1.Institute of Mountain Hazards and Environment, Chinese Academy of Sciences;2.Beijing Institute of Aerospace Control Devices;3.Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu;4.Shenzhen Institute of Information Technology;5.Shenzhen Pubulic Safety and Technology Institute
渣土场是容纳弃土和弃渣的主要场所，由于堆填材料和压实方法的差异性，研究初始渗流场对计算渣土场边坡的降雨入渗特征及其稳定性的影响具有现实意义。为此，以深圳市部九窝渣土场边坡为研究对象，运用非饱和渗流原理和非饱和土强度理论建立数值计算模型，设计了不同初始渗流条件和不同降雨强度的计算方案，揭示了渣土场边坡降雨作用下的渗流特征及其安全系数变化规律。结果表明：初始渗流场和降雨强度对渣土场边坡的降雨入渗特征和稳定性影响显著；竖直方向流速峰值和孔隙水压力上升速率与初始基质吸力呈正相关关系；当降雨强度为3.5 mm/h，监测点1在初始基质吸力为-25 kPa、-50 kPa和-75 kPa时分别达到饱和的时间为10.9 h、20.2 h和25.5 h；竖直方向流速、体积含水率上升速度和孔隙水压力上升速率与降雨强度呈正相关关系；在初始基质吸力为-25 kPa和降雨强度为3.5 mm/h情况下，渣土场边坡安全系数下降明显，需要采取必要的工程措施。
The municipal solid waste landfill is the main place to hold the waste soil and slag. Due to the difference between the filling material and the compaction method, it is of practical significance to study the influence of initial seepage field on the calculation of rainfall infiltration characteristics and stability of the municipal solid waste landfill. Therefore, taking the municipal solid waste landfill in BuJiuWo, Shenzhen as the research object, a numerical calculation model was established based on the unsaturated seepage principle and unsaturated soil strength theory. The calculation schemes of different initial seepage conditions and rainfall intensity are designed, and the seepage characteristics and the variation law of safety factor of the slope under rainfall are revealed. The results shown that the initial seepage field and rainfall intensity have significant influence on the rainfall infiltration characteristics and stability of the municipal solid waste landfill. The peak value of vertical velocity and the rise rate of pore water pressure are positively correlated with the initial matrix suction. When the rainfall intensity is 3.5mm/h, the saturation time of monitoring point 1 is 10.9h, 20.2h and 25.5h when the initial matrix suction is -25kpa, -50kPa and -75kpa, respectively. There is a positive correlation between rainfall intensity and velocity of flow, volume water content and pore water pressure in vertical direction. When the initial matrix suction is -25kpa and the rainfall intensity is 3.5mm/h, the safety factor of the waste dump slope decreases obviously, so necessary engineering measures need to be taken.