顺层岩质边坡变形破坏特征及稳定性数值模拟  

Numerical simulation of the deformation and failure characteristics of consequent rock slopes and their stability

作　　者：高永涛[1] 肖术[1] 吴顺川[1] 田庆梅[1] 刘波[1] 

机构地区：[1]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083

出　　处：《工程科学学报》2015年第11期1403-1409,共7页Chinese Journal of Engineering

基　　金：科技北京百名领军人才培养工程资助项目(Z151100000315014);国家自然科学基金资助项目(51174014)

摘　　要：针对顺层岩质边坡岩层结构面倾角θ和边坡角α两个参数,采用离散单元法研究了不同工况下总计270个边坡模型的变形破坏特征,统计得到不同变形破坏模式对应的岩层结构面倾角θ与边坡角α的范围,并基于强度折减法研究了两个参数与边坡稳定性的关系,揭示了顺层岩质边坡变形破坏机制及稳定性特征.研究结果表明:依据边坡变形破坏特征,提出了四种顺层岩质边坡变形破坏模式,即坡脚沿岩层结构面的滑移-剪切破坏,坡顶沿岩层结构面的滑动-剪切破坏,岩层下缘弯曲-剪切破坏,以及岩层上缘翻折-拉裂破坏.在此基础上,分析并归纳了这四种模式的产状、变形特征以及可能的破坏模式等一般规律.边坡安全系数fs随结构面倾角θ的增大先减小后增大,在减小过程中达到最小值后迅速上升,然后变缓回落.边坡安全系数fs随结构面倾角θ变化过程中,当θ约等于α-7.3°时,fs取得最小值,此时对应的边坡稳定性最差.The deformation and failure characteristics of total 270 consequent rock slopes under complicated working conditions are investigated by the discrete element method depending on two parameters,structural plane dip angle θ and slope angle α. Differentθ and α ranges corresponding to different failure modes are obtained by the statistical method. Moreover,the relationship between the two parameters and the slope stability is attempted based on the shear strength reduction method. The failure mechanism and stability characteristics of consequent rock slopes are revealed. Four deformation and failure modes of consequent rock slopes are proposed according to different deformation and failure characteristics： toe-slip- failure along the structural plane,top-sliding- failure along the structural plane,lower edge uplift bending-shear failure,and upper edge fracturing-fold-bending-failure. Further general rules of the four modes are analyzed and summarized such as occurrences,deformation characteristics and possible failure modes. The safety factor fsof the slopes decreases and subsequently increases with the increase of θ,it reaches a minimum and then rises quickly to a high value and finally slowing down. During the changing process of θ,the safety factor fswill obtain a minimum when θ is approximately equal to α- 7. 3°,which corresponds to the worst slope stability.

关 键 词：岩质边坡 边坡稳定性 变形特征 破坏模式 数值模拟 

分 类 号：TU457[建筑科学—岩土工程]