地震作用下黏性土坡失稳破坏的颗粒流模拟  

Particle Flow Simulation of Clay Slope Failure under Earthquake

作　　者：吴为东 胡康俊 叶旻 瞿章城 WU Weidong;HU Kangjun;YE Min;QU Zhangcheng(Hangzhou Urban Expressway Co. Ltd.,Hangzhou 310024,China;MOE Key Laboratory of Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;Geotechnical Research Institute,College of Civil and Transportation,Hohai University,Nanjing 210098,China)

机构地区：[1]杭州都市高速公路有限公司,杭州310024 [2]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [3]河海大学土木与交通学院岩土工程研究所,南京210098

出　　处：《河南科学》2019年第8期1283-1288,共6页Henan Science

基　　金：国家自然科学基金项目资助（51508160）

摘　　要：利用颗粒流程序建立了黏性土边坡模型,模拟在地震作用下黏性土坡变形破坏全过程,并对其破坏形式和机理进行了研究.结果表明,黏性土坡的变形破坏形式是渐进性破坏,由下至上、由浅入深形成一条贯通的“滑移带”,破坏过程表现为:坡脚周围土体先受拉破坏和剪切破坏,逐渐引起坡顶土体受拉产生拉裂缝、土坡深层土体受剪切破坏和挤压破坏.边坡破坏主要发生在地震作用的前段时间,剪切破坏多于拉裂破坏;地震作用的后段时间主要发生土体滑移,拉裂破坏多于剪切破坏.随着坡高、坡度、地震峰值加速度的增加,黏性土边坡破坏程度更加明显,破坏范围增大.In this paper,the slope model considering quiet boundaries is simulated based on PFC. And then numerical analysis is performed to study the failure behavior of clay slope under seismic loading. The failure mode is analyzed by the whole processes of clay slope. The failure behavior of the clay slope is progressive,which develops a deep failure surface from the base toward the crest. Moreover the failure mechanism of the clay slope is discussed in detail. Many shear fractures and tension fractures occur below the toe of slope in the beginning of earthquake,and then induce slip along a circular shape. Strength reduction method based on PFC is applied to evaluate the stability of slope. When some criterions for evaluating instability of the slope are content by the strength reduction at the same time,the slope could be regarded as instability and the strength reduction factor is defined as the safety factor of slope. The safety factor by this method is conservative in engineering practice compared with other methods.

关 键 词：边坡失稳 颗粒流 破坏机理 地震 渐进性破坏 峰值加速度 

分 类 号：TU13[建筑科学—建筑理论]