Recent earthquake disasters have revealed the importance of countermeasures against soil Liquefaction in seismic design. In particular, the 1995 Hyogoken Nanbu earthquake caused several types of severe damages to pile foundations. This paper describes an analysis method for soil liquefaction using simple parameters such as SPT-N values and seismic response analyses for the pile-supported structure to consider soil-structure interaction effects and soil non-linearity using a modified Penzien model. It is important to find a way to determine the region of surrounding soil whose behavior is identical to that of piles. This paper adopts the thin layer element method to systematically determine the volume of the surrounding soil. The responses of pile-supported structure are similar, whether soil liquefaction and nonlinearity of pile are considered or not. However, the bending moment of pile become large as to soil liquefaction, and small as to nonlinearity of pile. (author)
To use such sites very effectively, pile foundations will be used for soil stabilization and for important structures for the prevention of subsidence. Negative friction that may ensue from the differential settlement of the soil has to be prevented. Measures against gas will include gas collecting and exhausting facilities in the lower parts of structures, natural and forced exhaust systems, and gas detection/warning units. For revegetation, plants strong against bad soil should be selected, they should be protected from generated gas with protecting sheets or the like, and a thick layer of vegetation-capable soil needs to be laid. Replacement, compaction, and solidification are the fundamentals of soil improvement at wastes final treatment locations and of soil-related pollution prevention in the vicinity of the newly produced sites. Across the country, the service life expectancy is approximately 7-8 years for general wastes and approximately 2.3 years for industrial wastes, and ...