含不连续软弱夹层顺层边坡破坏机制与稳定性分析

Analysis on the Failure Mechanism and Stability of Contained Non-continuous Weak Interlayers Bedding Slope

含不连续软弱夹层顺层边坡失稳破坏是一个复杂的系统,主要涉及软弱夹层的空间分布形态和范围、不同条件下的力学效应等问题。以贵州某高速公路边坡为例,通过现场勘查以及大量室内外试验,分析计算软弱夹层分布面连续度km、线连续度kl,根据软弱夹层随含水量变化的力学参数弱化情况,分别获取相应剪应力计算方法以及确定边坡滑面的位置,并进行稳定性评价,结果显示符合实际工况。通过"宏观知其形,微观知其理"的思想,阐述了边坡失稳破坏过程影响因素,以及边坡开挖后岩体劣化、雨水下渗、滑面力学性状弱化过程,建立了"刚柔相济"的地质-力学量化模型,分析边坡滑移-拉裂的形成机制,系统总结了边坡演化过程。该边坡的研究成果可为此类以及类似边坡评价、设计及施工提供有价值的参考。

The instability failure of the slope containing non-continuous weak inter-layers bedding is a complex system, which is mainly related to spatial distribution form and scope of weak inter-layers, and the mechanical effects under different conditions. An expressway is taken as an example in Guizhou Province, through field exploration and a large number of indoor and outdoor experiments, the distribution of surface analysis and calculation of weak intercalations for km and line continuous degrees kl, according to the thickness of interlayer and the surface of the structure and relationship and weakening the mechanics parameters changing with water content of weak intercalations, respectively to obtain the corresponding shear stress calculation method and determine the sliding surface of slope position, and evaluate the stability, according to the results conform to the actual working condition. Through ＂form is known by macro, mechanism is known by micro＂ concept, this paper expounds the factors influencing process instability and failure of slope and slope after excavation, bunker quality degradation, rainwater infiltration, sliding surface mechanical properties is weakened and formed ＂ hardness with softness＂ geological mechanics of quantitative models. The sliding-cracking mechanism of the slop is studied and summarized the evolution of slope. The research results of the slope can provide valuable reference for design and construction.