Emergent Disaster Precursive Phenomena and Motion Prediction of the Giant Jinnosuke-dani Landslide in Haku-san Mountain, Japan

日本白山神之助谷特大滑坡突发灾害前兆现象及运动预测

基本信息

批准号：
15310127
负责人：
WANG Fawu
金额：
$ 7.94万
依托单位：
Kyoto University (2004-2005)Kanazawa University (2003)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

The Jinnosuke-dani landslide is a giant landslide 2,000 m long and 500 m wide in the Haku-san Mountain area, Japan. It was also the first landslide to be designated as a "Landslide Prevention Area" according to the "Japan Landslide Prevention Law". This landslide consists of alternating layers of sandstone and shale in the Tedori Formation, which was deposited from the Jurassic period to the Early Cretaceous. Based on deformation monitoring results for more than 7 years, the landslide is divided into upper and lower blocks. The upper block has moved at a speed of 80 to 170 mm/year, while the lower block has moved more slowly (3 to 15 mm/year). Monitoring data show that the variation of the groundwater level has a great influence on the landslide movement. The deteriorating effect of the weathering of the alternating layers of sandstone and shale on the landslide deformation has been confirmed by borehole exploration and monitoring.Concerning the landslide motion prediction when a giant … More potential landslide occurs, a prediction program for landslide motion was developed and improved. Through a back-analysis on the Bettou Failure occurred in 1934, the parameter of landslide during motion was obtained, and then used in the motion prediction on the Jinnosuke-dani landslide. The result shows that it is with high risk for the sliding mass rushes into the Tedori-gawa dam reservoir, and shows the high necessity of early -warning.In May 2004, a landslide occurred at the right flank of the Jinnosuke-dani landslide ; this slide was transformed into a debris flow after fluidization. By analysis of the monitored video images of the debris flow, field investigation of the source area of the landslide, and a series of simulation tests with a ring-shear apparatus on the initiation of the rainfall-induced landslide and its traveling process, the initiation and traveling mechanisms of the debris flow traveling in the valley were investigated. It is shown that concentrated groundwater flow was the main reason for the landslide initiation, and a rapid decrease of the mobilized shear resistance even under naturally drained condition caused the rapid landslide motion. During the debris motion in the valley, high potential for grain-crushing of deposits in upstream and lower potential for the downstream deposits controlled the traveling and stopping process. Different grain-crushing potential of the valley deposit played an important role in the debris flow traveling and stopping processes. Less

神之助谷滑坡是日本白山地区长2,000米、宽500米的巨型滑坡，也是根据《日本滑坡防止法》被指定为“滑坡防止地区”的第一个滑坡。 ”。这次滑坡由手取组的砂岩和页岩交替层组成，沉积于侏罗纪至早白垩世。根据7年多的变形监测结果，滑坡分为上块和下块，上块移动速度为80至170毫米/年，下块移动速度较慢（3至15毫米）。监测资料表明，地下水位的变化对滑坡运动影响较大，砂页岩交替层的风化对滑坡变形的恶化作用明显。针对潜在的巨大滑坡发生时的滑坡运动预测，通过对 1934 年 Bettou 失败的反演，制定并改进了滑坡运动的预测程序。结果表明，滑体冲入手取川坝水库的风险较高，具有较高的必要性。 2004年5月，神之助谷滑坡右翼发生滑坡，该滑坡流态化后转变为泥石流。通过对滑坡源区的研究，利用环剪装置对降雨诱发滑坡的萌生及其移动过程进行了一系列模拟试验，研究了泥石流在山谷中移动的萌生和移动机制。表明集中地下水流是引发滑坡的主要原因，即使在自然排水条件下，流动剪切阻力的迅速降低也导致了滑坡的快速运动，在山谷内的泥石流运动中，上游和下游沉积物的颗粒破碎潜力很大。下游沉积物的较低势控制了泥石流的移动和停止过程。