降雨条件下饱和-非饱和土坡的渗流分析

运用饱和-非饱和渗流有限元法模拟降雨条件下饱和-非饱和土坡暂态渗流场的变化情况,分析降雨强度、降雨历时以及土壤饱和渗透系数等参数对非饱和土坡基质吸力的影响.分析结果表明:当饱和渗透系数较大、降雨强度小时,降雨入渗充分,孔隙水压力梯度变化大;饱和渗透性小时,降雨影响的深度变浅,基质吸力逐渐丧失;降雨初期,孔隙水压力梯度变化最明显,在降雨8 h之后,基质吸力完全丧失,对于土坡稳定安全不利.

Seepage analysis of saturated-unsaturated slope under rainfall

Based on the finite element method of the saturated-unsaturated seepage,the variation of transient seepage field of saturated-unsaturated slope was simulated in the case of rainfall,and the influence of rainfall intensity,rainfall duration and saturation permeability coefficient on the matric suction of the unsaturated slope was also analyzed.The analysis results indicated that,when saturation permeability coefficient was greater and the rainfall intensity was small,the rainfall infiltration would be sufficient and the grads of pore water pressure would vary notably.On the contrary,when saturation permeability coefficient was small,the depth of rainfall influence area would be shallow and the matric suction would gradually vanish.At the initial stage of the rainfall,there was a most notable variation of the grads of pore water pressure.Eight hours later,the matric suction would vanish entirely,being very harmful to the stability of slope.