从力矩效应和地下水分析缓倾角结构面成因  

Analysis of low-angle structural-plane appearance from effect of moment of force and groundwater

作　　者：孙强[1] 张晓科[1] 钱海涛[1] 杨继红[1] 王媛媛[1] 

机构地区：[1]中国科学院地质与地球物理研究所工程地质力学重点实验室,北京100029

出　　处：《岩土力学》2008年第8期2111-2114,2120,共5页Rock and Soil Mechanics

基　　金：中国科学院知识创新工程重要方向项目资助(No.kzcx2-yw-113)

摘　　要：在岩石剪切破坏中引入力矩模型并就剪切破坏过程进行了分析。在发生剪切破坏时岩石的破坏带有一定宽度,剪切带上的剪应力和支持力不是均匀分布的,在剪切过程中存在一个调整过程,并在局部集中,导致了剪切力矩的存在。当轴向压力σ1较小时,支持力和剪切力都很小,可视为均匀分布;随着σ1的增大,支持力和剪切力都增大,出现非均匀分布,局部表现为应力集中,出现局部破坏,而在整体上表现为力矩平衡。当剪切力矩大于支持力矩时,宏观上剪切破坏出现;分析研究了地下水引起的接触面积的变化,由此并推导了静水压力情况下结构面的稳定性。随着水压力p的增大,除了对岩体材料力学性质的弱化外,结构面上有效压力σn和结构面上、下岩体的接触面积率λ变小,使得发生失稳破坏的临界角θ降低,也就是发生滑动的条件更容易满足。The model of moment of force is introduced to the rock shearing failure;and the shearing failure process is analyzed.The moment model is used to explain the formation of low-angle structural-plane.When the rock has the shearing failure,the shear band has a certain width.On the shear band,shear stress and the support strength are not the even distribution.There is a process alignment procedure in cuts;and the stress concentrated in some part caused the existence of shearing moment.Along with increasing ofσ 1,the supports strength and the shearing force all increase;the non-uniform distribution appears.The stress is concentrated partially;and the rock appears the partial failure.When the shearing moment is bigger than the support moment,the macroscopic shearing failure appears.Based on the destruction effect of groundwater,the change of interface with the variety of groundwater is analyzed.Along with the increasing of hydraulic pressure,the effective pressure and the contacted area rate of the structural surface and under the crag body changes slightly,the critical angle of the steady destruction reduces.So the rock block is easy to lose its steadily.

关 键 词：岩石力学 缓倾角结构面 剪切带 力矩 岩体状态 地下水 

分 类 号：TD313.5[矿业工程—矿井建设]