Study On The Construction Scheme Of Nakeli Sponge Expressway Service Area

The expressway service area is one of the important accessory facilities of expressway.Its concrete pavement area is large,and its surface rainwater overflow path is long.Rainwater drainage often adopts rapid drainage mode,and the utilization degree of water resources is low.Under the background of vigorously promoting the construction of"sponge city"in China,the organic combination of the concept of sponge city and low-impact development technical measures with the construction of the expressway service area will help to improve the level of rainwater conservation in expressway service area,promote the construction of green highway and optimize the public image of expressway service area.It is of great significance to promote the integration of the concept of sponge city into expressway construction.Firstly,the paper analyses the connotation and technical types of Sponge City and Low Impact Development(LID)concept,puts forward the concept and construction ideas of Sponge Service Zone of Expressway based on the research results at home and abroad.According to the characteristics of rainfall in Puer City,the selection of rainfall duration and the function of LID facilities in Nakeli expressway service area are clarified.According to the formula of storm intensity in Simao District of Puer City and the rainfall pattern design of Chicago,the hydrological model of Nakeli expressway service area was constructed by SWMM(Stormwater Management Model).The necessity of constructing sponge service area was concluded by comparing the characteristics of runoff before and after the traditional development.Then six LID facilities are selected according to the characteristics of different functional zones in the service area and their runoff control effects are analyzed one by one.A LID facility efficiency evaluation system was established.The effectiveness of a single LID facility was analyzed and evaluated from three aspects of runoff control effect,economy and social benefit by using the Analytic Hierarchy Process(AHP),and the effectiveness index values of a single LID facility were obtained.Finally,according to the location conditions of Puer city,the preliminary control objectives for the construction of Nakeli Sponge Service Area are put forward.Based on the evaluation results of single LID facility,four schemes of different development levels are constructed,and the optimal schemes are obtained by volume test and comprehensive efficiency comparison of the schemes:concave green space area 3075m~2,rainwater garden area 1222m~2,permeable brick pavement surface 1700 m~2,drainage asphalt pavement area 9060m~2,rainwater barrel volume25m~3.Combined with the scheme,the pavement structure and drainage mode,the number and specification of rainwater buckets,the improvement method of soil permeability in service area,the structure of concave green space and rainwater garden are laid out in detail.The simulation and analysis of runoff control effect of sponge service area under different rainfall duration and different design recurrence periods show that the sponge expressway service area basically meets the target of annual total runoff control rate and achieves better runoff control effect under different design recurrence periods.The concept and technical measures of sponge city are introduced into the construction of expressway service area.Based on SWMM model,the runoff control effect of LID facilities in expressway service area is studied,and the methods and measures of rainwater management suitable for expressway service area are explored,which enriches the theoretical and technical system of the construction of expressway sponge expressway service area and improves the level of rainwater conservation in expressway service area and reduces rainwater runoff in traditional expressway service area.