倾角变化条件下反倾层状斜坡倾倒变形演化研究  

A centrifuge study on effects of rock dip angle on toppling deformation of anti-dip layered rock slopes

作　　者：杜睿锡 郑达[1] 吴章雷 陶诗鑫 周鸿轲 DU Ruixi;ZHENG Da;WU Zhanglei;TAO Shixin;ZHOU Hongke(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;PowerChina Chengdu Engineering Corporation Limited,Chengdu 610059,China;Guangyuan Zhaohua District Transportation Bureau,Guangyuan 628021,China)

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059 [2]中国电建集团成都勘测设计研究院有限公司,四川成都610059 [3]广元市昭化区交通运输局,四川广元628021

出　　处：《人民长江》2024年第4期150-159,168,共11页Yangtze River

基　　金：国家自然科学基金项目(42293353);地质灾害防治与地质环境保护国家重点实验室自主课题(SKLGP2020Z008)。

摘　　要：倾倒变形是反倾层状岩质边坡的一种典型破坏模式,为了研究不同岩层倾角对反倾层状岩质边坡倾倒变形的影响,以澜沧江上游古水水电站坝前倾倒变形体为原型,从岩层倾角变化的角度出发,利用大型土工离心机试验分析了反倾层状岩质边坡的失稳破坏过程、变形演化特征与最终失稳模式等。结果表明:①反倾层状斜坡的变形演化过程基本概括为岩层压密-坡脚压裂阶段、弯折面形成-部分失稳阶段和弯折面贯通-彻底失稳3个阶段,岩层倾角的改变并不会影响斜坡阶段性演化过程;②岩层倾角越大的斜坡,斜坡形成弯折面所需时间越短,失稳破坏发生后坡体贯通性倾倒破坏深度更大,对应的变形范围越大,折断岩层的破坏程度越剧烈;③岩层倾角变化会导致斜坡的倾倒变形过程与最终失稳模式存在一定差异。倾角较小的55°和70°模型斜坡前部岩层在重力作用下发生明显弯曲倾倒变形,最终以“倾倒-弯曲-滑移”的失稳模式发生破坏;倾角最大的85°斜坡岩层发生的弯曲变形较小,最终以“倾倒-折断-崩塌”的模式发生破坏。研究结果对大型工程项目的顺利开展具有一定指导意义。Toppling deformation is a typical form of damage observed in anti-dip layered rock slopes.To investigate the impact of different rock dip angles on the toppling deformation of anti-dip layered rock slopes,we utilized the toppling deformation body in front of the dam of Gushui Hydropower Station in the upper reaches of Lancang River as a prototype.Based on the large-scale geotechnical centrifuge test,the failure process,deformation evolution characteristics,and final failure mode of the anti-dip layered rock slope were analyzed and studied from the perspective of the change of rock stratum dip angle.The outcomes are conducted as follows:①The change of rock dip angle does not affect the stage evolution process of the slope,which can be summarized as rock compaction-crack development at slope toe,formation of bending plane in slope-partial instability,and penetration of bending plane-rock mass complete instability.②The larger the dip angle of the rock stratum,the faster the formation of the bending plane of the slope,the deeper the penetrated toppling failure of the slope after the instability failure occurs,the larger the corresponding deformation range,and the more severe the damage degree of the broken rock stratum.③The change of rock dip angle will lead to a certain difference in the toppling deformation process and the final instability mode of the slope.For model slopes with small dip angles of 55°and 70°,the front rock strata of the slopes undergo obvious bending and toppling deformation under gravity,and finally fail in an instability mode of“toppling-bending-slip”.The bending deformation of the slope with the largest dip angle of 85°is small,and finally,it is destroyed in a mode of“toppling-breaking-collapse”.The results can provide significant guidance for the implementation of large-scale engineering projects.

关 键 词：倾倒变形 反倾层状岩质斜坡 破坏模式 弯折面 离心机模型试验 古水水电站 

分 类 号：TU413[建筑科学—岩土工程]