山区滑坡体降雨入渗及稳定性分析

Rainfall Infiltration at Landslides in Mountainous Area and the Stability Analysis

结合山区滑坡体工程实例,采用有限元法建立模型,研究降雨条件下滑坡体内雨水运移特征和雨水入渗对滑坡体稳定性的影响。研究结果表明:降雨强度与表层土体入渗能力的相互关系影响土体中饱和区运移、含水量以及孔隙水压力分布;滑坡体入渗分析中饱和区主要沿滑带由下而上、由内向表逐步发展,在雨后一段时间内达到最大,随后逐渐缩小;滑坡体的稳定性主要与滑带土中的孔隙水压力分布有关,孔隙水压力值越大,有效应力降低导致滑坡体的稳定性越差。该滑坡在降雨时处于不稳定状态,应采取相应的加固措施确保安全。

Combining with example of landslides engineering in mountainous area, the paper used FEM to establish a model and study that under the condition of raining, how the characteristics of rain water migration within the landslides and the rainfall infiltration affect the stability of landslide. The result shows that the interaction between rainfall intensity and infiltration performance of surface soil may affect the migration, water content and pore-water pressure distribution in the saturated zone of soilmass; according to landslide infiltration analysis, the saturated zone develops gradually along the sliding zone from the lower to the upper and from the inside to the surface till reaching the maximum in a certain period of time after raining, then diminishes step by step ; the stabilihy of landslide mainly relates to pore-water pressure distribution within the soilmass in the sliding zone, the higher the pressure, the worse the stability, which is caused by the decrease of effective stress. The landslide is in the state of instability when raining, thus requires corresponded rainforment to ensure the safety.