以汶川震区滑坡堆积体为研究对象,采用室内人工模拟降雨方法,探讨了堆积体坡面的入渗规律,并分析了滑坡堆积体在不同土石比(1∶1,1∶2和1∶4)、降雨强度(1.0,1.5,2.0mm/min)和坡度(40°,35°和30°)条件下的入渗特征。结果表明:(1)3种不同的土石比堆积体在不同的降雨强度条件下,土壤入渗率和累计入渗量所表现的规律各不相同,且两者之间差异显著;(2)根据3种入渗模型的对比分析,可知Horton模型为最适合震区堆积体的入渗模型;(3)当堆积体土石比为1∶1时,随着坡度的增大,堆积体的初始入渗率、稳定入渗率和累计入渗量随之增大,当堆积体土石比为1∶2时,随着坡度的增加,其稳定入渗率和累计入渗量大小为40°〉30°〉35°;当堆积体土石比为1∶4时,其入渗能力始终等于降雨强度,坡度对其入渗率和累计入渗量没有影响。
The landslide deposit formation was induced by the Wenchuan earthquake,which triggered soil and water loss and secondary geological disasters.The National Highway 213,Minjiang River and Longxi River basin in Wenchuan earthquake zone were chosen as the study area and artificial rainfall simulation were conducted to explore the infiltration characteristics on the slope surface of landslide deposit and the effects of soil/rock ratio,rainfall intensity and slope gradient were also investigated.The results showed that:(1)The infiltration rate and cumulative infiltration showed significantly different trends on landslide deposit with 3different soil/rock ratios under different rainfall intensities.(2)The Horton model was the most suitable model to reflect the characteristics of infiltration on landslide deposit in Wenchuan earthquake zone.(3)The initial infiltration rate,stable infiltration rate and cumulative infiltration increased with the increasing slope gradient when the deposit soil/rock ratio was 1∶1.When the soil/rock ratio was 1∶2,the stable infiltration rate and cumulative infiltration on landslide deposit of different slope gradients followed the order of 40°〉30°〉35°.When the soil/rock ratio was 1∶4,the infiltration rate was equal to the rainfall intensity,and slope gradient had no effect on the infiltration rate and cumulative infiltration.