An Application Of The Combination Of Rational Formula Method And Model Simulation In The Design Of Storm Water Pipe Network

This paper combines the reasoning formula method and mathematical model simulation of rain water network design.,The simulation and pipe network design of rainwater pipe network system in a certain area of Tianjin are carried out.By studying the results of pipeline flow,node water depth and drainage process,and considering the difficulty and ease of operation,puts forward the feasible way of combining the above two methods in the design of storm water pipe network.(1)The appropriate design standard is chosen for the selected area,and the flow rate of storm water system is calculated by the method of inference formula,and the storm water pipeline is arranged.In order to meet the requirements of sponge city construction,the construction of sunken green space and the addition of permeable pavement were adopted to meet the requirements of the construction of sponge city,and the design results were reviewed.(2)This paper uses model software for terrain analysis,calculate the flow and elevation of the storm water pipe network under different design recurrence periods,Using software to simulate the operation effect of pipe network,Summing up the results of pipeline discharge,nodal water depth and drainage process.Optimization of pipe network design based on reasoning formula method.The parameter block defined by the software is used to decompose the construction index of sponge city,and the scale and layout of the development facilities are reasonably designed.(3)This paper analyzes the results of the design of reasoning formula method and mathematical model method,and puts forward some suggestions on the combination of the two methods.For a small design area in Tianjin studied in this paper,there is no difference between the design results of mathematical model method and reasoning formula method.The peak flow of pipeline and the water depth of nodes in the mathematical model method are slightly larger than that of the reasoning formula method,and the layout of the low impact development facilities is greatly affected by the model limitation.It is suggested that the storm water system should be designed by the traditional reasoning formula method,and then the pipe network design and the sponge city construction index should be reviewed quickly by the mathematical model method.The combination of the two methods can not only achieve the design purpose of rainwater pipe network and sea level urban construction,but also review the design results and improve the working efficiency.