基于非饱和裂隙渗流的软硬相间顺层边坡降雨入渗计算模型及动态稳定评价方法研究

With the effects of climate change and rainstorm frequency enhance in recent years, the problem of slope stability under rainfall is more and more outstanding. Field investigation showed that, the bedding rock slope with soft and hard interbed is more prone to failure under rainfall conditions. However, the existing theory is hardly valid for this kind of slope when dealing rainfall infiltration evaluation and the dynamic stability problem. Aiming on the above questions, this study establish the corresponding macro evaluation model using rough set and support vector machine method, based on the domestic and foreign typical slope instability case. Secondly, for the slope of potential instability risk, a rainfall infiltration concept model will be build according to unsaturated fracture seepage theory considering slope infiltration and back crack infiltration. Meanwhile, control equation is deduced and solve by variable substitution and integral transform method. The physical field is achieved at the same time. Thirdly, this study slice the slope into several blocks by new slices method. Different block areas will be conduct mechanical analysis, and the stability status will be judged by the improved unbalanced thrust method. The research results can support the construction of infrastructure, especially in central and Western China mountain areas with typical bedding rock slope with soft and hard interbedding.

随着近年来气候变化的影响和暴雨灾害频率的提高，边坡降雨稳定性问题越来越突出。现场调研表明，软硬相间的顺层边坡以其特殊的坡体结构较易发生降雨失稳灾害。然而，现有的理论对于该类边坡的降雨入渗模型和动态稳定评价却无能为力。针对上述问题，本课题以近年来国内外典型边坡降雨失稳案例为基础，根据前期研究成果，采用粗糙集-支持向量机等方法建立相应的宏观评价模型。其次，对于存在潜在失稳风险的边坡，结合非饱和裂隙渗流理论建立考虑坡面渗流和后缘裂缝渗流的降雨入渗概念模型，推导得出降雨条件下的解析控制方程，通过变量代换和积分变换等方法得出不同降雨时刻坡体内部物理场状况。采用新型方法对坡体进行条块化处理，针对不同位置处的条块区域开展受力分析和失稳区域搜索，通过改进的不平衡推力法最终实现边坡在不同降雨时刻的动态稳定评估。研究成果可很好地服务于基础设施建设，特别是我国中西部典型软硬相间顺层岩质边坡分布的山岭地区。

随着近年来气候变化的影响和暴雨灾害频率的提高，边坡降雨稳定性问题越来越突出。现场调研表明，软硬相间的顺层边坡以其特殊的坡体结构较易发生降雨失稳灾害。然而，现有的理论对于该类边坡的降雨入渗计算和动态稳定评价却无能为力。针对上述问题，本课题以近年来国内外典型边坡降雨失稳案例为基础，根据前期研究成果，从11个影响因素中提取6个关键性影响因素，采用粗糙集-支持向量机等方法建立相应的宏观评价模型。其次，对于存在潜在失稳风险的边坡，结合非饱和裂隙渗流理论建立考虑坡面渗流和后缘裂缝渗流的降雨入渗概念模型，推导得出降雨条件下的解析控制方程，通过变量代换和积分变换等方法得出不同降雨时刻坡体内部物理场状况。采用新型方法对坡体进行条块化处理，针对不同位置处的条块区域开展受力分析和失稳区域搜索，通过改进的不平衡推力法最终实现对边坡在不同降雨时刻的动态稳定评估。本研究所提出的方法较好地提高了该种类型边坡降雨失稳的评估精度。研究成果可较好地服务于基础设施建设，特别是我国中西部典型软硬相间顺层岩质边坡分布的山岭地区。