不同降雨过程特征下的库区滑坡稳定性

降雨是滑坡的主要诱发因素之一.根据降雨强度随着降雨历时的变化特征划分了五种降雨过程.以澜沧江某水电站库区一典型土质滑坡为例,模拟滑坡体在不同工况下的渗流场,分析降雨过程对库区滑坡稳定性的影响.结果表明：在库水位不变的情况下,五种降雨过程对滑坡稳定性的影响由大到小的顺序为递增型、先强后弱型、先弱后强型、稳定型、递减型.在降雨过程不变的情况下,随着库水位的上升,滑坡稳定性会先减小再增大.水库蓄水前期及递增型降雨过程,滑坡处于最危险状态.该研究为库区滑坡稳定性评价提供了依据.

Study on stability of landslide in reservoir area under different rainfall processes

This paper follows from the acceptance that rainfall occurs as a one of the main contribu- tors to most landslides and introduces the division of the rainfall process into five different types based on the different change laws underlying rainfall intensity through the rainfall duration. The paper goes further by analyzing a typical soil landslide occurring in a hydropower station＇ s reservoir on Lancang River, sim- ulating the seepage field of the slope subjected to different conditions and investigating the effect of the rainfall process on the stability of the reservoir landslide. The investigation reveals that the constant reser- voir water level suggests the occurrence of the five rainfall processes which tend to influence the stability of landslide in the order of the effects varying from big to small, such as, the increasing type, the first strong and then weak type, the first weak and then strong type, the constant type, and the decreasing type. In the case of the constant rain process, landslide would have such stability as first decreases and then increases, depending on the rise of the reservoir water level. The earlier stage of reservoir storage and the increasing type rainfall pattern mean the greatest landslide danger. The study would provide a ba- sis for a better evaluation of the stability of the reservoir landslide.