地震荷载作用下二元结构反倾开挖斜坡的变形破坏模型试验

选取彭州市龙门山镇王家坪滑坡所处斜坡作为二元结构反倾开挖损伤斜坡的典型实例,进行了地震荷载作用下变形破坏的室内物理模型试验。结果表明,开挖加剧了斜坡在地震荷载作用下的变形破坏。从破坏形式来看,反倾斜坡的坡变形破坏分为2个部分,一为浅表覆盖层的整体滑动,二为反倾岩层受浅表覆盖层滑动牵引而发生倾倒—崩塌,与野外调查结果吻合。从整个变形破坏过程来看,可以划分为以下阶段:地震初始阶段(浅表覆盖层与基岩接触面逐渐贯通过程)—浅表覆盖层滑动启动阶段—浅表覆盖层全面滑动及基岩牵引—倾倒阶段。试验重现和揭示了斜坡的变形破坏过程和规律。

Deformation and Failure Model Test of Binary Structure Anti-dip Excavation Slope under the Action of Seismic Load

The slope of Wangjiaping landslide,which is located in Longmenshan Town,Pengzhou City,was selected as a typical example of binary structure anti-dip slope with excavation failure,and indoor physical model tests were carried out on its deformation and failure under seismic loading.The results showed that the deformation and failure of slope under seismic loading were exacerbated by excavation.As viewed from failure mode,the deformation and failure of anti-dip slope was characterized by both integral sliding of superficial overburden and dump-collapse of anti-dip rocks,consistent with the results of field surveys.The entire process of deformation and failure could be divided into the following phases,which were the initial stage of earthquake(a gradual connecting process between superficial overburden and bedrock interface),superficial overburden sliding initiation stage,and superficial overburden full sliding and bedrock traction-dumping stage.The deformation and failure process and laws of binary structure anti-dip slope were reproduced by the model test.