Suggested Method to Predict Catastrophic Landslides

1994年(1)来自加拿大、英国、新西兰、斯里兰卡和中国的调查人员和联合研究人员在京都举行了为期两周的联合研究会，并在日本长崎县马尾山滑坡区进行了联合实地考察。梯田土壤是从滑坡跑掉的地方采集的，并被带到了日本。他们用试件进行了不排水加载环剪试验，预测滑坡运动，发现其视摩擦角只有3.8度，这可以解释其长时间的滑动。Evans通过钻探在Frank Slide的沉积体下发现了剪切层。(3)Sassa、Fukuoka和Evans联合调查了由1995年1月17日Hyogoken-Nambu地震触发的日本西宫日川滑坡。他们对那里的土壤进行了采样，并进行了不排水循环加载环剪切试验。结果表明，滑动面液化是由于土体结构破坏和颗粒破碎而发生的。(4)来自加拿大、英国、新西兰、美国和意大利的调查人员和联合研究人员聚集在京都大学，举行了为期两周的联合研究会议，讨论了滑坡预测和评估的实用方法。(5)1996年12月6日，福冈萨沙对1996年12月6日的Gamaharazawa泥石流灾害进行了现场调查。他们从最近的溪流中采集了激流沉积物。不排水环剪试验表明，滑动面发生液化并启动了高速剪切，可以解释滑坡引发泥石流的机理。Sassa在IUGS(国际地质科学联合会)会议上与来自美国和加拿大的研究人员和联合研究人员讨论了结果。

1994(1) Investigators and joint researchers from Canada, U.K., New Zealand, Sri Lanka, and China held a joint research meeting for two weeks in Kyoto, and made a joint field investigation in Mt.Mayu Landslide area, Nagasaki Prefecture, Japan.1995(2) Sassa and Fukuoka investigated Frank Slide, Canada with Evans of Geological Survey of Canada. Terrace soils were sampled from where the slide ran away and brought to Japan. They carried out undrained loading ring shear tests for predicition of landslide movement with the sample and found that the apparent friction angle was only 3.8 degrees, which could explain its longrunout. Evans found sheared layr beneath the deposited mass of the Frank Slide by boring.(3) Sassa, Fukuoka and Evans jointly investigated the Nikawa landslide, Nishinomiya, Japan which was triggered by the 17 January 1995 Hyogoken-Nambu earthquake. They sampled soils there and carried out undrained cyclic loading ring shear tests. Results showed "sliding surface liquefaction" occurred due to destruction of soil structure and grain crushing. This phenomenon reduced the shear strength rapidly and dramatically and could explain the rapid landslide motion.(4) Investigators and joint researchers from Canada, U.K., New Zealand, United States, and Italy gathered at Kyoto University and held a joint research meeting for two weeks, and discussed on the practical method of landslide prediction and assessment.1996(5) Sassa Fukuoka carried out field investigation of the 6 December 1996 Gamaharazawa Debris Flow Disaster. They sampled torrent deposits from the nearest stream. Undrained ring shear tests on the sample revealed that the sliding surface liquefaction occurred and initiated high speed shearing, which could explain the landslide triggered debris flow mechanism. Sassa discussed the results with Investigators and joint researchers form United States and Canada at the occasion of IUGS (International Union of Geological Sciences) meeting.