阶梯状滑动断续节理顺层边坡稳定性分析  

Stability of stepped sliding of bedding rock slopes with discontinuous joints

作　　者：李得建 贾文韬 程肖 赵炼恒 张迎宾[1] 余鹏程[1] LI De-jian;JIA Wen-tao;CHENG Xiao;ZHAO Lian-heng;ZHANG Ying-bin;YU Peng-cheng(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Institute for Disaster Management and Reconstruction,MOE Key Laboratory of Deep Earth Science and Engineering,Sichuan University,Chengdu 610065,China;School of Civil Engineering,Key Laboratory of Heavy-Haul Railway Engineering Structure,Ministry of Education,Central South University,Changsha 410075,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]四川大学灾后重建与管理学院深地科学与工程教育部重点实验室,四川成都610065 [3]中南大学土木工程学院重载铁路工程结构教育部重点实验室,湖南长沙410075

出　　处：《岩土工程学报》2022年第11期2125-2134,共10页Chinese Journal of Geotechnical Engineering

基　　金：四川省科技厅项目(2021YJ0032,2021YJ0390);同济大学岩土及地下工程教育部重点实验室开放基金项目(KLE-TJGEB2004);中央高校基本科研业务费-科技创新项目(2682021CX007);专职博士后研发基金项目(2022SCU12126)。

摘　　要：阶梯状滑动顺层岩质滑坡在工程中较为常见,其岩桥和节理特性对阶梯状滑动面的形成至关重要。考虑岩桥和节理面之间强度参数弱化特性,构建阶梯状滑动顺层边坡稳定性分析模型。研究表明:与平面型滑动对比验证了分析模型的准确性。裂隙连通率k_(Y)、基本摩擦角φb、粗糙度系数JRC和弱化系数K_(c)对安全系数F_(s)影响显著。岩桥倾角β_(3)越大,F_(s)减小越显著,边坡越不稳定。台阶法中开挖次数和坡角角度对边坡稳定性影响显著,通过算例分析验证了该方法与极限平衡解差异率在1%以内。某些情况下当开挖使节理面出露时,F_(s)显著降低(如β=53°时降低了22.8%),易诱发滑坡的发生。同时,随着拉裂缝倾角β_(1)和充水高度h_(w)的增大,F_(s)显著降低,出流缝被堵塞时水力效应更为显著,此时边坡最不稳定。The bedding rock landslides with stepped sliding surface are common in engineering,and the characteristics of rock bridges and joints are very important to the formation of stepped sliding surface.The weakening characteristics of the strength parameters of rock bridges and joints are considered.The models for stability of stepped sliding of bedding slopes are established.The results show that the accuracy of the model is verified by comparing with the planar failure model.In addition,the fracture connectivity rate k_(Y),basic friction angleφb,roughness coefficient JRC and weakening coefficient K_(c) have significant influences on F_(s).In this mode,the greaterβ_(3) is,the more significant the reduction of F_(s) is,and the more unstable the slope is.In addition,the excavation times and slope angle have significant influences on the slope stability.The difference rate between the proposed method and the limit equilibrium solution is less than 1%.In some cases,when the joint surfaces are exposed by excavation,F_(s) is significantly reduced(the reduction of 22.8%whenβ=53°),which easily leads to the occurrence of landslides.Meanwhile,with an increase in angleβ_(1) of tensile cracks and height h_(w) of water,F_(s) significantly decreases.The water pressure is more significant when the outlets are blocked,and the rock slope is most unstable.

关 键 词：节理岩质边坡 阶梯状滑动 弱化系数 台阶型坡面 水力作用 

分 类 号：TU43[建筑科学—岩土工程]