| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1996: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
Housing land was damaged at about 5,100 locations in the foot of the Rokko Mountain system due to Hyogo-ken Nanbu Earthquake appeared in 1995, and it was evaluated that 2,400 out of 5,100 locations require some measures for the safety reason. In this project, the cause of deformation-induced damage of housing land is investigated through a dynamic response analysis. Damaged and undamaged sites appeared in a housing land were first chosen. In the housing land, a boring exploration was performed after the quake to know the underground condition. Then, seismic prospecting was carried out with reflection method to grasp the near-surface ground structure, and to know the shear wave velocity for damaged and undamaged sites. As the results, two-layr system, surface layr and base rock, was defined as a near-surface ground structure, and fill was thicher in the damaged site than the undamaged one. The shear wave velocity was obtained as 130m/s for the damaged site and 140m/s for the undamaged site. A seismic response analysis was performed using the input data and boundary condition determined based on the seismic prospecting. In the project, "Super FLUSH" which is a program for two dimensional FEM was used as a seismic response analysis. The results obtained were ; 1) the response acceleration was not so different between damaged and undamaged locations ; and 2) the response shear strain for undamaged location is small in comparison with that for damaged locations. Then, it was deduced that larger shear strain could develop in the damaged locations and that, as a result, deformation-induced damage occurred.
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