WorldWideScience

Sample records for bollards

  1. Optimal design and dynamic impact tests of removable bollards

    Science.gov (United States)

    Chen, Suwen; Liu, Tianyi; Li, Guoqiang; Liu, Qing; Sun, Jianyun

    2017-10-01

    Anti-ram bollard systems, which are installed around buildings and infrastructure, can prevent unauthorized vehicles from entering, maintain distance from vehicle-borne improvised explosive devices (VBIED) and reduce the corresponding damage. Compared with a fixed bollard system, a removable bollard system provides more flexibility as it can be removed when needed. This paper first proposes a new type of K4-rated removable anti-ram bollard system. To simulate the collision of a vehicle hitting the bollard system, a finite element model was then built and verified through comparison of numerical simulation results and existing experimental results. Based on the orthogonal design method, the factors influencing the safety and economy of this proposed system were examined and sorted according to their importance. An optimal design scheme was then produced. Finally, to validate the effectiveness of the proposed design scheme, four dynamic impact tests, including two front impact tests and two side impact tests, have been conducted according to BSI Specifications. The residual rotation angles of the specimen are smaller than 30º and satisfy the requirements of the BSI Specification.

  2. A DESIGN STUDY OF AN INNOVATIVE BARRIER SYSTEM FOR PERSONAL PARKING LOTS

    OpenAIRE

    BÖRKLÜ, Hüseyin; KALYON, Sadık

    2018-01-01

    The increase in the number of cars made it necessary to protectthe parking areas. This research includes a literature review aboutcommercially available barriers, which are arm barriers, rising bollards, chainbarriers, automatic and manual private barriers from the point of common andside-by-side parking lots. Their advantages and disadvantages are evaluated.After the literature review work, a design requirements list for a car parkprotector, which includes important and strong properties of ...

  3. Demonstration of Thermoplastic Composite I-Beam Design Bridge at Camp Mackall, NC: Final Report on Projects FY08-16 and FY09-31

    Science.gov (United States)

    2017-12-01

    of the earliest designs had the product performing well when new, but sagging over time. Successful applications for unreinforced plastic lumber...construction curbs, removable speed bumps, parking lot wheel stops, and bollards. Since then, manufacturers have learned to create designs with lower stress...crystalline polymer product as part of the manufacturing process leads to voids in the interior cross-section due to thermodynamic and physical chemistry

  4. USV Path Planning Using Potential Field Model

    Science.gov (United States)

    2017-09-01

    on the Clearpath USV is identified. A bollard pull test was performed in the CAVR test tank to evaluate this relationship. The USV was given thrust...commands from -1.0 (reverse) to 1.0 (forward) while statically attached to the side of the CAVR test tank with a load cell in line with mooring. The...and illustrates the lack of reverse thrust of the USV. The forward thrust direction is much more effective and increases until settling out at 40.0 N

  5. Volatility

    Directory of Open Access Journals (Sweden)

    María Sánchez

    2016-11-01

    Full Text Available The action consists of moving with small kicks a tin of cola refresh -without Brand-from a point of the city up to other one. During the path I avoid bollards, the slope differences between sidewalks, pedestrians, parked motorcycles, etc. Volatility wants to say exactly that the money is getting lost. That the money is losing by gentlemen and by ladies who are neither financial sharks, nor big businessmen… or similarly, but ingenuous people, as you or as me, who walk down the street.

  6. The materialization of fear

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    to matter in ways not simply reducible to security optimization, risk management and symbolic politics? To reach this aim, I draw on material studies, mobilities design and non-representational theories to provide a rich socio-material tale of how granite stones, bollards and other counter......-terrorist materials contribute to the construction and ‘feel’ of contemporary urban tourism. How do such prominent material designs influence, both affectively, practically and emotionally, tourists? How are they re-appropriated and imbued with (inter)subjective meanings, and how may a richer understanding of how...

  7. Case study of restaurant successfully designed, constructed, and operated for excellent dining acoustics

    Science.gov (United States)

    Bollard, Paul; Des Jardins, Stephen

    2005-09-01

    Prior to the construction of La Provence Restaurant in Roseville, California in 2004, the owner, Stephen Des Jardins, traveled with his cook, architect, and engineer to the Provence Region of France to study the cuisine, architecture, and acoustics of the local restaurants. This information was incorporated into the design, construction, and operation of his restaurant, with acoustical design assistance provided by the author, Paul Bollard. The result of the owner's painstaking attention to detail is a restaurant which has received very positive reviews for its architecture, quality of food, service, and acoustic ambience. This paper documents the measures included in the construction of the restaurant to ensure that the building acoustics enhance the dining experience, rather than detract from it. Photographs of acoustic treatments are included, as are reverberation time (RT60) test results and ambient noise level measurement results.

  8. Estelas funerarias islámicas de Ávila : clasificación e inscripciones

    Directory of Open Access Journals (Sweden)

    Javier Jiménez Gadea

    2009-01-01

    Full Text Available La excavación, entre los años 1999 y 2003, de la necrópolis islámica de Ávila, generó la entrega en el Museo de Ávila de un conjunto de estelas funerarias que, añadidas a las ya existentes en el museo, forman –en el contexto de la arqueología medieval española– un conjunto único de estelas funerarias mudéjares. En este trabajo se proporciona un sistema de clasificación para las mismas que ayuda a su estudio y que puede hacerse extensible al de las muchas que aún se encuentran reutilizadas por la ciudad de Ávila, como sillares en muchos de sus antiguos edificios y muros y como simples bolardos urbanos, así como para piezas similares que puedan aparecer en otros contextos, con el objetivo de simplificar la terminología y evitar confusiones interpretativas debidas al mal uso de ciertos arabismos. Aunque la mayoría son anepígrafas, se conservan, sin embargo, algunas con inscripciones en árabe, de las que aquí se ofrece también su traducción. El análisis formal, estilístico y epigráfico de las piezas y el contexto estratigráfico de aquellas aparecidas en excavación arqueológica sitúan cronológicamente el conjunto entre los siglos XIII y XV, confirmando, pues, el carácter mudéjar de la almacabra abulense.The excavation of the Islamic necropolis of Ávila (between 1999-2003 generated the delivery in the Museum of Ávila of an assembly of funeral gravestones, that added to the preexistents in the Museum, they form –in the context of the Spanish Medieval Archeology– an unique assembly of mudéjar funeral gravestones. In this work a systemof classification for the mis provided, that helps to its study and can be done extendible for that of the many of them that still are reused in the city of Ávila, like ashlars in many of their old buildings and walls and also as simple urban bollards, as well as for similar pieces that can appear in other contexts, with the objective to simplify the terminology and avoid