降雨型堆积层滑坡抗剪强度参数反演分析

Back Analysis of the Shear Strength Parameters of Rainfall-induced Colluvial Landslides

在研究实例工程滑坡约束条件和某一确定计算状态的基础上,利用极限平衡理论方法对滑坡的滑带土进行了计算参数反分析,获得了土层有效应力抗剪强度参数。研究表明:计算参数c(黏聚力),φ(摩擦角)值的反分析存在解的非唯一性,只有确定了边坡的临界状态并选定相应的评估指标后,才有可能获得准确结果;反分析得到的滑带土c,φ值与临界状态的滑带赋存条件相对应,当进行其他工况的稳定分析及工程设计时,应根据经验及工程类比结果进行折减。

Based on a study of constraint conditions and specific computation status of the example landslide, a back analysis was made on calculation parameters of the soil in slide zone by using limit equilibrium method, and the parameter values have been obtained. The result shows that the values of parameter c and φ derived from back analysis are not unique, and that the accurate values can be obtained only after the determination of critical state of the landslide and selection of the corresponding evaluation indices. It is also indicated that the values of parameter c and φ are in accordance with inherent conditions of the landslide in critical state. However, in the case of stability analysis and engineering design, the values should be modified according to experiences and comparison results with similar projects.