海绵城市透水砖铺装系统雨水入渗及重金属污染物迁移模拟

海绵城市透水砖铺装系统（PBPS）入渗特征是产流控制及径流污染物去除的重要影响因素之一。通过渗流实验，构建系统土壤层土水特征曲线，建立降雨入渗及径流重金属污染物迁移数学模型，以阐明找平层土壤粒径、基层与垫层厚度比对产流时间及径流重金属污染物去除的影响。研究表明:综合考虑延迟产流与径流重金属去除能力，中砂作为找平层介质最佳；依据结构层出水重金属污染物浓度，基层与垫层厚度比为15∶4时，PBPS对径流中重金属污染物吸附效率最高、去除效果较好。

SIMULATION OF INFILTRATION AND HEAVY METAL POLLUTANTS MIGRATION FOR PERMEABLE BRICK PAVEMENT SYSTEM FOR SPONGE CITY CONSTRUCTION

The infiltration characteristics in permeable brick pavement system (PBPS) of sponge city construction is its key factors, which influence the runoff producing time and the removal of heavy metals from runoff. Through the seepage test, the soil-water characteristic curves of PBPS soil layers were constructed, and then the infiltration model and the mathematical model for runoff heavy metal pollutant migration of PBPS was established. Finally, the effect of leveling layer soil particle size and base to cushion layer thickness ratio on the runoff producing time and the removal of heavy metals from runoff were illustrated. The results showed that with comprehensive consideration of the PBPS's ability in delaying runoff generation time and removal of heavy metal pollutants, medium sand was the best choice for leveling layer soil; according to the concentration of heavy metal pollutants in the effluent of the structure layer, when the ratio of base to cushion layer thickness ratio was 15∶4, PBPS had the highest adsorption efficiency and good effect on removing heavy metal pollutants in runoff.