不同降雨条件下的某航电枢纽工程砂砾体围堰稳定性分析

降雨入渗对岩土的力学性质和力学行为有较大影响，不同的降雨条件会导致土体内部产生不同的水力响应。基于江西省某航电枢纽工程，结合Abaqus通用有限元软件，分别考虑实际降雨的三个影响因素(降雨强度、降雨历时、降雨雨型)进行不同降雨条件下的砂砾体围堰渗流及稳定性数值计算与分析。结果表明，围堰体内部渗流速度、孔隙水压力及变形位移随降雨强度和降雨历时的增加而增加，而堰体安全系数则随之下降。同时，堰体渗流和稳定性与不同雨型的峰值分布有较强的相关性，雨强峰值出现越晚，在降雨终止时，堰体的非饱和区孔压、渗流速度等越大，堰体安全系数越小。

Stability Analysis of the Sand-gravel Cofferdam of A Navigation Power Junction Project Under Different Rainfall Conditions

Rainfall infiltration has a great impact on the mechanical properties and mechanical behavior of rock and soil. Different rainfall conditions will cause different hydraulic responses in the soil. The seepage and stability analysis of a sand-gravel cofferdam under different rainfall conditions is performed though Abaqus(general finite element software) considering the three influencing factors of actual rainfall, i.e., rainfall intensity, rainfall duration, and rainfall pattern. This study is based on a navigation power project in Jiangxi Province. The calculation results show that the internal seepage velocity, pore water pressure and deformation displacement of the cofferdam increase with the increase of rainfall intensity and rainfall duration, while the safety factor of the dam decreases. At the same time, the seepage and stability of the cofferdam has a strong correlation with the peak distribution of different rain patterns. The later the peak of rain intensity appears, the pore pressure and seepage velocity of the cofferdam in the unsaturated zone can be greater with a smaller safety factor at the end of the rainfall.