Research On Key Technologies Of Rainwater Control And Management For Underpass Road

Because of its special terrain,underpass road suffer waterlogging easily.As an important node of city traffic,once the occurrence of waterlogging,can not only cause traffic paralysis,but also a threat to life and property safety.In order to design drainage system of underpass road scientifically,enhance ability of preventing waterlogging,alleviate the city waterlogging pressure,it is necessary to study key technologies of rainwater control and management for underpass road.The main contents of this paper include three aspects:the application of hydrological simulation software in drainage design,the volume design of the peak flow regulating storage and the analysis of the influencing factors,the design of rainwater pumping station and the analysis of the influencing factors.Based on previous studies,using SWMM simulation software,Infoworks ICM software simulation analysis of the practical engineering.Designing the volume of the peak flow regulating storage.Analyzing the influence of different rainfall distribution,position,different storage setting and flow through and side overflow of storage in its capacity and current situation of the drainage system.Analyzing the influence of different ground catchment time formula and pump start and stop water level setting mode in pumping station design and operation management.Finally,through the Infoworks ICM software to simulate and analyze practical engineering,and puts forward the corresponding improvement measures for waterlogging reason.Through the simulation and analysis,the following research results are obtained:(1)Through the hydrological simulation theoretical analysis,found relying on the inference method of design has been unable to meet the requirements of the drainage system,especially in more and more complex climate conditions.In addition,the use of hydrological simulation method not only can learn the real flow in pipe flow in channel,and can obtain accurate flow hydrograph.Through the case analysis found that only using the inference method of design,preliminary design of the drainage system in the 2a design return period,the probability of node flood reached 82%,so the hydrological simulation software of the drainage system design is very necessary.(2)the design method of storage based on SWMM flow hydrograph can describe the water storage characteristics more effectively than the traditional simple geometric design method.Through the study found that rainfall distribution types have different effects on the volume of storage,the rainfall whose rain peak is later compared to the rainfall whose rain peak is early is more unfavorable for the drainage system,required a larger volume of storage.The location of peak flow regulating storage is closer to the flood node,and its peak elimination capability is more obvious.Under the same conditions,the effect of the dispersed storage basin is better than that of the centralized storage.Under the same conditions,the volume required by the side overflow storage is smaller than that of the through flow storage.(3)The analysis of designing rainwater-pumping station found that different ground water catchment time calculation formula of pumping station design scale is different.From a security perspective,underpass road surface catchment time should adopt the sunken bridge area or waterlogging control standard specification.Start stop mode of different pumping stations have different effects on the operation of pump station,recommended in light rain situation,improve the first pump water to avoid frequent starting,and heavy rain in the situation,it should be appropriate to reduce the first pump water pump.(4)the underpass road was analyzed by Infoworks ICM software based on one-dimensional and two-dimensional simulations,it shows that the reason of waterlogged is different in different design return period of rainfall.The reform measures have remarkable effect.