考虑参数时空演化规律的黄土边坡极限平衡分析法研究

考虑黄土特殊力学性质的边坡稳定性分析方法研究对于保障国家"西部大开发"战略和"一带一路"倡议的实施具有重要的意义。利用渗流—软化—稳定性分析顺序耦合的研究思路,对地下水位上升条件下的黄土边坡稳定性进行分析。首先借助非饱和非稳定渗流分析理论进行地下水位上升条件下黄土边坡的渗流分析;其次基于渗流分析的计算成果借助水致结构性劣化方程动态更新土体强度参数的空间分布;基于总重度、黏聚力、内摩擦角和孔隙水压力的时空分布规律,采用面力法提出了考虑参数时空演化规律的黄土边坡极限平衡分析法。最后以地下水位上升条件下白鹿塬边某黄土边坡为例,通过考虑参数时空演化规律的黄土边坡稳定性Spencer法和M-P法计算成果之间的相互对比分析,同时将这些成果与现场勘察迹象进行对比,从而说明考虑参数时空演化规律的黄土边坡极限平衡分析法的合理性和可靠性。

Limit equilibrium analysis method for loess slopes considering spatial-temporal evolution laws of parameters

The research on the slope stability analysis method considering the special mechanical properties of the loess is of great significance to the implementation of the national strategy of "Western Development" and the initiative of "Belt and Road". Based on the research idea of the sequential coupling of seepage-softening-stability analysis, the stability of the loess slope under rising of the ground water level is studied. Firstly, the seepage analysis of the loess slope under rising of the ground water level is carried out by using the unsaturated unsteady seepage analysis theory. Secondly, based on the calculated results of the seepage analysis, the spatial distributions of strength parameters are dynamically updated by the water-induced structural deterioration equation. Thirdly, based on the spatial-temporal distribution laws of total unit weight, cohesion, internal friction angle and pore pressure, the limit equilibrium analysis method for the loess slope considering spatial-temporal evolution laws of parameters is proposed. Finally, taking a loess slope in Bailuyuan of Xi'an city in China as an example, the stability of the loess slope is comparatively analyzed by using the Spencer’s method and the M-P’s method considering spatial-temporal distribution laws of parameters. Meanwhile, the comparative analysis of the calculated results by using the proposed method with the on-site investigation is done, thus the reasonability and reliability of the proposed method are verified.