对应上海“海绵城市”功能的平屋顶绿化蓄排水设计

Water Retaining and Drainage Design of Flat Roof Greening for Shanghai “Sponge City” Function

上海建设"海绵城市"需要屋顶绿化具备良好的蓄排水能力。对于上海地区常见的平屋顶绿化,蓄水能力主要取决于基质层,基质应选用湿容量大的改良土壤组合,宜将聚丙烯酸钠作为基质层中的保水剂,还应在屋顶载荷允许的范围内加大基质厚度;排水能力则取决于排水层及排水管道的布置,其中排水层可依据不同屋顶载荷采用多孔排水板材或砂砾、石屑和轻质陶粒的组合,排水管道可采取檐沟外排水设计或屋面排水与女儿墙排水的结合。

The construction of ＂sponge city＂ in Shanghai requires good water retaining and drainage capacity of roof greening. Forcommon flat roof greening in Shanghai area,water retaining capacity mainly depends on the substrate layer. Improved soil combination oflarge wet capacity may be used as the substrate,and sodium polyacrylate may be chosen as absorbent polymers. In addition,the substrateshould be thickened to the extent permitted by the roof load. Drainage capacity depends on the drainage layer and draining pipelinearrangement. Depending on different roof loads,drainage layer can use porous drainage plate or the combination of gravel,stone chips andlightweight ceramsite; and drainage pipe can adopt outside gutter drainage design or roof drainage combined with the parapet drainage.