中文摘要：

膨胀土是一种特殊的非饱和土。随着降雨的入渗,膨胀土中的吸力和抗剪强度都将减小,因而研究膨胀土边坡在降雨入渗作用下的稳定性具有重要意义。文章以合肥轨道交通1号线膨胀土边坡为研究对象,采用Geo-Studio软件研究了降雨强度及历时、土体裂隙、时间推移对边坡稳定性的影响。在此基础上,运用正交试验设计方法对膨胀土的水力学参数（土水特征曲线拟合参数a、n、m及饱和渗透系数Ksat）进行了边坡稳定性的敏感性分析。结果表明：长时间的弱降雨对膨胀土边坡的稳定性有较大影响;裂隙的存在使降雨入渗作用下边坡的安全系数有较大降低;降雨对边坡稳定性的影响是持续性的;在影响膨胀土边坡稳定性的4个水力学参数中,饱和渗透系数Ksat为主要因素,土水特征曲线拟合参数a、n为不重要因素。

英文摘要：

Expansive soil is a kind of special unsaturated soil.With the rainfall infiltrating into expansive soil,both of the suction and shear strength will decrease.Thus it＇s significant to research the expansive soil slope stability under the rainfall infiltration.This paper takes the expansive soil slope of Hefei Rail Transit Line1 test section as the study object.We use the Geo-Studio software to research the influence of the rainfall intensity,duration,soil cracks and the process of time on the stability of expansive soil slope.Based on this,the orthogonal experiment is used to research the slope stability sensitivity of expansive soil＇s hydraulic parameters（fitting parameter a,n,m of soil water characteristic curve and saturated hydraulic conductivity Ksat）.The results show that a long period of weak rainfall has a greater impact on the expansive soil slope stability.Soil cracks can reduce the stability of the expansive soil slope greatly.The influence of rainfall on the slope stability is continuous.Among the 4 hydraulic parameters which affect the expansive soil slope stability,Ksat is the main factor,and the fitting parameter a and n are unimportant factors.