地道排水系统设计与探讨

Design and Discussion of Tunnel Drainage System

以合肥市某地道排水设计为例,阐述了地道排水的设计参数的选择与计算过程,确定地道雨水设计流量为1623.5 m^(3)/h、废水设计流量为8 m^(3)/h。分析了该地道与相交道路、现状河道的高程关系,通过设计道路驼峰、辅道挡水墙保证周边道路的雨水不会进入地道。通过在道路驼峰处设置横截沟、地道两侧设置排水边沟,对地道雨水、冲洗废水、结构渗漏水进行收集。在地道最低点下方设置与地道合建的雨水泵房,泵房内分别设置雨水、废水提升泵,将收集到雨水、渗漏水提升排入附近河道,冲洗废水提升后排入道路污水井。并且利用SWMM模型校核了排水边沟的泄水能力。验证了在芝加哥雨型,暴雨重现期50 a,降雨历时2 h的条件下,宽×深=400 mm×450 mm的排水边沟可以满足排水需求。

Taking the drainage design of a tunnel in Hefei City as an example,the selection of design parameters and the calculation process of tunnel drainage are expounded.The designed rainwater flow in the tunnel is 1623.5 m^(3)/h and the designed wastewater flow is 8 m^(3)/h.The elevation relation among the tunnel,intersected road and existing river is analyzed.The hump of road and the water retaining wall of auxiliary road are designed to ensure the rainwater of surrounding roads not to flow into the tunnel.The tunnel rainwater,flushing wastewater and structural leakage water are collected by setting the transverse ditch at the road hump and the drainage side ditch at two sides of tunnel.The rainwater pumping house co-built with the tunnel is set below the lowest point of the tunnel.The rainwater and wastewater lifting pumps are set respectively in the pumping house to lift the collected rainwater and leakage water and discharge into the nearby rivers.The flushing wastewater is lifted and then discharged into the road sewage well.The discharge capacity of the drainage ditch is checked by SWMM model.It is verified that the width×depth=400 mm×450 mm drainage ditch can meet the drainage demand under the conditions of Chicago rain pattern,rainstorm return period of 50 a and rainfall duration of 2 h.