降雨特性对土质边坡失稳的影响

 通过降雨诱发土质边坡失稳的模型试验及已有研究成果来探讨降雨特性对边坡失稳的影响，并以此来选取出合适的雨量预警参数。研究结果表明：高强度降雨较易使边坡产生流滑破坏且冲蚀现象较为明显；而低雨强长历时的降雨较易使边坡深层土体的孔隙水压力增加，因此较易产生滑动型破坏且滑坡体的规模也较大；此外，降雨型滑坡存在“门槛累积雨量”。该研究成果揭示了降雨入渗对边坡稳定性的作用机制，并以此建议采用降雨强度与累积雨量作为雨量预警基准所需的参数，其中降雨强度参数可用时雨量表示，时雨量可用以衡量流滑型滑坡和泥石流灾害，而累积雨量则有助于评估滑动型滑坡的灾害。

INFLUENCE OF RAINFALL CHARACTERISTICS ON SOIL SLOPE FAILURE

Rainfall early warning criterion is a useful tool for rainfall-induced landslide mitigation. Unfortunately，it is hard to be used effectively in practice owing to the complexity between rainfall infiltration effects and slope stability. Hence，the landslide model test for soil slope and previous research results are used to study the influence of rainfall characteristics on soil slope failure. The results show that fluidized landslide and soil erosion will be triggered by high intensity rainfall easily；and the pore water pressure in the deep soil of slope will increase easily under the long duration rainfall with low intensity；and the landslide magnitude which is triggered by the long duration rainfall with low intensity will be larger than that triggered by high intensity rainfall. Besides，the threshold accumulative rainfall is an important factor of rainfall-induced landslide. Moreover，it is suggested that the rainfall intensity and accumulative rainfall are effective parameters in rainfall early warning criterion. The rainfall intensity can be represented by the rainfall amount per hour，which can predict fluidized landslide and debris flow. The accumulative rainfall is helpful to predict sliding landslide.