灌木式屋顶绿化设计及对屋面初期雨水的净化

目的]探讨灌木式屋顶绿化屋面承载力及对屋面初期雨水径流污染物的净化效果,为屋顶绿化设计及雨水资源化利用提供一定的理论指导。方法]根据屋面所能承受承载力大小及屋面雨水径流的特点设计灌木式屋顶绿化结构,采用蛭石、珍珠岩作为吸水剂,与红壤土、腐殖土按一定比例复配为屋顶灌木绿化的种植基质。通过将收集到的屋面雨水模拟降雨,淋洒屋顶灌木,对其干、湿重荷载和对雨水去除效果进行研究。结果]1m3复配的人工土壤的饱和吸水量为0.65m^3,种植基质湿容重为1 190kg/m^3,灌木式屋顶绿化的干、湿重荷载分别为261,529kg/m^2。对屋面初期雨水中的SS,COD,TN,TP的削减量分别在60.1%~71.3%,50.0%~61.8%,49.2%~53.2%和55.6%~67.7%之间。结论]灌木式屋顶绿化能满足一般建筑物屋顶的荷载要求,同时对初期雨水径流具有较好的净化效果。

Design of Green Shrub Roof and Purification of Initial Roof Runoff

Objective] The paper aims to explore the carrying capacity of the green shrub roof and the purification effect on initial roof runoff in order to provide theoretical support for green roof designing and runoff resources utilization.Methods] A green shrub roof structure was designed according to the carrying capacity of roof and the characteristics of roof runoff. Using vermiculite and perlite as water absorbent, and mixed with red loam and humus at a certain proportion. we made a substrate for roof greening. The roof shrubs were sprayed with simulated rainfall using collected roof runoff, and the dry and wet load and the effect of rainwater removal had been researched.Results] The saturated water absorption of 1 m³ artificial soil was 0.65 m³, and wet bulk density of the substrate was 1 190 kg/m³. The carrying capacity of green shrub roof under dry and wet conditions was 261 kg/m² and 529 kg/m², respectively. The pollutants SS, COD, TN and TP in initial roof runoff were reduced by 60.1%~71.3%, 50.0%~61.8%, 49.2%~53.2% and 55.6%~67.7%, respectively.Conclusion] The green shrub roof can meet the carrying capacity requirements of general building. Meanwhile, it has good purification effects on initial roof runoff.