降雨-裂缝耦合作用下堆积体斜坡渐进破坏过程与失稳机理研究

The progressive failure mechanism of rainfall-induced landslide is always the hot and difficult problems in the prevention and remediation of geohazard. As the inter-medium product of the slope deformation and failure, the existence landslide cracks is always be ignored or generalized during the assessment of the rain-induced landslide. However, the rain infiltration along landslide cracks will accelerate the progressive failure of the slope and the formation of crack system. Moreover, the enlarged cracks will further facilitate the rain infiltration and in turn increase the slope deformation. Taken the Zhaojiagou Landslide as the research area, the project is planned to carry out the following researches based on the comprehensive method of the in-situ natural rainfall monitoring, physical modeling of artificial rainfall on a slope with fissures and the dedicated numerical simulations. (1) the progressive deformation process of colluvial slope under the coupling of rainfall-landslide and its instability mechanism; (2) the time-spatial correlation between the crack evolution and the stage of slope deformation and failure; (3) Obtain of the useful information related to the slope failure. The results of the project could provide valuable basis for the stability assessment of rain-induced colluvial landslides and their failure forecast.

降雨型滑坡的渐进破坏过程与失稳机理历来是地质灾害防治领域的热点和难点问题。滑坡裂缝作为斜坡变形破坏的中间产物及事实存在，在降雨型滑坡稳定性评价时却经常被忽视。降雨沿裂缝的集中入渗加速了斜坡的渐进破坏和裂缝的扩展，而扩展后的裂缝将更便于雨水入渗，进而加速斜坡变形。课题拟以镇雄赵家沟滑坡为研究对象，采用天然降雨原位监测、人工降雨模型试验和精细数值模拟相结合的方法，研究降雨-裂缝耦合作用下堆积体滑坡的渐进变形过程与失稳机理，揭示裂缝演化与变形失稳阶段间的时空关联，获取滑坡失稳前兆信息。课题研究成果可为降雨型堆积体滑坡稳定性评价和失稳预测提供依据。

裂缝是斜坡变形破坏过程的中间产物，对降雨型堆积体滑坡的发生发展有重要影响。本项目开展了降雨-裂缝耦合作用下堆积体斜坡渐进破坏过程与失稳机理研究，包括分析了赵家沟崩滑堆积体坡体结构特征的成因演化，实施了天然降雨入渗原位TDR监测，对不同裂缝深度位置与数量下堆积体斜坡开展了降雨-裂缝耦合数值模拟并分析了各裂缝因素的敏感性，研究了黑多古滑坡体裂缝体系时空演化及其运动学意义，利用多时像高清遥感影像分析了裂缝坡体位移与降雨相关性，讨论了降雨对裂缝坡体稳定性的滞后效应，以及分析了裂缝堆积体滑坡失稳并转化为泥石流的机理等。相关研究有助于揭示降雨作用下裂缝堆积体的运动学、动力学特征等规律，有着很大的学术价值和实际意义。