李丞　蔡立明　张伟锋　侯建香　董凯　苏立君

摘 要：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。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，揭示了渣土场边坡在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、-50、-75 kPa时达到饱和的时间分别为10.9、20.2、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时，渣土场边坡安全系数下降明显，需要采取必要的工程措施。

关键词：渣土场;边坡;渗流场;渗流特征;边坡稳定性

中图分类号：TU431   文献标志码：A   文章编号：2096-6717（2021）02-0001-9

Abstract： The municipal solid waste landfill is the main place to hold the waste soil and slag.Due to the difference  in 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 intensities are designed. Then the seepage characteristics and the variation law of safety factor of the slope under rainfall are revealed. The results show that the initial seepage field and rainfall intensity have significant influence on the rainfall infiltration characteristics and therefore stability of the municipal solid waste landfill. The peak value of vertical velocity and the increase rate of pore water pressure are positively correlated with the initial matrix suction. When the rainfall intensity is 3.5 mm/h， the saturation time of monitoring point 1 is 10.9， 20.2， 25.5 h  and the corresponding initial matrix suction  equals to -25， -50， -75 kPa， respectively.Rainfall intensity，velocity of flow and volume water content  are positively correlated with pore water pressure in vertical direction.When the initial matrix suction is -25 kPa and the rainfall intensity is 3.5 mm/h， the safety factor of the waste dump slope decreases obviously，  and necessary engineering measures should be taken.

Keywords：municipal solid waste landfill; slope; seepage field; seepage characteristics; slope stability

隨着城市化进程的加快，产生了以大量废土和废渣为主的余泥渣土，对城市固体废弃物的管理和城市规划提出了挑战[1]，而填埋是最常见的渣土处理方法[2]。对于渣土场边坡而言，其稳定性受填料性质、施工工艺、降雨、地下水位等影响[3-4]，在众多因素中，降雨入渗将导致渣土场边坡含水率增加、基质吸力降低和地下水位上升，这是渣土边坡变形与稳定性下降的主要原因之一[5-7]。……