided by the key bolts (bolt length, spacing, distance between two rows, installation angle, and pre-tightening force). The results were analyzed and used to determine reasonable values for the support parameters. Field results show that the stability and strength of the RLCS can be effectively safeguarded using a combination of researched

  2. Research on space-time coupling action laws of anchor-cable strengthening supporting for rock roadway in deep coal mine

    Institute of Scientific and Technical Information of China (English)

    CHANG Ju-cai; XIE Guang-xiang

    2012-01-01

    In order to obtain space-time coupling relationship of anchor-cable to improve supporting effect for deep coal mine rock roadway,FLAC3D was used to investigate into mechanical characteristics of the roadway whose crosssection shape was vertical wall and semi-circular arch when the roadway was supported by bolts and metal mesh.The results show that the extent of stress concentrations,the range failure zone,and the deformation at the roof center and two spandrels of roadway are greater than those at other positions,except at the floor.The reasonable positions of anchor-cable supporting are the roof center and two spandrels of roadway.The anchor-cable should be installed at good time with bolts supporting after roadway driving because it can improve the stress states of deep surrounding rock around the roadway and control the roadway deformation effectively.The engineering practice has proven that the sustained deformation of deep surrounding rocks is effectively controlled when the anchor-cable supporting is adopted at reasonable positions of the roadway at good time.

  3. Rural Supremacy

    OpenAIRE

    Shah, Meera

    2011-01-01

    The success of any brand depends on it acceptance by the consumers. This project highlights the rural buying behaviour. The rural consumers tend to show a closed mind towards branded goods and services. Though the current scenario is improved than the past but still large amount of rural market is untapped. The marketers now understand the potential at the bottom of the pyramid but there are doubts regarding the way this market can be reached and converted into customers. Many factors like in...

  4. Rural Supremacy

    OpenAIRE

    Shah, Meera

    2011-01-01

    The success of any brand depends on it acceptance by the consumers. This project highlights the rural buying behaviour. The rural consumers tend to show a closed mind towards branded goods and services. Though the current scenario is improved than the past but still large amount of rural market is untapped. The marketers now understand the potential at the bottom of the pyramid but there are doubts regarding the way this market can be reached and converted into customers. Many factors like in...

  5. 底板巷穿层钻孔在煤巷掘进中的应用%Application of Crossing Hole of Floor Roadway in Coal Roadway Drivage

    Institute of Scientific and Technical Information of China (English)

    曹剑锋

    2015-01-01

    With the continuous improvement of coal mining technology in China, people have to face the problem that how to improve the production and efficiency of mining. The strategic concept of"Protecting the mine which should be protected, extracting the mine which should be extracted" is put forward. With the guidance of this strategic concept, technology development and technology innovation are carried out for the mining technology of raw coal by the various of large coal mines in China. The technology of crossing hole of floor roadway is developed. This technology has good effect on the coal gas drainage in the process of coal roadway drivage, and it ensure the stable yield high yield and safety production of the mine.%随着国内煤矿开采技术的不断提高,如何提高开采量及提高开采的效率问题摆在我们面前,随着国家提出了“可保尽保,应抽尽抽”的战略方针,在这个战略方针的指导下,国内各大型煤矿对原煤的开采技术进行了技术挖潜和技术革新,研制成了底板巷穿层钻孔技术,该项技术对煤巷掘进过程中,煤瓦斯突抽放的效果显著,确保矿井的稳产、高产及安全生产。

  6. Numerical simulations of full-wave fields and analysis of channel wave characteristics in 3-D coal mine roadway models

    Science.gov (United States)

    Yang, Si-Tong; Wei, Jiu-Chuan; Cheng, Jiu-Long; Shi, Long-Qing; Wen, Zhi-Jie

    2016-12-01

    Currently, numerical simulations of seismic channel waves for the advance detection of geological structures in coal mine roadways focus mainly on modeling twodimensional wave fields and therefore cannot accurately simulate three-dimensional (3-D) full-wave fields or seismic records in a full-space observation system. In this study, we use the first-order velocity-stress staggered-grid finite difference algorithm to simulate 3-D full-wave fields with P-wave sources in front of coal mine roadways. We determine the three components of velocity V x, V y, and V z for the same node in 3-D staggered-grid finite difference models by calculating the average value of V y, and V z of the nodes around the same node. We ascertain the wave patterns and their propagation characteristics in both symmetrical and asymmetric coal mine roadway models. Our simulation results indicate that the Rayleigh channel wave is stronger than the Love channel wave in front of the roadway face. The reflected Rayleigh waves from the roadway face are concentrated in the coal seam, release less energy to the roof and floor, and propagate for a longer distance. There are surface waves and refraction head waves around the roadway. In the seismic records, the Rayleigh wave energy is stronger than that of the Love channel wave along coal walls of the roadway, and the interference of the head waves and surface waves with the Rayleigh channel wave is weaker than with the Love channel wave. It is thus difficult to identify the Love channel wave in the seismic records. Increasing the depth of the receivers in the coal walls can effectively weaken the interference of surface waves with the Rayleigh channel wave, but cannot weaken the interference of surface waves with the Love channel wave. Our research results also suggest that the Love channel wave, which is often used to detect geological structures in coal mine stopes, is not suitable for detecting geological structures in front of coal mine roadways

  7. Composite active control system of roof and side truss cable for large section coal roadway in fold coal pillar area

    Institute of Scientific and Technical Information of China (English)

    Sheng-Rong XIE; Er-Peng LI; Fu-Lian HE; Shou-Bao ZHANG; Guang-Chao ZHANG; Mao-Yu PANG

    2013-01-01

    In order to solve the surrounding rock control problem of large section gangue replacement roadway under complicated conditions,this paper analyzed the impact to the roadway controlling produced by the geological conditions such as high ground stress,folded structure tilted roof asymmetry and soft wall rock,and built the tilt layered roof structural mechanics model to clarify the increase span mechanism of the weak coal instability.Then,we proposed the combined control system including roof inclined truss cable,coal-side cable-channel steel and intensive bolt support.And then by building the structural mechanics model of roof inclined truss cable system,the support principle was described.Besides,according to this model,we deduced the calculation formula of cable anchoring force and its tensile stress.Finally surrounding rock control technology of large section roadway in fold coal pillar area was formed.Field practice shows that the greatest roof convergence of gangue replacement roadway is 158 mm and coal-side deformation is 243 mm.Roadway deformation is controlled effectively and technical support is provided for replacement mining.

  8. Effective Stress and Permeability Redistributions Induced by Successive Roadway and Borehole Excavations

    Science.gov (United States)

    Hu, Shengyong; Zhou, Fubao; Liu, Yingke; Xia, Tongqiang

    2015-01-01

    Methane extraction from in-seam boreholes is the main approach for recovering methane in China. However, the methane concentration for this method is generally lower than 30 %, which incurs a risk of methane outbursts during pipeline transportation. To increase the methane concentration, we first conducted permeability experiments to investigate the relationships between the permeability and the effective stress at different stages in the complete effective stress-strain process. We then adopted FLAC3D software to calculate the stress distributions around roadways and boreholes after their consecutive excavations and thereby divided the coal mass around the roadway and borehole according to different effective stress stages to understand the gas flow characteristics. The results show that the coal mass along the radial direction of the roadway and borehole can be sequentially divided into four zones, including the full flow zone (FFZ), the transitive flow zone (TFZ), the flow-shielding zone (FSZ), and the in situ rock flow zone (IRFZ), which have been proven correct by field experiments. The methane in the IRFZ was difficult to extract because of the low permeability of coal mass in this zone. The permeability of the FSZ was lower than that of the IRFZ. The permeability along the interface between the FSZ and TFZ was nearly one time as low as that of the IRFZ, while the permeability of the FFZ was two orders of magnitude higher than that of the IRFZ. This four-zone division demonstrates the decaying mechanism of methane extraction concentration and flow in the in-seam borehole and can provide theoretical guidance for improvement of methane extraction.

  9. Design of primary ground support during roadway development using empirical databases

    Institute of Scientific and Technical Information of China (English)

    Ry Stone⇑

    2016-01-01

    There have been many design practices utilised within the coal mining industry to arrive at the minimum densities of primary ground support required during roadway development. This paper demonstrates the practical use of empirical databases, and focuses on the main drivers for ground support as demonstrated in conceptual models. Golder Associates’ empirical databases used for ground support include a primary roof support database and a primary rib support database. Both are based on successful ground support designs installed in mines in Australia, the US, the UK, South Africa, New Zealand, and Europe. The term‘successful”refers to those designs that were used on a repeated basis for the purpose of roadway devel-opment. The primary roof support database indicates that the major factors influencing successful roof support designs are roof competency, expressed as the coal mine roof rating (CMRR), and in situ stress. In regard to the primary rib support database, it is evident from the current database that the primary factors affecting the capacity of rib support required for a successful design are roadway height and depth of cover. These databases have been used to help determine the minimum primary ground support designs required at many mine sites in Australasia, Europe, and the US. This paper will demonstrate the effectiveness and practicality of these databases at two selected mines in Australia and the US. In order to improve the primary rib support database, this paper will also propose a new rib deformation rating based on the addition of site specific coal strength data for the Australian mines. The proposed rat-ing attempts to capture the main variables that define the behaviour of a buckling column.

  10. Stability assessment of rock surrounding an I-beam supported retreating roadway

    Institute of Scientific and Technical Information of China (English)

    严红; 张吉雄; 李林玥; 冯锐敏

    2015-01-01

    The installation of a back-wall guard-board is the key to successfully supporting underground retreating roadways in coal mines. Based on the coordinate support principle, and using an I-shaped steel support for the surrounding rock, a mechanical model was developed for the stability of the roadway support and surrounding rock. Analysis of the bearing capacity of the roof back-wall guard-board and modelling of the equations for the maximum deflection and the maximum compressive stress of the top and side beams of the I-shaped steel support were undertaken. Simultaneously, the model was used to calculate and analyse the stability of the top and side beams of the I-shaped steel support structure and analyse the criteria for their stability. The results provide a reliable theoretical basis for the judgment of the stability of the surrounding rock and support structure. The theoretical evaluation results are consistent with field data. Finally, the key support parameters of the top and side beams of the I-shaped steel support structure and the variation of the maximum deflection and the maximum compressive stress as affected by the influence of the guard-board length were investigated. It is concluded that, as the back-board length increases, the maximum compressive stress in the top beam of the I-shaped steel support increases while the compressive stress in the side beam decreases. The results show that the accuracy of judgment of the stability of a supported retreating roadway is improved, providing guidance for the design of such typical I-shaped steel support and back-board structures.

  11. In-situ measure to internal stress of shotcrete layer in soft-rock roadway

    Institute of Scientific and Technical Information of China (English)

    Shulin Fang; Jian Zhang

    2014-01-01

    In order to solve the difficult conditions of soft rock, water-trickling and hard-maintain of main air-return roadway in Tarangaole Colliery, high pretensioned stress and intensive bolt-shotcrete support program was designed and mechanical property of shotcrete layer was specially monitored through utilizing a type of concrete stress meter with oscillating chord after the program was carried out. It was indicated that, due to rock pressure and support resistance, the interior of shotcrete layer would emerge diverse stresses in axial, radial and tangential directions. With time passing internal stresses in three directions, whose average values were-0.061, 0.043 and 0.517 MPa respectively, fluctuated first and then tended to stability slowly. The axial and radial stresses were relatively smaller than tangential stress which was 11, 12 times the two formers respectively. Along the section of roadway, axial and tangential stresses distributed symmetri-cally and increased gradually from the top of arch to the waist of wall, but reduced at the foot of wall. Radial stresses reduced from the top of arch to the waist of arch first, and then increased in the waist of wall. Axial stresses were tensile substantially, except for stresses in arch vault tending to compressive, but all the radial stresses were compressive. Nevertheless, tangential stresses in the wall were compressive and tangential stresses in the arch were tensile. During the period of roadway excavating, the stress of shotcrete layer was less than its ultimate bearing capacity, with no significant stress concentration. At the end of this article, some suggests are given to shotcrete support design.

  12. Residential Proximity to Major Roadways, Fine Particulate Matter, and Hepatic Steatosis: The Framingham Heart Study.

    Science.gov (United States)

    Li, Wenyuan; Dorans, Kirsten S; Wilker, Elissa H; Rice, Mary B; Long, Michelle T; Schwartz, Joel; Coull, Brent A; Koutrakis, Petros; Gold, Diane R; Fox, Caroline S; Mittleman, Murray A

    2017-10-01

    We examined associations between ambient air pollution and hepatic steatosis among 2,513 participants from the Framingham (Massachusetts) Offspring Study and Third Generation Cohort who underwent a computed tomography scan (2002-2005), after excluding men who reported >21 drinks/week and women who reported >14 drinks/week. We calculated each participant's residential-based distance to a major roadway and used a spatiotemporal model to estimate the annual mean concentrations of fine particulate matter. Liver attenuation was measured by computed tomography, and liver-to-phantom ratio (LPR) was calculated. Lower values of LPR represent more liver fat. We estimated differences in continuous LPR using linear regression models and prevalence ratios for presence of hepatic steatosis (LPR ≤ 0.33) using generalized linear models, adjusting for demographics, individual and area-level measures of socioeconomic position, and clinical and lifestyle factors. Participants who lived 58 m (25th percentile) from major roadways had lower LPR (β = -0.003, 95% confidence interval: -0.006, -0.001) and higher prevalence of hepatic steatosis (prevalence ratio = 1.16, 95% confidence interval: 1.05, 1.28) than those who lived 416 m (75th percentile) away. The 2003 annual average fine particulate matter concentration was not associated with liver-fat measurements. Our findings suggest that living closer to major roadways was associated with more liver fat. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Analysis of Yielding Steel Arch Support with Rock Bolts in Mine Roadways Stability Aspect

    Science.gov (United States)

    Majcherczyk, Tadeusz; Niedbalski, Zbigniew; Małkowski, Piotr; Bednarek, łukasz

    2014-10-01

    The result of the search for new technological solutions in the field of support for roadways in coal mines has in recent years been the widespread use of steel arch with rockbolt support systems. The efficiency of these systems is affected among other things by the option of installing rock bolts after the actual driving the mine roadway, the increased load capacity that these systems can support, and their resistance to dynamic weight. Large variation in the way that these steel arch support can be connected using different types of rock bolts necessitates mining research revealing the effectiveness of such solutions. Although the steel arch with rockbolt support system is used in the majority of European coal mines, it is still not possible to apply templates of schemes due to the diversity of geological and mining conditions. Therefore, throughout a period of several years, the authors of this article conducted research in situ under conditions of different schemes related to connecting arched support frames with rock bolts, with only selected results being presented in the article. The measurements of convergence, load supported by the system frame, load supported by the rock bolts, and the stratification of roof rocks were analyzed, carried out in two roadways with yielding steel arch support in which strand bolts were applied. The article also proposes the index for working maintenance nuw, used in preliminarily assessing the stability of a given working with a limited number of data concerning geomechanical conditions. Additionally considered are empirical methods used in Poland for designing steel arch with rock bolt support systems. The results of mine research indicate that strengthening yielding steel support with strand bolts through steel beams maintains the stability of a roadway, even when exposed to the exploitation stress. Aside from the impact of exploitation, deformations of the support system are negligible, despite the fact that the tensile

  14. Numerical simulation on propagation and attenuation of shock waves in simplex turn roadway during gas explosion

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Wei; Qu, Zhi-ming; Pian, Long-jiang [University of Science and Technology Beijing, Beijing (China). School of Civil Engineering and Environment

    2009-04-15

    On the basis of a hypothesis, a physical and mathematical model of the propagation of shock waves in turn roadway was set up. The results of numerical simulation show that the pressure, velocity and temperature of shock wave will be attenuated during propagation. At the beginning of gas explosion, the quantity of parameters of shock wave front is increased gradually because of methane reaction. However, the pressure, velocity and temperature will be attenuated to a small extent after the chemical reaction. By comparison of the experiment, simulation and practice, the highly identical data shows that the numerical model is practicable. 9 refs., 7 figs.

  15. Technical Feasibility Assessment of LED Roadway Lighting on the Golden Gate Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Tuenge, Jason R.

    2012-09-01

    Subsequent to preliminary investigations by the Golden Gate Bridge Highway & Transportation District (GGB), in coordination with Pacific Gas & Electric (PG&E), the GATEWAY Demonstration program was asked to evaluate the technical feasibility of replacing existing roadway lighting on the bridge with products utilizing LED technology. GGB and PG&E also indicated interest in induction (i.e., electrodeless fluorescent) technology, since both light source types feature rated lifetimes significantly exceeding those of the existing high-pressure sodium (HPS) and low-pressure sodium (LPS) products. The goal of the study was to identify any solutions which would reduce energy use and maintenance without compromising the quantity or quality of existing illumination. Products used for roadway lighting on the historic bridge must be installed within the existing amber-lensed shoebox-style luminaire housings. It was determined that induction technology does not appear to represent a viable alternative for the roadway luminaires in this application; any energy savings would be attributable to a reduction in light levels. Although no suitable LED retrofit kits were identified for installation within existing luminaire housings, several complete LED luminaires were found to offer energy savings of 6-18%, suggesting custom LED retrofit kits could be developed to match or exceed the performance of the existing shoeboxes. Luminaires utilizing ceramic metal halide (CMH) were also evaluated, and some were found to offer 28% energy savings, but these products might actually increase maintenance due to the shorter rated lamp life. Plasma technology was evaluated, as well, but no suitable products were identified. Analysis provided in this report was completed in May 2012. Although LED technologies are expected to become increasingly viable over time, and product mock-ups may reveal near-term solutions, some options not currently considered by GGB may ultimately merit evaluation. For

  16. Roof separation characteristics of laminated weak roof strata of longwall roadway

    Institute of Scientific and Technical Information of China (English)

    LU Ting-kan; LIU Yu-zhou

    2004-01-01

    The roof separation was investigated in a coal mine as part of the site characterization of roof strata deterioration in a longwall roadway. The separation of laminated,weak roof strata was initially characterized as the maximum separation, effect of geological setting on separation and the effect of mining activities (heading development,time-dependent and longwall extraction) on separation. Then the separation process was studied, so as to answer the questions of: when the separation occurs; where the separation is located and what geological setting it relates to; how large of the separation is; and how the separation propagates.

  17. Controllable theory and applications for the wall bolting reinforcement in the roadway of seam

    Institute of Scientific and Technical Information of China (English)

    TAN Yun-liang; ZHANG Li-jun; XIAO Ya-xun

    2007-01-01

    By using the Radar penetrating technology and numerical simulations, the fractured zone could be easily determined. Both wall fractured zone and mining action of coal seam roadway were considered, and the bolt reinforcing criteria for wall including low limit condition and up limit condition were put up, which supply a basis for the bolt reinforcement design. For a particular engineering, there existed a bolt reinforcing controllable range which can be determined by the method put up in this paper. For the out of controllable range of bolt reinforcement in engineering, it is necessary to seek for other kind reinforcing technology, because the bolt reinforcing technology is not omnipotent.

  18. Rural Households

    DEFF Research Database (Denmark)

    2013-01-01

    dependency on state institutions under the Vietnamese transition to a market society. It discusses present poverty definitions and measures by comparing survey data with the formal economic categorization of rural households. Both the overall characteristics of rural society and qualitative data indicate...

  19. Going Rural

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Foreign banks are beginning to invest in China's rural financial system, helping to meet a strong need for capital As Chinese commercial banks retreat from the rural market, foreign banks appear ready to jump into a sector with a strong thirst for capital. In July, Rabobank Group, the International Finance Corp. and the United

  20. Rural Agrobusiness.

    Science.gov (United States)

    Treillon, Roland; And Others

    1992-01-01

    This publication describes the formation and evolution of rural agribusiness (RA) in the southern hemisphere as a precondition for improving the lives of families in rural communities, and focuses on RA endeavors created by development projects in Latin America, the Caribbean, and Africa. After a short introduction, the first section of this study…

  1. Experimental study on the bolt-cable combined supporting technology for the extraction roadways in weakly cemented strata

    Institute of Scientific and Technical Information of China (English)

    Meng Qingbin; Han Lijun; Sun Jingwu; Min Fengqing; Feng Wei; Zhou Xing

    2015-01-01

    Aiming at the characteristics of the poor steady ability, the short stable time and severe deformation behavior of weakly cemented soft surrounding rock around extraction roadway, a bolt–cable combined supporting technology was proposed. Numerical simulation was performed by using FLAC3D software to study the effects of different supporting systems. The simulation result proves that those supporting systems have good practical values. Based on real-time monitoring and analysis of the deformation of surrounding rock and the stress of supporting structure, real time information of deformation of sur-rounding rock and stress state of supporting structure of extraction roadway within weakly cemented strata was obtained. Monitoring results show that large deformation and failure of surrounding rock of extraction roadway within weakly cemented strata can be effectively controlled by the bolt–cable com-bined supporting technology, which ensures the long-term stability and safety of surrounding rock and supporting structure.

  2. 49 CFR 1242.28 - Roadway machines, small tools and supplies, and snow removal (accounts XX-19-36 to XX-19-38...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Roadway machines, small tools and supplies, and... PASSENGER SERVICE FOR RAILROADS 1 Operating Expenses-Way and Structures § 1242.28 Roadway machines, small tools and supplies, and snow removal (accounts XX-19-36 to XX-19-38, inclusive). Separate...

  3. Support failure of a high-stress soft-rock roadway in deep coal mine and the equalized yielding support technology:a case study

    Institute of Scientific and Technical Information of China (English)

    Lihui Sun; Haoyuan Wu; Bensheng Yang; Qiangqiang Li

    2015-01-01

    There are many soft-rock roadway coal mines in China. The surrounding rocks of the high-stress soft-rock roadways in deep mine are especially difficult to be supported using the traditional supporting way. In this study, the south wing rail roadway on the second level of Yunjialing coal mine in China was used as an example to analyze the deformation and failure characteristics and influencing factors of roadway. On this basis, this study proposed the equalized yielding support idea which employs the yielding rings to realize the pressure equalization on the bolts and cables in the section. To achieve this purpose, the first bolt-mesh-cable equalizing pressure yielding support was integrated with the second grouting reinforcement. The results proved that the yield rings of the bolts and cables on the spandrel of the arched roadway firstly developed yielding deformation;then the deformation extended to the vault of the roadway;the bolts and cables achieved a yielding extreme value of 15 and 18 tonnes, respectively. The roadway surrounding rock tended to be stable at the 26th day after the maintenance. The equalizing pressure yielding supporting technology plays a moderate pressure-releasing and actively controlling role on the surrounding rocks in the soft-rock roadway with large deformation.

  4. Determination of a potential set of factors which influence the situation of methane emission into roadways being driven

    Energy Technology Data Exchange (ETDEWEB)

    Marian Turek [Central Mining Institute, Katowice (Poland)

    2009-12-15

    The currently applied methodology of absolute gassiness forecasting in roadways being driven in Polish hard coal mines is based on the results of investigations over twenty years. The application of 'old' methods of forecasting of methane emission during driving of roadways often brings about great discrepancies between the results of the forecasts and actual situation. It is firstly necessary to determine a potential set of factors which exert an influence on situation regarding methane emission into roadways being driven in order to prepare a verified mathematical model of absolute gassiness forecasting. On the basis of available literature and the investigations conducted by the Central Mining Institute an initial list of factors has been prepared which can have an impact upon methane emission into roadways being driven. A prepared initial set has been scrutinized to be verified on the basis of a conducted expert survey among seventy specialists in this field. After collecting of the results of the survey their statistical elaboration was prepared. The co-efficient of agreement of multiple ordering, the so called concordance co-efficient has been taken advantage of in order to check the competency of experts. The investigations prove that the experts are in agreement in their opinions. The estimation of a collective assessment of all participants of the survey was conducted with the use of the rank sum's test by J. Gren. The results of the conducted analysis allowed determining a potential set of factors which influence the situation of methane emission into roadways being driven. This set, after conductance of further detailed investigations, can constitute a base for elaboration of a function describing methane emission into roadways being driven in hard coal mines. 11 refs., 3 tabs.

  5. Surrounding rock deformation regularity of roadway under extremely complicated geological conditions in deep mine and its control

    Institute of Scientific and Technical Information of China (English)

    刘长友; 何卓军; 万志军

    2003-01-01

    By combining the practices of deep mine mining in Changguang Mine field and using the Universal Distinct Element Code 3.0(UDEC3.0) numerical computing method, the distribution characteristics of deformation field and stress field as well as the surrounding rock deformation regularity of soft rock roadway are analyzed under extremely complicated geological conditions, a technical principle of bolting to control the surrounding rock of roadway is put forward. And also using a dynamic control for surrounding rocks designing method, the supporting parameters and implement plan are rationally determined. The experimental tests have obtained a good controlling result of surrounding rock.

  6. Study on Filling Cross-Roadway in Fully-Mechanized Coal Faces with High Water-Content Material

    Institute of Scientific and Technical Information of China (English)

    周华强; 王光伟; 雷文成; 曲庆贺; 李峰

    2001-01-01

    A new method using high water-content material to mechanically fill cross-roadways to form artificial bottom for coal faces was introduced. The reasonable determination of filling range, the optimization of the compounding ratio of high water-content material, and the filling technique were discussed in detail. This new method has been spread after industrial testing in Baodian Colliery. Compared with the traditional method, the manual wooden chock method, the new one decreases about 40% of the filling range and cost in dealing every one set of cross-roadway in the testing condition.

  7. Analysis of the danger zone liable to spontaneous ignition around coal roadway at fully mechanized long-wall top-coal caving face

    Institute of Scientific and Technical Information of China (English)

    邓军; 徐通模; 徐精彩

    2002-01-01

    The intensity of heat output of coal, the rate of oxygen consumption and the influence function of coal size are tested by the big coal spontaneous combustion experiment unit. The independence of the coefficient of heat convection is studied. And based on the conservation principle of energy and the real conditions, such as coal temperature,air temperature, the geometry size of roadway, air flux, the oxygen concentration in the loose coal around the roadway, the threshold parameters resulting coal spontaneous combustion are put forward, and the index determining the danger zone liable to self-ignite are evaluated. Finally, the method determining the danger zone liable to spontaneous ignition around coal roadway at fully mechanized long wall top-coal caving face is put forward. Based on the determination method and real conditions in the roadway, the coal around roadway can be divided four zones.

  8. Deformation characteristics of surrounding rock of broken and soft rock roadway

    Energy Technology Data Exchange (ETDEWEB)

    Jin-xi Wang; Ming-yue Lin; Duan-xin Tian; Cun-liang Zhao [Hebei University of Engineering, Handan (China)

    2009-03-15

    A similar material model and a numerical simulation were constructed and are described. The deformation and failure of surrounding rock of broken and soft roadway are studied by using these models. The deformation of the roof and floor, the relative deformation of the two sides and the deformation of the deep surrounding rock are predicted using the model. Measurements in a working mine are compared to the results of the models. The results show that the surrounding rock shows clear rheological features under high stress conditions. Deformation is unequally distributed across the whole section. The surrounding rock exhibited three deformation stages: displacement caused by stress concentration, rheological displacement after the digging effects had stabilized and displacement caused by supporting pressure of the roadway. Floor heave was serious, accounting for 65% of the total deformation of the roof and floor. Floor heave is the main reason for failure of the surrounding rock. The reasons for deformation of the surrounding rock are discussed based on the similar material and numerical simulations. 12 refs., 4 figs., 3 tabs.

  9. Technique and experiment of active direct gas pressure measurement in coal roadway

    Energy Technology Data Exchange (ETDEWEB)

    Xue-xi Chen; Shang-quan Ma; Li-ming Qi [North China Institute of Science and Technology, Beijing (China). School of Safety Engineering

    2009-06-15

    An active measurement method and its principle was introduced considering the low success rate, special difficulty, and long measurement time of the direct gas pressure measurement currently used in coal roadways. The technology of drilling, borehole sealing depth, borehole sealing length, sealing control of the measuring process, compensatory computation of gas loss quantity and other key techniques were discussed. Finally, based on the latest instrument the authors developed, a series of experiments of direct gas pressure measurement in the coal roadways of the Jincheng and Tongchuan mine district, were carried out. The experimental results show that active gas pressure measurement technique has advantages as follows: (1) the application scope of direct gas pressure measurement technique is wide and it does not have the restriction of coal hardness, coal seam fissure and other conditions; (2) the measured results are credible, which can be tested by the same gas pressure value acquired from a different borehole in the same place; (3) the measurement process is convenient and quick, it takes about 2 to 3 days to acquire the gas pressure value in a coal seam. 8 refs., 1 fig., 2 tabs.

  10. Near roadway air pollution across a spatially extensive road and cycling network.

    Science.gov (United States)

    Farrell, William; Weichenthal, Scott; Goldberg, Mark; Valois, Marie-France; Shekarrizfard, Maryam; Hatzopoulou, Marianne

    2016-05-01

    This study investigates the variability in near-road concentrations of ultra-fine particles (UFP). Our results are based on a mobile data collection campaign conducted in 2012 in Montreal, Canada using instrumented bicycles and covering approximately 475 km of unique roadways. The spatial extent of the data collected included a diverse array of roads and land use patterns. Average concentrations of UFP per roadway segment varied greatly across the study area (1411-192,340 particles/cm(3)) as well as across the different visits to the same segment. Mixed effects linear regression models were estimated for UFP (R(2) = 43.80%), incorporating a wide range of predictors including land-use, built environment, road characteristics, and meteorology. Temperature and wind speed had a large negative effect on near-road concentrations of UFP. Both the day of the week and time of day had a significant effect with Tuesdays and afternoon periods positively associated with UFP. Since UFP are largely associated with traffic emissions and considering the wide spatial extent of our data collection campaign, it was impossible to collect traffic volume data. For this purpose, we used simulated data for traffic volumes and speeds across the region and observed a positive effect for volumes and negative effect for speed. Finally, proximity to truck routes was also associated with higher UFP concentrations.

  11. Displacement, stress and seismicity in roadway roofs during mining-induced failure

    Energy Technology Data Exchange (ETDEWEB)

    Shen, B.; King, A.; Guo, H. [CSIRO Exploration & Mining, Kenmore, Qld. (Australia)

    2008-07-15

    Roof stability in gateroads is a long-standing issue in many of the underground mines in Australia that use longwall extraction methods, due primarily to a significant increase of vertical stresses ahead of the longwall face. Although numerous studies have been done in the past, the process of roof rock deformation and breakage prior to and during a roof failure in an actual mining environment is still being debated. This paper describes a new integrated roof monitoring system and the results from applying this system in an Australian underground coal mine. The system integrates displacement, stress and seismic monitoring. It has been applied to two roadways in an Australian underground coal mine during two field experiments. The key roof behaviour identified by the integrated monitoring package during the two field monitoring experiments is reported and discussed in this paper. The experiments were conducted in the 'tailgate' roadways that are adjacent to the caved zone, or 'goaf', of the previously mined panels. It was found in the experiments that, prior to roof falls, roof displacement accelerates whereas the horizontal stresses reduce. Seismic activity intensifies before major roof displacement or stress changes are evident, and subsides in the later stage of roof failure when large roof displacement is visible. The seismic resonance frequencies decrease during roof failure development. The field monitoring studies have also identified a number of quantitative and site-specific roof fall precursors potentially useful for roof fall prediction and prevention.

  12. Failure mechanism of Mesozoic soft rock roadway in Shajihai coal mine and its surrounding rock control

    Institute of Scientific and Technical Information of China (English)

    Yuan Yue; Zhu Yongjian; Wang Weijun; Yu Weijian

    2014-01-01

    In view of the buckling failure caused by large deformation of Mesozoic soft rock roadway in Shajihai mining area, such as serious roof fall, rib spalling, floor heave, etc., based on the detail site investigation, theoretical analysis, mineral composition test, microstructure test, water-physical property test and field experiments were carried out. And we revealed the compound failure mechanism of Mesozoic soft rock roadway in Shajihai mining area, namely the molecule expansion-shear slip of weak structural plane-construction disturbance. On this basis, the coupling support technology whose core is constant resistance with large deformation bolt was proposed. The feature of this supporting technology is that a new type of structural composite material was used, which makes the supporting system not only has the ideal deformation characteristics, but also has high supporting resistance. Thus the fully release of plastic energy within surrounding rock and reasonable control of the thickness of the plastic ring were realized. Then the differential deformation between the surrounding rock and support was eliminated by the secondary coupling support of bolt–mesh–cable, and the bolt with high strength was applied in the base angle to control floor. Eventually the collaborative bearing system of surrounding rock–support was formed. Through field tests the validity and rationality of support was also verified.

  13. Remote sensing-based detection and quantification of roadway debris following natural disasters

    Science.gov (United States)

    Axel, Colin; van Aardt, Jan A. N.; Aros-Vera, Felipe; Holguín-Veras, José

    2016-05-01

    Rapid knowledge of road network conditions is vital to formulate an efficient emergency response plan following any major disaster. Fallen buildings, immobile vehicles, and other forms of debris often render roads impassable to responders. The status of roadways is generally determined through time and resource heavy methods, such as field surveys and manual interpretation of remotely sensed imagery. Airborne lidar systems provide an alternative, cost-effective option for performing network assessments. The 3D data can be collected quickly over a wide area and provide valuable insight about the geometry and structure of the scene. This paper presents a method for automatically detecting and characterizing debris in roadways using airborne lidar data. Points falling within the road extent are extracted from the point cloud and clustered into individual objects using region growing. Objects are classified as debris or non-debris using surface properties and contextual cues. Debris piles are reconstructed as surfaces using alpha shapes, from which an estimate of debris volume can be computed. Results using real lidar data collected after a natural disaster are presented. Initial results indicate that accurate debris maps can be automatically generated using the proposed method. These debris maps would be an invaluable asset to disaster management and emergency response teams attempting to reach survivors despite a crippled transportation network.

  14. Millimeter wave scattering characteristics and radar cross section measurements of common roadway objects

    Science.gov (United States)

    Zoratti, Paul K.; Gilbert, R. Kent; Majewski, Ronald; Ference, Jack

    1995-12-01

    Development of automotive collision warning systems has progressed rapidly over the past several years. A key enabling technology for these systems is millimeter-wave radar. This paper addresses a very critical millimeter-wave radar sensing issue for automotive radar, namely the scattering characteristics of common roadway objects such as vehicles, roadsigns, and bridge overpass structures. The data presented in this paper were collected on ERIM's Fine Resolution Radar Imaging Rotary Platform Facility and processed with ERIM's image processing tools. The value of this approach is that it provides system developers with a 2D radar image from which information about individual point scatterers `within a single target' can be extracted. This information on scattering characteristics will be utilized to refine threat assessment processing algorithms and automotive radar hardware configurations. (1) By evaluating the scattering characteristics identified in the radar image, radar signatures as a function of aspect angle for common roadway objects can be established. These signatures will aid in the refinement of threat assessment processing algorithms. (2) Utilizing ERIM's image manipulation tools, total RCS and RCS as a function of range and azimuth can be extracted from the radar image data. This RCS information will be essential in defining the operational envelope (e.g. dynamic range) within which any radar sensor hardware must be designed.

  15. Technique and experiment of active direct gas pressure measurement in coal roadway

    Institute of Scientific and Technical Information of China (English)

    CHEN Xue-xi; MA Shang-quan; QI Li-ming

    2009-01-01

    An active measurement method and its principle was introduced considering the low success rate, special difficulty, and long measurement time of the direct gas pres-sure measurement currently used in coal roadways. The technology of drilling, borehole sealing depth, borehole sealing length, sealing control of the measuring process, com-pensatory computation of gas loss quantity and other key techniques were discussed. Fi-nally, based on the latest instrument the authors developed, a series of experiments of di-rect gas pressure measurement in the coal roadways of the Jincheng and Tongchuan mine district, were carried out. The experimental results show that active gas pressure measurement technique has advantages as follows: (1) the application scope of direct gas pressure measurement technique is wide and it does not have the restriction of coal hardness, coal seam fissure and other conditions; (2) the measured results are credible, which can be tested by the same gas pressure value acquired from a different borehole in the same place; (3) the measurement process is convenient and quick, it takes about 2 to 3 days to acquire the gas pressure value in a coal seam.

  16. Bolt-grouting combined support technology in deep soft rock roadway

    Institute of Scientific and Technical Information of China (English)

    Chen Yanlong; Meng Qingbin; Xu Guang; Wu Haoshuai; Zhang Guimin

    2016-01-01

    Analyzing the mineral composition, mechanical properties and ground stress testing in surrounding rock, the study investigated the failure mechanism of deep soft rock roadway with high stress. The bolt-grouting combined support system was proposed to prevent such failures. By means of FLAC3D numer-ical simulation and similar material simulation, the feasibility of the support design and the effectiveness of support parameters were discussed. According to the monitoring the surface and deep displacement in surrounding rock as well as bolt axial load, this paper analyzed the deformation of surrounding rock and the stress condition of the support structure. The monitor results were used to optimize the proposed support scheme. The results of field monitors demonstrate that the bolt-grouting combined support tech-nology could improve the surround rock strength and bearing capacity of support structure, which con-trolled the great deformation failure and rheological property effectively in deep soft rock roadway with high stress. As a result, the long term stability and safety are guaranteed.

  17. Impacts of Fog Characteristics, Forward Illumination, and Warning Beacon Intensity Distribution on Roadway Hazard Visibility.

    Science.gov (United States)

    Bullough, John D; Rea, Mark S

    2016-01-01

    Warning beacons are critical for the safety of transportation, construction, and utility workers. These devices need to produce sufficient luminous intensity to be visible without creating glare to drivers. Published standards for the photometric performance of warning beacons do not address their performance in conditions of reduced visibility such as fog. Under such conditions light emitted in directions other than toward approaching drivers can create scattered light that makes workers and other hazards less visible. Simulations of visibility of hazards under varying conditions of fog density, forward vehicle lighting, warning beacon luminous intensity, and intensity distribution were performed to assess their impacts on visual performance by drivers. Each of these factors can influence the ability of drivers to detect and identify workers and hazards along the roadway in work zones. Based on the results, it would be reasonable to specify maximum limits on the luminous intensity of warning beacons in directions that are unlikely to be seen by drivers along the roadway, limits which are not included in published performance specifications.

  18. Optimization of roadways support on El Bierzo (Spain); Optimizacion del Sostenimiento de Galerias en el Bierzo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    The aim of this project, carried out between 1993 and 1996, is based on the research of the possibilities for roadways support optimisation in EL BIERZO coal field, which is the carboniferous coal field in Spain where it is the most widespread the use of rock bolting combined with yielding arches as gates support system. This project has been carried out in the GRUPO ESCANDAL of Antracitas de Gaiztarro, at present integrated in Coto Minero del SIL and it has been focused on BIENHALLADA and PERDIZ layers, with the following tasks: I.- Taking of geomechanical data. II.- Setting up of a support calculation system III.- Validation of the calculation system in real situations. IV.- development of a friendly computer programme that can be used by technicians, without any special knowledge on computers, for the design of roadways support in EL BIERZO. This programme, in a very friendly manner, permits to establish the geometrical characteristics of a gate to be excavated in a certain seam and, once defined the geometry of the gate, this programme is able to select the support to be used, by combining fully grouted bolts, wooden chocks and steel arches. (Author)

  19. Rural Priority

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    As the Chinese economy soars ahead in the wake of the international financial crisis, more attention is being given to the country’s indus-trial, financial, investment and trade figures. But the Central Rural Work

  20. Rural nurses

    DEFF Research Database (Denmark)

    Wilson, Rhonda L.; Usher, Kim

    2015-01-01

    with descriptive techniques. In-depth interviews were conducted and the transcribed data were analysed using thematic techniques. Results: The results of this study demonstrate that in general rural people are willing to seek mental health care, and that rural nurses are well suited to provide initial care...... to young people. Conclusions: Non-traditional venues such as community, school and justice settings are ideal places where more convenient first conversations about mental health with young people and their families, and rural nurses should be deployed to these settings. Relevance to Clinical Practice......: Rural nurses are able to contribute important initial engagement interventions that enhance the early mental health care for young people when it is needed....

  1. 49 CFR 214.527 - On-track roadway maintenance machines; inspection for compliance and schedule for repairs.

    Science.gov (United States)

    2010-10-01

    ... operator's seat shall be replaced or repaired within 24 hours or by the start of the machine's next tour of duty, whichever is later. The machine may be operated for the remainder of the operator's tour of duty... roadway maintenance machines; inspection for compliance and schedule for repairs. (a) The operator of...

  2. Effect of pre-tensioned rock bolts on stress redistribution around a roadway - insight from numerical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fu-qiang Gao; Hong-pu Kang [Central Coal Research Institute, Beijing (China). Mining and Designing Branch

    2008-12-15

    The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investigate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carried out on a level drift at Chengzhuang coal mine using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lateral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases. 10 refs., 6 figs., 1 tab.

  3. High-resolution SH-wave seismic reflection investigations near a coal mine-related roadway collapse feature

    Science.gov (United States)

    Guy, Erich D.; Nolen-Hoeksema, Richard C.; Daniels, Jeffrey J.; Lefchik, Thomas

    2003-11-01

    We acquired crossline-crossline (SH-SH) shear-wave reflection data along a heavily trafficked section of Interstate highway 70 in eastern Ohio where the roadway had collapsed into underground coal-mine workings. We acquired these data to determine whether subsurface subsidence processes had continued at the collapse location after remediation, and to identify additional areas of potential collapse along this section of the roadway. A reflection correlating to the overburden and bedrock interface (above the mine workings) was consistently identified in raw field records, and our data processing and imaging targeted this high impedance contrast. Data quality was high enough to permit resolution of vertical offsets of 3-4 ft (0.91-1.2 m) and horizontal disruptions of about 20 ft (6.1 m) in the otherwise continuous bedrock horizon at two locations close to the previous collapse, suggesting a relatively high risk for future roadway failure in these areas. SH-wave data interpretations were supported by exploratory drilling results which confirmed that bedrock had subsided into underlying coal-mine workings at these two locations. Our results show that high-resolution SH-wave seismic reflection surveys can be effective for diagnosing mine-induced subsidence potential beneath heavily traveled roadways.

  4. Occupational exposure to roadway emissions and inside informal settlements in sub-Saharan Africa: A pilot study in Nairobi, Kenya

    Science.gov (United States)

    Ngo, Nicole S.; Gatari, Michael; Yan, Beizhan; Chillrud, Steven N.; Bouhamam, Kheira; Kinneym, Patrick L.

    2015-01-01

    Few studies examine urban air pollution in sub-Saharan Africa (SSA), yet urbanization rates there are among the highest in the world. In this study, we measured 8-hr average occupational exposure levels of fine particulate matter (PM2.5), black carbon (BC), ultra violet active-particulate matter (UV-PM), and trace elements for individuals who worked along roadways in Nairobi, specifically bus drivers, garage workers, street vendors, and women who worked inside informal settlements. We found BC and re-suspended dust were important contributors to PM2.5 levels for all study populations, particularly among bus drivers, while PM2.5 exposure levels for garage workers, street vendors, and informal settlement residents were not statistically different from each other. We also found a strong signal for biomass emissions and trash burning, which is common in Nairobi’s low-income areas and open-air garages. These results suggest that the large portion of urban residents in SSA who walk along roadways would benefit from air quality regulations targeting roadway emissions from diesel vehicles, dust, and trash burning. This is the first study to measure occupational exposure to urban air pollution in SSA and results imply that roadway emissions are a serious public health concern. PMID:26034383

  5. 49 CFR 1242.15 - Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged... culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged...

  6. Effect of pre-tensioned rock bolts on stress redistribution around a roadway insight from numerical modeling

    Institute of Scientific and Technical Information of China (English)

    GAO Fu-qiang; KANG Hong-pu

    2008-01-01

    The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investigate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carded out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lateral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.

  7. Mechanism of rock deformation and failure and monitoring analysis in water-rich soft rock roadway of western China

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-bin; HAN Li-jun; QIAO Wei-guo; LIN Deng-ge; YANG Ling

    2012-01-01

    Aiming to get the strata behavior and stability rules of surrounding rock of the main return airway of Yushujing Coal Mine,convergence deformation of two sides and force of U-shaped steel yieldable support and bolt were monitored,and deformation of surrounding rock and mechanical characteristics of support structure were timely obtained to guide the information construction and optimize supporting parameters in water-rich soft rock roadway.The field monitoring results indicate the following.(1) Convergence displacement of rock surface increases with time continuity and shows surrounding rock's intense rheological behavior.The original support scheme cannot control the large deformation and strongly rheological behavior;(2) Without backfilling,the U-shaped steel support begins to bear load after erecting for 4-7 days and increases rapidly in the first 30 days.The U-shaped steel support at the right shoulder and top of roadway bears a larger force and the left side and shoulder bears a smaller force; (3) The stress of bolt increasing over time and at the right shoulder of roadway has larger growth and value.The mechanism of rock deformation and the failure and strata behavior in water-rich soft rock roadway are revealed based on the results of the measured relaxation zone of surrounding rock,measured stresses,and the rock mechanics tests.

  8. Temporal and Spatial Distribution of Respirable Dust After Blasting of Coal Roadway Driving Faces: A Case Study

    Directory of Open Access Journals (Sweden)

    Shengyong Hu

    2015-10-01

    Full Text Available Coal roadway driving is an important part of the underground mining system, and very common in Chinese coal mines. However, the high concentration of respirable dust produced in the blasting operation poses a great hazard to miners’ health as well as the underground environment. In this paper, based on the direct simulation Monte Carlo method, the gas–solid two-phase flow model of particle movement is established to study the respirable dust distribution in blasting driving face. The results show that there is an obvious vortex region in which airflow velocity is lower than that close to the roadway wall and driving face. After blasting, respirable dust in the front of the dust group jet from the driving face cannot be discharged timely, with the result that its concentration is higher than the critical value until it is expelled from the roadway, whereas respirable dust concentration at the back of the dust group is gradually diluted and exhibits an alternate thin dense phase distribution. Meanwhile, respirable dust concentration in the breathing zone is relatively higher than that at the top and bottom of roadway. The accuracy of numerical simulation results is verified by field measurements. The research results are helpful for further understanding the evolution of respirable dust distribution after blasting, and are good for providing guidance for efficient controlling of respirable dust and improving the working environment for underground miners.

  9. Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting, I-35W Bridge, Minneapolis, Minnesota, Phase I Report

    Energy Technology Data Exchange (ETDEWEB)

    Kinzey, B. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Myer, M. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2009-08-01

    On the I-35W Bridge in Minneapolis, Minnesota, the GATEWAY program conducted a two-phase demonstration of LED roadway lighting on the main span, which is one of the country's oldest continuously operated exterior LED lighting installations. The Phase I report provides an overview of initial project results including lighting performance, economic performance, and potential energy savings.

  10. Risk factors for roadway single- and multi-vehicle all-terrain vehicle crashes in Pennsylvania: 2010-2013.

    Science.gov (United States)

    Gorucu, Serap; Murphy, Dennis; Kassab, Cathy

    2017-01-01

    All Terrain Vehicles on public roadways become major risk factors for the motorists. To compare characteristics of crashes and injury severity related to single vehicle (SV) and multi-vehicle (MV) All-Terrain Vehicle (ATV) roadway crashes in Pennsylvania, USA. Data on ATV crashes occurring on public roads during the years 2010-2013 was obtained from the Pennsylvania Department of Transportation (PennDOT) and analyzed. Almost two-thirds of the incidents were single-vehicle incidents. Single-ATV incidents have a greater risk for incapacitating injury to drivers than do multi-vehicle ATV incidents. Other factors that increase risk for incapacitating injury in SV crashes include being male, being a driver, alcohol/drug involvement, hitting a fixed object, and the incidents in non-daylight hours. For MV ATV incidents, head on and rear-end crashes and drivers who had alcohol/drug involvement were the two major incapacitating injury risk factors. This study has enabled us to better understand roadway ATV incidents, characteristics of SV and MV ATV crashes, and the incapacitating injury risks in both SV and MV crash incidents. Our study suggests that road safety and public health programs should focus on the users' knowledge on laws regarding ATV usage on public roadways.

  11. Determination of a potential set of factors which influence the situation of methane emission into roadways being driven

    Institute of Scientific and Technical Information of China (English)

    Marian Turek

    2009-01-01

    The currently applied methodology of absolute gassiness forecasting in roadways being driven in Polish hard coal mines is based on the results of investigations from before more than twenty years. At present the roadways are being driven in majority of cases in quite different conditions than those which had been the subject of the said investigations. The application of "old" methods of forecasting of methane emission during driving of roadways often brings about great discrepancies between the results of the forecasts and actual situation. It is firstly necessary to determine a potential set of factors which exert an influence on situation regarding methane emission into roadways being driven in order to prepare a verified mathematical model of absolute gassiness forecasting. On the basis of available literature and the investigations conducted by the Central Mining Institute an initial list of factors has been prepared which can have an impact upon methane emission into roadways being driven. The assumptions of heuristic method have been taken advantage of for selection of parameters and indices describing the phenomenon of methane emission. It has been dictated by the fact that the available literature is lacking a pretty unambiguous viewpoint on the subject under consideration and at the same time it is necessary to perform an a priori assessment of the information contained in a given feature (factor). A prepared initial set has been scrutinized to be verified on the basis of a conducted expert survey among seventy specialists in this field. After collecting of the results of the survey their statistical elaboration was prepared. The co-efficient of agreement of multiple ordering, the so called concordance co-efficient has been taken advantage of in order to check the competency of experts. The investigations prove that the experts are in agreement in their opinions. The estimation of a collective assessment of all participants of the survey was conducted

  12. What Is Rural?

    Science.gov (United States)

    ... of mind. For others, rural is an objective quantitative measure. The USDA , Economic Research Service, provides insight to rural definitions with an article, Defining the "Rural" in Rural America: The use ...

  13. Numerical simulation and disaster prevention for catastrophic fire airflow of main air-intake belt roadway in coal mine-A case study

    Institute of Scientific and Technical Information of China (English)

    周刚; 程卫民; 张睿; 沈宝堂; 聂文; 张磊; 王昊

    2015-01-01

    Coal mine belt fire develops very rapidly and is difficult to control. If not suppressed quickly, a belt fire could easily lead to airflow disorder and undermine the ventilation system. However, belt fire can be prevented effectively by establishing fire airflow control system. In this work, the 5th belt roadway of Kongzhuang coal mine was taken as the object of investigation, where geometrical models of this roadway were established firstly. Then, based on mathematical model of fire smoke flow, the CO volume fraction, smoke density distribution, air temperature and pollutant velocity vector in the roadway before and after taking airflow control measures were simulated by using Fluent software. It can be known from the simulation that with the normal ventilation status in 5th belt roadway, the countercurrent of smoke does not happen when a fire occurs; the roadway’s section is almost filled with CO at 10 m downstream from the fire source, and with air velocity getting stable gradually, the CO concentration reaches about 15 %. After taking airflow control measures, the effect range of temperature field which are harmful to the miners decreases from 69 m to 30 m; and the distance of the roadway fully filled with CO is 5 m farther than that before taking measures. Finally, according to the numerical simulation results and the actual condition of the belt roadway, the warning and automatic remote airflow control system with short-circuit method for the 5th belt roadway was designed to guarantee the safety production.

  14. Test and application of hydraulic expansion bolts in a roadway under goaf with ultra-close separation

    Institute of Scientific and Technical Information of China (English)

    Wang Xiangyu; Bai Jianbiao; Guo Guanlong; Yu Yang

    2014-01-01

    The roof of a roadway under goaf with ultra-close separation consists of thin rock strata and rocks caving in upper goaf. Influenced by the mining of the upper coal seam, the roof is loose and broken, and its integ-rity is poor. Resin anchored bolts cannot provide an effective anchoring force in such roof conditions. By conducting free expansion tests and field pull-out tests on a hydraulic expansion bolt, this study has ana-lyzed the influencing factors and laws of radial expansion and anchoring force changes in the rod body. This has revealed the anchoring mechanism of such bolts, and has obtained reasonable water injection pressures and suitable drilling diameters (which are 20–25 MPa and 32–35 mm respectively) for the hydraulic expansion bolt (u28 mm) used in these tests. Based on pull-out tests at different interlayer spacing, the applicability of hydraulic expansion bolts had been verified for controlling the roof of road-ways under goaf with ultra-close distance. Combined with the deformation and failure characteristics of the test roadway roof, this paper proposes a united roof-control technology based on the use of hydraulic expansion bolts and advancing intubation for the roof. Engineering practice indicated that the roof of the test roadway did not generate leaking and caving phenomenon, and the amount of roof deformation was controlled to within 150 mm. Maintenance of the roadway roof has been improved significantly, which ensures safe mining in coal seams with ultra-close separation.

  15. Comprehensive automation of work on delivering and laying rail tracks in mine roadways

    Energy Technology Data Exchange (ETDEWEB)

    Mazin, S.P.; Volkov, V.Yu.; Ignatova, E.M.; Puleev, S.F.

    1988-07-01

    Presents the KD-1 and NPSh-900 sets of equipment for automation of track laying work in underground mine roadways. Analysis of track laying in mines in the USSR shows that about 200 km of track are laid annually, with energy at 1600 kJ/m expended in the form of manual labor. The KD-1 equipment, developed by VNIIOMShS, is based on a track delivery container holding 10-12 rails 8-12 m long. The NPSh-900 set is a set of tools and accessories for track laying - a rail cutting unit, a rail drilling unit, a rail bender, ballast cars, grips, jacks, etc. All this equipment is handed to the track laying site on a special rail/wheeled trolley. Both sets of equipment have been successfully tested in Donbass mines.

  16. Traffic Impact Analysis of the Access to Projects on Traffic Performance of Nearby Roadways

    Institute of Scientific and Technical Information of China (English)

    SONG Fei; CAO Jing; YANG Xiao-kuan

    2010-01-01

    Access to any development is a connection between the buildings and urban roadways. The impact of access on urban roads varies with location of the access. This paper studies the impact of access to large buildings on the surrounding road network by exploring traffic conflicts based on the configuration of the access. The concept of conflict intensity is introduced in this study as a new evaluation indicator to evaluate the traffic conflict triggered by the presence of access. The results show that the greater the speed, the greater the conflict intensity of access. Meanwhile, a similar situation exists when other variables (e.g., conflict angle or the number of conflicts) change. The larger the conflict intensity, the more dangerous the access. Results from this study can help developers and traffic engineers choose suitable locations of access and organize the traffic in a logical manner.

  17. Numerical Investigation of Rockburst Effect of Shock Wave on Underground Roadway

    Directory of Open Access Journals (Sweden)

    Cai-Ping Lu

    2015-01-01

    Full Text Available Using UDEC discrete element numerical simulation software and a cosine wave as vibration source, the whole process of rockburst failure and the propagation and attenuation characteristics of shock wave in coal-rock medium were investigated in detail based on the geological and mining conditions of 1111(1 working face at Zhuji coal mine. Simultaneously, by changing the thickness and strength of immediate roof overlying the mining coal seam, the whole process of rockburst failure of roadway and the attenuation properties of shock wave were understood clearly. The presented conclusions can provide some important references to prevent and control rockburst hazards triggered by shock wave interferences in deep coal mines.

  18. Deformation and failure of stratified weak roof strata of longwall roadway

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A comprehensive underground monitoring was conducted in a coal mine. The purpose of this research was to clarify the deformation and failure behavior of stratified weak roof strata of longwall roadway in adverse ground conditions. The field investigation incorporating a range of geotechnical instrumentation was conducted over a period of time ever since the formation of opening the site was buried into the goaf of a retreating longwall panel. The roof layer deformation and failure characteristics associated with the three stages of heading development, after development and before extraction, as well as after longwall extraction were identified on the basis of field investigation and analyticai study, the results clearly demonstrated that how the roof deformation and failure progress were strongly related to these three stages of the mining activities mentioned.

  19. Numerical analysis of gas emission rule from a goaf of tailing roadway

    Institute of Scientific and Technical Information of China (English)

    LI Zong-xiang; HUANG Zhi-an; ZHANG Ai-ran; SONG Jian-guo

    2008-01-01

    Targeting the problem of large amounts of gas emission from the goaf of the No.14201 working face in the Shaqu coal mine of Huajin Coking Coal Co. Ltd., we used a negative exponential function to describe the attenuation process of gas emission in goaf (the stable source) based on the principle of field flow. Equations of two-component flow (gas and air) and see- page-diffusion in a heterogeneous goaf flow field are solved by means of numerical simulation and fluid mechanics principles of air movement and gas distribution during gas emission from goaf. The results indicate that the air diversion volume has a negative, exponential relation with the volume of gas emitted from goaf to the working face and is clearly inversely related to gas concentration. We calculated the minimum amount of air diversion and distributed air volume in the tailing roadway required for safe production.

  20. Framework and implementation of a continuous network-wide health monitoring system for roadways

    Science.gov (United States)

    Wang, Ming; Birken, Ralf; Shahini Shamsabadi, Salar

    2014-03-01

    According to the 2013 ASCE report card America's infrastructure scores only a D+. There are more than four million miles of roads (grade D) in the U.S. requiring a broad range of maintenance activities. The nation faces a monumental problem of infrastructure management in the scheduling and implementation of maintenance and repair operations, and in the prioritization of expenditures within budgetary constraints. The efficient and effective performance of these operations however is crucial to ensuring roadway safety, preventing catastrophic failures, and promoting economic growth. There is a critical need for technology that can cost-effectively monitor the condition of a network-wide road system and provide accurate, up-to-date information for maintenance activity prioritization. The Versatile Onboard Traffic Embedded Roaming Sensors (VOTERS) project provides a framework and the sensing capability to complement periodical localized inspections to continuous network-wide health monitoring. Research focused on the development of a cost-effective, lightweight package of multi-modal sensor systems compatible with this framework. An innovative software infrastructure is created that collects, processes, and evaluates these large time-lapse multi-modal data streams. A GIS-based control center manages multiple inspection vehicles and the data for further analysis, visualization, and decision making. VOTERS' technology can monitor road conditions at both the surface and sub-surface levels while the vehicle is navigating through daily traffic going about its normal business, thereby allowing for network-wide frequent assessment of roadways. This deterioration process monitoring at unprecedented time and spatial scales provides unique experimental data that can be used to improve life-cycle cost analysis models.

  1. Temporal Variation of Carbon Monoxide Concentration at Congested Urban Roadways Intersection

    Directory of Open Access Journals (Sweden)

    Ghanshyam

    2014-01-01

    Full Text Available The carbon monoxide (CO is dominant among major traffic emitted pollutants such as respirable suspended particulate matter (RSPM, oxides of nitrogen (NOx, volatile organic carbons(VOCs and ozone (O3 etc. It is generated by automobiles due to incomplete combustion of the fuel. The vehicles that queue up at an intersection spend more time in idle driving mode generating more pollutant leading to higher pollutant concentrations. Therefore, the trends of average hourly CO concentrations at various locations of congested roadways intersection have been investigated. The four approach roads making intersection have been selected for the present study. CO monitoring has been carried out at 2 selected locations of each approach road. The CO concentration has been monitored from 8:00 AM to 8:00 PM at each location using portable online CO monitor. The average hourly CO concentrations data have been analyzed using MS excel spread sheet for each approach road. The average hourly concentration of monitored CO concentration at all receptors locations shows two peak CO concentration values (i.e., the morning peak and evening peak throughout the monitoring programme (March to May, 2011. The comparison of monitored values of average 1 hourly CO concentration levels as well as 8 hourly average concentration levels of CO showed non compliance with the prescribed standards (4000 µg/m3 average hourly and 2000 µg/m3 average 8 hourly CO concentration. The temporal CO concentration at various approach roads making roadway intersection shows non-uniform. The highest CO concentration has been observed to be towards high rise building and vice-versa. The least CO concentration has been observed towards either low rise building or open area.

  2. Road and Street Centerlines - FUNCTIONAL_CLASS_INDOTMODEL_IN: Functional Classification of Roadways in Indiana, 2015 (Indiana Department of Transportation, Line Shapefile)

    Data.gov (United States)

    NSGIC State | GIS Inventory — FUNCTIONAL_CLASS_INDOTMODEL_IN is a line shapefile that shows the Federal Highway Administration functional classification of roadways from the Road Inventory of the...

  3. Deformation mechanism of surrounding rocks and key control technology for a roadway driven along goaf in fully mechanized top-coal caving face

    Institute of Scientific and Technical Information of China (English)

    李学华

    2003-01-01

    The variation of the stress in the bolted surrounding rocks structure of the roadway driven along goaf in a fully mechanized top-coal caving face with moderate stable conditions are studied by using numerical calculation. The essential deformation characteristics of the surrounding rocks in this kind of roadway are obtained and the key technology of bolting support used under these conditions is put forward.

  4. Deformation mechanism of surrounding rocks and key control technology for a roadway driven along goaf in fully mechanized top-coal caving face

    Energy Technology Data Exchange (ETDEWEB)

    Li, X. [China University of Mining and Technology, Xuzhou (China). School of Energy Science and Engineering

    2003-06-01

    The variation of the stress in the bolted surrounding rocks structure of the roadway driven along the goaf in a fully mechanized top-coal caving face with moderate stable conditions are studied by using numerical calculation. The essential deformation characteristics of the surrounding rocks in this kind of roadway are obtained and the key technology of bolting support used under these conditions is put forward. 3 refs., 2 figs., 1 tab.

  5. 井下巷道矸石充填技术%On filling technique of underground roadway waste rocks

    Institute of Scientific and Technical Information of China (English)

    张越

    2015-01-01

    Combining with the allocation of the filled roadway of No. 2 east mining area at Longdong coal mine,the paper introduces the key e-quipment and structural principle of the filling technique of underground roadway waste rocks,and analyzes its factual craft procedure,so as to improve the recovery ratio of underground coal resources.%结合龙东煤矿东二采区充填巷道的布置情况,介绍了井下巷道矸石充填技术的关键设备及其结构原理,并对该施工技术的具体工艺流程进行了分析,以提高井下煤炭资源的回收率。

  6. Monitoring and analysis of nonlinear dynamic damage of transport roadway supported by composite hard rock materials in Linglong Gold Mine

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The study concentrates mainly on the development of failure process in composite rock mass. By use of acoustic emission(AE), convergence inspection, pressure monitoring, level measurement techniques and the modem signal analysis technology, as wellas scan electron microscopy (SEM) experiment, various aspects of nonlinear dynamic damage of composite rock mass surroundingthe transport roadway in Linglong gold mine are discussed. According to the monitoring results, the stability of the rock mass can besynthetically evaluated, and the intrinsic relation between the damage and the characteristic parameters of acoustic emission can bedetermined. The location of the damage of rock mass can also be detected based on the acoustic emission couple monitoring signals.Finally, the key factors which influence the stability of the transport roadway supported by composite hard rock materials are foundout.

  7. De-stressed mining of multi-seams: Surrounding rock control during the mining of a roadway in the overlying protected seam

    Institute of Scientific and Technical Information of China (English)

    Wang Cheng; Zhang Nong; Li Guichen; Zhang Nianchao

    2011-01-01

    Surrounding rock control in the overlying protective coal seam is a challenging topic for de-stressed mining of multi-seamed coal. Current research findings on roadway control were used in the design of a physical model of a complex textured roof having a varying thickness. The model was used to study roadway instability and collapse caused by dynamic pressure. The results show that when the thickness of the roof exceeds the bolted depth the roadway security is least and the roof has the greatest possibility for collapse. Numerical simulations were also carried out to study stress redistribution before and after roadway excavation during underlying protective seam mining. The evolution of roadway displacement and fracture, as affected by support methods, has been well studied. A series of support principles and technologies for mining affected roadways has been proposed after demonstration of successful practical application in the Huainan Mines. These principles and technologies are of extended value to deep coal mining support in China.

  8. Control Mechanism of Rock Burst in the Floor of Roadway Driven along Next Goaf in Thick Coal Seam with Large Obliquity Angle in Deep Well

    Directory of Open Access Journals (Sweden)

    Yunhai Cheng

    2015-01-01

    Full Text Available This paper deals with the theoretical aspects combined with stress analysis over the floor strata of coal seam and the calculation model for the stress on the coal floor. Basically, this research presents the relevant results obtained for the rock burst prevention in the floor of roadway driven along next goaf in the exploitation of thick coal seam with large obliquity in deep well and rock burst tendency. The control mechanism of rock burst in the roadway driven along next goaf is revealed in the present work. That is, the danger of rock burst can be removed by changing the stress environment for the energy accumulation of the floor and by reducing the impact on the roadway floor from the strong dynamic pressure. This result can be profitable being used at the design stage of appropriate position of roadway undergoing rock burst tendency in similar conditions. Based on the analysis regarding the control mechanism, this paper presents a novel approach to the prevention of rock burst in roadway floor under the above conditions. That is, the return airway is placed within the goaf of the upper working face that can prevent the rock burst effectively. And in this way, mining without coal pillar in the thick coal seam with large obliquity and large burial depth (over a thousand meters is realized. Practice also proves that the rock burst in the floor of roadway driven along next goaf is controlled and solved.

  9. Application of high-pressure water jet technology and the theory of rock burst control in roadway

    Institute of Scientific and Technical Information of China (English)

    Yang Zengqiang; Dou Linming; Liu Chang; Xu Mengtang; Lei Zhen; Yao Yahu

    2016-01-01

    This paper puts forward using high-pressure water jet technology to control rock burst in roadway, and analyzes the theory of controlling rock burst in roadway by the weak structure zone model. The weak structure zone is formed by using high-pressure water jet to cut the coal wall in a continuous and rota-tional way. In order to study the influence law of weak structure zone in surrounding rock, this paper numerically analyzed the influence law of weak structure zone, and the disturbance law of coal wall and floor under dynamic and static combined load. The results show that when the distance between high-pressure water jet drillings is 3 m and the diameter of drilling is 300 mm, continuous stress super-position zone can be formed. The weak structure zone can transfer and reduce the concentrated static load in surrounding rock, and then form distressed zone. The longer the high-pressure water jet drilling is, the larger the distressed zone is. The stress change and displacement change of non-distressed zone in coal wall and floor are significantly greater than that of distressed zone under dynamic and static com-bined load. And it shows that the distressed zone can effectively control rock burst in roadway under dynamic and static combined load. High-pressure water jet technology was applied in the haulage gate of 250203 working face in Yanbei Coal Mine, and had gained good effect. The study conclusions provide theoretical foundation and a new guidance for controlling rock burst in roadway.

  10. Stability of Roadway in Upper Seam of Deep Multiple Rich Gas Coal Seams through Ascending Stress-relief Mining

    OpenAIRE

    2015-01-01

    The first mining of a protective coal seam through ascending stress-relief mining is one of the most effective techniques for eliminating the risk of coal and gas outburst during the exploitation of multiple coal seams containing high rich gas. However, the difficulty of controlling roadway stability in the upper protected coal seam above the goaf increases greatly after ascending mining. Based on the geological conditions in Guqiao Coal Mine in China, a numerical simulation model is establis...

  11. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    Science.gov (United States)

    Hess, George; Peterson, M Nils

    2015-01-01

    Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  12. Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting, I-35W Bridge, Minneapolis, Minnesota, Phase II Report

    Energy Technology Data Exchange (ETDEWEB)

    Kinzey, B. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Davis, R. G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-30

    On the I-35W Bridge in Minneapolis, Minnesota, the GATEWAY program conducted a two-phase demonstration of LED roadway lighting on the main span, which is one of the country's oldest continuously operated exterior LED lighting installations. The Phase II report documents longer-term performance of the LED lighting system that was installed in 2008, and is the first report on the longer-term performance of LED lighting in the field.

  13. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    Directory of Open Access Journals (Sweden)

    George Hess

    Full Text Available Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  14. Rural Health Information Hub

    Science.gov (United States)

    ... issues that impact rural health in RHIhub’s Topic Guides. Recently updated: Social Determinants of Health for Rural People Browse all 50+ topics Community Health Gateway Find rural project examples in Rural Health Models and Innovations and proven strategies for strong rural programs with ...

  15. A Study on the Fracture Control of Rock Bolts in High Ground Pressure Roadways of Deep Mines

    Directory of Open Access Journals (Sweden)

    Wen Jinglin

    2015-01-01

    Full Text Available According to the frequent fractures of rock bolts in high ground pressure roadways of deep mines, this paper analyzes the mechanism of fractures and concludes that high ground pressure and material de-fects are main reasons for the fracture of rock bolts. The basic idea of fracture control of rock bolts in high ground pressure roadways of deep mines is to increase the yield load and the limit load of rock bolt materials and reduce the actual load of rock bolts. There are four ways of controlling rock bolt fracture: increasing the rock bolt diameter, strengthening bolt materials, weakening support rigidity and the implementation of double supporting. With the roadway support of the 2302 working face of a coal mine as the project background, this paper carries out a study on the effect of two schemes, increasing the rock bolt diameter and the double supporting technique through methods of theoretical analysis, numerical simulation and so on. It determines the most reasonable diam-eter of rock bolts and the best delay distance of secondary support. Practices indicate that rock bolt fracture can be effectively controlled through the double supporting technique, which strengthens the roof and two sides through the first supporting technique and strengthens side angles through the secondary supporting technique.

  16. An experimental study of a yielding support for roadways constructed in deep broken soft rock under high stress

    Institute of Scientific and Technical Information of China (English)

    Lu Yinlong; Wang Lianguo; Zhang Bei

    2011-01-01

    A rationally designed support for deep roadways excavated in broken soft rock under high stress was investigated.The deformation and failure characteristics and the mechanism of “yielding support” was studied for anchor bolts and cables.The rail roadway of the 2-501 working face in the Liyazhuang Mine of the Huozhou coal area located in Shanxi province was used for field trials.The geological conditions used there were used during the design phase.The new “highly resistant,yielding” support system has a core of high strength,yielding bolts and anchor cables.The field tests show that this support system adapts well to the deformation and pressure in the deep broken soft rock.The support system effectively controls damage to the roadway and ensures the long term stability of the wall rock and safe production in the coal mine.This provides a remarkable economic and social benefit and has broad prospects for further application.

  17. Dissipation of Impact Stress Waves within the Artificial Blasting Damage Zone in the Surrounding Rocks of Deep Roadway

    Directory of Open Access Journals (Sweden)

    Jianguo Ning

    2016-01-01

    Full Text Available Artificial explosions are commonly used to prevent rockburst in deep roadways. However, the dissipation of the impact stress wave within the artificial blasting damage zone (ABDZ of the rocks surrounding a deep roadway has not yet been clarified. The surrounding rocks were divided into the elastic zone, blasting damage zone, plastic zone, and anchorage zone in this research. Meanwhile, the ABDZ was divided into the pulverizing area, fractured area, and cracked area from the inside out. Besides, the model of the normal incidence of the impact stress waves in the ABDZ was established; the attenuation coefficient of the amplitude of the impact stress waves was obtained after it passed through the intact rock mass, and ABDZ, to the anchorage zone. In addition, a numerical simulation was used to study the dynamic response of the vertical stress and impact-induced vibration energy in the surrounding rocks. By doing so, the dissipation of the impact stress waves within the ABDZ of the surrounding rocks was revealed. As demonstrated in the field application, the establishment of the ABDZ in the surrounding rocks reduced the effect of the impact-induced vibration energy on the anchorage support system of the roadway.

  18. Sizing Dynamic Wireless Charging for Light-Duty Electric Vehicles in Roadway Applications

    Energy Technology Data Exchange (ETDEWEB)

    Foote, Andrew P [ORNL; Ozpineci, Burak [ORNL; Chinthavali, Madhu Sudhan [ORNL; Li, Jan-Mou [ORNL

    2016-01-01

    Dynamic wireless charging is a possible cure for the range limitations seen in electric vehicles (EVs) once implemented in highways or city streets. The contribution of this paper is the use of experimental data to show that the expected energy gain from a dynamic wireless power transfer (WPT) system is largely a function of average speed, which allows the power level and number of coils per mile of a dynamic WPT system to be sized for the sustained operation of an EV. First, data from dynamometer testing is used to determine the instantaneous energy requirements of a light-duty EV. Then, experimental data is applied to determine the theoretical energy gained by passing over a coil as a function of velocity and power level. Related simulations are performed to explore possible methods of placing WPT coils within roadways with comparisons to the constant velocity case. Analyses with these cases demonstrate what system ratings are needed to meet the energy requirements of the EV. The simulations are also used to determine onboard energy storage requirements for each driving cycle.

  19. Driver behavior in use of guide and logo signs under distraction and complex roadway conditions.

    Science.gov (United States)

    Kaber, David; Pankok, Carl; Corbett, Brendan; Ma, Wenqi; Hummer, Joseph; Rasdorf, William

    2015-03-01

    White-on-blue logo signs on the sides of highways are typically used to notify drivers of food, gas, and lodging at an upcoming interchange. The current research assessed driver performance and attention allocation in a simulated freeway driving task when exposed to six-panel logo signs, nine-panel logo signs, mileage guide signs, and roadway work zones both with and without an in-car navigation device. The objective was to identify the impact of signage types on driver behavior under realistic driving conditions. Results revealed glance durations and fixation frequencies to guide signs to be significantly lower than with six-panel and nine-panel logo signs, but no differences were found between six-panel and nine-panel logo signs. There were also statistical differences among the independent variables for speed deviation and lane deviation, but magnitudes were not large enough to be considered practically significant in terms of driving safety. Overall, there were minor differences in sign processing time between logo signs and mileage guide signs, but such differences did not translate to degradations in vehicle control.

  20. Numerical Simulation of Polarity Characteristics of Vector Elastic Wave of Advanced Detection in the Roadway

    Directory of Open Access Journals (Sweden)

    Deng Shuaiqi

    2013-05-01

    Full Text Available The high-order staggering grid Finite-Difference (FD scheme based on first-order velocity-stress elastic wave equation has been deduced. The calculation method of PML boundary condition and stability condition established in this study can be used for numerical simulation of advanced detection of elastic wave in roadway, with the obtaining of high-precision seismogram. Then we systematically analyze the polarity of vector wave field in post-source observation system. The results indicate that the relationship between the vector wave field and the polarity of direct wave is related to reflection coefficient on the interface, while the polarity relationship between horizontal and vertical components of vector wave field is related to vertical position of the interface. During data processing for advanced detection of elastic waves, the sign of the reflection coefficient on the interface ahead can be determined based on the polarity relationship between reflected wave and direct wave from the seismograms; the soft and hard rock and other geological information on both sides of the interface is thus be determined. In addition, the direction of source wave depends on polarity relationship between horizontal and vertical components of reflected wave and is used to achieve the separation of up going and down going waves.

  1. Numerical Simulation of Methane Distribution and Sensor Placement in 2-Dimension Roadway

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-ping; TANG Liang; CHEN Wei; WANG Fu-zeng

    2007-01-01

    In order to provide a theoretical basis for methane sensor placement in the vertical direction of a tunnel, the software Fluent was used to simulate methane distribution. A geometric roadway model was established and divided by grids. Methane distribution in both level and vertical sections was simulated using a realizable k-ε model with the Fluent software according to a conservation equation in a turbulent state, a turbulent kinetic energy equation and a turbulent dissipation rate equation. The realizable k-ε model and the Fluent software were used to simulate methane distribution according to the principle of the conservation equation in a state of turbulent flow. The results show that after overflowing, a methane level with a certain thickness is formed. Methane density curves at three specific levels were internally consistent and methane density at higher levels is denser than that at lower levels. Methane distribution becomes thinner in the direction of wind and methane in the vertical direction becomes uniform if wind speed is high. The distance between sensors and roof should be less than 300 mm which is in agreement with mine safety regulations.

  2. Implementation Scenarios for Electric Vehicle Roadway Wireless Power Transfer; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Meintz, A.; Markel, T.; Burton, E.; Wang, L.; Gonder, J.; Brooker, A.

    2015-06-05

    Analysis has been performed on the Transportation Secure Data Center (TSDC) warehouse of collected GPS second-by-second driving profile data of vehicles in the Atlanta, Chicago, Fresno, Kansas City, Los Angeles, Sacramento, and San Francisco Consolidated Statistical Areas (CSAs) to understand in-motion wireless power transfer introduction scenarios. In this work it has been shown that electrification of 1% of road miles could reduce fuel use by 25% for Hybrid Electric Vehicles (HEVs) in these CSAs. This analysis of strategically located infrastructure offers a promising approach to reduced fuel consumption; however, even the most promising 1% of road miles determined by these seven analysis scenarios still represent an impressive 2,700 miles of roadway to electrify. Therefore to mitigate the infrastructure capital costs, integration of the grid-tied power electronics in the Wireless Power Transfer (WPT) system at the DC-link to photovoltaic and/or battery storage is suggested. The integration of these resources would allow for the hardware to provide additional revenue through grid services at times of low traffic volumes and conversely at time of high traffic volumes these resources could reduce the peak demand that the WPT system would otherwise add to the grid.

  3. Automated bolting and meshing on a continuous miner for roadway development

    Institute of Scientific and Technical Information of China (English)

    van Duin Stephen; Meers Luke; Donnelly Peter; Oxley Ian

    2013-01-01

    Automated installation of primary roof support material can potentially increase productivity and operator safety in the roadway development process within underground coal mining.Although the broader manufacturing sector has benefited from automation,several challenges exist within the Australian underground coal industry which makes it difficult to fully exploit these technologies.At the University of Wollongong a series of reprogrammable electromechanical manipulators have been designed to overcome these challenges and automatically handle the installation of roof and rib containment consumables on a continuous miner.The automated manipulation removes personnel from hazards in the immediate face area,particularly those associated with working in a confined and unstable working environment in close proximity to rotating and moving equipment.In a series of above ground trials the automated system was successfully demonstrated without human intervention and proven to be capable of achieving cycle times at a rate of 10 m per operating hour,consistent with that required to support high capacity longwall mines.The trials also identified a number of refinements which could further improve both cycle times and system reliability when considering the technology for underground use.The results have concluded that conventional manual handling practices on a continuous miner can be eliminated,and that the prototypes have significantly reduced the technical risk in proceeding to a full underground trial.

  4. Effect of Weight and Roadway Grade on the Fuel Economy of Class-8 Frieght Trucks

    Energy Technology Data Exchange (ETDEWEB)

    Franzese, Oscar [ORNL; Davidson, Diane [ORNL

    2011-11-01

    In 2006-08, the Oak Ridge National Laboratory, in collaboration with several industry partners, collected real-world performance and situational data for long-haul operations of Class-8 trucks from a fleet engaged in normal freight operations. Such data and information are useful to support Class-8 modeling of combination truck performance, technology evaluation efforts for energy efficiency, and to provide a means of accounting for real-world driving performance within combination truck research and analyses. The present study used the real-world information collected in that project to analyze the effects that vehicle speed and vehicle weight have on the fuel efficiency of Class-8 trucks. The analysis focused on two type of terrains, flat (roadway grades ranging from -1% to 1%) and mild uphill terrains (roadway grades ranging from 1% to 3%), which together covered more than 70% of the miles logged in the 2006-08 project (note: almost 2/3 of the distance traveled on mild uphill terrains was on terrains with 1% to 2% grades). In the flat-terrain case, the results of the study showed that for light and medium loads, fuel efficiency decreases considerably as speed increases. For medium-heavy and heavy loads (total vehicle weight larger than 65,000 lb), fuel efficiency tends to increase as the vehicle speed increases from 55 mph up to about 58-60 mph. For speeds higher than 60 mph, fuel efficiency decreases at an almost constant rate with increasing speed. At any given speed, fuel efficiency decreases and vehicle weight increases, although the relationship between fuel efficiency and vehicle weight is not linear, especially for vehicle weights above 65,000 lb. The analysis of the information collected while the vehicles were traveling on mild upslope terrains showed that the fuel efficiency of Class-8 trucks decreases abruptly with vehicle weight ranging from light loads up to medium-heavy loads. After that, increases in the vehicle weight only decrease fuel

  5. Effect of Stresses and Strains of Roadway Surrounding Rocks on Borehole Airtightness

    Directory of Open Access Journals (Sweden)

    WU Wei

    2016-02-01

    Full Text Available At present, many high gas and outburst mines have poor gas drainage effects. An important reason influencing the gas drainage effect is a poor hole-sealing effect. Most studies on gas drainage borehole sealing focus on local and foreign borehole sealing methods, borehole sealing equipment, and borehole sealing materials. Numerical simulations of initial drilling sealing depth are insufficient because studies on this subject are few. However, when the initial sealing depth of the borehole is not chosen reasonably, air can enter the gas drainage drill hole through the circumferential crack of roadway surrounding rocks under the influence of suction pressure of the drainage system. This phenomenon ultimately affects the hole-sealing effect. To improve the drilling hole sealing of gas drainage boring, we deduced the expression formulas of the crushing zone, plastic zone, and elastic zone around the coal-seam floor stone drift and conducted a stress–strain analysis of the coal-seam floor stone drift of the 2145 working surfaces of the Sixth Coal Mine of Hebi Coal Mine Group Company by using theoretical analysis, numerical simulation, and on-scene verification. Finally, we obtain the initial drilling sealing depth, which is a main contribution of this study. The results prove the following. The performed hole-sealing process with an initial drilling sealing depth of 8 m has a gas drainage efficiency of 55%. Compared with the previous 6.8 m initial drilling sealing depth with a gas drainage efficiency of less than 30%, which was adopted by the mine, the initial sealing depth of 8 m chosen in the numerical simulation is reasonable and conforms to the actual situation on the spot. Therefore, the initial drilling sealing depth chosen in the numerical simulation will produce practical and effective guidance to study the field hole-sealing depth.

  6. THE PERSISTENCE OF TRACHYTE-TRACHYANDESITE BUILT INTO PEDESTRIAN-ROADWAY CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Ivan Tomašić

    2000-12-01

    Full Text Available Natural stone defined as trachyte-trachyandesite from the locality Colli Euganei near Padua in Italy is built into roadway-pedestrian construction of the Tkalčićcva street in Zagreb. Stone samples were subjected before in-building, to determinations of physical and mecha¬nical properties (density, bulk density, water absorption, porosity, compressive strength, resistance to abrasion, flexural strength, frost resistance and to Na2SO4, velocity of ultrasonic propagation, micros¬copic and X ray analyses and to photographing by electronic micros¬cope. It was found that about 30% in-built stones do not suit to existing criteria on the quality of natural stone. Water absorption and porosity are increased, compressive strength in the water saturated condition is very decreased, the stone is not enough resistant to wear-out and to Na2S04, it is anisotropic and contains swelling clays of the smectite group and numerous defects especially in form of microblocks as consequences of postdiagenetic processes. Although the samples belong to the same rock type, the differences among stone elements are great. Macroscopically materia! is very heterogeneous. In less qualitative stone samples there are more or less numerous sub-parallel brown and gray partings of the thickness approximately 1 -2 mm with enlarged share of secondary iron minerals. Iron oxides and hydroxides mainly impregnate the rock parts, spotty or stripy; somewhere the complete sample is impregnated intensively. The impregnation is intensified by swelling clays and numerous holes along which stone is crumbling (the paper is published in Croatian.

  7. Increasing the efficiency of roadway drivages through the application of advanced information, automation and maintenance technologies

    Energy Technology Data Exchange (ETDEWEB)

    A. Rodriguez; M. Schmid; T. Winkler (and others) [Asociacion para la Investigacion y el Desarrollo Industrial de los Recursos Naturales, Leganes (Spain)

    2009-07-01

    The main goal of the IAMTECH project was increasing the efficiency of road-heading by applying advanced information, automation and maintenance technologies. Some of its results will allow for increasing the availability of the machinery through the decrease of both programmed maintenance time and medium time to repair. Other results are related to the adoption of new types (in coal mining) of support considered promising from a productivity increase perspective, such as concrete spraying. Research topics addressed in the project could be classified roughly in two groups: horizontal (underlying common technologies) and vertical (related to the actual implementation of devices, software and systems). Among the results for horizontal activities, those that deserve special mention are the development of an Atex 3D laser scanner, Atex WLAN (WiFi) access points, cameras and PDA, as well as methods for storing and representing in 3D machinery components, subassemblies and complete machines. Amid results of vertical activities is the implementation of a central maintenance control mining machinery is concentrated. Engineers in charge of CMCR have online access to all machinery-related information, including direct access to manufacturers' databases. Images, voice and data flowing from the underground, and diagrams and advice flowing from the surface are transmitted and displayed using the technologies developed during horizontal activities. Other important results are the development of methods for assessing the quality of execution of roadway support when using sprayed concrete for this purpose, also using technologies (such as laser scanning) developed within the horizontal activities. 10 refs., 162 figs., 7 tabs.

  8. An analysis of continuous black carbon concentrations in proximity to an airport and major roadways

    Science.gov (United States)

    Dodson, Robin E.; Andres Houseman, E.; Morin, Barbara; Levy, Jonathan I.

    Black carbon (BC), a constituent of particulate matter, is emitted from multiple combustion sources, complicating determination of contributions from individual sources or source categories from monitoring data. In close proximity to an airport, this may include aircraft emissions, other emissions on the airport grounds, and nearby major roadways, and it would be valuable to determine the factors most strongly related to measured BC concentrations. In this study, continuous BC concentrations were measured at five monitoring sites in proximity to a small regional airport in Warwick, Rhode Island from July 2005 to August 2006. Regression was used to model the relative contributions of aircraft and related sources, using real-time flight activity (departures and arrivals) and meteorological data, including mixing height, wind speed and direction. The latter two were included as a nonparametric smooth spatial term using thin-plate splines applied to wind velocity vectors and fit in a linear mixed model framework. Standard errors were computed using a moving-block bootstrap to account for temporal autocorrelation. Results suggest significant positive associations between hourly departures and arrivals at the airport and BC concentrations within the community, with departures having a more substantial impact. Generalized Additive Models for wind speed and direction were consistent with significant contributions from the airport, major highway, and multiple local roads. Additionally, inverse mixing height, temperature, precipitation, and at one location relative humidity, were associated with BC concentrations. Median contribution estimates indicate that aircraft departures and arrivals (and other sources coincident in space and time) contribute to approximately 24-28% of the BC concentrations at the monitoring sites in the community. Our analysis demonstrated that a regression-based approach with detailed meteorological and source characterization can provide insights

  9. Using Quasi-Horizontal Alignment in the absence of the actual alignment.

    Science.gov (United States)

    Banihashemi, Mohamadreza

    2016-10-01

    Horizontal alignment is a major roadway characteristic used in safety and operational evaluations of many facility types. The Highway Safety Manual (HSM) uses this characteristic in crash prediction models for rural two-lane highways, freeway segments, and freeway ramps/C-D roads. Traffic simulation models use this characteristic in their processes on almost all types of facilities. However, a good portion of roadway databases do not include horizontal alignment data; instead, many contain point coordinate data along the roadways. SHRP 2 Roadway Information Database (RID) is a good example of this type of data. Only about 5% of this geodatabase contains alignment information and for the rest, point data can easily be produced. Even though the point data can be used to extract actual horizontal alignment data but, extracting horizontal alignment is a cumbersome and costly process, especially for a database of miles and miles of highways. This research introduces a so called "Quasi-Horizontal Alignment" that can be produced easily and automatically from point coordinate data and can be used in the safety and operational evaluations of highways. SHRP 2 RID for rural two-lane highways in Washington State is used in this study. This paper presents a process through which Quasi-Horizontal Alignments are produced from point coordinates along highways by using spreadsheet software such as MS EXCEL. It is shown that the safety and operational evaluations of the highways with Quasi-Horizontal Alignments are almost identical to the ones with the actual alignments. In the absence of actual alignment the Quasi-Horizontal Alignment can easily be produced from any type of databases that contain highway coordinates such geodatabases and digital maps.

  10. The Rural Development Dilemma.

    Science.gov (United States)

    Swanson, Louis E.

    1991-01-01

    Progress toward rural development has been hampered by flawed views of rural America; serious limitations to existing social and economic data on sparsely populated areas; treatment of rural America as a geographical entity unconnected to the larger U.S. economy and society; perceived lack of feasible political solution to rural problems; and…

  11. Rural-Urban Connections.

    Science.gov (United States)

    Perkins, Daniel F.; LaGreca, Anthony J.; Mullis, Ronald L.

    This publication combines three papers on rural and urban youth issues. "Key Issues Facing Rural Youth" (Daniel F. Perkins) notes that rural adolescents share the same concerns and exhibit the same problem behaviors as their urban counterparts. But in addition, geographic isolation presents problems unique to rural areas. A framework is proposed…

  12. Extended visual glances away from the roadway are associated with ADHD- and texting-related driving performance deficits in adolescents

    OpenAIRE

    Kingery, Kathleen M.; Narad, Megan; Garner, Annie A.; Antonini, Tanya N.; Tamm, Leanne; Epstein, Jeffery N.

    2015-01-01

    The purpose of the research study was to determine whether ADHD- and texting-related driving impairments are mediated by extended visual glances away from the roadway. Sixty-one adolescents (ADHD = 28, non-ADHD = 33; 62% male; 11% minority) aged 16–17 with a valid driver’s license were videotaped while engaging in a driving simulation that included a No Distraction, Hands-Free Phone Conversation, and Texting condition. Two indicators of visual inattention were coded: 1) percentage of time wit...

  13. Micro-deformation measurement on the concrete roadway surface slabs using Fiber Bragg Grating and analysis by computational simulation

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, C M; Gomez, N D [Instituto Tecnologico Metropolitano Institucion Universitaria (ITM), Medellin A. A. 54954 (Colombia); Velez, F J, E-mail: claudiaserpa@itm.edu.co [Universidad EAFIT, Medellin (Colombia)

    2011-01-01

    This work shows a non-invasive method for micro-deformation measurements on concrete structures using Bragg grating sensors in optical fibers adhered to the surface. We present the measurements on roadway slabs under a load of 10 kN, and we find an approximated ratio of 2:1 between the deformation registered by the sensors and the values from a computational simulation with the finite element method. We propose the use of these sensors for structural monitoring of the slabs and this installation shape for avoiding bends that can damage the edges in the optical fiber in embebed sensors in vertical shape.

  14. Study on the law of methane seepage in the wall of drainage roadway in mining seam-group

    Institute of Scientific and Technical Information of China (English)

    LIU Jian; LUO Yong; LIU Ze-gong; SHI Bi-ming

    2005-01-01

    Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded.By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to related research, it provides preventing coal and gas outbursts with theoretical gist.

  15. 泥化巷道底板控制技术研究%Floor Controlling Technology of Argillization Roadway

    Institute of Scientific and Technical Information of China (English)

    阚甲广; 张农; 李桂臣; 梁国栋; 陈亮; 司光耀

    2011-01-01

    为了有效控制泥化巷道底鼓,本文结合淮南矿区潘一东矿工程地质条件,在典型岩样组分测试的基础上,数值模拟研究了巷道开挖过程中底板应力分布和破坏情况,研究结果表明,样品矿物组成主体为高岭石、石英,有部分伊蒙混层和少量的蒙皂石、长石、方解石等矿物;得到了同等应力条件下巷道开挖过程中围岩塑性区的分布特征,指出存在低效加固区,得到了泥化巷道底板合理加固深度;提出了底板锚注一体化加固技术,并在潘一东矿得到应用,底板变形、离层及钻孔探测结果表明,底板锚注一体化技术有效的控制了巷道底板变形,消除因巷道底板变形严重导致的围岩结构变形失稳.%In order to control floor heaving of argillization roadway efficiently, a numerical simulation study was applied to analyze the stress distribution and failure situation of the floor during roadway excavation in this paper, based on the engineering geological conditions and experimental tests of rock sample components in Panyidong coal mine, Huainan Mining Group, The results showed that the main mineral compositions of samples are kaolinite and quartz, and also with partly illite-montmorillonite mixed layer and slightly smectite, feldspar, calcite etc. We concluded the distribution characteristics of plastic zone in surrounding rock under the same stress condition during roadway excavation, proposed the inefficient reinforcement area and obtained reasonable reinforcing depth of the floor in argillization roadway. Meanwhile, an integrated technology of floor bolting and grouting was introduced and applied successfully in Panyidong coal mine. Floor deformation, layer separation and borehole monitoring results show that the integrated technology of floor bolting and grouting can efficiently control floor heaving and eliminate deformation instability of surrounding rock structure caused by serious floor deformation.

  16. Using rockbolting in constructing a double entry roadway system arranged skin to skin with a coal pillar; Einsatz der Ankertechnik bei der Auffahrung einer Abbaubegleitstrecke neben einer Kohlenfeste

    Energy Technology Data Exchange (ETDEWEB)

    Woll, T.; Polysos, N.; Luettig, F. [Deutsche Steinkohle AG (Germany)

    2004-07-01

    The common procedure of mining at Saar mine is the extraction of two panels for the same time. The faces are following close to each other in the mid roadway. It is neccessary to develop about 10 km of roadways for one double-panel system. In the Schwalbach seam it was planned due to geological and operational requirements to develop a double entry roadway system arranged skin to skin with a 3 m coal pillar between the panels. The leading face uses the mainway in retreat and at the same time the tailgate for the next panel is developed using a combined support system with backfilled steel arches and rockbolts. The geotechnical planning, the support design and the development technique are described in this report.

  17. Stability principle of big and small structures of rock surrounding roadway driven along goaf in fully mechanized top coal caving face

    Energy Technology Data Exchange (ETDEWEB)

    Hou, C.; Li, X. [China University of Mining and Technology, Xuzhou (China)

    2001-02-01

    Based on the characteristics of the surrounding rock of roadway driven along the goaf in a fully mechanised top coal caving face, the stability principle of big and small structures is put forward, which provides the theoretical basis to the application of bolting. The mechanical characteristics of the arc-triangle key block in the main roof and the stability of the roadway during drivage and extraction and the effect on the roadway driven along the next goaf are analysed. The main factors which affect the stability of the small structure of the surrounding rock are discussed. The bolting surrounding strength reinforcement theory is applied to study the important significance of improving the pre-tension of bolting and the support strength. 4 refs., 7 figs., 2 tabs.

  18. Characterizing and predicting coarse and fine particulates in classrooms located close to an urban roadway.

    Science.gov (United States)

    Chithra, V S; Nagendra, S M Shiva

    2014-08-01

    The PM10, PM2.5, and PM1 (particulate matter with aerodynamic diameters Chennai City. The 24-hr average PM10, PM2.5, and PM1 concentrations at indoor and outdoor environments were found to be 136 +/- 60, 36 +/- 15, and 20 +/- 12 and 76 +/- 42, 33 +/- 16, and 23 +/- 14 microg/m3, respectively. The size distribution of PM in the classroom indicated that coarse mode was dominant during working hours (08:00 a.m. to 04:00 p.m.), whereas fine mode was dominant during nonworking hours (04:00 p.m. to 08:00 a.m.). The increase in coarser particles coincided with occupant activities in the classrooms and finer particles were correlated with outdoor traffic. Analysis of indoor PM10, PM2.5, and PM1 concentrations monitored at another school, which is located at urban reserved forest area (background site) indicated 3-4 times lower PM10 concentration than the school located at roadside. Also, the indoor PM1 and PM2.5 concentrations were 1.3-1.5 times lower at background site. Further, a mass balance indoor air quality (IAQ) model was modified to predict the indoor PM concentration in the classroom. Results indicated good agreement between the predicted and measured indoor PM2.5 (R2 = 0.72-0.81) and PM1 (R2 = 0.81-0.87) concentrations. But, the measured and predicted PM10 concentrations showed poor correlation (R2 = 0.17-0.23), which may be because the IAQ model could not take into account the sudden increase in PM10 concentration (resuspension of large size particles) due to human activities. Implications: The present study discusses characteristics of the indoor coarse and fine PM concentrations of a naturally ventilated school building located close to an urban roadway and at a background site in Chennai City, India. The study results will be useful to engineers and policymakers to prepare strategies for improving the IAQ inside classrooms. Further, this study may help in the development of IAQ standards and guidelines in India.

  19. Demonstration Assessment of LED Roadway Lighting: NE Cully Boulevard Portland, OR

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P.; Poplawski, Michael E.; Tuenge, Jason R.

    2012-06-29

    A new roadway lighting demonstration project was initiated in late 2010, which was planned in conjunction with other upgrades to NE Cully Boulevard, a residential collector road in the northeast area of Portland, OR. With the NE Cully Boulevard project, the Portland Bureau of Transportation hoped to demonstrate different light source technologies and different luminaires side-by-side. This report documents the initial performance of six different newly installed luminaires, including three LED products, one induction product, one ceramic metal halide product, and one high-pressure sodium (HPS) product that represented the baseline solution. It includes reported, calculated, and measured performance; evaluates the economic feasibility of each of the alternative luminaires; and documents user feedback collected from a group of local Illuminating Engineering Society (IES) members that toured the site. This report does not contain any long-term performance evaluations or laboratory measurements of luminaire performance. Although not all of the installed products performed equally, the alternative luminaires generally offered higher efficacy, more appropriate luminous intensity distributions, and favorable color quality when compared to the baseline HPS luminaire. However, some products did not provide sufficient illumination to all areas—vehicular drive lanes, bicycle lanes, and sidewalks—or would likely fail to meet design criteria over the life of the installation due to expected depreciation in lumen output. While the overall performance of the alternative luminaires was generally better than the baseline HPS luminaire, cost remains a significant barrier to widespread adoption. Based on the cost of the small quantity of luminaires purchased for this demonstration, the shortest calculated payback period for one of the alternative luminaire types was 17.3 years. The luminaire prices were notably higher than typical prices for currently available luminaires

  20. Residential Proximity to Major Roadways Is Not Associated with Cardiac Function in African Americans: Results from the Jackson Heart Study

    Directory of Open Access Journals (Sweden)

    Anne M. Weaver

    2016-06-01

    Full Text Available Cardiovascular disease (CVD, including heart failure, is a major cause of morbidity and mortality, particularly among African Americans. Exposure to ambient air pollution, such as that produced by vehicular traffic, is believed to be associated with heart failure, possibly by impairing cardiac function. We evaluated the cross-sectional association between residential proximity to major roads, a marker of long-term exposure to traffic-related pollution, and echocardiographic indicators of left and pulmonary vascular function in African Americans enrolled in the Jackson Heart Study (JHS: left ventricular ejection fraction, E-wave velocity, isovolumic relaxation time, left atrial diameter index, and pulmonary artery systolic pressure. We examined these associations using multivariable linear or logistic regression, adjusting for potential confounders. Of 4866 participants at study enrollment, 106 lived <150 m, 159 lived 150–299 m, 1161 lived 300–999 m, and 3440 lived ≥1000 m from a major roadway. We did not observe any associations between residential distance to major roads and these markers of cardiac function. Results were similar with additional adjustment for diabetes and hypertension, when considering varying definitions of major roadways, or when limiting analyses to those free from cardiovascular disease at baseline. Overall, we observed little evidence that residential proximity to major roads was associated with cardiac function among African Americans.

  1. Heat transfer process of roadway embankments with different type and width of road surface in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    YU Qihao; PAN Xicai; CHENG Guodong; BAI Yang

    2007-01-01

    The stability of roadbed in permafrost areas has become a big concern with rapid development and construction of throughways, highways and railways in these areas under the current climate change since it is governed by the thermal condition, or in other words, the heat transfer process in the embankment. We carried out a finite element analysis to analyze the effects of different types of road surface and the effect of breadth of embankment on the embankment heat transfer process. The results indicated that the mean annual heat transfer rate at the bottom of the roadway embankment with asphalt surfaces is 3 times that with sandy gravel surfaces. This means annual heat transfer rate increased by 60 % when the breadth of asphalt surface was doubled. The increased heat transfer rate was mainly located at the bottom of the embankment and resulted in the effect of thermal concentration, leading to degradation of the permafrost by as much as 1.6 times. It was also found that increasing embankment height would not reduce these increases of the heat transfer rate. Therefore both asphalt road surface and increased embankment breadth can lead to an intensified heat transfer rate in roadway embankment, consequently degradating the underlying permafrost and embankment instability.

  2. Rural Entrepreneurship or Entrepreneurship in the Rural

    DEFF Research Database (Denmark)

    Korsgaard, Steffen; Müller, Sabine; Tanvig, Hanne Wittorff

    2015-01-01

    ” and “space” from human geography are applied to develop a nuanced understanding of rural entrepreneurship as a spatial phenomenon. Space consists of processes of movement and mobility, while places consist of localized material, social and economic relations. Findings: Two ideal types are developed, namely......Purpose: This article investigates how rural entrepreneurship engages with place and space. It explores the concept of “rural” in rural enterprise, and illustrates the importance of distinguishing between types of rural entrepreneurship. Design/methodology/approach: The constructs of “place...... (i) entrepreneurship in the rural and (ii) rural entrepreneurship. The former represents entrepreneurial activities that have limited embeddedness and enact a profit-oriented and mobile logic of space. The latter represents entrepreneurial activities that leverage local resources to re-connect place...

  3. Office of Rural Health Policy

    Science.gov (United States)

    ... Information Hub Rural Health Research Gateway Rural Community Health Gateway White House Rural Council  Eligibility Analyzer Contact Us Subscribe to FORHP weekly announcement for rural health grantees and stakeholders by e-mail Subscribe to ...

  4. Rural Logistics System Based on Rural Informatization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Current status of rural informatization construction in China,including the relatively weak rural informatization,asymmetric market information,low level of information sharing,dispersedly allocated resources and no cross point among each other are analyzed.The importance of informatization in rural logistic system is introduced:firstly,decision making of logistics system plan is based on information.Secondly,improvement of the overall efficiency of logistics system is based on information.Thirdly,logistics transmission takes the Internet as the carrier.Necessity of rural logistics system is discussed from five aspects of increasing the employment of farmers,enhancing the income of farmers,reducing the blindness of agricultural production and circulation,sharing the risks of agricultural management,and promoting the rural economic restructuring.According to the above five steps,five countermeasures are posed in order to improve the rural logistics system.The countermeasures cover the aspects of deepening the information awareness of government,establishing a rural informatization system suited to the national condition of China,strengthening the information infrastructure in rural areas,promoting the integration of rural information resources and establishing the training system for agricultural information talents.

  5. Optimizing Work Zones for Two-Lane Urban Road Maintenance Projects

    Institute of Scientific and Technical Information of China (English)

    HUANG Qian; SHI Jing

    2008-01-01

    Road maintenance work brings costs to the govemment and delays to users.The setting up of work zones often leads to severe congestion during peak hours,especially in busy urban areas.A road maintenance delay model is presented here that includes consideration of excessive traffic flow and non-motorists.A trial-and-error method is used to find the optimal work zone length and the best work starting time to minimize the total cost of maintenance and delays.A numerical example with a sensitivity analysis is also given.The results show that optimal starting time is not sensitive to the flow speed and the increase of work zone speeds sharply reduces the total cost when the road is congested.

  6. Analysis of Traffic Capacity on Mountainous Two Lane Highway Adding Climbing Lane

    Directory of Open Access Journals (Sweden)

    Meng Yunwei

    2016-01-01

    Full Text Available During the construction of mountainous double lane highway, climbing lane plays a certain role for enhancing the traffic capacity. In order to explore traffic capacity improvement effect for different conditions of climbing lane, 20 representative models are chosen, which contain various combinations of alignment and traffic parameters. The changes of traffic capacity, average speed, delays, and saturation in models are obtained before and after the use of a climbing lane by means of numerical simulation. The results show that the use of a climbing lane could improve traffic capacity, average speed, while reducing delays and saturation. The improvement effect is different according to different combinations of alignment and traffic parameters. The research could provide a reference for mountainous climbing lane construction intend.

  7. National Rural Health Association

    Science.gov (United States)

    ... History of Rural Health Globalization Urban Bias Dependency Theory Political Economy History of Rural Health IV: '60s ... Data Grassroots Action Center Policy Documents Legislative and Regulatory Agenda Medicaid News Response to 2013 OIG CAH ...

  8. Rural Health Disparities

    Science.gov (United States)

    ... and International Patterns , the authors found that rural American Indian and Alaska Native (AI/AN) youth have a higher mortality rate than their urban counterparts. Additionally, the rate of substance abuse admissions was higher for rural AI/AN ...

  9. Association of Roadway Proximity with Fasting Plasma Glucose and Metabolic Risk Factors for Cardiovascular Disease in a Cross-Sectional Study of Cardiac Catheterization Patients

    Science.gov (United States)

    Background: The relationship between traffic-related air pollution (TRAP) and risk factors for cardiovascular disease needs to be better understood in order to address the adverse impact o.f air pollution on human health.Objective: We examined associations between roadway proximi...

  10. Stress Evolution in Roadway Rock Bolts During Mining in a Fully Mechanized Longwall Face, and an Evaluation of Rock Bolt Support Design

    Science.gov (United States)

    Zhang, Kai; Zhang, Guimin; Hou, Rongbin; Wu, Yu; Zhou, Hongqi

    2015-01-01

    Rock bolts are widely used in coal mines throughout China. Approximately 8,000 km of roadways are excavated in coal mines every year in China, 80 % of which are supported by rock bolts. At present, the design of rock bolt support schemes is mainly based on analogies and experience from previous projects. In the present study, in order to evaluate the design of rock bolt support in roadways, several cross sections of a roadway were monitored for rock bolt stress during the roadway excavation and mining. The study results show that the stress in the rock bolts varied in the areas 20 m behind the excavating face and 30 m ahead of the mining face. For the rock bolts observed in this study, the max axial force was within the design limit of the bolts, thus the support design was shown to be acceptable. Then, numerical simulation was performed using FLAC3D to investigate the stress evolution in the rock bolts during the mining of the fully mechanized longwall face. The simulation results show an overall agreement with the in situ measurements. Finally, parametric study pertaining to length, anchorage length, and rock bolt spacing was carried out with the numerical model, and several suggestions for the support design were proposed.

  11. 深部矿井准备巷道联合布置设计优化%Design optimization of combined arrangement for deep mine roadway

    Institute of Scientific and Technical Information of China (English)

    房博; 王明; 宁廷洲

    2016-01-01

    华丰煤矿深部准备巷道均为全岩掘进,开拓准备时间长,掘进成本较高。通过将大断面扩修过的水平大巷采用机轨合一联合布置,取消胶带运输巷及转载煤仓,实现运料、运煤集中化,达到了简化准备工程,缓解采掘接续,降低万吨掘进率的目的。%The deep preparation roadway in HuaFeng coal mine, is excavated in the whole rock , which has a long preparation time and high cost. The expansion of completed the expanded level roadway with large section was used as the comprchensive transportation roadway, which cancel the convoy transportation roadway, implement the transport material, coal concentration, simplify the preparation of engineering, ease the mining continuing, and reduce million-ton drivage rate.

  12. 复采煤层巷道支护技术与应用%Re-mining roadway supporting technology and Application

    Institute of Scientific and Technical Information of China (English)

    刘胜利; 王晋正; 黄亚寅

    2016-01-01

    This paper by understanding the typical re-mining coal seam geological and production conditions , the mining roadway support dififculty were analyzed, the roadway support points were proposed , and taking the vice roadway and cross-cut supporting of Xiang Xue Hu Gou mine 102 mining face as example, using of the existing support technology, he combined with the supporting effect of the underground, making the use of targeted technique better solved the mining coal roadway support problem.%本文在介绍典型复采煤层的地质和生产条件基础的上,分析了复采巷道的支护难点,提出了复采煤层巷道的支护要点,并以薛虎沟矿102回采工作面副巷和切巷掘进支护为具体实例,结合井下支护效果,利用现有支护技术通过针对性的工艺方法较好地解决了复采煤层巷道支护难题。

  13. Association of Roadway Proximity with Fasting Plasma Glucose and Metabolic Risk Factors for Cardiovascular Disease in a Cross-Sectional Study of Cardiac Catheterization Patients

    Science.gov (United States)

    Background: The relationship between traffic-related air pollution (TRAP) and risk factors for cardiovascular disease needs to be better understood in order to address the adverse impact o.f air pollution on human health.Objective: We examined associations between roadway proximi...

  14. Rural Education Issues: Rural Administrators Speak Out

    Science.gov (United States)

    Williams, Julia; Nierengarten, Gerry

    2010-01-01

    The purpose of this study was to identify the issues that most affect Minnesota's rural public school administrators as they attempt to fulfill the mandates required from state legislation and communities. A second purpose was to identify exemplary practices valued by individual Minnesota rural schools and districts. Electronic surveys were sent…

  15. Medicare and Rural Health

    Science.gov (United States)

    ... 1.9 million rural beneficiaries participated in Medicare Advantage (MA) and other prepaid plans, accounting for 13.4% of MA enrollees. While rural participation is not proportionate to urban participation, strong rural enrollment in ... Medicare Advantage – The ACA reduces the payments to companies providing ...

  16. 预掘底板岩巷卸压增透方法∗%Methods of destressing and increasing penetration at pre-excavated rock roadway under floor

    Institute of Scientific and Technical Information of China (English)

    王中华

    2016-01-01

    针对难抽采煤层,提出了预掘底板岩巷卸压增透方法,理论分析了底板岩巷卸压影响范围一般为巷道半径r 的2~6倍.现场考察了曲江煤矿702底板岩巷围岩位移量最大为38 mm,钻孔瓦斯流量、煤层透气性系数分别为原始煤层的11.1倍、43.2倍,实践表明曲江煤矿702底板岩巷布置在待掘煤巷正下方8~10 m处增透效果显著.%Proposing methods of destressing and increasing penetration at pre-excavated rock road-way under floor for coal seams which are difficult to be drained;theoretically analyzing that the influen-tial incidence of destressing at rock roadway under floor is generally as 2 to 6 times of roadway radius r. In-situ measurements show that the maximum surrounding rock displacement of rock roadway under 702 floor of Qujiang Mine is 38 mm;gas flow rate in borehole and permeability coefficient of coal seam is 1 1.1 and 43.2 times of those of the original coal seam,respectively. The practice shows that rock road-way under 702 floor of Qujiang Mine could make significantly increasing penetration effect when it is placed 8-1 0 meters directly below coal lanes to be excavated.

  17. Laneway's Side Stability Mechanism and Support Technology in Super-high Roadway%巨高巷道巷帮稳定机理及支护技术

    Institute of Scientific and Technical Information of China (English)

    李积星; 许磊; 蒋红军

    2012-01-01

    以山西某矿5203轨道巷的巨高巷道为研究对象,采用对比分析方法,描述了巨高巷道巷帮水平位移和下沉特征及塑性区的分布特征。通过分析巷帮片帮力学模型、巷帮锚固墙的对深部围岩约束原理、巨高巷道金属支架腿部易产生压杆失稳等,最终采用高强锚杆、带、网、索支护方式加固巷帮并确定了合理支护参数。实践结果表明,巨高巷道巷帮稳定原理适用于巨高巷道巷帮支护。%Taking super-high roadway appeared in 5203 track roadway in a mine of Shanxi as research object.The horizontal displacement,subsidence features and plastic zone distribution characteristics of laneway's side in super-high roadway are described with comparison analysis method in this paper.Through analyzing mechanical model of rib spalling,constraint theory of anchor wall of laneway's side on deep surrounding rock and pressure bar destabilization of metallic support generated in steel timber leg of super-high roadway,finally,the support form of using high strength bolts,steel strip,anchor net and anchor cable to reinforce laneway's side is adopted,and the reasonable supporting parameters are determined.The result of engineering practice proves that the laneway's side stabilization theory of super-high roadway is suitable to the laneway's side support of super-high roadside.

  18. An overview of the thermography-based experimental studies on roadway excavation in stratified rock masses at CUMTB

    Institute of Scientific and Technical Information of China (English)

    Gong Weili; Peng Yanyan; He Manchao; Xie Tian; Zhao Shijiao

    2015-01-01

    This paper presents an overview of experimental investigations conducted at China University of Mining and Technology Beijing (CUMTB) on roadway excavation using large-scale geomechanical model tests. The simulated sedimentary rocks are composed by alternating layers of sandstone, mudstone and coal seam inclined at varied angles with respect to the horizontal including 0?, 45?, 60?, and 90?. During the excavation, infrared thermography was employed to detect the thermal response of the surrounding rocks under excavation. The obtained raw thermograms were processed using denoising algorithm, data reduction procedure and Fourier analysis. The infrared temperature (IRT) characterizes the overall rock response; the processed thermal images represent the structural behavior, and the Fourier spectrum describes damage development in the frequency domain. Deeper understanding was achieved by the comparative analyses of excavation in differently inclined rock masses using the image features of IRTs, thermal images and Fourier spectra.

  19. 井巷轮廓仪的研发和应用%Research and application of roadway profile meter

    Institute of Scientific and Technical Information of China (English)

    杨卫林; 王多武; 赵富石; 郭峰

    2015-01-01

    introduced the R&D and on-site inspection well lane profilometer, through the application of the instrument in the heading face, provides the convenience for the roadway drivage constructionfor safety production of precision, time saving at the same time, create more eco-nomic benefit.%介绍了井巷轮廓仪的研发和现场检验,通过该仪器在掘进工作面应用,对于井巷掘进精确施工提供便利,为安全生产节省时间的同时,创造更多经济效益。

  20. A study of support strategies in deep soft rock: The horsehead crossing roadway in Daqiang Coal Mine

    Institute of Scientific and Technical Information of China (English)

    Guo Zhibiao; Yang Xiaojie; Bai Yunpeng; Zhou Feng; Li Erqiang

    2012-01-01

    Geomechanics in deep mines becomes more complex and structural support in soft rock can be very difficult.Highly stressed soft rock subject to expansion deformation is particularly difficult to control.The Tiefa Coal Industry Group Daqiang Coal Mine is used as an example.A ventilation shaft,-550 horsehead,is located in tertiary soft rock.Analysis of the reasons for deformation shows an intumescent rock,which is easily damaged.Field observations and theoretical analysis led to a design capable of stabilizing the rock.A combination of spray,anchors,anchor bolts,and soft comer coupled truss supports allowed the deformation to be controlled.This provides a model for similar designs when support ofa horsehead roadway is required.

  1. Association of Roadway Proximity with Indoor Air Pollution in a Peri-Urban Community in Lima, Peru

    Directory of Open Access Journals (Sweden)

    Lindsay J. Underhill

    2015-10-01

    Full Text Available The influence of traffic-related air pollution on indoor residential exposure is not well characterized in homes with high natural ventilation in low-income countries. Additionally, domestic allergen exposure is unknown in such populations. We conducted a pilot study of 25 homes in peri-urban Lima, Peru to estimate the effects of roadway proximity and season on residential concentrations. Indoor and outdoor concentrations of particulate matter (PM2.5, nitrogen dioxide (NO2, and black carbon (BC were measured OPEN ACCESS Int. J. Environ. Res. Public Health 2015, 12 13467 during two seasons, and allergens were measured in bedroom dust. Allergen levels were highest for dust mite and mouse allergens, with concentrations above clinically relevant thresholds in over a quarter and half of all homes, respectively. Mean indoor and outdoor pollutant concentrations were similar (PM2.5: 20.0 vs. 16.9 μg/m3, BC: 7.6 vs. 8.1 μg/m3, NO2: 7.3 vs. 7.5 ppb, and tended to be higher in the summer compared to the winter. Road proximity was significantly correlated with overall concentrations of outdoor PM2.5 (rs = −0.42, p = 0.01 and NO2 (rs = −0.36, p = 0.03, and outdoor BC concentrations in the winter (rs = −0.51, p = 0.03. Our results suggest that outdoor-sourced pollutants significantly influence indoor air quality in peri-urban Peruvian communities, and homes closer to roadways are particularly vulnerable.

  2. Mechanism and technology study of collaborative support with long and short bolts in large-deformation roadways

    Institute of Scientific and Technical Information of China (English)

    Yu Hui⇑; Niu Zhiyong; Kong Linggen; Hao Caicheng; Cao Peng

    2015-01-01

    Common short bolts of equal length are widely used to support the roofs of roadways in coal mines. However, they are insufficient to keep the roof stable against large deformations, so docking long bolts with high levels of elongation that can adapt to large deformations of the surrounding rock have been adopted. This paper proposes a collaborative support method that uses long and short bolts. In this study, the mechanism of docking long bolts and collaborative support was studied. Numerical simulation, sim-ilarity simulation, and field testing were used to analyze the distribution law of the displacement, stress, and plastic failure in the surrounding rock under different support schemes. Compared with the equal-length short bolt support, the collaborative support changed the maximum principal stress of the shallow roof from tensile stress to compressive stress, and the minimum principal stress of the roof significantly increased. The stress concentration degree of the anchorage zone clearly increased. The deformation of the roof and the two sides was greatly reduced, and the subsidence shape of the shallow roof changed from serrated to a smooth curve. The roof integrity was enhanced, and the roof moved down as a whole. Plastic failure significantly decreased, and the plastic zone of the roof was within the anchorage range. The similarity simulation results showed that, under the maximum mining stress, the roof collapsed with the equal-length short bolt support but remained stable with the collaborative support. The collaborative support method was successfully applied in the field and clearly improved the stability of the surrounding rock for a large deformation roadway.

  3. Rural Entrepreneurship or Entrepreneurship in the Rural

    DEFF Research Database (Denmark)

    Korsgaard, Steffen; Müller, Sabine; Tanvig, Hanne Wittorff

    2015-01-01

    Purpose: This article investigates how rural entrepreneurship engages with place and space. It explores the concept of “rural” in rural enterprise, and illustrates the importance of distinguishing between types of rural entrepreneurship. Design/methodology/approach: The constructs of “place” and ...... these processes are enabled and constrained by the immediate context or “place”. The paper weaves space and place in order to show the importance of context for entrepreneurship, which responds to the recent calls for contextualizing entrepreneurship research and theories....

  4. Rural Poverty Rate Edges Downward.

    Science.gov (United States)

    Nord, Mark

    1997-01-01

    Although rural poverty began to decline, 1994-95, many rural households had incomes just above poverty. Rural minorities were especially disadvantaged; racial differences in educational attainment accounted for 20-33% of income gaps. One-quarter of rural children lived in poverty, most in single-parent households. Most rural poor families lived in…

  5. Development of a distance-to-roadway proximity metric to compare near-road pollutant levels to a central site monitor

    Science.gov (United States)

    Barzyk, Timothy M.; George, Barbara Jane; Vette, Alan F.; Williams, Ronald W.; Croghan, Carry W.; Stevens, Carvin D.

    The primary objective of the Detroit Exposure and Aerosol Research Study (DEARS) was to compare air pollutant concentrations measured at various neighborhoods, or exposure monitoring areas (EMAs), throughout a major metropolitan area to levels measured at a central site or community monitor. One of the EMAs was located near a busy freeway (annual average daily traffic (AADT) of ˜130,000) so that impacts of mobile sources could be examined. Air pollution concentrations from the roadway-proximate sites were compared to the central site monitor. The volatile organic compounds (VOCs) selected (benzene, toluene, ethylbenzene, m,p- and o-xylene, 1,3 butadiene, 1,3,5-trimethylbenzene and 4-ethyltoluene) are typically associated with mobile sources. Gradients were also evident that demonstrated the amplification of pollutant levels near the roadway compared to the community monitor. A novel distance-to-roadway proximity metric was developed to plot the measurements and model these gradients. Effective distance represents the actual distance an air parcel travels from the middle of a roadway to a site and varies as a function of wind direction, whereas perpendicular distance is a fixed distance oriented normal to the roadway. Perpendicular distance is often used as a proxy for exposures to traffic emissions in epidemiological studies. Elevated concentrations of all the compounds were found for both a summer and winter season. Effective distance was found to be a statistically significant ( p p-xylene and o-xylene for summer 2005. For each of these pollutants, effective distance yielded lower p-values than the corresponding perpendicular distance models, and model fit improved. Results demonstrate that this near-road EMA had elevated levels of traffic-related VOCs compared to the community monitor, and that effective distance was a more accurate predictor of the degree to which they were elevated as a function of distance. Effective distance produced a range of distance-to-roadway

  6. 巷道振波超前探测技术在煤矿巷道掘进中的应用%Application of Advance Detection Technology of Tunnel Vibration Wave Roadway Excavation in Coal Mine

    Institute of Scientific and Technical Information of China (English)

    罗鹏; 张恒; 常永峰

    2016-01-01

    本文主要介绍了巷道振波超前探测技术在煤矿巷道掘进的实践应用,主要是利用矿井震波超前探测法控制巷道前方的构造发育情况,减少巷道的报废,为巷道的设计修改和安全掘进提供地质资料。%This paper mainly introduces the application of the advanced detection technology of tunnel vibration wave roadway tunneling in coal mine, mainly uses mine seismic advanced sensor to development of the front structure of the roadway, to reduce roadway scrap and provide geological data for design modification and safety excavation of roadway.

  7. Traffic Analysis Zones - TRAFFIC_COUNTS_INDOTMODEL_IN: Traffic Counts on Roadways (from INDOT Statewide Travel Demand MODEL version 4, ISTDM4) in Indiana (Indiana Department of Transportation, Line Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — TRAFFIC_COUNTS_INDOTMODEL_IN is a line shapefile that shows traffic counts (factored to year 2000) for the roadways in the Indiana Statewide Travel Demand Model,...

  8. Exploration of Rural Informatization and Urban-rural Information Fusion

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Based on the status quo of rural informatization and information service,this article conducts analysis and discussion of problems in rural informatization and urban-rural information fusion,using statistics. And corresponding countermeasures are put forward as follows: building rural information platform; strengthening information literacy training in rural areas and cultivating new farmers; making information network serve production and operation to increase jobs and income for farmers; developing rural e-commerce; enhancing network information security and prevention.

  9. Education for rural people

    OpenAIRE

    2015-01-01

    Nearly one out of six people in the world is suffering from hunger and illiteracy. This book was developed to assist policy makers dealing with rural poverty, food insecurity and education challenges confronting rural people. It seeks to address the correlation between education, training, empowerment and food security, mainly through a number of examples from all over the world. It is about strengthening the capacity of rural people to achieve food security. It identifies different dimension...

  10. Oral Health in Rural Communities

    Science.gov (United States)

    ... Guide Rural Health Topics & States Topics View more Oral Health in Rural Communities Adequate access to oral healthcare ... about oral health programs in my area? What oral health disparities are present in rural America? According to ...

  11. Enlargement of a rectangular bolted roadway by use of the longwall machinery; Erweiterung einer Rechteckankerstrecke zur Strebstartstrecke durch den Einsatz der strebeigenen Gewinnungseinheit

    Energy Technology Data Exchange (ETDEWEB)

    Zilligen, W. [Bergwerk Auguste Victoria/Blumenthal der Deutschen Steinkohle AG (DSK), Marl (Germany)

    2004-09-09

    The modern coal-face installation, with its high-performance face supports, requires a cavity up to 9.5 m in width to serve as a set-up chamber. The single-phase excavation of wide-section roadways with rockbolt support tends to pose problems in terms of the drivage method used and the stability of the roadway during its service life. The positive experience acquired from the conventional drivage of rockbolted set-up chambers has now led to the development of a new system for the mechanized excavation of cavities of this type. A DSK colliery has now for the first time successfully deployed the existing SL 300 drum shearer loader to cut the extension for the set-up chamber. The success of this project has meant that the same technique will now be used in subsequent coal panels. (orig.)

  12. 岩巷中深孔爆破在实际生产中的应用%Application of Rock Roadway Deep Hole Blasting in Actual Production

    Institute of Scientific and Technical Information of China (English)

    赤孟博

    2014-01-01

    吕沟煤矿是一个生产50多年的老矿井,技术水平和掘进方式都较为落后。岩巷掘进一直是吕沟煤矿生产管理中的重点和难点,尤其是在巷道成形和掘进速度上难以突破并且已经成为了制约矿井生产的重要问题。针对这种情况,在总工程师的牵头带领下,开始在12采区轨道下山进行试验推广“岩巷中深孔爆破技术”以提高岩巷的掘进速度。%Lvgou coal mine is an old mine with a production history of more than 50 years, and the technical level and tunneling method is relatively backward. Rock roadway drivage has been the key points and difficulties in Lvgou coal mine production and management, especially in roadway forming and driving speed, which has become the important problem restricting the mine production. For this kind of circumstance, under the chief engineer's lead, rock roadway deep hole blasting technology began to de promoted in the 12 mining area track downhill in order to improve the drivage speed.

  13. Coal Mine Blasting Roadway Fast Tunneling Process Research and Discussion%炮掘巷道快速掘进工艺研究与探讨

    Institute of Scientific and Technical Information of China (English)

    张培龙; 赵强; 宋更亮

    2015-01-01

    从地质条件、装备水平、劳动组织、施工工艺等方面研究了影响巷道掘进有关因素,结合蒋庄煤矿炮掘工程实际,在传统炮掘工艺基础上,找出了制约巷道快速掘进的瓶颈问题,有效提高了炮掘巷道效率,实现了炮掘巷道快速掘进。%From the geological conditions, equipment level, labor organization, construction technology, etc, to study the inlfuence factors of jiangzhuang coal mine roadway drivage about gun digging jiangzhuang coal mine engineering practice, the traditional gun digging process, on the basis of finding out the bottleneck problem of the quick roadway drivage, effectively improve the efifciency of the cannon dig tunnel, implements the gun digging roadway drivage quickly.

  14. 煤巷围岩稳定性分类指标确定研究%Research on Coal Roadway Wall Rock Stability Classification Index Determination

    Institute of Scientific and Technical Information of China (English)

    张小康

    2009-01-01

    Based on the engineering geological conditions and production technology conditions of Huozhou coal electricity group limited liability company, this paper makes a deep analysis on the factors that impact the wall rock stability of the coal seam roadway, in this basis, by using analytic hierarchy process established the AHP model to determine the index of the coal seam roadway wall rock stability classification and extracted nine key index. Has very important significance to the study of the roadway wall rock stability classification.%以霍州煤电集团有限责任公司煤层巷道的具体工程地质条件和生产技术条件为背景,深入分析了影响煤层巷道围岩稳定性的诸多因素,在此基础上,运用层次分析法的基本原理,建立了煤层巷道围岩稳定分类指标确定的AHP分析模型,提取了9个关键指标.对于研究煤层巷道围岩稳定性分类具有十分重要的意义.

  15. Urbanizing rural waters

    NARCIS (Netherlands)

    Hommes, Lena; Boelens, Rutgerd

    2017-01-01

    This article studies how urbanization processes and associated rural-urban water transfers in the Lima region (Peru) create water control hierarchies that align the municipal drinking water company, hydropower plants and rural communities on unequal positions. By scrutinizing the history of water tr

  16. Energy for rural India

    NARCIS (Netherlands)

    Urban, Frauke; Benders, René M.J.; Moll, Henri C.

    2009-01-01

    About 72 million households in rural India do not have access to electricity and rely primarily on traditional biofuels. This research investigates how rural electrification could be achieved in India using different energy sources and what the effects for climate change mitigation could be We use t

  17. Ad Hoc Rural Regionalism

    Science.gov (United States)

    Hamin, Elisabeth M.; Marcucci, Daniel J.

    2008-01-01

    A new regionalism has been much documented and researched for metropolitan areas; this article documents that there is a new rural regionalism as well. In the United States, these groups appear most likely to emerge in areas that are challenged by outcomes characterizing globalization's effects on the rural condition: namely, exurban or…

  18. Urbanizing rural waters

    NARCIS (Netherlands)

    Hommes, Lena; Boelens, Rutgerd

    2017-01-01

    This article studies how urbanization processes and associated rural-urban water transfers in the Lima region (Peru) create water control hierarchies that align the municipal drinking water company, hydropower plants and rural communities on unequal positions. By scrutinizing the history of water tr

  19. Rural Credit in Vietnam

    DEFF Research Database (Denmark)

    Barslund, Mikkel Christoffer; Tarp, Finn

    This paper uses a survey of 932 rural households to uncover how the rural credit market operates in four provinces of Vietnam. Households obtain credit through formal and informal lenders, but formal loans are almost entirely for production and asset accumulation. Interest rates fell from 1997...... to credit policy is clearly inappropriate....

  20. RURAL TOURISM IN DOBRUDGEA

    Directory of Open Access Journals (Sweden)

    Elena, SIMA

    2014-11-01

    Full Text Available The natural and anthropic tourism resources of a certain area generate specific tourism forms, which complete each other within the different destination categories.The rural area in Dobrudja has diversified tourism potential, provided by the contrast of natural environment factors, ranging from the oldest and to the youngest relief units, natural protected areas, spa resources and cultural, historical, religious sites, as well as multicultural local customs and traditions of the rural area. This potential can be used under various kinds in the rural area: cultural tourism, historical tourism, religious tourism, ecotourism, fishing tourism or bird-watching tourism, and other kinds of rural tourism. By linking these tourism resources and tourism forms, tourism routes can result, which together with the local customs, traditions and cuisine may contribute to the social and economic development of Dobrudja's rural area, through sustainable tourism as alternative to seasonal seashore tourism.

  1. 35 years of drilling technology in the drivage of roadways and tunnels; 35 Jahre Bohrtechnik im Strecken- und Tunnelvortrieb

    Energy Technology Data Exchange (ETDEWEB)

    Wennmohs, Karl-Heinz [Atlas Copco MCT GmbH, Essen (Germany)

    2011-03-15

    The period of 35 years in the development of drilling technology in roadway and tunnel drivage was characterised by the developments in hydraulic hammer drill technology. This is clearly illustrated by the comparison of the percussive power of 8 to 10 kW in the 1970's with 30 kW in 2011. This trend is also underlined by the increase in the gross drilling rates of the drilling jumbos. Further development has been virtually overlooked on the supported pneumatic hammer drills, which are still widely used all over the world. The hammer drills used 35 years ago are still being built with a virtually unchanged technology. However the hydraulic hammer drills and the carrier components will undergo further development. In the next few years the maximum percussive power will exceed a further threshold, which is currently 40 kW. The use of powerfull computer systems permits further increases in the automation, precision and speed also on drilling jumbos. This opens up new possibilities in the interlinking of drilling and blasting technology as a system module of conventional tunnel drivage. (orig.)

  2. AVSA. Parallelised bolting and cutting in roadways with arch supports; AVSA. Parallelisiertes Ankern und Schneiden in Bogenstrecken

    Energy Technology Data Exchange (ETDEWEB)

    Matusche, T. [Bergwerk West, Kamp-Lintfort (Germany); Stratmann, T. [Deutsche Steinkohle AG (DSK), Herne (Germany). Abt. TB

    2002-09-05

    In the middle of the 90's a research project was initiated to improve the drivage rates of roadway headings in the German hard coal industry. The target of the project was to get a significant increase in performance by parallelisation of cutting and bolting in mechanical headings, also in very hard rock conditions. In the first operation the prototype of the developed heading machine achieved not the expected performance. Although the aim of parallel cutting and bolting was gained, the drivage performance was especially hampered due to a high amount of hunks during the cutting process. Additionally geological difficulties occurred. Steps were made to optimize this system getting a clear increase in performance for the second operation to achieve the initial target. (orig.) [German] Vor dem Hintergrund stagnierender Vortriebsgeschwindigkeiten im Floezstreckenvortrieb des deutschen Steinkohlenbergbaus wurde Mitte der 90er Jahre des letzten Jahrhunderts ein Forschungsvorhaben initiiert. Ziel war es, durch Parallelisierung von Schneid- und Ankerarbeit bei maschinellen Vortrieben eine signifikante Leistungserhoehung auch in schwer schneidbarem Gestein zu erzielen. Der entwickelte Prototyp erreichte in einem ersten Einsatz die erwartete Leistung nicht. Obwohl die angestrebte Parallelisierung der Vorgaenge Schneiden und Ankern erreicht wurde, behinderte insbesondere ein hoher Brockenanfall die Vortriebsleistung. Zusaetzlich traten geologische Probleme auf. Optimierungsmassnahmen sollen in einem zweiten Einsatz deutliche Leistungssteigerungen bewirken, um die urspruengliche Zielsetzung zu erreichen. (orig.)

  3. Analyses the quick roadway drivage method%浅析巷道快速掘进方法

    Institute of Scientific and Technical Information of China (English)

    成飞; 杨晓勇; 张冬冬

    2014-01-01

    黄陵矿业公司一号煤矿随着开采深度的增加,从低瓦斯矿井变成了高瓦斯矿井。在掘进时需做掘前预抽工作,增加掘进工序,造成采面接续紧张。煤巷快速掘进技术成为解决采面接续紧张的有效方式。一号矿井采用快速掘进技术并加强管理,成功解决接续问题,保证矿井正常、高效生产。%No. 1 Coalmine of Huangling Mining Group with the increase of mining depth, number one coal mine from low gas mines into gas mines. In front of the tunneling increases when digging drainage work, increase the tunneling process, caused by surface tension. Rapid drivage technology to solve the mining face in coal roadway in the way of tension. One mine the rapid excavation technology and strengthen management, successfully solve the problem of replacement, ensure the normal and efifcient production.

  4. Particulate Matter Mass and Number Concentrations Inside a Naturally Ventilated School Building Located Adjacent to an Urban Roadway

    Science.gov (United States)

    Chithra, V. S.; Shiva Nagendra, S. M.

    2014-09-01

    This work presents the temporal characteristics of Particulate Matter (PM) mass and number concentrations measured inside a naturally ventilated school building, located close to a busy roadway in Chennai city. Two environmental dust monitor instruments (GRIMM Model 107 and Model 108) were used for measuring PM mass and number concentrations. The 1-h mean values of PM10, PM2.5 and PM1 mass concentrations were found to be 262 ± 161, 68 ± 24, 40 ± 15 µg/m3 and 81 ± 26, 56 ± 2, 45 ± 19 µg/m3 during working hours (8am-4pm) and non-working hours (4pm-8am)/holidays, respectively. The PM number concentrations inside the room during working hours were found to be 2.4 × 105, 2.2 × 103 and 8.1 × 102 particles/l in the size range of 0.3-1, 1-3 and 3-10 µm, respectively. The present study reveals that during working hours, indoor PM concentrations of the classroom were influenced by the activities of occupants and during non working hours it was affected by outdoor vehicular emissions.

  5. MSP技术在任楼煤矿巷道超前探测中的应用%Application of MSP Technology in Renlou Coalmine Roadway Advance Detection

    Institute of Scientific and Technical Information of China (English)

    赵晶

    2011-01-01

    The adverse geologic conditions of fault, subsided column, coal and rock masses structural fracture zone may exist in coalmine roadways driving not only can impact driving operation, but also have potential water and gas bursting safety hazards existed. Usually larger physical property differences of density, velocity etc have existed between fault, subsided column etc abnormal geological structures and country rocks, thus can use multiwave, multicomponent seismic reflection methods to detect coalmine underground abnormal structures. In recent two years, the Renlou coalmine has carried out multiple MSP seismic wave advance detection aimed at roadway front undiscovered structures. Taking the II7322 mechanized roadway as an example, at 76m directly ahead of roadway j 19 point, two advance detections have been carried out on left and right walls respectively. Positions of two interpreted anomalous interfaces are 82m, 101m and 85m, 102m respectively; positions of two actually revealed faults are 82m, 109m basically accord with detection result, thus realized correct advance prediction of geologic structural belt within driving roadway.%煤矿巷道中的断层、陷落柱和煤岩体结构破碎带等不良地质条件不但影响掘进施工,同时也存在突水、瓦斯突出等安全隐患.断层、陷落柱等地质异常构造与围岩在密度、速度等物性方面存在较大差异,因此可利用多波多分量地震反射法探测煤矿井下异常构造.近两年来,任楼煤矿针对矿井巷道前方的未知隐伏构造做了多次MSP震波超前探测.以Ⅱ7322机巷为例,在巷道j19点前76m处,分别于巷道的左帮及右帮对迎头前方进行了两次超前探查,2次探测解释的2个异常界面位置分别为82m、101m和85m、102m,实际揭露2个断层位置为82m、109m,探测结果与实际基本相符,实现了对掘进巷道内地质构造带的准确超前预测预报.

  6. Association of Roadway Proximity with Fasting Plasma Glucose and Metabolic Risk Factors for Cardiovascular Disease in a Cross-Sectional Study of Cardiac Catheterization Patients

    Science.gov (United States)

    Kraus, William E.; Blach, Colette; Haynes, Carol S.; Dowdy, Elaine; Miranda, Marie Lynn; Devlin, Robert B.; Diaz-Sanchez, David; Cascio, Wayne E.; Mukerjee, Shaibal; Stallings, Casson; Smith, Luther A.; Gregory, Simon G.; Shah, Svati H.; Hauser, Elizabeth R.; Neas, Lucas M.

    2015-01-01

    Background The relationship between traffic-related air pollution (TRAP) and risk factors for cardiovascular disease needs to be better understood in order to address the adverse impact of air pollution on human health. Objective We examined associations between roadway proximity and traffic exposure zones, as markers of TRAP exposure, and metabolic biomarkers for cardiovascular disease risk in a cohort of patients undergoing cardiac catheterization. Methods We performed a cross-sectional study of 2,124 individuals residing in North Carolina (USA). Roadway proximity was assessed via distance to primary and secondary roadways, and we used residence in traffic exposure zones (TEZs) as a proxy for TRAP. Two categories of metabolic outcomes were studied: measures associated with glucose control, and measures associated with lipid metabolism. Statistical models were adjusted for race, sex, smoking, body mass index, and socioeconomic status (SES). Results An interquartile-range (990 m) decrease in distance to roadways was associated with higher fasting plasma glucose (β = 2.17 mg/dL; 95% CI: –0.24, 4.59), and the association appeared to be limited to women (β = 5.16 mg/dL; 95% CI: 1.48, 8.84 compared with β = 0.14 mg/dL; 95% CI: –3.04, 3.33 in men). Residence in TEZ 5 (high-speed traffic) and TEZ 6 (stop-and-go traffic), the two traffic zones assumed to have the highest levels of TRAP, was positively associated with high-density lipoprotein cholesterol (HDL-C; β = 8.36; 95% CI: –0.15, 16.9 and β = 5.98; 95% CI: –3.96, 15.9, for TEZ 5 and 6, respectively). Conclusion Proxy measures of TRAP exposure were associated with intermediate metabolic traits associated with cardiovascular disease, including fasting plasma glucose and possibly HDL-C. Citation Ward-Caviness CK, Kraus WE, Blach C, Haynes CS, Dowdy E, Miranda ML, Devlin RB, Diaz-Sanchez D, Cascio WE, Mukerjee S, Stallings C, Smith LA, Gregory SG, Shah SH, Hauser ER, Neas LM. 2015. Association of roadway

  7. Research on reinforcement technology of retaining roadway influenced by multiple mining%受多次采动影响留巷加固技术研究

    Institute of Scientific and Technical Information of China (English)

    王涛

    2016-01-01

    详细调查了成庄矿五盘区大采高5308孤岛工作面留巷的地质条件、支护状况和变形特征;采用FLAC3D数值模拟分析大采高孤岛工作面矿压显现规律和研究此类巷道的变形破坏机理;针对53082巷变形特点提出,先注浆提高破碎围岩整体性,增强围岩自身承载能力,后采用强力锚索支护控制锚固区围岩的二次离层,在锚固区内形成次生承载层来提高其围岩稳定性;并配合采用围岩表面喷浆封闭堵漏和浅深孔注浆相结合加固方案在53082巷进行现场试验。试验表明,加固后有效控制了大采高孤岛面留巷围岩变形,能够满足安全使用的要求,同时降低了巷修成本,具有显著的经济效益。%Investigated the geological conditions and the supporting conditions,failure characteristics of roadway retaining on 5308 island coal face with large mining height in No.5 panel area of Chengzhuang Mine in detail,mine pressure appear regularly of island coal face with large mining height and deformation failure mechanism of roadway was analysed by using FLAC3D numerical simulation.According to the deformation damage characteristics of roadway on 53082 roadway,it was proposed that,firstly,grouting was carried out to improve integrity and strengthen the self-bearing capacity of surrounding rock,secondly,powerful anchor supporting is applied to control the sec-ond abscission layer of surrounding rock,whose purpose is to form secondary load bearing layer to improve the stability of surrounding rock;and then,with the application of surface grouting on surrounding rock and combined supporting of shallow and deep holes grou-ting,field test was implemented in 53082 roadway.Results of test show that,the deformation of surrounding rock on island working face with large mining height is effectively controlled after the reinforcement,and the reinforced roadway can satisfy the safe usage,cost of roadway repair is also reduced

  8. Rural Literacy Issues in Alberta.

    Science.gov (United States)

    Bell, James H.

    This paper reviews results of a questionnaire distributed to literacy workers in rural Alberta (Canada) to ascertain their views on rural literacy. The questionnaire was designed to identify: (1) distinctive features of the issue of adult illiteracy in rural areas; (2) the strengths of literacy efforts in rural Alberta; (3) the weaknesses of…

  9. Rural development as economic category

    OpenAIRE

    KOSTYRKO I.G.; GROMIAK T.D.

    2012-01-01

    Is conducted scientific analysis of such concepts as “steady development of village”, “development of rural territories”, “development of rural locality”, “rural development”, “steady economic development”, “economic relations”. Reasonably and the vision of determination of rural development is given from the economic point of view.

  10. Considering the Effective Factors on Land Use Changes in the Villages Around Metropolises (Case Study: City Of Rasht, Khomam Rural

    Directory of Open Access Journals (Sweden)

    Reza Samimi Sharami

    2014-08-01

    Full Text Available Land use in villages around metropolises, especially in fertile areas such as Guilan plain, is experiencing basic changes. Mutual dependence between the metropolis and its surrounding villages will change rural perspective to urban one and it leads to change rural functions and structures. This review is in the area of Rasht metropolis and about Khomam rural land use changes during 1966-2013. In this study, research method is descriptive analytical, the data in use is observed through documents and evidences (the oldest and newest map of Khomam rural, and questionnaires and interviews are collected. Research results indicate a significant change in agricultural and horticultural lands and an increase in constructed lands and roadways. This research has tested different indices in order to considering and determining effective factors on land use change. According to research founding, 21 factors have the most effects on agricultural and horticultural land use respectively and 4 factors have the most effects on land use in order to staying unchanged, respectively.

  11. Rural pharmacy closures: implications for rural communities.

    Science.gov (United States)

    Todd, Kelli; Ullrich, Fred; Mueller, Keith

    2013-01-01

    Retail pharmacies provide essential services to residents of rural areas and serve many communities as the sole provider of pharmacist services. Losing the only retail pharmacy within a rural community (census designated city), and within a 10 mile radius based on driving distance ("sole community pharmacy"), may affect access to prescription and over-the-counter drugs and, in some cases, leave the community without proximate access to any clinical provider. This policy brief documents the closure of local retail pharmacies in which the pharmacist was the only clinical provider available in the community at the time the pharmacy closed. Characteristics of the community and the retail pharmacy are described. The findings may suggest future policy actions to minimize the risk or mitigate the negative consequences of pharmacy closures. Key Findings. (1) Between May 1, 2006, and October 31, 2010, 119 sole community pharmacies closed. (2) Of those 119 pharmacies, 31 were located in rural communities with no other health professionals or clinical providers. (3) In 16 states, at least 1 community lost a sole community retail pharmacy, and there was no other pharmacy within 10 miles (actual driving distance). (4) Of the 31 pharmacy closures in communities with no other providers, 17% were located in remote rural areas designated with a Rural-Urban Commuting Area (RUCA) score of 10 or higher. Such a score means that, on average, 60 minutes of travel time is required to reach an urbanized area, and 40 minutes is required to reach a large urban cluster of 20,000 population or more.

  12. Informe rural 2006

    OpenAIRE

    César Falconi; Peter Pfaumann; Nicolás Mateo; Rocío González; Alejandra Palma; José Rente Nascimento; Mark D. Wenner; María Eugenia Kyburz

    2007-01-01

    Esta edición del Informe Rural contiene siete artículos: La influenza aviar y el sector avícola de América Latina, Biocombustibles y oportunidades para el desarrollo rural, Enfoques sectoriales amplios en desarrollo rural: ¿instrumento viable para mejorar el impacto de la cooperación internacional?, Financiamiento de las cadenas agroalimentarias de valor, Cómo mejorar el clima para los negocios forestales, Avances en el Fondo Regional de Tecnología Agropecuaria (FONTAGRO) y Financiamiento rur...

  13. Changing Rural Paradigms

    DEFF Research Database (Denmark)

    Høst, Jeppe Engset

    2016-01-01

    paradigm” (OECD 2006) and its implications for ethnological scholars and practitioners of today. In the “new rural paradigm”, bottom-up processes, “place-bound” cultural and historical values are highlighted as essential to local development. This of course empowers the ethnologists, but also put us...... in a position at the very centre of a commodification of “the rural” and rural communities. The article therefore concludes with a discussion of currents trends in regional and rural development and the...

  14. Rural-urban Migration, Rural Household Income and Sustainable Development in Rural Areas of China

    Institute of Scientific and Technical Information of China (English)

    Lu Qi; Yang Chunyue; Li Juan

    2008-01-01

    The objective of this paper is to investigate the rela-tionships among rural-urban migration, rural household income and sustainable development in rural areas of China. The typical case study is done and 288 questionnaires are collected from five villages in Hebei and Guangxi provinces, China. The migration and remittance status, household income and sustainable devel-opment of rural areas are analyzed on the basis of questionnaires. Rural-urban migration is becoming a part of routine life in rural areas. And remittance is an important component in rural house-hold income. Rural-urban migration increases the arable land area per labor, which releases the tight human-land relationship in villages. In total, the migration increases the rural household in-come and accelerates the sustainable development of rural areas.

  15. Mozambique - Rural Water Supply

    Data.gov (United States)

    Millennium Challenge Corporation — This report provides the results from (1) an impact evaluation of the MCA's Rural Water Point Implementation Program ('RWPIP') in Nampula and (2) an evaluation of...

  16. Rural Veterans by State

    Data.gov (United States)

    Department of Veterans Affairs — This speadsheet contains data from the 2014 American Community Survey and shows the demographic and socioeconomic characteristics of Veterans who live in rural and...

  17. Innovating for Rural Development

    DEFF Research Database (Denmark)

    Christensen, Dorthe

    is that policies, agricultural research and extension should pay attention to these financial structural aspects, since they regulate the extent of ‘public good extension services’ like rural development services and ‘innovation intermediation’ in Danish agricultural extension agencies. The capacity differs among...... the individual agencies and among individual agents. There are agencies that financially invest in rural development service, including in innovation intermediation. On the other hand, there are agencies where the presence of rural development service is merely as a formal structure, possibly to signal...... interactions, by exploring the perspective of the participants; and the paper also seeks to understand possible constraining or supportive extension aspects at play. Paper 3 examines how the apparent change effort: ‘rural development service’ is reflected in the management strategies of individual agricultural...

  18. "Ruralizing" Presidential Job Advertisements

    Science.gov (United States)

    Leist, Jay

    2007-01-01

    Rural community college presidential job advertisements that focus on geography, politics, and culture can improve the likelihood of a good fit between the senior leader and the institution. (Contains 2 figures.)

  19. Tourism in Rural Environment

    Directory of Open Access Journals (Sweden)

    MIHAI IELENICZ

    2013-01-01

    Full Text Available Rural tourism is now determined by limited economic opportunities, poor infrastructure, low motivation to possible offers, lack of proper service guarantees. Nearly 500 Romanian villages are already tourist locations, with certain characteristics determined by a heritage item, or complex ones when multiple components lead to various activities. This paper includes a typology of tourist villages in Romania according to the types of practiced tourist activities, insisting on the use of a more comprehensive terminology: tourism in rural environment, participative and creative tourism in rural areas. Tourism becomes a system accepted in the rural environment as a real opportunity for economic development with multiple social consequences. By multiplying tourism potential to meet tourists’ demands, many villages will get tourism valences with various activities in this filed, including environment protection.

  20. "Ruralizing" Presidential Job Advertisements

    Science.gov (United States)

    Leist, Jay

    2007-01-01

    Rural community college presidential job advertisements that focus on geography, politics, and culture can improve the likelihood of a good fit between the senior leader and the institution. (Contains 2 figures.)

  1. Medicaid and Rural Health

    Science.gov (United States)

    ... programs. How does Medicaid impact rural healthcare and the economy? In many ways, Medicaid plays a larger role ... supporting the social services infrastructure; and contributing to the economy through revenue and jobs it generates.” Findings in ...

  2. Rural Health Clinics (RHCs)

    Science.gov (United States)

    ... rural healthcare organizations attract healthcare providers by posting job opportunities online by state. Candidates who are interested in ... areas may register with 3RNet to search for job opportunities. The National Health Service Corps (NHSC) provides scholarships ...

  3. Rural road maintenance management

    OpenAIRE

    Johannessen, B.

    1999-01-01

    This manual summarizes relevant Cambodian government policies regarding rural road maintenance. Chapter 2 defines the various components of road maintenance and describes an effective strategy and organization which addresses the maintenance requirements of rural roads in Cambodia. Chapter 3 is a brief description of the planning, implementation and reporting cycle required in an effective road maintenance management system. Chapter 4 summarizes the contracts management procedures, and finall...

  4. producto turismo rural

    Directory of Open Access Journals (Sweden)

    Blanca García Henche

    2005-01-01

    Full Text Available El turismo rural lleva un largo periodo establecido en Europa, pero en los últimos años crece su importancia ya que supone un nuevo producto turístico y una fuente de ingresos para la economía rural. Actualmente, los turistas buscan experiencias distintas al tradicional turismo de sol y playa, prefieren un turismo más individualizado y flexible, buscan nuevas formas de alojamiento y muestran un interés creciente por el contacto con la naturaleza. La oferta turística rural ha de adaptarse a las exigencias de esta demanda, lo que implica más flexibilidad y alojamientos y pueblos adaptados a las necesidades emergentes. Se ha de definir el turismo rural como una alternativa de adaptación a los cambios en las necesidades de los consumidores. El presente documento muestra los componentes del turismo rural. Los recursos turísticos son la materia prima, a la que se ha de añadir los servicios. Estos servicios pueden ser básicos o complementarios. Además de los servicios hay que añadir las actividades complementarias e infraestructuras No hay duda de que el turismo rural puede beneficiarse de la aplicación del marketing. El marketing implica entender qué es lo que los consumidores desean y crear productos para satisfacer sus necesidades, además de comercializar el producto correctamente.

  5. Rural maternity care.

    Science.gov (United States)

    Miller, Katherine J; Couchie, Carol; Ehman, William; Graves, Lisa; Grzybowski, Stefan; Medves, Jennifer

    2012-10-01

    To provide an overview of current information on issues in maternity care relevant to rural populations. Medline was searched for articles published in English from 1995 to 2012 about rural maternity care. Relevant publications and position papers from appropriate organizations were also reviewed. This information will help obstetrical care providers in rural areas to continue providing quality care for women in their communities. Recommendations 1. Women who reside in rural and remote communities in Canada should receive high-quality maternity care as close to home as possible. 2. The provision of rural maternity care must be collaborative, woman- and family-centred, culturally sensitive, and respectful. 3. Rural maternity care services should be supported through active policies aligned with these recommendations. 4. While local access to surgical and anaesthetic services is desirable, there is evidence that good outcomes can be sustained within an integrated perinatal care system without local access to operative delivery. There is evidence that the outcomes are better when women do not have to travel far from their communities. Access to an integrated perinatal care system should be provided for all women. 5. The social and emotional needs of rural women must be considered in service planning. Women who are required to leave their communities to give birth should be supported both financially and emotionally. 6. Innovative interprofessional models should be implemented as part of the solution for high-quality, collaborative, and integrated care for rural and remote women. 7. Registered nurses are essential to the provision of high-quality rural maternity care throughout pregnancy, birth, and the postpartum period. Maternity nursing skills should be recognized as a fundamental part of generalist rural nursing skills. 8. Remuneration for maternity care providers should reflect the unique challenges and increased professional responsibility faced by providers in

  6. Repeated mining of goaf roadway drivage construction method%采空区复采巷道掘进施工方法

    Institute of Scientific and Technical Information of China (English)

    刘炳法; 王凯; 延雷

    2016-01-01

    采空区复采巷道的掘进一般围岩较破碎,需要先把前探钢钎插入掘进工作面内,再进行装药、爆破等工作,确认安全后,铺设联顶网,使用液压支柱配合长木料将顶网顶起,然后移前探梁,放棚梁,再出煤(矸),栽棚腿,以此为一个巷道掘进循环。在掘进工程的探索中,发明了一种采空区复采破碎围岩掘进超前支护装置,保证了掘进工作面爆破掘进时顶板的完整性,缩短了采空区复采巷道掘进的时间。%Goaf roadway drivage mining, surrounding rock broken, so need to take the former steel in tunneling working face, and then to charge and blasting work, after conifrmed safe, laid landing net, will use hydraulic prop with long wood top jacking, and then move the ground beam before, put a tent to beam, the coal (bottles) and then planted tent leg, as a roadway drivage cycle.At the same time, developed a goaf mining are broken surrounding rock tunneling advance supporting device, ensure the integrity of the main roof during the blasting excavation tunneling faces, shortens the time of mining roadway drivage of mined-out area.

  7. Grouting reinforcement technology for mine roadway repair in fault fracture zone%断层破碎带巷修注浆加固技术

    Institute of Scientific and Technical Information of China (English)

    兰永伟; 李凤义

    2012-01-01

    为了完善断层破碎带巷道维修方法,以注浆加固理论为基础,通过注浆材料配比实验,分析不同体积配比条件下,水泥水玻璃与凝固时间、抗压强度的关系,确定水泥水玻璃体积比为1∶0.4的注浆加固最佳配比方案。根据现场实际情况,提出了利用注浆加固技术、U型钢梁棚和喷射混凝土相结合的巷道维修方案,成功解决了现场问题。该研究对于类似矿井的断层破碎带巷道维修具有借鉴意义。%Aimed at improving mine roadway repair in fault fracture zone,this paper,building on grouting reinforcement theory and the experiments of grouting material ratio,presents an analysis of the relation between the geling time and cement-water-glass in different volume ratio conditions,and an analysis of the relation between the compressive strength and cement-water-glass in different volume ratio conditions.The paper features the best volume ratio of cement-water glass of 1:0.4 for grouting reinforcement,offers the mine roadway repair scheme tailored to the grouting reinforcement by combining U-shaped shed with shotcrete according to the practical conditions,and provides a better solution to on-site problems.The research has reference to repairing similar mine roadway with fault fracture zones.

  8. Study on the reinforcement technology of floor roadway with dynamic pressure%动压影响底板巷道加固技术研究

    Institute of Scientific and Technical Information of China (English)

    陈鹏飞

    2016-01-01

    某矿Ⅱ13回风上山原支护采取 U29型钢支护,受上覆工作面跨采影响,巷道维护极其困难。通过分析 U 型钢支护破坏的原因,决定采取高强锚网索高强补强支护。数值模拟分析结构表明,高强锚网索支护对帮顶支护结构的薄弱部位进行加强支护,对帮中和顶中位置的弯矩分布改善最为明显,现场工业性试验结果表明:巷道加固效果良好,巷道围岩变形得到有效控制。%Affected by the cross mining, a mine II 13 return air rise that adopted in the U29 type steel support, and the roadway maintenance extremely difficult. The reasons for the failure of U type steel support are analyzed, and the high strength reinforcement support with high strength anchor mesh cable is determined. Numerical simulation analysis shows that, high-strength bolt mesh cable support added the support strengthen of the weak parts which has help for the obvious improvement of the moment distribution in the top position, the industrial test results show that the roadway reinforcement effect is good, the surrounding rock of roadway deformation effectively control.

  9. 弱胶结软岩巷道支护技术研究%Study on Support Technology of Weakly Consolidated Soft Rock Roadway

    Institute of Scientific and Technical Information of China (English)

    任冬冬; 周纪华

    2013-01-01

    Roadway surrounding rock in Yili No.1 mine belongs to the weakly consolidated soft rock in western and has the characteristics with low strength and poor cement. As applying the results of the rock physical-mechanical properties research and combined with in-situ stress spatial distribution, a new support concept with “moderate release the pressure, enhanced support, coupling deformation, combination of active and passive support, key position reinforcement”was introduced on the basis of analyzing the main cause of deformation and failure of surrounding rocks in inclined shafts. In the process of practice production it brings good supporting effect through applying it in conducting roadway excavation, support technology. The roadway stability control can be achieved ultimately.%  伊犁一矿巷道围岩属于西部弱胶结软岩,具有强度低、胶结差等特性,应用岩石物理力学测试结果,配合地应力空间分布情况,在分析该矿主斜井围岩变形破坏的原因的基础上,提出了“适度让压、强化支护、耦合变形、主被动支护相结合、关键部位补强”的新支护理念,通过该支护理念指导巷道开挖、支护工艺,在实践生产过程中取得了良好的支护效果,最终实现了巷道的稳定性控制。

  10. Workforce issues in rural surgery.

    Science.gov (United States)

    Lynge, Dana Christian; Larson, Eric H

    2009-12-01

    Almost one quarter of America's population and one third of its landmass are defined as rural and served by approximately 20% of the nation's general surgeons. General surgeons are the backbone of the rural health workforce. There is significant maldistribution of general surgeons across regions and different types of rural areas. Rural areas have markedly fewer surgeons per population than the national average. The demography of the rural general surgery workforce differs substantially from the urban general surgery workforce, raising concerns about the extent to which general surgical services can be maintained in rural areas of the United States.

  11. 利用卸压槽治理软岩巷道底鼓%Pressure Releasing Groove Applied to Floor Heave Control of Mine Sof t Rock Roadway

    Institute of Scientific and Technical Information of China (English)

    郝建斌; 魏巍; 董长龙

    2014-01-01

    在建矿井奇台一矿主采B3煤层,厚度约22m ,埋深518~540m。中央辅助运输大巷沿煤层底板掘进。底板属极软岩,遇水易膨胀,出现底鼓现象。巷道掘进后,底板即鼓起,且速度较快,平均底鼓速度达10mm/d ,原采用常规浇筑混凝土底板的办法来加以治理,未获成功。后根据具体情况,在巷道底板中间开挖卸压槽,并采用反底拱支护方式来治理底鼓,效果良好,为软岩巷道底鼓治理提供了新的经验。%In a construction mine of Qitai No.1 mine ,a main mining seam was B3 seam ,a thickness of the seam was about 22m and a depth of the seam was 518~540m. A mine central auxiliary transporta‐tion roadway was headed along the seam floor. The seam floor was an ultra soft rock ,could be easily swelled with water and would cause a floor heave phenomenon.After the mine roadway headed ,the floor would be soon heaved ,the heave speed was fast and an average floor heave speed was 10mm/day. A previous conventional method with a site pouring concrete floor was applied to control the floor heave and the method was not success.Late ,according to the certain condition ,a pressure releasing groove was excavated in the middle of the mine roadway ,a reverse floor arch support method was ap‐plied to control the floor heave and excellent effect was obtained. Thus a new experience was provided to the floor heave control of the mine soft rock roadway.

  12. Pedagogy for rural health.

    Science.gov (United States)

    Reid, Stephen J

    2011-04-01

    As the body of literature on rural health has grown, the need to develop a unifying theoretical framework has become more apparent. There are many different ways of seeing the same phenomenon, depending on the assumptions we make and the perspective we choose. A conceptual and theoretical basis for the education of health professionals in rural health has not yet been described. This paper examines a number of theoretical frameworks that have been used in the rural health discourse and aims to identify relevant theory that originates from an educational paradigm. The experience of students in rural health is described phenomenologically in terms of two complementary perspectives, using a geographic basis on the one hand, and a developmental viewpoint on the other. The educational features and implications of these perspectives are drawn out. The concept of a 'pedagogy of place' recognizes the importance of the context of learning and allows the uniqueness of a local community to integrate learning at all levels. The theory of critical pedagogy is also found relevant to education for rural health, which would ideally produce 'transformative' graduates who understand the privilege of their position, and who are capable of and committed to engaging in the struggles for equity and justice, both within their practices as well as in the wider society. It is proposed that a 'critical pedagogy of place,' which gives due acknowledgement to local peculiarities and strengths, while situating this within a wider framework of the political, social and economic disparities that impact on the health of rural people, is an appropriate theoretical basis for a distinct rural pedagogy in the health sciences.

  13. Medical graduates becoming rural doctors: rural background versus extended rural placement.

    Science.gov (United States)

    Clark, Tyler R; Freedman, Saul B; Croft, Amanda J; Dalton, Hazel E; Luscombe, Georgina M; Brown, Anthony M; Tiller, David J; Frommer, Michael S

    2013-12-16

    To determine whether recruitment of rural students and uptake of extended rural placements are associated with students' expressed intentions to undertake rural internships and students' acceptance of rural internships after finishing medical school, and to compare any associations. Longitudinal study of three successive cohorts (commencing 2005, 2006, 2007) of medical students in the Sydney Medical Program (SMP), University of Sydney, New South Wales, using responses to self-administered questionnaires upon entry to and exit from the Sydney Medical School and data recorded in rolls. Students' expressed intentions to undertake rural internships, and their acceptance of rural internships after finishing medical school. Data from 448 students were included. The proportion of students preferring a rural career dropped from 20.7% (79/382) to 12.5% (54/433) between entry into and exit from the SMP. A total of 98 students took extended rural placements. Ultimately, 8.1% (35/434) accepted a rural internship, although 14.5% (60/415) had indicated a first preference for a rural post. Students who had undertaken an extended rural placement were more than three times as likely as those with rural backgrounds to express a first preference for a rural internship (23.9% v 7.7%; χ(2) = 7.04; P = 0.008) and more than twice as likely to accept a rural internship (21.3% v 9.9%; χ(2) = 3.85; P = 0.05). For the three cohorts studied, rural clinical training through extended placements in rural clinical schools had a stronger association than rural background with a preference for, and acceptance of, rural internship.

  14. Rural Science Education Program

    Energy Technology Data Exchange (ETDEWEB)

    Intress, C. [New Mexico Museum of Natural History and Science, Albuquerque, NM (United States)

    1994-12-31

    The Rural Science Education Project is an outreach program of the New Mexico Museum of Natural History and Science with the goal of helping rural elementary schools improve science teaching and learning by using local natural environmental resources. This program is based on the assumption that rural schools, so often described as disadvantaged in terms of curricular resources, actually provide a science teaching advantage because of their locale. The natural environment of mountains, forests, ponds, desert, or fields offers a context for the study of scientific concepts and skills that appeals to many youngsters. To tap these resources, teachers need access to knowledge about the rural school locality`s natural history. Through a process of active participation in school-based workshops and field site studies, teachers observe and learn about the native flora, fauna, geology, and paleontology of their community. In addition, they are exposed to instructional strategies, activities, and provided with materials which foster experimential learning. This school-museum partnership, now in its fifth year, has aided more than 800 rural teachers` on-going professional development. These educators have, in turn, enhanced science education throughout New Mexico for more than 25,000 students.

  15. Agriculture and Rurality: Beginning the "Final Separation"?

    Science.gov (United States)

    Friedland, William H.

    2002-01-01

    When is a farm a farm? When is rural rural? Has the issue of the rural-urban continuum returned? Decades ago rural sociology worked itself into two blind alleys: rural-urban differences and attempts to define the rural-urban fringe. Although these conceptual problems eventually were exhausted, recent developments in California raise the…

  16. Researching Rural Places: On Social Justice and Rural Education

    Science.gov (United States)

    Roberts, Philip; Green, Bill

    2013-01-01

    This paper explores some of the political and methodological challenges involved in researching rural education. It begins by outlining the situation in Australia regarding the relationship between social justice and rural education. It first describes the disadvantages experienced by many rural communities and presents an analysis of rural…

  17. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>The Rural Development Foundation (RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college in Andhra

  18. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>The Rural Development Foundation ( RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providin gquality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college in

  19. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>The Rural Development Foundation ( RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children. RDF founded and continues to operate five schools

  20. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>The Rural Development Foundation ( RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college in

  1. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>The Rural Development Foundation(RDF),founded in1996,is an Indian nonprofit organization with the mission of providingquality education for underprivileged rural children.RDF founded and continues to operate five schools and one junior college in

  2. 渗水泥化巷道锚杆支护围岩稳定性控制研究%Surrounding rock stability control with bolt support in seepage argillaceous roadway

    Institute of Scientific and Technical Information of China (English)

    王成; 韩亚峰; 张念超; 钱德雨

    2014-01-01

    Because of the poor reliability of bolt support in seepage argillaceous roadway, roof fall accidents occur frequently. In this paper, typical rock disintegration and weathering experiments, field tests of roadway deformation rules and bolt anchorage performance in water seepage roadways were studied. The results indicate that once the clay mineral in roadway surrounding rock meet water, the rock will become sliming and weathering embrittlement, which will cause a sharply decrease in the load bearing capability. In addition, the deformation of seepage argillaceous roadway has obvious stage cha-racteristics, which shows whole process of “decelerated deformation-weak argillization-accelerated deformation-strong argillization-instability”. Thus, the key point of stability control in such roadway is to control the argillaceous process effectively. Meanwhile, the surrounding rock control technology in seepage argillaceous roadway was proposed, which is composed of “there-high” bolt enhancement technology and lag grouting strengthening technology. Moreover, the best grouting time which is 10 to 30 days after the roadway drivage was given, engineering practice was then conducted, and good results were obtained.%渗水泥化巷道锚杆支护可靠性差,导致此类巷道冒顶事故频发。通过典型岩样崩解和风化实验、渗水泥质巷道变形规律及锚杆锚固性能实测开展研究。结果表明:煤系地层含有黏土类矿物,使得巷道围岩遇水崩解,发生泥化现象,且风化脆裂,导致自身承载力急剧降低;渗水泥质巷道围岩变形破坏具有明显阶段性,演绎“减速变形-弱泥化-加速变形-强泥化-失稳”全过程,有效控制泥化进程是该类巷道稳定性控制的关键;提出了渗水泥化巷道围岩的控制技术,即新型“三高”锚杆强化控制技术和滞后注浆加固技术,给出巷道掘进后10~30 d最佳注浆时机,开展了典型的工程实践

  3. Modelling of Rayleigh-type seam waves in disturbed coal seams and around a coal mine roadway

    Science.gov (United States)

    Essen, Katja; Bohlen, Thomas; Friederich, Wolfgang; Meier, Thomas

    2007-08-01

    Wave propagation in coal seams is numerically modelled in order to identify approaches towards the reconnaissance beyond the heading face of an advancing coal mine roadway. Complete synthetic wavefields including P-SV body waves and Rayleigh-type seam waves are calculated using a Green's function approach for simple, laterally homogeneous models and a parallel elastic 2-D/3-D finite difference modelling code for more realistic geometries. For a simple three-layer model the wavefield within the seam is dominated by a fundamental Rayleigh seam mode symmetrical with respect to the centre of the seam on the vertical component and antisymmetrical on the horizontal component. If the seam contains an interleaved dirt band with higher velocities and density, higher modes dominate the wave propagation, depending on the thickness of the dirt band. Wave propagation in laterally inhomogeneous coal seam models with disturbances like seam ends, faults, thinning, washouts and seam splitting is strongly influenced by the type of disturbance. Amplitudes of seam waves reflected from these disturbances strongly depend on the fault throw and the degree of thinning or washout. In some cases, conversion to higher modes can occur. In all investigated models, those Rayleigh seam wave phases are preferably reflected, which have frequencies above the fundamental mode Airy phase. Lower frequency phases are preferably transmitted. However, seam waves are not reflected from a seam splitting disturbance. Thus a detection of seam splitting with reflected seam waves appears to be impossible. FD computations for 3-D models containing an ending tunnel parallel to the seam and a source beyond the heading face of the tunnel show that seam waves are converted into Rayleigh waves at the tunnel face. They propagate along the surface of the tunnel and interfere with the seam waves propagating beside the tunnel. This effect has to be taken into account for subsequent treatment of experimental data, where

  4. Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, Minneapolis, MN

    Energy Technology Data Exchange (ETDEWEB)

    Kinzey, Bruce R.; Myer, Michael

    2009-08-31

    relamping fixtures along interstate roadways of between $130-150 per pole. The previous bridge saw a lamp mortality rate of approximately 50% every two years, though the new bridge was designed to minimize many of the vibration issues. A voluntary Web-based feedback survey of nearly 500 self-described bridge users showed strong preference for the LED lighting - positive comments outnumbered negative ones by about five-to-one.

  5. Changes in air quality at near-roadway schools after a major freeway expansion in Las Vegas, Nevada.

    Science.gov (United States)

    Brown, Steven G; McCarthy, Michael C; DeWinter, Jennifer L; Vaughn, David L; Roberts, Paul T

    2014-09-01

    Near-roadway ambient black carbon (BC) and carbon monoxide (CO) concentrations were measured at two schools adjacent to a freeway and at an urban background school 2 km from the freeway to determine the change in concentrations attributable to vehicle emissions after the three-lane expansion of U.S. Highway 95 (US 95) in Las Vegas, Nevada. Between summer 2007 and summer 2008, average weekday small-vehicle volume increased by 40% +/- 2% (standard error). Average weekday large-vehicle volume decreased by 17% +/- 5%, due to a downturn in the economy and an associated decline in goods movement. Average vehicle speed increased from 58 to 69 mph, a 16% +/- 1% increase. The authors compared BC and CO concentrations in summer 2007 with those in summer 2008 to understand what effect the expansion of the freeway may have had on ambient concentrations: BC and CO were measured 17 m north of the freeway sound wall, CO was measured 20 m south of the sound wall, and BC was measured at an urban background site 2 km south of the freeway. Between summer 2007 and summer 2008, median BC decreased at the near-road site by 40% +/- 2% and also decreased at the urban background site by 24% +/- 4%, suggesting that much of the change was due to decreases in emissions throughout Las Vegas, rather than only on US 95. CO concentrations decreased by 14% +/- 2% and 10% +/- 3% at the two near-road sites. The decrease in BC concentrations after the expansion is likely due to the decrease in medium- and heavy-duty-vehicle traffic resulting from the economic recession. The decrease in CO concentrations may be a result of improved traffic flow, despite the increase in light-duty-vehicle traffic. Implications: Monitoring of BC and CO at near-road locations in Las Vegas demonstrated the impacts of changes in traffic volume and vehicle speed on near-road concentrations. However, urban-scale declines in concentrations were larger than near-road changes due to the impacts of the economic recession that

  6. Organizing Rural Health Care

    DEFF Research Database (Denmark)

    Bunkenborg, Mikkel

    2012-01-01

    The liberalization of health care in the course of three decades of ‘reform and opening up’ has given people in rural China access to a diverse range of treatment options, but the health care system has also been marred by accusations of price hikes, fake pharmaceuticals, and medical malpractice....... This chapter offers an ethnographic description of health as an issue in a Hebei township and it focuses on a popular and a statist response to the perceived inadequacy of the rural health care system. The revival of religious practices in rural China is obviously motivated by many factors, but in the township...... in question, various forms of healing play a significant role in religious movements and the rising cost of medical services as well as a general distrust of formal medical institutions seem to be part of the reason why people choose to follow spirit mediums and religious movements that offer alternative...

  7. Modeling driver stop/run behavior at the onset of a yellow indication considering driver run tendency and roadway surface conditions.

    Science.gov (United States)

    Elhenawy, Mohammed; Jahangiri, Arash; Rakha, Hesham A; El-Shawarby, Ihab

    2015-10-01

    The ability to model driver stop/run behavior at signalized intersections considering the roadway surface condition is critical in the design of advanced driver assistance systems. Such systems can reduce intersection crashes and fatalities by predicting driver stop/run behavior. The research presented in this paper uses data collected from two controlled field experiments on the Smart Road at the Virginia Tech Transportation Institute (VTTI) to model driver stop/run behavior at the onset of a yellow indication for different roadway surface conditions. The paper offers two contributions. First, it introduces a new predictor related to driver aggressiveness and demonstrates that this measure enhances the modeling of driver stop/run behavior. Second, it applies well-known artificial intelligence techniques including: adaptive boosting (AdaBoost), random forest, and support vector machine (SVM) algorithms as well as traditional logistic regression techniques on the data in order to develop a model that can be used by traffic signal controllers to predict driver stop/run decisions in a connected vehicle environment. The research demonstrates that by adding the proposed driver aggressiveness predictor to the model, there is a statistically significant increase in the model accuracy. Moreover the false alarm rate is significantly reduced but this reduction is not statistically significant. The study demonstrates that, for the subject data, the SVM machine learning algorithm performs the best in terms of optimum classification accuracy and false positive rates. However, the SVM model produces the best performance in terms of the classification accuracy only.

  8. Social Welfare in Rural Europe.

    Science.gov (United States)

    Shucksmith, Mark; And Others

    1994-01-01

    Literature review on social exclusion and disadvantage in rural Europe suggests that rural poverty arises from unemployment, low wages, and, most significantly, inadequate income in old age. Discusses difficulties in identifying rural incidence of exclusion and disadvantage, as well as the need for such research in light of major ongoing social…

  9. Interdisciplinarity and young rural researchers

    NARCIS (Netherlands)

    Derkzen, P.H.M.; Mustakangas, E.; Gambino, M.; Kucerova, E.

    2006-01-01

    The European Society for Rural Sociology (ESRS) organised a round table discussion for young rural researchers at the XXI ESRS Congress, 22-26 August, 2005 in Keszthely, Hungary. In the discussion, participants focused on interdisciplinarity in rural research from their own personal points of view b

  10. Planning Schools for Rural Communities.

    Science.gov (United States)

    Harmon, Hobart; Howley, Craig; Smith, Charles; Dickens, Ben

    School improvement in rural places cannot succeed without attention to the rural context of learning. Most especially, smaller schools need to be preserved and sustained in rural areas, particularly impoverished communities, for the sake of student achievement and personal development. This school improvement tool suggests the character of a "good…

  11. Juvenile Justice in Rural America.

    Science.gov (United States)

    Jankovic, Joanne, Ed.; And Others

    Producing a much-needed organized body of literature about rural juvenile justice, 14 papers (largely from the 1979 National Symposium on Rural Justice) are organized to identify current issues, identify forces causing changes in current systems, review programs responding to rural juvenile justice problems, and provide planning models to aid…

  12. Rural Mental Health Ecology

    DEFF Research Database (Denmark)

    Wilson, Rhonda L.; Wilson, G. Glenn; Usher, Kim

    2015-01-01

    The mental health of people in rural communities is influenced by the robustness of the mental health ecosystem within each community. Theoretical approaches such as social ecology and social capital are useful when applied to the practical context of promoting environmental conditions which...... maximise mental health helping capital to enhance resilience and reduce vulnerably as a buffer for mental illness. This paper explores the ecological conditions that affect the mental health and illness of people in rural communities. It proposes a new mental health social ecology framework that makes full...

  13. Rural Credit in Vietnam

    DEFF Research Database (Denmark)

    Barslund, Mikkel Christoffer; Tarp, Finn

    This paper uses a survey of 932 rural households to uncover how the rural credit market operates in four provinces of Vietnam. Households obtain credit through formal and informal lenders, but formal loans are almost entirely for production and asset accumulation. Interest rates fell from 1997...... to 2002, reflecting increased market integration; but the determinants of formal and informal credit demand are distinct. Credit rationing depends on education and credit history, but we find no evidence of a bias against women. Regional differences are striking, and a ‘one size fits all’ approach...

  14. Rural energy and development

    Energy Technology Data Exchange (ETDEWEB)

    Stern, R.

    1997-12-01

    The author discusses the worldwide problem and need for rural electrification to support development. He points out that rural areas will pay high rates to receive such services, but cannot afford the capital cost for conventional services. The author looks at this problem from the point of energy choices, subsides, initial costs, financing, investors, local involvement, and governmental actions. In particular he is concerned with ways to make better use of biofuels, to promote sustainable harvesting, and to encourage development of more modern fuels.

  15. Teachers as Rural Educators

    Science.gov (United States)

    Kristiansen, Andrew

    2014-01-01

    In the article, education is seen as a hierarchical cultural encounter between urban and rural values and ways of life. Good teachers do not only deliver curriculum, they also consider the needs and values of their students, as well as those of the local community. The article discusses how teachers' competence, knowledge and attitudes can affect…

  16. Rural Lending Reform

    Institute of Scientific and Technical Information of China (English)

    FIONAWANG

    2005-01-01

    Impended by the lack of a rural financial service network, farmers in China are prone to encounter many difficulties when attempting to secure loans. According to statistics, agriculture accounted for 14.8 percent of China's gross domestic product (GDP) in 2003, but it only used no more than 6 percent of outstanding loans released by all China's financial institutions.

  17. Rural Students Falling Behind

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Access to leading universities more difficult than ever for students from rural areas As a sophomore majoring in English at the Department of Foreign Languages and Literature at Tsinghua University, Zhao Jun has learned the true meaning of "spiritual solitude" over the past year.

  18. Reluctant Rural Regionalists

    Science.gov (United States)

    Hall, Peter V.; Stern, Pamela

    2009-01-01

    Recently, scholars have begun to explore questions of regionalism and regionalization in rural contexts. Regionalism is often understood and presented as a pragmatic solution to intractable problems of fragmentation, inefficiency, accountability, spillover and neglect in the face of economic restructuring and other external threats. These…

  19. Anomia in Rural Nigeria

    Science.gov (United States)

    Odokara, E. O.

    1971-01-01

    Describes the results of a study to determine the relationship of various social and personal factors to adjustment and to identify the attitudes, values and motivations which either facilitate or retard adjustment. Provides guidelines for planning adult education programs to revitalize the rural people in war affected areas. (RB)

  20. Rural Domestic Violence

    Science.gov (United States)

    ... Response (CCR), in which healthcare providers, community groups, criminal justice, and social service agencies work together, is ... Email © 2002–2017 Rural Health Information Hub. All rights reserved. About RHIhub | ... Disclaimer | Privacy Policy | Sitemap Phone: 1-800-270-1898 Email: info@ ...

  1. Accident rates related to rural road geometry elements and daily traffic

    CSIR Research Space (South Africa)

    Skinner, DG

    1994-02-01

    Full Text Available The available data bases for accidents, road geometry (photolog output) and traffic counts were combined and the accident rates determined for two lane, four lane and six lane road categories as well as for 22 geometric element categories...

  2. Analysis on Narrow Coal Pillar Supporting Technology in Roadway Drilling of Coal Mine Insular Face%煤矿孤岛面顺槽掘进窄煤柱支护技术分析

    Institute of Scientific and Technical Information of China (English)

    张继兵

    2011-01-01

    淮南矿业集团顾桥煤矿1116(1)工作面运输顺槽为沿空掘进巷道,并受上方1117(3)工作面回采采动影响。为研究巷道在上方工作面回采时围岩变形特征、围岩应力分布及矿压显现规律,特在采动范围内设置一系列矿压观测点对巷道两帮变形、锚杆锚索及木点柱载荷进行持续观测,为将来巷道的支护提供可靠的分析数据。%1116(1) working section transport roadway in Guqiao mine of Huainan Mining Group is a roadway along the goof,and it is impacted by the above 1117(3) working section.To study the character of the deformation of the rock,stress distribution and pressure behavior law around the road,a series of mining pressure observation point on the roadway deformation,anchor and wood column load for continuous observation are set.And the observation will provide reliable analysis of data for the future roadway support.

  3. 岩巷过断层破碎带联合支护技术的应用%Application of Combined Support Technology of Crossing Fault Fracture Zone in Rock Roadway

    Institute of Scientific and Technical Information of China (English)

    彭荣; 彭斌武

    2014-01-01

    The characteristic of loose ,soft ,low strength ,easy expansion and plasticity rheology of fault fracture zone surrounding rock increased the difficulty of rock roadway driving and supporting .Combined supporting tech-nology of arching + support arch + floor ram + grouting behind segment was used while crossing geological fracture zone at -380 m level east roadway in Xifenglun Colliery ,according to one year of observation ,the big-gest level displacement of roadway wall was 20 mm ,the largest convergence of roof and floor was 4 mm ,which effectively controlled the roadway deformation of fracture zone .%断层破碎带围岩具有松散、软弱等特征,强度低,易膨胀和发生塑性流变,增加了岩巷掘进与支护的困难。西峰仑煤矿-380 m水平东大巷过地质破碎带时采用砌碹+拱形支架+底板捣制+壁后注浆联合支护技术,根据1年的观测,巷道帮部最大水平位移20mm,顶底板最大移近量4mm,有效地控制了破碎带巷道的变形。

  4. Technology of Roadway Support of High Confined Water Fault under Instability State with Long -term Rheology%高承压水致断层长期流变失稳状态下巷道支护技术

    Institute of Scientific and Technical Information of China (English)

    丁允杰; 张浩

    2014-01-01

    Aiming at the supporting problems of fracture zone large -scale roadway under instability state with long -term rheology ,the paper analyzed roadway confined water and the changing of surrounding rock flowing mud argillization ,used effective relieving confined water technology and strong rheology spurting prevention technology ,researched and developed roadway supporting technology of pillar displacement ,large floor support-ing blocking and slow releasing superposition stress ,which proved supporting stability was improving compared with traditional support and provided examples for similar roadway supporting .%针对断层破碎带大断面巷道在长期流变与泥化失稳围岩状态下的支护问题,从分析巷道承压水、围岩泥流体泥化变化入手,采取有效的导解承压水技术、防强流变突喷技术,研发以点柱置换、大板底支护封堵、缓释叠加应力为特点的巷道支护技术,支护稳定性较传统支护显著提高,为同类巷道支护提供范例。

  5. Rigorous and asymptotic models of coherent scattering from random rough layers with applications to roadways and geoscience

    Science.gov (United States)

    Pinel, Nicolas; Bourlier, Christophe; Le Bastard, Cédric

    2014-05-01

    This paper presents the rigorous efficient PILE (Propagation-Inside-Layer Expansion) numerical method [1] and an extension of the Ament model [2] to calculate the field scattered by three homogeneous media separated by two random rough surfaces. Here, the study is applied to ground penetrating radar (GPR) (nadir angle, wide band) for nondestructive survey by taking the roughness of the surfaces into account and by calculating the contribution of each echo coming from the multiple scattering inside the layer. Applications to roadways and geoscience are investigated. The PILE method starts from the Method of Moments (MoM), and the impedance matrix is inverted by blocks from the Taylor series expansion of the inverse of the Schur complement. Its great advantage is that it is rigorous, with a simple formulation and has a straightforward physical interpretation. Actually, this last property relies on the fact that each block of the impedance matrix is linked to a particular and quasi-independent physical process occurring during the multiple scattering between the two rough surfaces. Furthermore, the PILE method allows us to use any acceleration algorithm (MLFMM, BMIA/CAG, Forward-Backward with or without Spectral Acceleration, etc.) developed for a single interface. In addition, an asymptotic approach is extended to rough layered media: the scalar Kirchhoff-tangent plane approximation (SKA), for calculating the coherent scattering from the rough layer. The numerical rigorous PILE method is used as a reference to validate this asymptotic model. The study focuses on 2D problems with so-called 1D surfaces, for computational ease of the reference numerical method. Nevertheless, it must be highlighted that the SKA approach can readily be applied to 3D problems. This approach is applied to rough layers with two slightly rough surfaces characterized by either Gaussian or exponential correlation functions. The height probability density function (PDF) is assumed to be Gaussian

  6. [Environment and rural development].

    Science.gov (United States)

    Dufumier, M

    1992-01-01

    Management of natural resources and preservation of ecological balance are perceived today as essential elements of rural development. The recently multiplying environmental ministries in developing countries are intended not only to correct the damages resulting from uncontrolled urbanization and industrialization, but to address ecosystemic degradation in the countryside. The aptitude demonstrated by numerous peasant societies for exploiting their environments over the long term while preserving their potential should be recognized and their specific, detailed knowledge incorporated into environmental protection projects. It is a mistake to conclude that peasants do not care about environmental problems; they often lack the resources to take needed action. Active participation of impoverished rural dwellers requires that measures taken do not reduce their incomes or resources in the short term. Rural development projects must assure protection of the environment while taking into account the interests of diverse categories of rural dwellers, such as farmers, herders, or wood cutters. There has been considerable progress in the past 2 decades in understanding the functioning of cultivated and pasture ecosystems and in developing techniques to limit damage to them. A vast effort is now needed to understand the economic, social, and cultural functions of customs and practices of different social groups involved in agricultural development and territorial management in order to prioritize problems and arrive at a consensus of all those affected concerning environmental protection. Social science research is needed into marketing of agricultural products, circulation of cooking fuels, village-town relations, and migration in order to determine the effects of these phenomena on management and conservation of natural resources in rural areas. Experimental research should be directed toward finding practical solutions to problems encountered by rural cultivators

  7. Institucionalidad y desarrollo rural

    Directory of Open Access Journals (Sweden)

    Laureano Ruiz Camargo

    2016-04-01

    Full Text Available La institucionalidad entendida como el conjunto de normas y reg las formales e informales que regulan una comunidad determinada puede influir al impulsar y acrecentar el desarrollo rural o también frenarlo, permitiendo o no la participación o también obstaculizando la organización y la expresión de las comunidades rurales; lo cual puede reflejarse en carencias de sentido económico, social y cultural. Estas temáticas han sido exploradas en el presente trabajo, mediante el contacto directo con las comunidades rura les del municipio de Paipa (Boyacá y complementado con la revisión teórica a nivel bibliográfica sobre los temas de la institucionalidad y el desarrollo rural sustentable. Dada la importancia de las familias campesinas asentadas en estos territorios de minifundios y economía campesina, en la reproducción de su propia subsistencia y el aporte a la producción de bienes para la alimentación de la población urbana y suministro de mano de obra necesaria en la prestación de servicios y la industria nacional, se encontró que las carencias de tipo económico y social por parte de la población se reflejan en índices de pobreza elevada, debido a la poca capacidad de consumo y acumulación, pues la propiedad privada sustentada en el minifundio utilizado en actividades agropecuarias no genera ingresos suficientes para financiar la alimentación, la educación, la salud, la vivienda, la recreación y tampoco posibilita el ahorro. Por otra parte, la producción de bienes y servicios de origen rural es vendida o intercambiada en el mercado a precios por debajo de los costos de producción, con lo cual se transfiere la riqueza producida en el campo hacia la ciudad, reproduciéndose el circulo de la pobreza rural donde la institucionalidad practicada y existente no permite la participación de los habitantes rurales en la toma de decisiones; entre otras cosas, porque carecen de organización y liderazgo y porque tradicionalmente la

  8. Study on Roadway Reinforcement Technique by Retractable Circular Support and Backfilling Grouting%可缩性圆形支架壁后充填注浆加固技术研究

    Institute of Scientific and Technical Information of China (English)

    李书民; 孙小岩; 张丰

    2011-01-01

    By analyzing the failure of traditional support by 36 U-shaped steel and wire mesh in the track dip in Changcun coal mine, it can be concluded that anchoring property is the primary cause for the low anchorage force and the poor effect of anchoring. Through analyzing the cross section of roadway and roadway reinforcement theory by backfilling grouting, roadway reinforcement technique by retractable circular support and backfilling grouting is put into effect This industrial practice demonstrates that this technique can solve the matter of deformation failure of soft rock roadway and can be used in other roadways with the similar situation in Changcun coal mine.%通过对常村煤矿轨道下山采用锚网(索)+ 36U型钢等常规支护形式失败的原因进行分析,得出巷道可锚性差是造成锚杆锚固力低和锚固效果差的主要因素;同时对巷道断面的选择和壁后充填注浆加固机理的分析,提出采用可缩性圆形支架壁后充填注浆加固技术.实践证明,采用可缩性圆形支架壁后充填注浆加固技术可有效解决软岩巷道变形的难题,为常村煤矿类似的巷道提供了一个有效的支护新途径.

  9. Effect of vehicle speed and roadway surface condition on the random dynamic loads of the wheels%车轮随机动载与路面及车速相互关系的研究

    Institute of Scientific and Technical Information of China (English)

    郑泉; 杨方廷

    2001-01-01

    文章利用车辆的两自由度模型,分析了车速与路 面不平度对车轮随机动载的功率谱密度和方差变化趋势的影响。同时也分析了车轮随机动载 的大小对路面疲劳应力的影响,指出了不同的车速和路面状况引起的路面动力反应及损伤变 化规律的不同,提出了针对路面状况来调整车速可以降低车轮随机动载,从而达到减轻对路 面损伤的要求。%By setting up a two-degree-of-freedom vehicle mode l,this paper analyzes the effect of vehicle speed and roadway surface condition on the random dynamic loads of the wheels. The effect of the random dynamic load s of the wheels on the fatigue stress of the roadway is also analyzed. The analy tic result shows that the different vehicle speed and roadway surface condition cause different changes in the dynamic response and fatigue damage of the roadwa y.It is put forward that the demand of reducing the random dynamic loads of the wheels can be met by properly considering the relation between vehicle speed an d roadway surface condition,so that the damage of the roadway can be decreased.

  10. Road Networks Winter Risk Estimation Using On-Board Uncooled Infrared Camera for Surface Temperature Measurements over Two Lanes

    Directory of Open Access Journals (Sweden)

    M. Marchetti

    2011-01-01

    Full Text Available Thermal mapping has been implemented since the late eighties to establish the susceptibility of road networks to ice occurrence with measurements from a radiometer and some atmospheric parameters. They are usually done before dawn during wintertime when the road energy is dissipated. The objective of this study was to establish if an infrared camera could improve the determination of ice road susceptibility, to build a new winter risk index, to improve the measurements rate, and to analyze its consistency with seasons and infrastructures environment. Data analysis obtained from the conventional approved radiometer sensing technique and the infrared camera has shown great similarities. A comparison was made with promising perspectives. The measurement rate to analyse a given road network could be increased by a factor two.

  11. Rural Develoment Policies and Rural Governability: the Andalusian case

    OpenAIRE

    López Moreno, Ignacio; Aguilar Criado, Encarnación; Lozano Cabedo, Carmen; Pérez Chueca, Alberto

    2009-01-01

    Since the beginning of the 90s, the EU Rural Development Policy (RDP) embodied on different programmes and initiatives -such as Leader- has been changing the institutional way to approach rural communities among State Members. This new policy has been introducing new ideas such as multi-level governance or bottom-up decision making process, which have unfolded a new model of rural governance in Europe. Therefore, the hypothesis of this p...

  12. RURAL MARKETS IN BANGLADESH AND THE RURAL MAINTENANCE PROGRAMME

    OpenAIRE

    Uddin, M. Mosleh; Kabir, M.; Alam, M. Mostafa; Boss, G. K.

    1989-01-01

    This study describes the Impact of rural maintenance programme on rural markets in Bangladesh. Rural Maintenance programme (RMP) is a year-round programme for maintenance ol 16 miles earthen roads In each selected union. The programme is run by crews consisting of 15 destitute women. The findings suggest that better road maintenance by RMP in the programme areas has resulted in more traffic f low through which the markets in the programme areas have been expanded. Better supply of services su...

  13. Rural health clinics infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Olson, K.

    1997-12-01

    The author discusses programs which were directed at the installation of photovoltaic power systems in rural health clinics. The objectives included: vaccine refrigeration; ice pack freezing; lighting; communications; medical appliances; sterilization; water purification; and income generation. The paper discusses two case histories, one in the Dominican Republic and one in Colombia. The author summarizes the results of the programs, both successes and failures, and offers an array of conclusions with regard to the implementation of future programs of this general nature.

  14. Mechanism of Floor Heave and Control Technology of Roadway Induced by Mining%采动巷道底鼓机理与控制技术

    Institute of Scientific and Technical Information of China (English)

    柏建彪; 李文峰; 王襄禹; 徐营; 霍灵军

    2011-01-01

    采用理论分析、数值计算、现场钻孔窥视等方法研究分析了采动巷道底板变形破坏特征,揭示了浅部鼓起、深部下沉的底鼓机理,进一步分析了不同深度底板岩层的位移规律,发现了底鼓的"两点三区"特征:即采动巷道底板存在零位移点、零应变点,由这两个点将采动巷道底板分为拉应变上升区、拉应变压缩区、压应变压缩区.研究得到了底板岩性、水平应力对底鼓特征的影响规律,据此提出采动巷道底鼓控制重点是加固破碎底板,增大其峰后强度和残余强度,以加固的方法实现改良底板岩性,同时尽量减小底板自由面积,控制水平应力对底鼓的影响.提出了采动巷道底鼓控制技术:1)优化巷道布置以降低围岩应力环境;2)采用全长锚固的水力膨胀锚杆加固底板.并在一条典型的煤柱采动巷道进行工程应用,现场应用结果表明该技术控制底鼓效果显著.%With theoretical analysis, numerical computation, observation through boring, the figure of floor heave of roadway affected by mining is analyzed, finding the mechanism of floor heave is that the shallow strata are likely to heave whereas the deep strata are likely to sink down.Meanwhile, the law of displacements of different depths for strata is discussed, with conclusion“two dots and three areas” in floor:zero displacement dot and zero strain dot.On the basis of this, the floor can be divided into three areas: tensional strain rising area, tensional strain sinking areas, and compressive strain sinking areas.Furthermore, the effect of floor surrounding rock and horizontal stress on floor heave features is discussed.Then some research views have been proposed to control the floor heave of roadway affected by mining which we should support the broken floor in order to increase the intensity after peak and residual intensity, improve the floor surrounding rock hy supporting, reduce the size of floor without

  15. Quantification of rural livelihood dynamics

    DEFF Research Database (Denmark)

    Walelign, Solomon Zena

    of both forest and non-forest environmental resources towards poverty reduction, (ii) to reduce poverty faster, policies should enable households in low remunerative livelihood strategies to move to medium remunerative livelihood strategies/high remunerative livelihood strategies, while protecting......Improved understanding of rural livelihoods is required to reduce rural poverty faster. To that end, this PhD study quantified rural livelihood dynamics emphasizing (i) the role of environmental resources use in helping rural households to escape poverty, (ii) development of a new approach...... for livelihood strategy clustering, (iii) assessment dynamics in rural livelihood strategies, and (iv) the effect of attrition on rural livelihood dynamics assessments. A wide range of quantitative methods were employed using a unique environmentally augmented panel dataset combined with tracking attrite...

  16. Stability Control of Underground Roadways Subjected to Stresses Caused by Extraction of a 10-m-Thick Coal Seam: A Case Study

    Science.gov (United States)

    Chen, Yong; Ma, Shuqi; Yu, Yang

    2017-09-01

    Extraction of a 10-m-thick coal seam in one single lift using the longwall top coal caving method caused severe deformations in underground roadways in Majialiang coal mine in Shanxi Province, China. Field monitoring of stress changes in the roof and in the coal pillar, and deformation of the 14202 tailgate, were carried out. The deformation monitoring found that the maximum floor heave of the 14202 tailgate was 1.85 m when the monitoring point was 250 m behind the longwall working face, while the maximum roof subsidence and the maximum rib-rib convergence was 0.93 and 1.14 m, respectively. The deformation rate of the 14202 tailgate increased dramatically when the monitoring point was at distances of 100-150 m behind the longwall working face, which reflected the fact that the tailgate underwent sharply increased loads within this range. Field monitoring of stress changes and the displacement of the 14202 tailgate revealed that the impact range of the mining-induced stresses in longitudinal direction (the same as the mining direction) was from 60 m ahead of the longwall face to 250 m behind the longwall face. Additionally, the mining impact range in transverse direction was more than 45 m, indicating that the coal pillar width should be larger than 45 m to avoid significant influences of mining-induced stresses. This finding was applied to the 14103 tailgate, which was subjected to similar mining and geological conditions as the 14202 tailgate. A coal pillar with width of 56 m was adopted in the 14103 tailgate, and displacement monitoring showed that large deformation was successfully controlled. The field investigations in this study provide a basis for design of a proper coal pillar width of underground roadways when subjected to large stresses induced by mining of thick coal seams in a single lift.

  17. Safety Hoisting Intelligent Monitoring and Control System of Mine Inclined Roadway%斜巷安全提升智能监控系统

    Institute of Scientific and Technical Information of China (English)

    耿延方; 孟维波

    2014-01-01

    斜巷安全提升智能监控系统主要是为防止矿井斜巷运输中发生跑车、溜车、断绳等事故而研发的。这些事故不仅会对提升系统造成破坏,更会给工人人身安全带来严重威胁。扼要介绍了该智能监控系统工作原理、功能、安装方法、操作要点及主要特点。该智能监控系统适用于煤矿、金属矿山等所有倾角在40°以下的轨道提升运输斜巷,可对矿车运行提供有效保护。%A safety hoisting intelligent monitoring and control system of a mine inclined roadway was mainly researched and developed to prevent a car running,sliding car,rope breaking and other acci dent• Those accidents would not only cause a failure to the hoisting system of the mine,but also would bring serious threats to the personal safety of the miners.The paper briefly introduced the working principle,function,installation method,key points of the operation and main features of the intelligent monitoring and control system.The intelligent monitoring and control system would be suitable ap plied to the coal mine,metal mine and all railway hoisting inclined roadways with a inclination bellow 40° and could provide an effective protection to the mine car operation.

  18. School Reform for Rural America

    Science.gov (United States)

    Fishman, Dan

    2015-01-01

    Overall, one in four rural children live in poverty, and of the 50 U.S. counties with the highest child-poverty rates, 48 are rural. Drug usage abounds. In the mid-2000s, rural 8th graders were 59 percent more likely than peers in large cities to use methamphetamines and 104 percent more likely to use any amphetamine, according to the National…

  19. Alba County - Rural Tourism Destination?

    Directory of Open Access Journals (Sweden)

    Claudia Olimpia Moisa

    2016-12-01

    Full Text Available The purpose of this paper is to identify the main rural touristic resources available in Alba County and also the preferred tourist destinations, highlighting the role and the importance of the rural tourism and agro-tourism in the economy of Alba County and, not least, identifying the main direction for its development and promotion. In other words, the aim of this paper is to answer the question "Is it or not Alba County a rural tourist destination?"

  20. Greenways for rural sustainable development

    DEFF Research Database (Denmark)

    Ottomano Palmisano, Giovanni; Govindan, Kannan; Loisi, Rosa V.

    2016-01-01

    within the CAP because they help to protect and manage environmental heritage, promote economic activities and enhance the social assets of rural areas; furthermore, given their natural ability to simultaneously connect these resources, greenways promote Rural Sustainable Development (RSD......Policy makers have recently begun to agree on environmental, economic and social aspects of rural areas that are enhanced according to the European Union (EU) Common Agricultural Policy (CAP), and in particular in the national Rural Development Programmes (RDPs).Greenways are an acknowledged tool...

  1. Urban-rural migration and cultural transformation of rural areas

    DEFF Research Database (Denmark)

    Nørgaard, Helle

    loss but also due to in-migration. This paper addresses how rural communities change due to urban-rural migration by investigating reasons and motivations that influence migration decisions, studying relations between newcomers and local residents and exploring social relations and sense of belonging...

  2. ROLE OF RURAL TOURISM FOR DEVELOPMENT OF RURAL AREAS

    Directory of Open Access Journals (Sweden)

    Andrej Udovč

    2001-09-01

    Full Text Available The paper analyse the role of rural tourism for the development of rural areas, on the comparison of two regions with different types of rural tourism. One area is of highly diversifi ed rural tourism with wide range of tourist products (rafting, hiking, cycling, farm tourism, skiing …. The tourism offer in the second area is much more uniform (mainly farm tourism and some spa. The study analysed how the two different types of tourist product diversifi cations influence the development possibilities of studied rural areas. We analysed how different systems are able to maintain its functions in the context of identifi ed perturbations (socio-economic and geophysical. We analysed the infl uence of different factors on systems stability, its resilience, robustness and integrity. The gained results show that only the higher level of diversifi cation is not a guarantee for systems higher stability, resilience, robustness and integrity, but there also other

  3. Instalaciones para hotel rural

    OpenAIRE

    Roig Riera, José Antonio

    2015-01-01

    El presente proyecto cuenta con la información necesaria para el desarrollo de las instalaciones de un hotel rural. Dichas instalaciones son; la eléctrica, la de agua caliente sanitaria, las telecomunicaciones y la climatización. En el apartado de la instalación eléctrica, se han calculado todos los cables necesarios para el correcto funcionamiento del hotel, partiendo de las potencias demandadas en cada punto de consumo. Se ha calculado la línea general de alimentación, acomet...

  4. Crecimiento en escolares rurales

    OpenAIRE

    Bolzán,Andrés Guillermo; Guimarey, Luis Manuel

    1996-01-01

    Con el objeto de identificar las curvas de peso y talla y evaluar el efecto del nivel educativo y ocupacional en escolares del distrito rural de General Lavalle (Provincia de Buenos Aires),se llevó a cabo en 1992 un estudio transversal en 366 escolares (80% de la matrícula). Se midieron el peso y la talla, codificando la ocupación y educación institucional de los padres en dos clases: baja y alta. Los datos antropométricos se convirtieron a score z, agrupando -debido al N- las edades. Los res...

  5. Chile rural electrification cooperation

    Energy Technology Data Exchange (ETDEWEB)

    Flowers, L. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-01

    The author describes a joint program to use renewables for rural electrification projects in Chile. The initial focus was in a limited part of the country, involving wind mapping, pilot project planning, training, and development of methodologies for comparative evaluations of resources. To this point three wind hybrid systems have been installed in one region, as a part of the regional private utility, and three additional projects are being designed. Additional resource assessment and training is ongoing. The author points out the difficulties in working with utilities, the importance of signed documentation, and the need to look at these programs as long term because of the time involved in introducing such new technologies.

  6. The Struggle of Rural Mexico.

    Science.gov (United States)

    Esteva, Gustavo; And Others

    Diverse aspects of rural problems and the social organization of Mexican labor are explored in this summary of Mexican rural history. Achnowledging Mexico's rich, unexhausted, and unexplored natural resources, Mexico is described as a poverty-stricken, hungry nation, with high degrees of malnutrition, deprivation, and illiteracy heavily…

  7. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>The Rural Development Foundation ( RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providingquality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college inAndhra Pradesh State,

  8. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The Rural Development Foundation(RDF),founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children.RDF founded and continues to operate five schools and one junior college in Andhra Pradesh State,taking a unique holistic approach to education through innovative programs and methodology.Rather than using the

  9. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>The Rural Development Foundation(RDF),founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children.RDF founded and continues to operate five schools and one junior college in Andhra Pradesh State,taking a unique holistic approach to education through innovative programs and methodology.Rather than using the con-

  10. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>The Rural Development Foundation ( RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college in Andhra Pradesh State,taking a unique holistic approach to education through innovative programs and methodology. Rather than

  11. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The Rural Development Foundation(RDF),founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children.RDF founded and continues to operate five schools and one junior college in Andhra

  12. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>The Rural Development Foundation (RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providingquality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college in AndhraPradesh State,taking a unique holistic approach to education through innovative programs and methodology. Rather than using the con-

  13. Rural Adult Education in Australia.

    Science.gov (United States)

    Roberts, Hew

    Adult education in rural areas in Australia provides a contrast both in its general mood and intentions and in its organization with that in the United States. Particularly in rural areas, there seems to be less of the compulsion to organize groups (there are usually no school boards, no chambers of commerce, no women's clubs, no youth centers)…

  14. Noise Exposures of Rural Adolescents

    Science.gov (United States)

    Humann, Michael; Sanderson, Wayne; Flamme, Greg; Kelly, Kevin M.; Moore, Genna; Stromquist, Ann; Merchant, James A.

    2011-01-01

    Purpose: This project was conducted to characterize the noise exposure of adolescents living in rural and agricultural environments. Methods: From May to October, 25 adolescents ages 13 through 17, living either on a farm or a rural nonfarm, were enrolled in the study. Subjects received training on the correct operation and use of personal noise…

  15. The Appalachian Rural Systemic Initiative

    Directory of Open Access Journals (Sweden)

    Stephen A. Henderson

    2000-03-01

    Full Text Available This article was written in response to "Top-Down, Routinized Reform in Low-income, Rural Schools: NSF's Appalachian Rural Systemic Initiative, by Robert Bickel, Terry Tomaskek, and Teresa Hardman Eagle which was published in the Education Policy Analysis Archives as Number 12 of Volume 8 on February 21, 2000.

  16. Mixed embeddedness and rural entrepreneurship

    DEFF Research Database (Denmark)

    Ferguson, Richard; Gaddefors, Johan; Korsgaard, Steffen

    Entrepreneurship is a key driver of development in rural areas. Some studies have shown that in-migrants and returnees are overrepresented among rural entrepreneurs, and that their entrepreneurship might be more important for local development than the efforts of local entrepreneurs, at least......, of the kind that in-migrants and returnees who find a place in a local rurality are likely to embody, may be particularly conducive to entrepreneurial activity. In this paper we explore the nature and function of mixed embeddedness of rural entrepreneurs. We do this through a qualitative multiple case study...... of rural entrepreneurs in the Nordic countries. Preliminary results suggest that mixed embeddedness is in fact important and that this may be the reason for the overrepresentation of in-migrants and returnees....

  17. Mixed embeddedness and rural entrepreneurship

    DEFF Research Database (Denmark)

    Ferguson, Richard; Gaddefors, Johan; Korsgaard, Steffen

    in terms of economic value creation. Other studies have shown that local embeddedness is a significant source of opportunities for rural entrepreneurs, yet at the same time, over-embeddedness can inhibit entrepreneurial activities. These contrasting studies suggest that some form of mixed embeddedness......Entrepreneurship is a key driver of development in rural areas. Some studies have shown that in-migrants and returnees are overrepresented among rural entrepreneurs, and that their entrepreneurship might be more important for local development than the efforts of local entrepreneurs, at least......, of the kind that in-migrants and returnees who find a place in a local rurality are likely to embody, may be particularly conducive to entrepreneurial activity. In this paper we explore the nature and function of mixed embeddedness of rural entrepreneurs. We do this through a qualitative multiple case study...

  18. Mechanical ventilation in rural ICUs.

    Science.gov (United States)

    Fieselmann; Bock; Hendryx; Wakefield; Helms; Bentler

    1999-01-01

    BACKGROUND: In recent years, rural hospitals have expanded their scope of specialized services, which has led to the development and staffing of rural intensive care units (ICUs). There is little information about the breadth, quality or outcomes of these services. This is particularly true for specialized ICU services such as mechanical ventilation, where little, if any, information exists specifically for rural hospitals. The long-term objectives of this project were to evaluate the quality of medical care provided to mechanically ventilated patients in rural ICUs and to improve patient care through an educational intervention. This paper reports baseline data on patient and hospital characteristics for both rural and rural referral hospitals. RESULTS: Twenty Iowa hospitals were evaluated. Data collected on 224 patients demonstrated a mean age of 70 years and a mean ICU admission Acute Physiology and Chronic Health Evaluation (APACHE) II score of 22, with an associated 36% mortality. Mean length of ICU stay was 10 days, with 7.7 ventilated days. Significant differences were found in both institutional and patient variables between rural referral hospitals and rural hospitals with more limited resources. A subgroup of patients with diagnoses associated with complex ventilation had higher mortality rates than patients without these conditions. Patients who developed nosocomial events had longer mean ventilator and ICU days than patients without nosocomial events. This study also found ICU practices that frequently fell outside the guidelines recommended by a task force describing minimum standards of care for critically ill patients with acute respiratory failure on mechanical ventilation. CONCLUSIONS: Despite distinct differences in the available resources between rural referral and rural hospitals, overall mortality rates of ventilated patients are similar. Considering the higher mortality rates observed in patients with complicated medical conditions requiring

  19. Rurality and capital: educational expectations and attainments of rural, urban/rural and metropolitan youth

    National Research Council Canada - National Science Library

    Looker, E Dianne; Andres, Lesley

    2001-01-01

    The Nova Scotia sample involves not a school cohort but a birth cohort. Names and addresses of youth born in 1971 were obtained from school boards in five regions of Nova Scotia, including rural and urban/rural areas as well as Halifax...

  20. The Reported Value of Rural Internal Medicine Residency Electives and Factors That Influence Rural Career Choice.

    Science.gov (United States)

    Jensen, Christine C.; DeWitt, Dawn E.

    2002-01-01

    A survey of 58 medical residents participating in a 1-2 month rural elective and 51 matched nonparticipants found that participants' interest in rural practice increased significantly after the elective. Respondents suggested means to increase rural career choice, barriers to rural practice, and ways of increasing the rural elective's influence on…

  1. Prevalence of Hunger Declines in Rural Households.

    Science.gov (United States)

    Nord, Mark; Winicki, F. Joshua

    2000-01-01

    The prevalence of hunger in rural households declined slightly from 1995 to 1998, and food insecurity rates stayed constant. Food insecurity was almost three times as prevalent among rural Blacks as among rural Whites. For rural Hispanics, the rate was about twice that of Whites. Food insecurity was higher in single-parent families than in any…

  2. The Impact of Agribusiness on Rural Education.

    Science.gov (United States)

    Theobald, Paul

    The dramatic growth of multinational agribusiness corporations has led to all types of rural decline--social, demographic, institutional, and environmental. Historically, rural inhabitants and rural land have been abused and neglected in the name of progress. Rural development efforts often attract small assembly or light manufacturing plants that…

  3. Economic strength in rural New York

    OpenAIRE

    Richard Deitz; Ramon Garcia

    2000-01-01

    In New York State, where economic growth has been sluggish for much of the last decade, the rural economy has done relatively well. The population and labor force in rural areas are expanding, and the number of jobs growing. We take a look at this robust rural economy, examining population and job growth, industrial composition, and income patterns in the state's rural areas.

  4. 77 FR 4885 - Rural Business Investment Program

    Science.gov (United States)

    2012-02-01

    ...-Cooperative Service Rural Utilities Service 7 CFR Part 4290 RIN 0570-AA80 Rural Business Investment Program... the Rural Business Investment Program (RBIP) regulation, including one to conform to the 2008 Farm Bill provision that allows a Rural Business Investment Company two years to raise its capital....

  5. Gender, Class and Rurality: Australian Case Studies

    Science.gov (United States)

    Bryant, Lia; Pini, Barbara

    2009-01-01

    The interrelationship between gender and class in rural spaces has received little attention. While rural scholars have focused on the implications for class from processes of gentrification and agricultural and rural restructuring, these analyses have remained largely ungendered. Similarly, feminist rural studies have rarely explored subjectivity…

  6. Rural Areas Feel Effects of Macroeconomic Policy.

    Science.gov (United States)

    Malley, James R.; Hady, Thomas F.

    1987-01-01

    Diversification of rural economies and changes in financial markets and world trade have broken down many barriers that insulated rural areas in the past. United States rural areas--the rural South and Northeast in particular--now appear to be affected slightly more than urban areas by national monetary and fiscal policies. (JHZ)

  7. APRECIERI ASUPRA FENOMENULUI TURISTIC RURAL

    Directory of Open Access Journals (Sweden)

    Puiu NISTOREANU

    2007-06-01

    Full Text Available The rural areas are rich in their ecological and cultural diversity. The dimension and complexity of the rural communities make difficult a generalization regarding their problems or values, even if some common characteristics exist. For a long time in their existence, the rural communities have relied on the abundance of natural resources. But, in the 20th century, the great technological, political and economical changes have brought a profound transformation in agriculture, and other renewable industrial resources, fact which led the rural communities to a dependency towards these. Although these changes occurred, many reasons for optimism still exist. Involvement of new households in offering touristic services constitutes a new dimension of the development of the rural areas, and on a secondary plane the touristic activity in the rural environment registers new ways of manifestation. Even more, we are able to appreciate the dimensions and evolution of one of the most spectacular social – economic phenomena; the rural tourism.

  8. Numerical simulation of stress distributions and displacements around an entry roadway with igneous intrusion and potential sources of seam gas emission of the Barapukuria coal mine, NW Bangladesh

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Rafiqul; Shinjo, Ryuichi [Department of Physics and Earth Sciences, University of the Ryukyus, Okinawa, 903-0213 (Japan)

    2009-06-01

    This paper uses two-dimensional boundary element method (BEM) numerical modeling to analyze the deformation and failure behavior of a coal seam and to understand the nature of gas flow into a roadway entering the Barapukuria coal mine in Bangladesh. The Barapukuria basin contains Permian-aged Gondwana coals with high volatile B bituminous rank. Three models (A, B, and C) are presented here. Model A assumes horseshoe-shaped geometry, model B assumes trapezoid-shaped geometry, and model C assumes horseshoe-shaped geometry coupled with a roof fall-induced cave generated by the break-up of rock materials along the vertical dimension of an igneous dyke. The simulation results show that there is little difference in strata deformation between models A and B. In model A, there is no horizontal tensional stress and the overall horizontal stress patterns are compressive, while the distribution and magnitude of vertical stress show higher tensional stresses on the immediate rib sides and floor. In model B, both horizontal and vertical stress distributions indicate low to medium tensional stresses on the immediate roof, floor, and rib sides, but compressive stresses are prominent toward the interior of the coal seam. Deformation vectors indicate that failure extends laterally to about 7.5 m around the excavation geometry. On the contrary, for model C, the distributions and magnitudes of horizontal and vertical stress show higher tensional stresses in both rib sides of the roof fall zone. The deformation around the dyke-induced perturbation zone affects a large volume of coal. The deformation vectors with high magnitudes are nearly horizontal and propagate laterally up to 30 m; whereas, low-magnitude deformation vectors extend about 25 m toward the roof and 20 m toward the floor. The vertical tensional displacement, which is concentrated in the floor and the left and right hand sides of the roof, propagates about 30 m on both sides and about 22 m in the floor. From these

  9. Mining-induced fault reactivation associated with the main conveyor belt roadway and safety of the Barapukuria Coal Mine in Bangladesh: Constraints from BEM simulations

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Rafiqul; Shinjo, Ryuichi [Department of Physics and Earth Sciences, University of the Ryukyus, Okinawa, 903-0213 (Japan)

    2009-09-01

    Fault reactivation during underground mining is a critical problem in coal mines worldwide. This paper investigates the mining-induced reactivation of faults associated with the main conveyor belt roadway (CBR) of the Barapukuria Coal Mine in Bangladesh. The stress characteristics and deformation around the faults were investigated by boundary element method (BEM) numerical modeling. The model consists of a simple geometry with two faults (Fb and Fb1) near the CBR and the surrounding rock strata. A Mohr-Coulomb failure criterion with bulk rock properties is applied to analyze the stability and safety around the fault zones, as well as for the entire mining operation. The simulation results illustrate that the mining-induced redistribution of stresses causes significant deformation within and around the two faults. The horizontal and vertical stresses influence the faults, and higher stresses are concentrated near the ends of the two faults. Higher vertical tensional stress is prominent at the upper end of fault Fb. High deviatoric stress values that concentrated at the ends of faults Fb and Fb1 indicate the tendency towards block failure around the fault zones. The deviatoric stress patterns imply that the reinforcement strength to support the roof of the roadway should be greater than 55 MPa along the fault core zone, and should be more than 20 MPa adjacent to the damage zone of the fault. Failure trajectories that extend towards the roof and left side of fault Fb indicate that mining-induced reactivation of faults is not sufficient to generate water inflow into the mine. However, if movement of strata occurs along the fault planes due to regional earthquakes, and if the faults intersect the overlying Lower Dupi Tila aquiclude, then liquefaction could occur along the fault zones and enhance water inflow into the mine. The study also reveals that the hydraulic gradient and the general direction of groundwater flow are almost at right angles with the trends of

  10. Control of Mine Water Inrush and Flooded Occurred in Mine Roadway Heading Face%巷道工作面突水淹井治理

    Institute of Scientific and Technical Information of China (English)

    邱显水; 林丛丛

    2014-01-01

    During a mine roadway heading in a Mine Ventilation Shaft of Mabianshan Iron Mine ,a mine strong water inrush was occurred in the heading face with a water inrush volume about 800m3/h.Thus the mine was flooded ,a control plan of a first water drainage and then water sealing was applied and the water drainage target was hard to be reached.After the expert argumentation conducted ,a control plan of a first water sealing and then water drainage was determined and applied.During the construc-tion ,two boreholes were drilled from the surface ground to the mine roadway in the underground mine and were applied individually to build a water retaining wall and to make the grouting ,backfill and sealing operations.After the construction ,the water retaining wall formed could have good pressure resistances ,the grout could have good backfill and sealing to the water flow channel with the predicted effect.In June ,2013 ,the inrush water in the mine was successfully drained off and the mine was suc-cessfully restored in production.%马鞭山铁矿风井巷道掘进中,工作面强突水,突水量800m3/h左右,造成淹井后,采用先排后堵的方案治理,无法达到排水目标。后经专家论证,决定采用先堵后排的方案治理。施工时,从地面向井下巷道施工2个钻孔,分别用于构筑挡水墙和注浆充填封堵。施工后,所形成的挡水墙耐压较好,浆液对导水通道充填封堵较好,达到了预期效果。2013年6月,矿上顺利将矿井水排掉,矿井顺利恢复生产。

  11. Overview of Rural Tourism Development in China

    Institute of Scientific and Technical Information of China (English)

    Tianhui; XIE

    2015-01-01

    Rural tourism is a form of tourism relying on rural environment,with rural unique natural scene and cultural characteristics( production pattern,life style,folk customs,and rural culture) as object,and integrating sightseeing,vacation,recreation and shopping. Rural tourism provides recreation products for urban residents,promotes national and local economy,promotes rural employment,keeps traditional culture,improves rural ecological environment,and promotes urban and rural exchange. From concept and characteristics of rural tourism,this paper made a brief overview of development background,realistic significance,influence factors,development mode,and existing problems,in the hope of providing favorable references for grasping development situation of rural tourism in China.

  12. 深部高应力煤巷围岩变形与控制技术研究%Research on Surrounding Rock Deformation of Deep Coal Roadway under High Stress and Its Control Technology

    Institute of Scientific and Technical Information of China (English)

    翟金腾

    2012-01-01

    Using methods of theoretical analysis, physical simulation,industrial test and in - situ measurement, the deformation laws of coal roadway along gob in different depth were researched in Chensilou Coal Mine. The results showed that when the depth is up to 950 m over the deformation velocity of surrounding rock for roadway drivage along goaf increases rapidly, and the deformation of 6 m coal pillar is small er than that of 4 m coal pillar. The researched results provide a theoretical basis for the design of mining roadway support in working face.%采用理论分析、物理模拟、工业性试验与实测方法,对陈四楼煤矿沿空煤巷不同深度的变形规律进行了研究,结果表明,当采深达到950m以上时,沿采空区掘巷的围岩变形速度将会迅速增加,此时6m煤柱比4m煤柱的围岩变形要小,研究结果为工作面回采巷道支护设计等提供了理论依据。

  13. Rapid Passing through Small Kiln and Abandoned Roadway Technology and Application in Coal Laneway in Small Coal Mine%煤巷机掘快速通过小窑空巷技术及应用

    Institute of Scientific and Technical Information of China (English)

    张鸿

    2015-01-01

    According to the location and profile of XV3214 small kiln and abandoned roadway in Fenghuangshan Mine, we should make safeguard measures in advance and perform accurate drilling and waterproof. This paper set support design of small kiln and abandoned roadway, wind current adjustment, construction scheme in detail, which has a certain reference significance for quick comprehensive mechanized drivage, and safe and efficient passing through small kiln and abandoned roadway.%根据凤凰山矿XV3214巷小窑空巷的位置及概况,提前制定保障措施并进行精确钻探和防水,详细制定了空巷支护设计、风流调整及施工组织方案,对综合机械化掘进快速、安全、高效通过小窑空巷具有一定的借鉴意义。

  14. 义安煤矿顶板走向高抽巷的层位选定%layer selection of extraction of high gas drainage roadways lying the strike of roof In Yi'an coal mine

    Institute of Scientific and Technical Information of China (English)

    殷庆超; 王恩营; 刘度

    2015-01-01

    为了解决义安矿工作面瓦斯涌出量大,上隅角瓦斯浓度经常超限问题,依据覆岩采动裂隙演化规律和“O”形圈理论,提出在工作面顶板布置高抽巷抽采采空区瓦斯,通过理论计算与数值模拟对采空区上覆岩层“两带”高度范围进行研究,确定裂隙带发育范围。而为了防止高抽巷被破坏,将高抽巷的设计层位选定为1.5倍采高。%In order to solve the gas emission quantity of Yi'an mine working face, the upper corner gas excess problem, on the basis of overlying fissure evolution law and "O" ring theory, proposed the layout of high level suction roadway in the working face roof to extract the gobs gas, through theoretical calculation and numerical simulation to study the ‘two zone' height of overlying strata in gobs, determined the fracture zone development scope. In order to prevent the destruction of the high level suction roadway, and selected the location of the high level suction roadway being 1.5 times for the mining height.

  15. 采动剧烈垮冒煤巷的支承压力分布规律研究%Study on Abutment Pressure Distribution Law in Collapse Coal Roadway with Mining-induced Violently

    Institute of Scientific and Technical Information of China (English)

    李开晴; 何富连; 严红; 韩红强

    2011-01-01

    针对阳煤集团新元公司采动剧烈的垮冒煤巷普遍存在顶板严重下沉、巷帮严重臌帮和巷道底鼓等问题,对煤柱支承压力进行了现场实测和计算机三维数值模拟,分析研究采动剧烈影响下的煤巷支承压力分布规律,得出应力集中系数平均值达3.2及煤巷支承压力的分布范围,从而为采动剧烈垮冒煤巷的支护方案设计提供科学依据。%Aiming at the problems such as roof severe subsidence,the ribs of roadway ingression and floor heave in roadway of Yangguan coal industry Co.Ltd Xinyuan corporation,abutment pressure of coal pillars are analyzed by field measurements and 3D numerical simulation to research on the distribution law of abutment pressure in the mining-induced violently collapse coal roadway.The average value of stress concentration factor is 3.2,and the abutment distribution scale is obtained.These results can supply the scientific basis for the supporting scheme design.

  16. 汽车防撞雷达对弯道行驶目标的车道识别%Roadway'judgement of aim car in curve road with automotive anti-collision radar

    Institute of Scientific and Technical Information of China (English)

    钟霞; 于灏

    2011-01-01

    假设汽车行驶在同凹向弯道上,并且弯道的曲率不变.通过本车的前后车轮转向结合汽车的结构参数,计算出本车的车道半径,然后根据安装在本车上的防撞雷达对前方车辆的实时探测数据,计算前车行驶车道半径,通过与本车所在车道半径进行比较,从而判断前方汽车是否与本车在同一车道.%In the paper, we consider aim car in curve road. Through moving' state of the car, we compute the radius of roadway, then, analysis radar data, compute the aim car's radius of roadway. So we can know the two car's roadway by comparing the two radius.

  17. 煤矿巷道支护技术现状及发展趋势分析%Analysis on status and development trend of supporting technology in coal mine roadway

    Institute of Scientific and Technical Information of China (English)

    杨存清

    2016-01-01

    with the development of increasing intensity, the depth of coal mining is also deepening, the safety of coal mine roadway is particularly important. In this paper, through analyzing the application of coal mine roadway support technology , aiming at the existing problems and deifciencies of the mine support technology, some support suggestions and opinions were put forward in the paper, it made a prospect on the future development of coal mine roadway support technology .%随着开发力度不断加大,煤矿开采的深度也不断加深,煤矿巷道的安全性就显得尤为重要。本文通过对煤矿巷道支护技术的应用分析,对现存的煤矿支护技术存在的问题和不足提出了建议和意见,对今后煤矿巷道支护技术的发展做出了展望。

  18. Interface between urban and rural

    DEFF Research Database (Denmark)

    Brandt, Jesper

    2007-01-01

    for new trends in rural landscapes have been related to a model for urban pressure on rural areas in Denmark however without any convincing results. A model for the historical development of a typical Danish village has been made, to see if the socially differentiated process of counterurbanisation can...... be related to the differentiation in the development of different types of village developments. Such a model can elucidate the potentials of a multifunctional landscape as a basis for a varied and and attractive fulfilment of human needs in an urban-rural continuum....

  19. Rurality study of restricted areas

    Directory of Open Access Journals (Sweden)

    Sergio Rivaroli

    2011-02-01

    Full Text Available Two main perspectives of investigation emerge from the study of a territory’s rurality: a geographical approach and a sociological approach. The research examines the sub-regional study case of ‘Nuovo circondario imolese’. The analysis shows that the combination of traditional institutional criteria with detailed informations about the territory, generates more accurate results which determine a better comprehension of the characteristics of restricted areas’ rurality. Over the period 1991-2001, the study highlights an increase in rural areas. This result could be interpreted as an effect of urban sprawl’s intensification, that increases the competition between non-farm residences and agricultural activities.

  20. Innovating for Rural Development

    DEFF Research Database (Denmark)

    Christensen, Dorthe

    Whereas the primary challenge for agriculture after World War II was improving food security by increasing productivity, the challenges faced by today’s agriculture are more complex and diverse. In this context it is interesting to investigate Danish agricultural extension. Firstly, the more...... complex and diverse a situation that farmers have to deal with, the more support farmers may need. Secondly, agricultural extension is important to Danish farmers, pointing to a significant arena for learning and change. Thirdly, privatizing agricultural extension (in Denmark since 1994) should...... interactions, by exploring the perspective of the participants; and the paper also seeks to understand possible constraining or supportive extension aspects at play. Paper 3 examines how the apparent change effort: ‘rural development service’ is reflected in the management strategies of individual agricultural...

  1. Rural entrepreneurship: Between place and space

    DEFF Research Database (Denmark)

    Korsgaard, Steffen; Müller, Sabine; Tanvig, Hanne Wittorff

    This paper proposes a distinction between rural entrepreneurship and entrepreneurship in the rural. While the latter is incidentally located in a rural area, the former engages with the localised resources of the rural area. We argue that rural entrepreneurship in this form holds promise for a be...... embeddedness, capped growth and the realisation of multiple forms of value. Furthermore, the paper argues for a more central role for spatial qualities in entrepreneurship research...

  2. Rural Quality Education and the Balance between Urban and Rural Compulsory Education

    Institute of Scientific and Technical Information of China (English)

    Jiangfeng; LI

    2013-01-01

    On the basis of analyzing the gap between urban and rural quality education and the existing limiting factors to that in rural areas,a suggestion was proposed to promote the balanced development of rural quality education.

  3. Methodology for Evaluating the Rural Tourism Potentials: A Tool to Ensure Sustainable Development of Rural Settlements

    Directory of Open Access Journals (Sweden)

    Alexander Trukhachev

    2015-03-01

    Full Text Available The paper analyses potentials, challenges and problems of the rural tourism from the point of view of its impact on sustainable rural development. It explores alternative sources of income for rural people by means of tourism and investigates effects of the rural tourism on agricultural production in local rural communities. The aim is to identify the existing and potential tourist attractions within the rural areas in Southern Russia and to provide solutions to be introduced in particular rural settlements in order to make them attractive for tourists. The paper includes the elaboration and testing of a methodology for evaluating the rural tourism potentials using the case of rural settlements of Stavropol Krai, Russia. The paper concludes with a ranking of the selected rural settlements according to their rural tourist capacity and substantiation of the tourism models to be implemented to ensure a sustainable development of the considered rural areas.

  4. Photoactive roadways: Determination of CO, NO and VOC uptake coefficients and photolabile side product yields on TiO2 treated asphalt and concrete

    Science.gov (United States)

    Toro, C.; Jobson, B. T.; Haselbach, L.; Shen, S.; Chung, S. H.

    2016-08-01

    This work reports uptake coefficients and by-product yields of ozone precursors onto two photocatalytic paving materials (asphalt and concrete) treated with a commercial TiO2 surface application product. The experimental approach used a continuously stirred tank reactor (CSTR) and allowed for testing large samples with the same surface morphology encountered with real urban surfaces. The measured uptake coefficient (γgeo) and surface resistances are useful for parametrizing dry deposition velocities in air quality model evaluation of the impact of photoactive surfaces on urban air chemistry. At 46% relative humidity, the surface resistance to NO uptake was ∼1 s cm-1 for concrete and ∼2 s cm-1 for a freshly coated older roadway asphalt sample. HONO and NO2 were detected as side products from NO uptake to asphalt, with NO2 molar yields on the order of 20% and HONO molar yields ranging between 14 and 33%. For concrete samples, the NO2 molar yields increased with the increase of water vapor, ranging from 1% to 35% and HONO was not detected as a by-product. Uptake of monoaromatic VOCs to the asphalt sample set displayed a dependence on the compound vapor pressure, and was influenced by competitive adsorption from less volatile VOCs. Formaldehyde and acetaldehyde were detected as byproducts, with molar yields ranging from 5 to 32%.

  5. Rural migration and health care

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Jensen, Marit Vatn

    This literature study focuses on possible links between access to health services and migration in rural areas. Why do people move to or from rural areas or why do they stay? What determines where people settle? And, in this context, do local health care services play an important or minor role......, or no role at all? First, the paper reports on key findings from rural migration studies, in order to shed light on two migration trends: urbanization and counter-urbanization. Then we take a closer look on settlement preferences in rural areas, including the impact of health care facilities. Finally, we end...... up with a more deepgoing review of the relatively small number of studies, which explicitly deal with settlement preferences related to access to health care....

  6. Rural Veterans by State (2015)

    Data.gov (United States)

    Department of Veterans Affairs — This spreadsheet contains data from the 2015 American Community Survey and shows the demographic and socioeconomic characteristics of Veterans who live in rural and...

  7. Rural Veterans by State (2014)

    Data.gov (United States)

    Department of Veterans Affairs — This speadsheet contains data from the 2014 American Community Survey and shows the demographic and socioeconomic characteristics of Veterans who live in rural and...

  8. GROUNDWATER HYDROCHEMISTRY EVALUATION IN RURAL ...

    African Journals Online (AJOL)

    Osondu

    2012-10-09

    Oct 9, 2012 ... the quality of groundwater from domestic water supply boreholes across rural Botswana. Ionic ... quality limits the supply of potable fresh water. To utilize and protect valuable water ..... prescribed specification of World Health.

  9. 8224 OCCUPATIONAL DIVERSIFICATION AMONG RURAL ...

    African Journals Online (AJOL)

    income to take care of economic responsibilities during off-season periods. This paper reviews current .... employment now offers the most common diversification strategy for rural women. Several .... For instance, the directorate has four main.

  10. Rural migration and health care

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Jensen, Marit Vatn

    This literature study focuses on possible links between access to health services and migration in rural areas. Why do people move to or from rural areas or why do they stay? What determines where people settle? And, in this context, do local health care services play an important or minor role......, or no role at all? First, the paper reports on key findings from rural migration studies, in order to shed light on two migration trends: urbanization and counter-urbanization. Then we take a closer look on settlement preferences in rural areas, including the impact of health care facilities. Finally, we end...... up with a more deepgoing review of the relatively small number of studies, which explicitly deal with settlement preferences related to access to health care....

  11. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>The Rural Development Foundation ( RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college in Andhra Pradesh State,taking a unique holistic approach to education through innovative programs and methodology. Rather than using the conventional method of rote memorization,RDF focuses on cultivating critical thinking skills and encouraging students to

  12. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>The Rural Development Foundation(RDF),founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children.RDF founded and continues to operate five schools and one junior college in Andhra Pradesh State,taking a unique holistic approach to education through innovative programs and methodology.Rather than using the conventional method of rote memorization,RDF focuses on cultivating critical thinking skills and encouraging students to understand and

  13. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The Rural Development Foundation(RDF),founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children.RDF founded and continues to operate five schools and one junior college in Andhra Pradesh State,taking a unique holistic approach to education through innovative programs and methodology.Rather than using the conventional method of rote memorization,RDF focuses on cultivating critical thinking skills and encouraging students to understand and

  14. About The Rural Development Foundation

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>The Rural Development Foundation ( RDF) ,founded in 1996,is an Indian nonprofit organization with the mission of providing quality education for underprivileged rural children. RDF founded and continues to operate five schools and one junior college in Andhra Pradesh State,taking a unique holistic approach to education through innovative programs and methodology. Rather than using the conventional method of rote memorization,RDF focuses on cultivating critical thinking skills and

  15. Welfare service in rural areas

    DEFF Research Database (Denmark)

    Nørgaard, Helle

    Many rural municipalities are challenged due to overall population decline and demographic changes and thus need to make adjustment to municipal services. Demographic profiles are central for assessing both needs, place bound resources and development potential of individual localities.Assessment...... and whether service adjustments are incorporated in municipal plans for strategic development.  Keywords: place bound potential, development in rural communities, municipal services and strategic planning....

  16. Understanding Integrated Rural Health Networks

    OpenAIRE

    Moscovice, Ira; Wellever, Anthony; Christianson, Jon; Casey, Michelle; Yawn, Barbara; Hartley, David

    1997-01-01

    In an era of constraints on public and private sector health care budgets, organizational restructuring of hospital and physician practice, and the shifting of financial risk to patients and providers, rural health professionals and communities are grappling with the issue of how to assure access to a comprehensive and affordable set of health care services. In recent years, rural health providers have turned to the strategy of developing voluntary network relations as an alternative to syste...

  17. TOURIST MOTIVATION FOR RURAL DESTINATIONS

    OpenAIRE

    2014-01-01

    City daily overexertion impels tourists wish to travel. Rural tourism behavior is determined by a set of motivational factors that makes him appreciate favorable tourist destinations. In order to analyze and assess the opinions and attitudes of tourists in rural areas we realized a market survey, the results being presented in the article below. Future trends, the growth rate of market depend largely on the wishes and intentions of goods or services consumers. This study involves the engageme...

  18. Quantification of rural livelihood dynamics

    DEFF Research Database (Denmark)

    Walelign, Solomon Zena

    for livelihood strategy clustering, (iii) assessment dynamics in rural livelihood strategies, and (iv) the effect of attrition on rural livelihood dynamics assessments. A wide range of quantitative methods were employed using a unique environmentally augmented panel dataset combined with tracking attrite...... role in lifting poor out poverty which could be due to restricted access to more remunerative environmental resources, (ii) the developed approach for livelihood clustering (combining household income and asset variables using regression models) outperform both existing income and asset approaches (iii...

  19. TOURIST MOTIVATION FOR RURAL DESTINATIONS

    Directory of Open Access Journals (Sweden)

    Angela BOTEZATU

    2014-04-01

    Full Text Available City daily overexertion impels tourists wish to travel. Rural tourism behavior is determined by a set of motivational factors that makes him appreciate favorable tourist destinations. In order to analyze and assess the opinions and attitudes of tourists in rural areas we realized a market survey, the results being presented in the article below. Future trends, the growth rate of market depend largely on the wishes and intentions of goods or services consumers. This study involves the engagement of a number of 658 respondents, which were interviewed to determine the basic motivations in choosing countryside. The working methods used were analysis, synthesis and questionnaire survey as a research method. Results refer to the following: about 59 percent, spend up to 10% of annual income for vacations and travel, for rural tourism this amount is much lower; the association of the term „rural tourism” in the local tourist mind, oscillates among „a villa” in rural areas or „active vacation” (biking, hiking, riding, swimming or hunting; customer loyalty is one of the goals of marketing activities undertaken in hostels or other travel service providers. In conclusion, we mention that the variety of motivational factors in choosing tourist destinations in rural areas drive this type of tourism.

  20. Imbalance and Correction of the Rural Credit Cooperatives and Rural Economic Relations

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    This article expounds the manifestations of imbalance between the rural credit cooperatives and rural economic relations: the rural credit cooperatives fail to effectively promote economic development in rural areas; the rural economy is also incapable of effectively promoting the development of the rural credit cooperatives. It analyses the reasons for imbalance between the rural credit cooperatives and rural economic relations,including the direct reason (loss of function of the rural credit cooperatives) ,the fundamental reason (restricted economic development of agriculture and countryside and relative pauperization of farmers) ,and the deep-seated reason (sluggish rural economic development) . Corresponding countermeasures and proposals are put forward for promoting balanced development of the rural credit cooperatives and rural economy as follows: first, deepen reform of the rural credit cooperatives,strengthen the function of the rural credit cooperatives in serving the needs of agriculture; second, speed up economic development in rural areas,eliminate the economic constraints for the development of the rural credit cooperatives; third,transform the development pattern and the development strategies,foster the macro-institutional environment for balanced development of rural credit cooperatives and rural economy.