降雨条件下黄土填方边坡促滑机理研究

为了解降雨条件下黄土路基填方边坡的促滑机理,以G310号公路路基填方边坡为研究对象进行降雨数值模拟,分析孔边坡内部隙水压力、有效饱和度和位移等参数的响应情况,随着时间的增加,在降雨初期边坡的安全系数变化较慢,随着降雨的不断入渗,安全系数不断减小,8~24 h安全系数变化较大,减小趋势显著,随后变化不大。促滑机理概括为降雨过程黄土填方边坡强度劣化,加之降雨坡顶、坡脚积水,后缘坡体率先产生沉降变形,坡脚土体吸力逐渐丧失随后发生湿剪破坏,进而坡体内土体应力调整,促使塑性区贯通,最终造成边坡溃滑。

In order to understand the slide promoting mechanism of loess subgrade fill slope under rainfall condition,the numerical simulation of rainfall was carried out on the roadbed fill slope of Highway G310,and the responses of parameters such as pore water pressure,effective saturation and displacement were analyzed.with the increase of time,the safety factor of the slope changes slowly at the initial stage of rainfall,and decreases continuously with the continuous infiltration of rainfall,and changes greatly during 8~24 hours.The decreasing trend is significant,and then it does not change much.The sliding promotion mechanism is summarized as follows:The strength of loess fill slope deteriorates in the process of rainfall,coupled with the accumulation of water at the top and foot of the slope,the back edge of the slope first produces settlement and deformation,and the suction of the soil at the foot of the slope is gradually lost,followed by wet shear failure,so that the stress of the soil in the slope is adjusted to promote the penetration of the plastic zone,thus resulting in the collapse of the slope.