Study On The Sponge City Facilities Suitable For Urban Rail Transit Project

With the water environmental problems becoming increasingly serious,the impact of rail transit construction on it cannot be ignored.In the construction of ecological civilization,Sponge City is an important method to solve many environmental problems,such as urban floods and water logging,water shortage,and water pollution.However,by the end of 2018,there is no actual project of applying sponge city technology to rail transit construction.In view of this,the author combines the scientific research project of "Study on the Application of Sponge City Concept in Metro Construction"(Contract No.: DT306-KY002/2018)and comprehensively study the application and effectiveness of sponge city in the construction of rail transit from the perspective of stormwater management and technology innovation.In the research method,in order to avoid some errors in terms of the select of parameter,calculation,program,it adopts the method— “first calculation,and then verification”.In addition,three quantitative analysis methods— Volumetric Method,Water Balance Method and Storm Water Management Model(SWMM),are selected to calculate the scale of the facility separately,compare and verify each other and comprehensively evaluate the effect of the layout of sponge city.First of all,the research on low impact development,spongy city and stormwater management in rail transit is reviewed and the related concepts are defined.Then,this paper analyzes the difficulties and necessity of the application of the technology of sponge city in rail transit.And it also puts forward the principles and design goals of the project.Secondly,the basic principles and application steps of the three methods(Volumetric Method,Water Balance Method and SWMM are explained in detail,which lays a solid foundation for the case study in chapter 5.Thirdly,the Changzhen Depot of Shenzhen Metro Line 6 is taken as the research object.In this process,the Volumetric Method and Water Balance Method are used to calculate the demand storage volume and determine the scale of the facilities,and the SWMM model is used to study the application effect of sponge city facilities in rail transit construction in terms of the control rate of the total runoff,runoff peak and diffused pollution.Finally,based on aboved research,following conclusions can be put forward:(1)As an effective way to reduce surface source pollution,it is necessary to explore the application of the facilities of sponge city in urban rail transit projects.(2)At present,the application of the technology of sponge city in the field of rail transit has problems and obstacles in planning management and specific design.(3)The planning principle and design specifications of sponge city which are suitable for the construction of rail transit are proposed based on the concept of sponge city and the functional principle of rail transit.(4)Through the calculation and self-evaluation analysis of Volumetric Method,Water Balance Method,the proposed program of sponge city is feasible.(5)The results of SWMM simulation show that under the normal rainfall conditions,the effect of the facilities of sponge city on rail transit is significant,but the effect decreases with the increase of the recurrence of rainfall recurrence period.(6)The innovative facilities proposed in the sponge design program are specific.It can not only meet the architectural characteristics to the maximum extent,but can realize the system function of the sponge city facilities,which has a high reference significance.In conclusion,the study is aimed at the particularity of urban rail transit projects,it's the first time that the sponge city concept and construction technology have been used in urban rail transit projects,opening up the application scope of the sponge city concept,and it's implementable and innovative.