强降雨是碎石土滑坡的主要诱发因素。通过室内人工强降雨对碎石土边坡进行研究,在雨强为1.6 mm/min下研究了初始含水率与降雨历时相同时不同斜坡坡度(缓坡22°和陡坡31°)下模型边坡的变形特征和雨水入渗特征。结果表明:随降雨历时增加,坡体沉降值及坡体内部水平位移不断增加,其中在坡腰0.5 m处和坡脚处最大累积水平位移分别为1.99 mm、1.82 mm(缓坡),0.42 mm、0.29 mm(陡坡);降雨过程中,坡体入渗过程是自上而下发展变化的,降雨结束时坡脚雨水入渗深度最大,坡顶次之,坡腰最小,且在缓坡坡顶和坡腰处雨水入渗深度比陡坡大;在同一雨强下,降雨结束后缓坡最终沉降值比陡坡大,且在坡脚处沉降值最大。以上结果有利于对降雨入渗诱发碎石土滑坡的失稳机理和变形机制的进一步研究。
The present paper is aimed to study the impact of the slope-angled gravel-soil mixed landslide deformation under the same rainfall intensity( 1. 6 mm / min). For our research purpose,we have made indoor experiments of such a slope model in the conditions of a particular slope angle( e. g. 22° for the gentle slope and 31° for the steep slope) with the same rainfall intensity,with the initial moisture content and rainfall duration based on the self-constructed experimental facility through a rectangular model slot with the size of 4 m( length) × 1. 5 m( wide) ×2. 5 m( high). In the experiment,we have also adopted a horizontal displacement monitoring slope deformed frame of the gravel soil with the heavy rainfall impact while registering the infiltration data and the settlement data of the slope table,which helps us to analyze the rainfall infiltration characteristics and the sliding mechanism of the said soil slope in the process of the rainfall.The experimental results we have achieved show that the settlement and the internal horizontal displacement of the slope tends to increase with the continuation of the rainfall duration. We have also noticed that the cumulative horizontal displacements in the mid and the toe of the slope are 1. 99 mm and 1. 82 mm,respectively,with the slope angles being 22°,0. 42 mm and 0. 29 mm at the slope angle of 31°. Besides,the rainwater can infiltrate changes in the top-down direction to the toe of slope in the rainfall process. After the rainfall,the depth of the rainwater infiltration at the toe of the slope can be the greatest,while it is smallest at the mid of the slope. And the depths of the rainwater infiltration at the top and mid of the slope till the gentle slope can be found more profound than that of the steep slope. Moreover,with the same rainfall intensity,the final settlement of the gentle slope can be greater than for the steep slope after rain falling,and the maximum lies on toe of slope. The results of our study prove to be helpful for furth