黄土滑坡地震液化数值模拟分析——以宁夏石碑塬滑坡为例  

Numerical simulation on seismic liquefaction of loess landslides:case of Shibeiyuan landslide in Ningxia

作　　者：王双[1] 裴向军[1] 张晓超[1] 张硕[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《人民长江》2015年第11期25-29,共5页Yangtze River

基　　金：国家重点基础研究发展"973"计划项目(2014CB744703);中国地质调查局项目(1212011140005)

摘　　要：以宁夏石碑塬滑坡为研究对象,在工程地质测绘和试验测试的基础上建立了有限差分数值模型,对该黄土坡液化过程进行了模拟。分析结果表明:该黄土边坡在天然工况下处于稳定状态;在地震作用下,非饱和黄土几乎没有液化现象,而在地下水位附近的饱和黄土易发生液化,导致其物理力学参数降低,即使在很缓的角度下也易产生边坡失稳;地震结束之后,由于液化导致孔压比减小,黄土渗透性较之前更低,边坡的孔隙水压力消散缓慢,滑带强度恢复也缓慢,易产生长距离滑动。Taking Shibeiyuan landslide in Ningxia Autonomous Region as a research object, based on engineering geological mapping and laboratory tests, a loess landslide model of finite difference is established to simulate the liquefaction process. The results showed that the loess slope was in stable state under natural condition. In the earthquake process, no liquefaction phenom-enon occurred in unsaturated loess, but the saturated loess near the groundwater line is prone to liquefaction, decreasing the physical and mechanical parameters of loess, so landslide could occur for gentle slope. After the earthquake, the liquefaction re-sulted in the decrease of pore pressure ratio, so the loess permeability dropped down, and the pore water pressure dissipated slow-ly. As a result, the soil strength of sliding layer recovered slowly, causing long-range sliding.

关 键 词：地震 黄土液化 孔隙水压 黄土滑坡 

分 类 号：P642[天文地球—工程地质学]