地震作用下陈庄黄土-泥岩接触面滑坡失稳机理及稳定性研究  

Instability mechanism and stability analysis of Chenzhuangloess-mudstone interface landslide under seismic action

作　　者：马紫娟 张有龙 刘小丰 郑龙 高中南 MA Zijuan;ZHANG Youlong;LIU Xiaofeng;ZHENG Long;GAO Zhongnan(Gansu Earthquake Agency,Lanzhou 730000,Gansu,China)

机构地区：[1]甘肃省地震局,甘肃兰州730000

出　　处：《地震工程学报》2023年第4期810-818,共9页China Earthquake Engineering Journal

基　　金：甘肃省地震局地震科技发展基金项目(2021M7,2016M04)。

摘　　要：以甘肃礼县陈庄黄土-泥岩接触面滑坡为研究对象,在对该滑坡的地震地质环境、基本特征等调查的基础上,运用数值分析对陈庄黄土-泥岩接触面滑坡在各人工计算场地基岩地震动时程作用下的失稳机理及稳定性进行动态模拟研究。结果表明,陈庄滑坡在地震诱发下变形破坏模式为受拉和受剪的复合破坏模式。失稳机理过程可概括为:地震作用→底部岩体受张拉→潜在滑面主滑段上部剪应力增大→剪应变集中带出现→剪应变集中带延伸扩展贯通→滑坡失稳;滑坡稳定性方面,随着输入地震动的增大,陈庄黄土-泥岩接触面滑坡稳定性降低,其中在50年超越概率2%的基岩地震动时程作用下滑坡处于不稳定状态。The loess-mudstone interface landslide in Chenzhuang Village,Lixian County,Gansu Province,was investigated in this study.A dynamic numerical simulation of the instability mechanism and stability of the landslide subjected to ground motion at various artificial calculation sites was conducted based on an analysis of the seismic geological environment and basic characteristics of the landslide.Results show that the deformation and failure of the Chenzhuang landslide are associated with a composite failure mode of tension and shear when subjected to ground motion.The process of instability can be summarized as follows:ground motion due to an earthquake→tension at the bottom of rock mass→increase in shear stress at the upper part of the main slip section of the potential slip surface→emergence of a shear strain concentration zone→extension and penetration of the shear strain concentration zone→landslide instability.The stability of the Chenzhuang loess-mudstone interface landslide decreases with an increase in the ground motion,and the landslide is in an unstable state when subjected to bedrock ground motion with a exceeding probability of 2%in 50 years.

关 键 词：黄土-泥岩接触面滑坡 陈庄滑坡 失稳机理 稳定性 

分 类 号：P642.22[天文地球—工程地质学]