西南某电站坝址右岸含软弱层带岩质斜坡变形破坏机制  

Deformation and failure mechanism of rock slope with soft strata in the right bank of a power station dam site in Southwest China

作　　者：李远征 陈强[3] 潘远阳 黄鑫 LI Yuanzheng;CHEN Qiang;PAN Yuanyang;HUANG Xin(CCCC Fourth Harbor Engineering Institute Co., Ltd., Guangzhou ,Guangdong 510230, China;Key Laboratory of Environmental Protection & Safety of Transportation Foundation Engineering, Guangzhou ,Guangdong 510230,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu , Sichuan 610059, China)

机构地区：[1]中交四航工程研究院有限公司,广东广州510230 [2]中交交通基础工程环保与安全重点实验室,广东广州510230 [3]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),四川成都610059

出　　处：《中国地质灾害与防治学报》2020年第4期1-10,共10页The Chinese Journal of Geological Hazard and Control

基　　金：国家重点研发计划项目(2017YFC1501000);四川省教育厅科研计划重点项目(18ZA0045)。

摘　　要：四川雅砻江某拟建电站坝址右岸岩质斜坡主要由顺层的变质砂岩、炭质板岩及大理岩组成,在褶皱过程中形成多条贯穿性的层间弱带,其变形破坏模式为蠕滑-剪切型破坏。在获取各类地质要素和各层工程地质特性等资料基础上,利用有限元法建立斜坡三维模型对现场工程地质分析成果进行验证并对斜坡的变形破坏机制进行探讨。研究结果表明:由于层间弱带的存在,右岸坡体在重力和残余构造应力的作用下使岩体出现渐进破坏的累积过程,岩层不断弯曲、开启,发生层间剪切蠕变,并逐渐向下延伸,沿控制性结构面产生层间错动,坡体下部应力集中使前部剪切扩展,最终岩桥被剪断,滑移面贯通,岩体沿中缓倾结构面滑出。The rocky slope on the right bank of a proposed power station dam site in the Yalong River in Sichuan is mainly composed of bedding metamorphic sandstone,carbonaceous slate,and marble.During the fold process,several penetrating interlayer weak bands are formed.The failure mode is creep-shear.On the basis of various geological elements and engineering geological characteristics of each layer,a three-dimensional model of the slope was established using the finite element method to verify the results of on-site engineering geological analysis and explore the deformation and failure mechanism of the slope.The research results show that:due to the existence of weak interlayers,the right bank slope under the action of gravity and residual tectonic stress causes a cumulative process of progressive failure of the rock mass;the rock layer is continuously bent,opened,interlayer shear creep occurs,and gradually extending downward;interlayer displacements occur along the control structure plane.Stress concentration at the lower part of the slope causes shear expansion at the front.Eventually,the rock bridge is sheared and the slip surface penetrates,then the rock body slides out along the moderately inclined structural surface.

关 键 词：岩质边坡 蠕滑-剪切 软弱层带 数值模拟 变形机理 

分 类 号：P642[天文地球—工程地质学]