Analysis of the mechanisms of slope failures triggered by the 2007 Chuetsu Oki earthquake
Analysis of the mechanisms of slope failures triggered by the 2007 Chuetsu Oki earthquake
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DOI：
10.1007/s10706-011-9411-3
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发表时间：
2011-05
影响因子：
1.7
通讯作者：
I. Gratchev;I. Towhata
中科院分区：
文献类型：
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作者：
I. Gratchev;I. Towhata
2007年中越大地震（MJMA= 6.6）在日本新泻县西北部引发了100多起边坡失稳。作者进行的一项勘察表明，尽管大多数故障只有几米深，但它们仍然对公路，铁路和房屋造成了重大破坏。研究还发现，大量的浅层滑坡集中在日本海沿岸沿着，而在研究区域的一个山区发生的滑坡数量很少，但相对较大，该地区距离震中相当远。本文总结了勘察观测结果，描述了滑坡覆盖区的地质特征，提供了滑坡的主要类型的特征，并探讨了典型故障的原因和机制。此外，本文试图调查的机制，大住滑坡，最大的滑坡触发的中越冲地震。为此，进行了全面的分析，包括实地调查和土壤样品的实验室测试。现场调查结果表明，大津米滑坡的破坏面形成在与基岩交界处的饱和桑迪层中。不排水循环加载三轴压缩试验的数据表明，桑迪材料是非常容易产生高的超孔隙水压力在地震荷载。根据地震响应和边坡稳定性分析的结果，作者对大泉滑坡的机理提出了解释。
The 2007 Chuetsu Oki earthquake (MJMA= 6.6) triggered more than one hundred slope failures in the northwest part of Niigata prefecture, Japan. A reconnaissance survey conducted by the authors revealed that although most of the failures were only a few meters deep, they still caused significant damage to roads, railways, and houses. It was also found that a vast number of shallow slides were concentrated along the coastal line of the Japan Sea, while only few, but relatively larger failures occurred in a mountainous part of the study area, which is located in a considerable distance from the earthquake’s epicenter. This paper summarizes the reconnaissance observations, describes the geologic characteristics of the area covered by landslides, provides characterization of major types of the landslides, and examines the causes and mechanisms of typical failures. In addition, this paper seeks to investigate the mechanism of the Ohzumi landslide, the largest slide triggered by the Chuetsu Oki earthquake. For this purpose, a comprehensive analysis that included field investigation and laboratory testing of soils samples was performed. Results of field investigation suggested that the failure plane of the Ohzumi landslide formed in a saturated layer of sandy soil near a boundary with bedrock. Data from undrained cyclic loading triaxial compression tests indicated that the sandy material was highly susceptible to generation of high excess pore-water pressures during earthquake loading. On the basis of the obtained results and the outcome of seismic response and slope stability analyses, the authors posited an explanation on the mechanism of the Ohzumi landslide.