水位下降对沿湖路堤边坡渗流特征及稳定性的影响

Influence of water decline on seepage characteristic and slope stability of embankment along lake

为分析沿湖路堤边坡在水位下降条件下的渗流特征及稳定性,采用非饱和渗流及非饱和抗剪强度理论对算例路堤边坡在不同水位下降速率及不同形式下的渗流特征及稳定性进行数值分析。研究结果表明:水位降低将引起沿湖路堤内部受影响区域孔隙水压力降低,在相同时间内降低幅度与外部水位下降速率呈正比例关系;水位降低将导致沿湖路堤边坡稳定性系数在整个水位下降过程中持续减小;引起沿湖路堤边坡失稳的主要原因是不同位置的孔隙水压力下降幅度差异较大、外部水体推力消失和基质吸力恢复缓慢。

In order to analyze the seepage characteristics and slope stability of embankment along lake when the water level declines, unsaturated flow theory and unsaturated shear strength theory were used to analyze the embankment＇s seepage characteristics and slope stability when the rates of water level declined and embankment forms were different. The results show that the decrease of pore water pressure in the embankment along lake is caused by the decrease of the water level, and the magnitude of the decrease is proportional to decline of the water level at the same time. The deline of water level leads to sustained decrease of slope stability factor. The large difference of the decreased magnitude of the pore water pressure in different places, and the fact that the thrust caused by lake water disappears and the matric suction recovers slowly, are the main reasons for slope collapse.