Application Of Model Technology In Design And Calculation Of Dual Drainage System

In recent years,due to the frequent waterlogging disasters in China,it has a great impact on China’s social and economic development.The Chinese government attaches great importance to improve the ability to resist urban waterlogging disasters.Foreign developed countries in dealing with urban waterlogging has a wealth of experience,many countries have built a minor drainage system and major drainage system,to deal with urban waterlogging.In our country,waterlogging prevention system lack of major drainage system in recent years,many scholars have called for the reference of foreign experience of developed countries,the construction of the major drainage system to improve the ability to resist the city waterlogging,has been widely recognized.This paper from the model technology in minor drainage system(stormwater drainage system)and major drainage system(waterlogging prevention engineering)in the application of flood drainage planning in Cangzhou city as an example,briefly introduces the basic principle of SWMM and USRAMS,followed by USRAMS status assessment and city waterlogging risk analysis of rain water pipe network in Cangzhou City and puts forward the optimization design method of network based on USRAMS,can overcome the shortcomings of reasoning formula method in a certain extent,and finally put forward a calculation method based on the model of waterlogging prevention engineering design.The main results are as follows:(1)add the isochrones module of USRAMS model based on SWMM software calculation engine;surface runoff model to catchment runoff coefficient and time;in the two-dimensional inundation by water balance principle in the calculation process,the stability model of fast calculation speed and good.This paper discusses the method of evaluation and analysis of city drainage capacity of waterlogging risk based on USRAMS;through two-dimensional inundation simulation of flooding depth,distribution and risk level of waterlogging waterlogging time.In a word,the USRAMS model can provide reference for the formulation of waterlogging control measures and the planning and design of pipe network system.(2)according to the lack of reasoning formula method and the 2014 edition of "outdoor drainage design specifications" requirement,the use of motion wave pipe flow calculation,the existence of node overflow as evaluation criteria,put forward an optimum design method of rainwater pipe network based on USRAMS.And in the process of a GIS and Hongye catchment point based on the spatial connection method improves the accuracy and speed of data processing.(3)put forward the calculation method of the model of waterlogging prevention engineering design based on the road almost as open channel as the excess surface runoff over rainwater drainage capacity of the extreme rainfall events in the flood pathway,do organized stormwater,avoid the occurrence of waterlogging.Using USRAMS and SWMM to rainwater inspection wells overflow hydrograph for the convergence conditions,construction of stormwater pipe network(minor drainage system)and waterlogging prevention engineering model(major drainage system)model offline coupling model was designed for flood pathway,to provide ideas for the planning and design of waterlogging prevention engineering.