反倾边坡块状倾倒-滑移复合型大变形机理研究——以某水电站大变形岸坡为例  

LARGE DEFORMATION MECHANISM OF BLOCK TOPPLING-SLIDING COMPOSITE ANTICLINAL SLOPE-CASE STUDY AT LARGE DEFORMED BANK SLOPE OF HYDROPOWER STATION

作　　者：夏敏[1] 吕松梅 宋昊 任光明[1] 杨天俊[2] 万宗礼 XIA Min;LÜSongmei;SONG Hao;REN Guangming;YANG Tianjun;WAN Zongli(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology),Chengdu 610059,China;China Hydropower Consulting Group,Northwest Institute of Survey and Design,Xi’an 710065,China)

机构地区：[1]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),成都610059 [2]中国电建集团西北勘测设计研究院有限公司,西安710065

出　　处：《工程地质学报》2023年第6期1999-2007,共9页Journal of Engineering Geology

基　　金：青年科学基金项目(资助号:41907246)。

摘　　要：本文以某水电站大变形岸坡为例,在深入研究岸坡所处的地质背景基础上,调查了岸坡大变形破坏模式,包括“下沉-楔入”破坏、塌滑破坏、倾倒拉裂变形、深部岩体“张裂”。基于物理模拟试验揭示了边坡变形破坏模式受控于多组结构面控制,即表现为花岗岩板裂岩体沿陡倾坡内组结构面倾倒、沿陡倾坡外组结构面拉张、下沉,倾倒导致块状岩体根部折断,折断面追踪坡体内中缓倾角结构面且伴有剪切蠕滑;随变形的加剧,倾倒折断追踪坡体已有陡缓结构面而逐渐形成宏观的连续破裂面,岩体深部变形边界具有典型的阶梯状形态。在岸坡变形破坏模式的地质分析及物理模拟基础上,对岸坡大变形成因进行了分析,并阐明了岩质大变形岸坡形成演化机制。研究表明现今岸坡大变形机制为上部楔入-倾倒产生的推挤性变形与下部鼓张、倾倒性牵引变形的复合变形机制,地质力学模式概括为:块状倾倒-滑移复合型变形破坏模式。This paper investigates a large deformation bank slope of a hydropower station.On the basis of researches of geological environment background,this paper investigates the failure modes of the bank slope.The modes include subsiding wedge failure,rock falls,toppling and tension cracking in deep-seated rock mass.The physical simulation test reveals that the failure mode is controlled by multiple structural planes.That is to say,the granite slab-cracked rock mass is toppled along the structural surfaces dipping into the slope face,and is stretched and sinked along the structural surfaces dipping out of the slope face.The toppling causes the root of the massive rock mass to break.The fracture surface traces the moderately inclined structural surface.The toppling and breaking trace steeply and gently inclined structural surfaces,and gradually form a macroscopic continuous fracture surface.The deep deformation boundary of the rock mass is a typical stepped shape.Moreover,on the basis of geological analysis and physical simulation of bank slope deformation and failure modes,the formation mechanism of large deformation of slope is demonstrated.This paper concludes that the genetic mechanism of large deformation of unstable slope is a combination of the upper pushing deformation and the lower traction deformation.The geomechanical model is summarized as that block toppling-slip composite deformation failure mode.

关 键 词：块状倾倒-滑移 物理模拟 形成机制 地质力学模式 

分 类 号：P642.3[天文地球—工程地质学]