坡脚开挖诱发滑坡机理——以沙井驿滑坡为例

发布时间：2018-04-09 02:32

  本文选题：坡脚开挖　切入点：滑坡机理　出处：《山地学报》2017年02期

【摘要】：坡脚开挖、坡面堆载、不合理灌溉等人类活动诱发的工程性黄土滑坡灾害频频发生,对于当地居民的生命财产安全构成极大威胁。本文以兰州市沙井驿滑坡为研究对象,在工程地质勘测的基础上,研究滑坡的基本特征及导致滑坡发生的关键因素。通过减围压三轴试验研究黄土边坡开挖过程中土体的变形破坏特征。基于FLAC3D数值模拟方法,对黄土边坡的开挖过程进行模拟,分析开挖过程中边坡不同深度的土体应力及变形发展规律,揭示开挖过程中坡体稳定性变化规律及滑坡启动机理。结果表明,沙井驿滑坡是由于坡脚不合理开挖导致老滑坡复活,为牵引式滑坡;在开挖过程中,坡体内发生应力重分布,应力状态不断发生变化,随着开挖的进行,坡体变形逐渐增大;开挖结束后,坡体中部产生大量剪切裂缝,后缘产生张拉裂缝,坡体稳定性降至最低,中上部均有较大变形,最后发生失稳。
[Abstract]:Engineering loess landslides caused by human activities such as slope excavation, slope loading and unreasonable irrigation frequently occur, which pose a great threat to the safety of local residents' lives and property.Taking Shajingyi landslide in Lanzhou as the research object, based on the engineering geological survey, this paper studies the basic characteristics of landslide and the key factors leading to the occurrence of landslide.The deformation and failure characteristics of loess slope during excavation are studied by triaxial test of reducing confining pressure.Based on the FLAC3D numerical simulation method, the excavation process of loess slope is simulated, and the development law of soil stress and deformation in different depth of the slope during excavation is analyzed, and the variation law of slope stability and the starting mechanism of landslide during excavation are revealed.The results show that the Shajingyi landslide is caused by unreasonable excavation of the slope foot, which leads to the revival of the old landslide, which is the traction landslide. During the excavation process, the stress redistribution occurs in the slope, and the stress state changes continuously with the excavation.After excavation, a large number of shear cracks appeared in the middle of the slope, tensile cracks in the back edge, the stability of the slope decreased to the lowest, and there was a large deformation in the middle and upper part of the slope, and finally the instability occurred.
【作者单位】： 地质灾害防治与地质环境保护国家重点实验室(成都理工大学);四川华地建设工程有限责任公司;四川省第二测绘地理信息工程院;
【基金】：国家重点基础研究发展计划项目(2014CB744703) 中国地调局项目(No.1212011140005) 四川省测绘地理信息局科技项目 创新平台开放基金(2016ZC02)~~
【分类号】：P642.22
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本文编号：1724481