Research On The Drainage System Of Hefei City

Since twenty-first century, the process of city to speed up the pace, the urban multi-level transportation construction in full swing.There are 55 underpass bridges within second ring road in Hefei.The underpass bridges playing a leading and relieving effect in respect of the heavy traffic pressure. However, waterlogging of the underpass during the rainy season has became the Hefei travel nightmare. From the beginning of last year, Hefei municipal drainage department in order to solve this problem, within the important sections in one ring under the overpass installed the electronic measuring gauge, depth of electronic voice warning pile through the bridge of rainstorm during the real-time monitoring and alarm. But underneath the bridge has already lost the most important traffic role and became the traffic network embolism. Therefore, the necessary to solve the serious problems of water drainage must start from the drainage system design.On the discovery of study design parameters of underpass in Hefei, underpass water problems mainly due to the low design standard of drainage system, drainage pumping station ability is insufficient and operation regulation is not in place, as a result, the rain can not be discharged. In order to solve the two problems, the author accessed to the domestic and foreign literature, respectively carrying on analysis research about beneath the overpass drainage system design, road rain water quantity calculation, design of pump station operation crossing road water problems.First of all, the calculation formula of the rain water flow in the overpass is given, and the formula of the drainage standard and the capacity level method proposed by Professor Deng Peide in Tongji University are given.Then they based on the rainstorm intensity formula of Hefei city, discussing on the value of the return period of Rainstorm in Hefei City,carrying on the research about runoff coefficient, value of the catchment area,raiseing a value reference for the exact calculation formulas are given, thereby greatly improving the standard calculation of rain water.In the design of rainwater port, the characteristics and application scope of various types of rain water outlet and the calculation formula of water discharge are studied. In respect of the rainwater pump station optimal operation, this paper lists the various forms of pump stations, pump and the advantages and disadvantages, proposing that underpass rainwater pump station to take the submersible pump as the drainage pump, combined with the PLC system, conducting automatic control of pump station and operation of pumping station system. Based on the PLC system, and it points out that automatic control pump station can improve the operation efficiency of pumping station and reduce the input of human and financial resources in the later stage.Projects in this article starting with rainfall data and status of underpass in Hefei,conducting research about Ma'anshan Road and under the Changjiang East Main Street underpass drainage system and making design modifications. On the one hand, improved the design return period, catchment area runoff coefficient and other parameters, obtained the underpass rainwater design flow and reforming the pumping station. It comes out the pumping station under the PLC control system automatic runtime system program flow chart, system structure diagram of pumping station with two pumps and PLC diagram of three pumps rotation operation of pump station.The design and transform of underpass bridge,greatly improving the design flow of the rainwater drainage system, and the operation of pumping station is optimized and improved the efficiency of the pump and the life of the pump.