非饱和下蜀土边坡稳定性数值分析研究

Numerical Analysis on Stability of Unsaturated Xiashu Soil Slope

为了避免岩土体滑坡所带来的地质灾害给人民的生命财产安全造成严重危害,考虑到土体处于非饱和状态下,土质边坡的稳定性评价显得尤为重要.以南京市某下蜀土边坡工程为研究对象,根据室内试验得到土体的抗剪强度和非饱和土水土特征曲线,分析了下蜀土的强度变化情况;利用有限元分析软件ABAQUS,采用强度折减法,分析了土质边坡处于饱和状态和不饱和状态下时边坡的稳定性,采用强度折减法来模拟降雨或者水位上升的影响,发现在降雨过程中边坡的安全系数会减小,不利于边坡稳定;对比两种状态下下蜀土边坡的塑性图,发现随着土体饱和度的降低或基质吸力的增加,土坡失稳破坏的塑性区深度加深.

In order to avoid the geological disasters caused by rock landslide to the people’s lives and property caused serious harm,taking into account the soil in the unsaturated state,soil slope stability evaluation is particularly important.The soil shear strength and soil-water characteristic curves of soil in Xiashu soil slope of Nanjing are studied,and the strength of Xiashu soil is analyzed.By using the finite element analysis software ABAQUS and the strength reduction method,the stability of the slope is analyzed when the soil slope is saturated and unsaturated.The strength reduction is used to simulate the effect of rainfall or water level rise.It is found that the safety factor of the slope decreases during rainfall,and it is not conducive to slope stability.It is found that the depth of the plastic zone of the soil slope is weakened with the decrease of the soil saturation or the increase of the matrix suction,by comparing with the plastic map of Xiashu soil slope under the two conditions.