Development of new cyclic loading ring shear apparatus

地震引发的山体滑坡在世界范围内造成了巨大的灾害。地震的时间预报不能减少滑坡灾害。滑坡的预测预报是非常必要的。本研究发展了一种新的装置，以再现地震时边坡到达滑动面的应力和应变，以及由此产生的快速剪切位移。2）加载与排水条件下边坡应力相似的静应力3）加载不排水条件下的地震应力4）监测由此产生的剪切位移和产生的孔隙压力。1984年长野县西武地震引发的Ontake滑坡使用的样品从滑坡区的浮石再现。我们从1980年伊朗地震引起的Galdian滑坡和Fatalok滑坡中取样，再现了观测到的滑坡，并对西安皇家宫殿后的骊山滑坡进行了调查，对该滑坡进行了黄土样的测试。结果给出了引起滑坡的临界地震加速度和运动过程中的摩擦力。

Landslides triggered by earthquakes have caused great disasters in the world. Time prediction of earthquakes could not reduce those landslide disasters. Prediction of landslides are very necessary. This research has developed a new apparatus to reproduce the stress and strain reaching to a sliding surface, and the resulting rapid shear displacement in slopes during earthquakes.The test procedures are 1) setting samples in the shear box, 2) loading the static stress similar to the stress in the slope under the drained condition 3) loading seismic stress under the undrained condition 4) monitoring the resulting shear displacement and the generated pore pressure.The Ontake landslide triggered by the 1984 Naganoken-Seibu earthquake was reproduced using the samples of pumice taken from the landslide area. We took samples from the Galdian landslide and the Fatalok landslide caused by 1980 Iran earthquake and also reproduced the observed landslides.Then, we investigated the Lishan mountain behind the Royal Palace in Xian, China which has a precursor landslide phenomena and the possibility to cause a catastrophic landslide, and tested the sample of loess taken from this slope. The result gave a critical seismic acceleration to cause landslides and the mobilized friction during motion.