考虑渐进破坏过程的滑坡推力计算方法

在滑坡防治工程设计当中，推力确定是治理工程设计是否合理有效的前提。本文进行了3种类型滑坡的渐进变形破坏模式分析，从滑带参数弱化的角度阐述了不同类型滑坡的渐进演化过程，并以滑带力学参数经历峰前应力阶段、软化阶段、残余应力阶段刻画了滑带空间形态所经历的峰前应力状态、临界应力状态、残余应力状态3个阶段；基于不平衡推力法，提出3种类型滑坡临界状态条块的确定方法，把滑坡划分为发生剪切段和未发生剪切段，提出了不同类型滑坡渐进破坏过程中推力计算公式及计算过程中滑带参数取值方法。以任意滑坡为例，从不同类型滑坡角度分析了滑坡在渐进破坏过程中推力的变化规律，结果表明：不同类型滑坡渐进破坏到第5状态时，牵引式滑坡、推移式滑坡和复合式滑坡的推力大小分别为4 100，4 980和3 150 kN/m，推移式滑坡推力最大，说明滑坡以不同模式破坏时推力存在明显差异。此计算方法不仅反应了不同类型滑坡的渐进破坏过程，又解决了具有应变软化性质的滑坡推力计算问题，在实际工程中为滑坡的设计提供合理的推力。

Calculation Method of Landslide Thrust Considering Progressive Failure Process

In the design of landslide prevention,the determination of thrust is a precondition for reasonable design of control engineering.The progressive deformation failure modes of three types of landslides were analyzed,and the progressive evolution process of the different types of landslides were described based on the weakening of sliding zone parameters in this study.The different part of sliding zone were portrayed spatially for going through three states of the pre-peak stress state,critical stress state and residual stress state according to the corresponding mechanical strength in the three stages of the pre-peak stress stage,the softening stage and the residual stress stage.The distinguishcriterion of sliding block of critical state was proposed based on the unbalanced thrust method.The calculation model and calculation formula of thrust of progressive failure of landslides were established,and the parameter value method of sliding zone was proposed.Moreover,the thrust variation in the process of progressive failure was analyzed from the points of view of different types of landslides.The results show that when the different types of landslides were progressively damaged to the fifth states,the thrust of retrogressive landslide,load-caused landslide and complex landslide was 4 100,4 980 and 3 150 kN/m respectively,and the thrust of load-caused landslide is the largest,indicating that there is a significant difference in landslide thrust in different modes.This method can not only reflects the progressive failure process of different types of landslides,but also solves the problem of the thrust calculation of landslide with strain softening properties,and further can provide a reasonable thrust estimation for the design of landslide prevention.