降雨作用下青藏高原季节性冻土区滑坡分析
Analysis of Landslides in the Seasonal Permafrost Area of the Qinghai-Xizang Plateau under the Influence of Rainfall
摘要: 本研究选取了中国青藏高原青海省东南部果洛藏族自治州玛沁县季节性冻土区某滑坡，通过FLAC 3D软件对该边坡在自然条件及降雨入渗作用下边坡变形的演化过程进行数值模拟对比分析。研究结果表明：降雨显著增加了滑坡体的变形，尤其是在x方向的位移上，在降雨条件下，滑坡体的x方向位移增加了约25.186 m。此外，最大剪切应变和最大应力的分布特征也发生了明显变化，其中最大剪切应变在滑坡体堆积层的中部区域显著增加，而最大应力则在滑坡体后缘中间位置以及表面堆积层区域。进一步的分析揭示了降雨对滑坡体塑性区安全系数的影响，模拟结果表明，降雨导致塑性区安全系数大幅降低，从而增加了滑坡失稳的风险。综上所述，降雨增加了滑坡体的含水率，降低了土体的抗剪强度，孔压持续上升，从而加剧了滑坡体的变形和失稳。本研究旨在为理解和预测降雨条件下青藏高原季节性冻土区滑坡的动态行为提供了重要的理论依据和技术支持。
Abstract: In this study, a landslide in the seasonal permafrost area of Maqin County, Guoluo Tibetan Autonomous Prefecture, southeast of Qinghai Province on the Qinghai-Xizang Plateau, China was selected, and the evolution process of slope deformation under natural conditions and rainfall infiltration was analyzed by FLAC 3D software. The results show that the rainfall significantly increases the deformation of the landslide, especially in the x-direction, and the x-direction displacement of the landslide increases by about 25.186 m under rainfall conditions. In addition, the distribution characteristics of the maximum shear strain and maximum stress also changed significantly, in which the maximum shear strain increased significantly in the middle of the landslide accumulation layer, while the maximum stress was in the middle of the trailing edge of the landslide and the surface accumulation layer. Further analysis reveals the influence of rainfall on the safety factor of the plastic zone of the landslide, and the simulation results show that the rainfall leads to a significant decrease in the safety factor of the plastic zone, which increases the risk of landslide instability. In summary, rainfall increases the moisture content of the landslide, reduces the shear strength of the soil, and the pore pressure continues to rise, thereby aggravating the deformation and instability of the landslide. The purpose of this study is to provide an important theoretical basis and technical support for understanding and predicting the dynamic behavior of landslides in the seasonal permafrost area of the Qinghai-Xizang Plateau under rainfall conditions.
文章引用：尹丽娥, 王章东, 武湘栋. 降雨作用下青藏高原季节性冻土区滑坡分析[J]. 土木工程, 2024, 13(12): 2370-2382. https://doi.org/10.12677/hjce.2024.1312260

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