溪古水电站消力池边坡降雨条件下渗流场三维有限元分析

Study on Seepage Characteristics of Xigu Stilling Basin Slope Rainfall Infiltration Based on Three-dimensional Finite Element Method

针对因公路改线在坝顶高程附近开挖溪古水电站消力池高边坡时雨季曾出现局部塌滑破坏、边坡顶部变形较大并出现明显的坡面拉裂缝等问题,基于饱和—非饱和渗流理论,建立了该边坡渗流分析三维有限元模型,模拟了坡面张拉裂缝等入渗通道和内部主要结构面,根据坝址气象资料拟定了典型降雨过程线,研究了该边坡在降雨条件下的渗流场及其变化规律,并计算分析了工程治理措施对边坡渗流场的影响。结果表明,同时封闭后缘透水带和坡面张拉裂缝等入渗通道可显著减小坡体暂态饱和区,且暂态饱和区向坡内延伸的垂直深度最大可减小约15m,有利于提高边坡稳定性。

The high slope of Xigu hydropo the crest with apparent tension cracks of the sl wer station＇s stilling basin appeared local collapse and large deformation of ope during the rainy season when excavating near the crest because of relo- cation of highway. Based on the saturated-unsaturated seepage theory, three-dimensional finite element model of slope seepage analysis is established to simulate infiltration channels and the internal surface of the main structure. According to the meteorological data in dam site, the typical rainfall process line is proposed to study the slope seepage field and its variation law under rainfall conditions. In addition, the influence of engineering measures on slope seepage is also ana- lyzed. The results show that both closing the trailing permeable zone and slope surface seepage channel of tension crack can reduce the slope transient saturated zone significantly slope transient saturated zone extends to the depth of the verti- cal slope can be reduced by about maximum of 15 m that is helpful to imnrove the slope stability.