Research On Modeling And Application Technology Of Urban Drainage Pipe Network

Urban drainage pipe network is the Lifeline Project of City and an indispensable link in the modernization construction.It is an important infrastructure to maintain the operation of the city and to ensure people normal life.With the development of the city and the expansion of the population,the pressure of the urban drainage network is increasing and the problems in the pipeline are also increasing.The problems of pipeline overflow,pipeline leakage,pipeline siltation and initial Rain Water pollution in the distributary drainage system are becoming more and more serious,which bring a lot of inconvenience to peopleundefineds life.This not only destroyed the urban water environment,but also seriously restricted the development of the city.Combining the urban drainage pipe network model with all kinds of outstanding problems,it can provide reference for solving these problems.In view of the classification of drainage systems in China,the advantages and disadvantages of various drainage systems and many outstanding problems existing in the current drainage systems,through the comparison of domestic and foreign drainage pipe network models,the SWMM model is finally selected as the model used in this study.The function module of SWMM is introduced systematically,and the calculation principle of runoff module and transportation module are introduced respectively.The natural geography,landform and climate characteristics of the study area are summarized.Then the hydraulic model of sewage pipe network and the model of rainwater pipe network are constructed,and the deterministic parameters are generalized,then the parameter rate of the preliminary model is determined,thus the relatively accurate hydraulic model of sewage pipe network and the model of rainwater pipe network are established.In this paper,the hydraulic operation status of the sewage pipe network in the study area is evaluated,and the siltation diagnosis of the pipe network is carried out according to the results of the model simulation analysis,and the siltation degree of the pipe section with different filling degree and velocity is compared.It is found that the velocity and fullness of the model simulation data are the most intuitively important indexes for predicting the easy silting in the sewage pipe network,in which the velocity of velocity is the main index and the fullness is the secondary index.The hydraulic status of the pipeline under different siltation degree simulation scenarios is studied.The simulation results show that the more serious the silting degree in the pipeline,the slower the velocity of flow in the pipeline,the greater the filling degree,and the higher the water depth of the node,which will make the pipeline more prone to silt at the same time.In view of the siltation problem in the pipeline,the corresponding countermeasures are put forward.According to the actual situation,the simulation scenario of Rain Water mixed connection or wrong access sewer network is designed,and the hydraulic operation of the pipe network under different recurrence periods and the influence of mixed connection on the sewerage network are analyzed.Based on the systematic analysis of the principle of the closure control in the SWMM model and the method of determining the volume of closure,the hydraulic status of the sewage pipe network after Rain Waterundefineds inflow in the initial period is discussed in detail.And studied the initial Rain Water regulating pool through different ways to regulate the pipe network.The research shows that by assigning runoff time series to the node of the main sewage pipe to realize the initial Rain Waterundefineds closure control in the SWMM model,the limit of the capacity of sewage pipe network to accept the initial stage Rain Water can be found out step by step.In order to determine a reasonable initial Rain Water closure of a region.When higher interception is set,it is found that it is better to set up the initial Rain Water storage pool near the overflow position than to set up a relatively large volume in the upper or lower reaches.The former not only can effectively control the overflow of nodes,but also can greatly reduce the peak flow at the end of the pipe network in the initial period when Rain Water enters the flow,while the latter can only act on the nodes near the upstream or downstream.And the initial Rain Water flow into the pipe network end of the flow regulation function is weak.