Research on Structures and Foundations Considering with Gravity Restoring Effect during Large Earthquake

第1部分：已经阐明，允许在大地震期间隆起地基将减少建筑物的损坏。有几项研究假设地基条件是完全牢固的。本研究假设地基为弹性地基，以地基的竖向刚度为主要参数，在振动台上进行了试验。另外，还进行了考虑基础上拔效应的分析，并通过试验和分析结果验证了基础上拔现象对建筑物的影响。第二部分：在基础隔震结构的抗震设计中，大震作用下橡胶支座一般不允许有拉力。在某些情况下，橡胶支座中的张力可能允许在建筑物形状的纵横比大的建筑物中。本研究主要探讨隔震结构在基础发生上拔时的反应。以隔震界面的合理周期为参数，以地面的垂直刚度为参数，进行了模型试验。利用正确评价重力恢复效果等的理论，得到了能够计算实验结果的数值分析结果。

Part 1 : It has already been clarified that allowing the uplifting of foundations during large earthquake would decrease the damage of the building. There were several researches that the ground condition was assumed to be perfectly firm. The ground was assumed to be elasticity in this research, a perpendicular stiffness of the ground was assumed to be a parameter chiefly, and they were experimented on the shaking table. In addition, the analysis that considered the effect of uplifting of foundation was done, and the influence from an experiment and an analytical result to the building by the phenomenon of uplifting of foundation was examined.Part 2 : In seismic design of the base isolated structures, generally tension force in rubber bearing is prohibited under large earthquake. In some case, tension force in the rubber bearings might be allowed in the building where the aspect ratio of the building shape is large. In this research, behavior when uplifting of foundation is caused at the base of the seismic isolated structures is examined. The model experiment of which the parameters a proper period of seismic isolation interface, and was a perpendicular stiffness of the ground was done. The numerical analysis result that it was able to calculate the experiment result was obtained by using the theory that correctly evaluated the effect etc. of the restoration of gravity.