Wide / narrow-area slope stability analysis considering infiltration and runoff during heavy precipitation
Wide / narrow-area slope stability analysis considering infiltration and runoff during heavy precipitation
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DOI：
10.1016/j.sandf.2022.101248
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发表时间：
2023-02
影响因子：
3.7
通讯作者：
Wentao He;T. Ishikawa;Yulong Zhu
中科院分区：
文献类型：
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作者：
Wentao He;T. Ishikawa;Yulong Zhu
天然集水区强降雨产生的径流和人工构筑物堵塞沟渠产生的径流增加了边坡的稳定性。在传统的降雨失稳分析中，往往忽略径流的影响。为了考虑径流对坡面失稳的影响，本研究尝试在宽/窄区域同时模拟径流、入渗和坡面失稳。为此，本研究首先基于扩散波动方程、Richards方程、Green-Ampt入渗能力模型和广域模拟中的局部安全系数，建立了地表径流、地下径流和土壤力学的耦合模型。其次，在窄带模拟中还考虑了融雪和地表草层的影响。最后，将所提出的耦合模型应用于日本北海道Nissho Pass和Kuromatsunai的两个斜坡。坡面失稳评价方法为模拟径流和坡面失稳提供了一种有效的方法。在大范围内，安全系数分布图对于准确确定危险点和准确发布预警信息具有重要意义。在狭小区域，提取了沟渠堵塞引起的边坡灾害点，论证了草层对边坡稳定性评价的影响。排水系统的建设和维护可以重新设计，以确保降水产生的所有地表水流顺利排出。
Runoff generated by heavy rainfall in natural catchment area and caused by ditch clogging in artificial structure increases the instability of the slope. The effects of runoff are usually neglected in traditional rainfall-induced slope failure analysis. In order to consider the effects of runoff on the slope instability, this study attempts to simulate the runoff, infiltration and slope instabilities simultaneously on both wide/narrow area. For this purpose, this study firstly proposes a coupled model of surface flow, subsurface flow, and soil mechanics based on Diffusion wave equations, Richards’s equation, Green-Ampt infiltration capacity model, and local factor of safety approach in wide area simulation. Next, snowmelt and surface grass layer are additionally considered in narrow area simulation. Finally, the proposed coupled model is applied to two slopes at Nissho Pass and Kuromatsunai in Hokkaido, Japan. The slope instabilities assessment approach provides an effective method for simulating runoff and slope instabilities. In wide area, the distribution map of the factor of safety has significant implications for precisely determining the dangerous spots and accurately releasing the warning information. In narrow area, the slope disaster points caused by the ditch clogging are extracted and effect of grass layer on slope stability assessment is demonstrated. The construction and maintenance of the drainage system can be re-designed to ensure all the surface flow caused by the precipitation drain out smoothly.