基于滑动面深度的地震作用下边坡强度参数反分析

Back Analysis of Slope Strength Parameter under Earthquake Based on Slip Surface Depth

边坡参数反演是获取边坡强度参数的重要手段。与传统的安全系数及位移反分析不同,提出了基于滑动面深度的边坡参数反演方法。基于极限分析上限定理,利用拟静力方法,计算了地震力作用下边坡的外力功率与内能耗散表达式,并结合强度折减法,推导了简单边坡在地震力作用下的安全系数公式。利用优化算法得到边坡的最小安全系数后,可以求出边坡在地震力作用下临界滑动面的方程,得到边坡不同位置的滑动面深度。并利用滑动面深度对强度参数进行反演。计算结果表明,随着地震加速度的增大,边坡的滑动面深度逐渐增大。通过数值计算与工程实例的对比,证明新方法是有效可靠的。

Back analysis is an important means for obtaining slope strength parameter. Different from traditional back analysis based on safety factor and soil displacement, a new back analysis method of slop parameter based on slip surface depth is proposed. Based on the upper-bound theorem of limit analysis and quasi-static method, the external force power and internal energy dissipation of slope under earthquake is calculated. With strength reduction method, the safety coefficient formula of normal slope is derived under earthquake is derived. Using the minimum safety factor obtained by optimized algorithm, the equation of critical slip surface and the slip surface depth of different positions are solved. Based on this, the slope strength parameters are back analysed. The calculated result shows that the depth of slip surface increases with the increase of earthquake acceleration. Comparing the results of the numerical calculation with engineering example, it is proved that this method is effective and reliable.