边坡局部和整体稳定性评价方法的辩证统一

边坡稳定性评价方法有局部和整体两类，两者之间存在差异有其历史的局限性和存在的合理性。以极限平衡法和有限元强度折减法为例，分析了典型整体与局部稳定性评价方法在滑面搜索、平衡条件、安全系数的定义、材料参数和失稳等5个方面存在的异同。利用PFC算例揭示了真实边坡带有强烈空间和时间特征的渐进破坏特性，发现边坡失稳是自然地形的重塑、再造和稳定的过程，也是一个动势能转换和耗散的过程。针对边坡稳定问题及其特点，提出了基于广义软化的边坡稳定矢量和法的理论构架和技术路线，并进行了程序实现，克服了传统强度折减脱离实际材料劣化特征的不足，安全系数求解仅与应力状态相关，假设条件少，可以实现局部与整体稳定评价的辩证统一，可以反映边坡失稳的渐进特性和参数演化的时空效应。与传统极限平衡法(LEM)和强度折减法(SRM)在滑面和安全系数方面的综合对比发现，局部稳定揭示的滑面更稳定，获取的安全系数是全周期的，文中方法所得安全系数比整体方法的结果稍高，差异是整体方法的假设条件造成的。

Dialectical unity of slope local and global stability analysis methods

Analysis method of slope stability can be classified into local and global kinds. These different points have their historical rationality and limit. Taking limit equilibrium method and strength reduction method for examples, the difference of typical local and global one such as slip surface, equilibrium condition, definition of safety factor, material parameters and un-stability is studied and summarized. Using a PFC slope fail case presents that real slope un-stability has observably spatiotamporal series and progressive features. Practical slope failure is a process of terrain reconstruction and stabilization and a process of potential and kinetic energy transition and dissipation. Aiming at these, the theoretical framework and technical route of slope stability vector sum method considering generalized softening are established. The relative program is implemented too. Whose reduction has material degradation back-ground. Its safety factor only relates to stress state of the slope. There are few assumed conditions in the method, which can realize dialectical unity of local and global stability and reflects progressive characteristics and spatiotamporal effect of slope un-stability. The safety factor and slip surface obtained by the method proposed compared with results of LEM and SRM, show that slip surface of local one is more stable, safety factor is whole life cycle and is larger than that of global one by 5%. The difference between local and global slope stability analysis method is caused by their assumed conditions.