降雨过程中，堆积碎石土渗透特性改变是触发滑坡等灾害的主要因素。碎石土中封闭气泡阻碍水相流动，从而对雨水入渗产生影响。通过自制渗流沉降综合测试仪，进行入渗试验，探究不同雨强（1.2 mm/min、1.6 mm/min、2.0 mm/min）下，碎石土的渗透规律与沉降变形。通过Seep/w软件耦合Air/w软件进一步分析不同雨强下气阻作用对湿润锋迁移速度的影响。结果表明：入渗深度-时间曲线存在阶梯状趋势，即湿润锋迁移速度首先随表层土含水率的突增迅速增加至最大值（约30~40 mm/min），然后随气压的增加缓慢减小，最后湿润锋迁移速度随气压减小略微增大，湿润锋平均迁移速率（无积水状态）随雨强的增大趋近线性增长；碎石土沉降变形在入渗过程中经历缓慢增长、急剧增大、逐渐停滞三个阶段，雨强为2.0 mm/min时，碎石土发生急剧沉降变形时间最早（约50 min）；碎石土渗透系数与干密度呈线性负相关关系。%During the rainfall,the main factor for triggering landslides and other disasters is the changing of aggre-gate gravel soil permeability. Specifically,the entrapped air in gravel soils impedes aqueous phase flow,thus will have an effect on the rainwater permeability. The experiment of infiltration under different rainfall intensity(1. 2 mm/min,1. 6 mm/min,2. 0 mm/min),investigates the permeability of gravel soil and sedimentation deformation by our own infiltration and sedimentation integrated tester. Then,further research will focus on the relationship between the air entrapment impact with different rainfall intensity and wetting front migration rate through Seep/w and Air/w soft wares. The results show that:there is stepladder trend between wetting front and time curve. More specifical-ly,wetting front migration rate will rapidly increase with the sudden increase of the topsoil moisture to a maximum (30~40 mm/min approximately),then will slowly decrease with increased pressure. Finally the wetting front mi-gration rate will slightly increase with the decreased pressure. The average rate of wetting front migration( without hydrops water)approach linear growth with the increased rainfall intensity. Development of soil settlement deforma-tion passes through three stages:slow growth,sharply rises and gradually stagnation. The minimum time( approxi-mately 50 min)for sharp morph and sedimentation of gravel soil with the rainfall intensity is 2. 0 mm/min. There is a negative linear correlation between the permeability coefficient of gravel soil and the dry density.
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