老城区雨水排水系统改造工程设计案例

为提高城市排水防涝能力,满足国家、地方政策及标准要求,老城区低标排水系统提标改造需求日益迫切。但许多老城区存在现状条件复杂、地下公用管线多、道路狭窄、施工条件苛刻等问题,提标改造难度较大。文中以上海市宝山区月浦城区雨水排水系统提标改造工程为例,详细介绍工程设计方案,结合Info Works ICM排水模型对系统内积水风险、管网水力条件进行分析,结果表明:提标改造后的管网系统在3年一遇设计降雨时,可保证城区内无积水产生,系统内大部分管道的水力坡度与管道坡度接近,基本未出现非满管或超载的情况;在100年一遇的设计降雨时,城区内积水深度普遍在0.15 m以下。针对排水系统改造中的重点、难点,提出充分利用现状设施、合理选择顶管与开槽埋管相结合的施工方案、减少骑马井数量、利用已建雨水管道收集路面雨水、合理确定井位管位,减小管线搬迁工程量等解决方案,同时,对关键节点进行具体分析。案例可为其他老城区的雨水排水系统提标改造工程提供一定的借鉴。

An Engineering Design Case of Renovation of Rainwater Drainage System in Old Urban District

To improve drainage capacity and waterlogging resistance in urban area,and meet national and local policies and standards,upgrading and renovation of low-standard drainage system in old urban district is increasingly urgent.However,there are many problems that are not conducive to renovation in old urban district,such as recently complicated conditions,intricate underground public pipelines,narrow roads and harsh construction conditions.Taking Yuepu rainwater drainage system in Baoshan District of Shanghai as an example,engineering design scheme is introduced in detail.InfoWorks ICM drainage model is used to analyse the risk of road waterlogging before and after renovation,as well as the hydraulic conditions of sewerage network.Simulation results show that drainage system after upgrading and renovation can eliminate rainwater accumulation in the downtown and drainage pipeline is basically in a state of full flow when it meets the design rainfall frequency of once every 3 years.Hydraulic slope of most pipelines in the system is close to the gradient of pipeline,and there is no non-full pipe flow or overload condition.When it meets design rainfall frequency of once every 100 years,seeper depth is generally below 0.15 m.Engineering measures are taken to resolve key and difficult points in drainage system renovation,such as making full use of existing facilities,reasonable selection of pipe-jacking and slotted buried pipe construction,reducing the number of riding wells by collecting rainwater through existing rainwater pipes,proper determination of well position and pipe position and reducing the engineering quantities of pipeline relocation.Key nodes are also analyzed in detail.This design case can provide a reference for other rainwater drainage system upgrading projects in old urban district.