两段式顺层滑坡的稳定性分析  

Stability Analysis of Two-segment Bedding Landslide

作　　者：杨威 柴波[2] 

机构地区：[1]仙桃市勘测设计院,湖北仙桃433000 [2]中国地质大学环境学院,武汉430074

出　　处：《安全与环境工程》2013年第2期53-58,共6页Safety and Environmental Engineering

基　　金：中央高校优秀青年教师基金项目(2012049018)

摘　　要：对于大型的突发顺层滑坡,滑面通常具有主滑和锁固的两段特征。为了分析两段滑面共同作用下滑坡的稳定性,本文提出了两段式顺层滑坡的尖点突变模型,对于主滑段和锁固段分别采用应变软化介质和弹脆性介质的本构模型,并在此基础上,探讨了影响两段式顺层滑坡稳定性的控制性参数,分析了降雨、库水位变化反复作用下滑坡预测预报应注意的问题,同时基于尖点突变模型研究了白岩沟桥西滑坡随坡脚开挖不同阶段其稳定性的变化过程。结果表明:大型突发顺层滑坡的稳定性与刚度比密切相关,影响刚度比的主要参数为剪切模量和滑面形态,当锁固段卸载或主滑段加载时,刚度比降低,斜坡越容易滑动;随着降雨、库水的反复加载作用,滑面产生刚度硬化和刚度软化两种趋势,且临界滑动的位移随之发生变化,通常滑坡发生前要经历多次变形加速。本研究提出的尖点突变模型对于两段式顺层滑坡的预测预报具有一定的理论指导意义。Slip face is composed of main sliding segment and locking segment for the giant bedding landslide that has sudden and drastic failure.The cusp catastrophe model is applied to analyzing the stability of bedding landslide under the combined action of main sliding segment and locking segment using constitutive models of strain softening material and elastic brittle material.The controlling parameters of stability of two-segment bedding landslide and the noticeable problem of landslide prediction under the repeated loading of rainfall and reservoir water are studied by this model.Lastly,the model is used to analyze the stability of landslide at the west of Baiyangou Bridge,Badong,in Three Gorges reservoir area in the process of cutting the slope toe.The results indicate that the stability of landslide has close relationship with stiffness ratio,which is affected by shear modulus and slip surface shape.The stiffness ratio decreases and landslide slips more easily when the main sliding segment is loaded or the locking segment is unloaded.The stiffness of slip face has two different trends of hardening and softening after repeated loading of rainfall and reservoir water.Then,the slipping displacement will change and have multiple deformation accelerations before landslide failure.This model has guidance significance for predicting landslide failure.

关 键 词：顺层滑坡 稳定性分析 主滑段 锁固段 尖点突变模型 刚度比 

分 类 号：X45[环境科学与工程—灾害防治] P642.22[天文地球—工程地质学]