无坡降地面式暗沟在居住区雨水系统中的应用与设计

Design and Application of Underdrain without Slope in Rainwater System of Residential Area

针对珠江三角洲某大型居住区地形低洼、平缓,雨水在洪水季节不能自流排入水体的特点,在顺德碧桂园雨水排水系统的设计中采用了既能用于排除雨水又可用于雨水调蓄的无坡降地面式暗沟。地面式暗沟是一种无覆土的盖板渠,其盖板可兼作路面,可减少雨水工程全系统的沟槽挖深,又因不需提高整个小区的地面标高而减少大量外借土方,一般都能节约造价。重点介绍了无坡降地面式暗沟实施方案的确定及其断面的两种作法。分析计算了雨水设计流量、排渍流量和调蓄容量,并给出了雨水调蓄容积的计算方法。工程竣工以来一直安全使用、正常运行,达到了设计要求。

Because the terrain is low-lying and fiat in a large-scale residential area of the Pearl River Delta, the rainwater can not flow by gravity into the water body during the flood season. An underdrain without slope is used to drain the rainwater and store rainwater in the design of rainwater drainage system of Shunde Bigui Park. The underdrain is a covered ditch without soil. The cover can be used as road surface. It can reduce the ditch depth of rainwater system and the substantial earthwork without raising the ground elevation of the entire residential area, and generally, the cost is saved. The determination of implementation scheme of underdrain without slope and two kinds of practices of its section are introduced. The rainwater design discharge, drainage flow and rainwater storage volume are analyzed and calculated, and the calculation method of rainwater storage volume is given. Since the completion of the engineering, the underdrain is in safe use and normal operation, meeting the design requirement.