考虑流固耦合作用的库岸滑坡变形失稳机制

 当前，在库水位下降引起滑坡变形失稳机制的认识上，仍存在不足。基于渗流计算结果，采用有效应力法对边坡进行应力–变形分析和稳定性计算的传统方法，仅考虑由水体自重渗流产生孔隙水压力，而没有考虑水位下降引起滑带处的超孔压，从而产生不切实际的变形分析和稳定性计算结果，对滑坡的变形和失稳机制产生错误的认识。在流固耦合理论基础上，以黄土坡滑坡前缘临江崩滑堆积体作为工程实例，通过对泄水下滑坡流固耦合作用的数值模拟，得到应力场、变形场及孔压场的变化规律，探讨考虑应力场与渗流场耦合作用的滑坡变形失稳机制，并进行非耦合和耦合计算方案下滑坡稳定性变化趋势。研究结果表明，库水位下降引起滑带附近的超孔隙水压力是诱使滑坡变形和失稳的重要原因。

DEFORMATION AND FAILURE MECHANISMS OF RESERVOIR LANDSLIDE CONSIDERING FLUID-SOLID COUPLING EFFECT

Three are limitations in comprehension of reservoir landslide deformation and failure under conditions of water level decreasing. Traditionally，stress-deformation and stability analysis are based on results from seepage calculations in terms of pore water pressure treatment，and without taking into account the excess pore water pressure around slip-band zone for sluicing. Therefore，the unpractical deformation analysis and stability are obtained，which result in mistake understanding of mechanism of landslide failure. Taking the front part of Huangtupo landslide as an engineering example，the fluid-solid coupling numerical analysis is carried out under conditions of water level decreasing. The stress field，deformation field and pore water pressure field are obtained so as to probe into deformation and failure mechanism of landslide considering the double-field coupling effect. Moreover，the stability varying trends with time is obtained. Study shows that the excess pore water pressure resulting from sluicing is a significant factor inducing deformation and failure of landslide.