Study On The Planning And Design Of Sponge City Road

In recent years,China’s economy has developed rapidly,and the uncontrolled expansion of the city has brought a lot of urban problems.The city’s original natural watersheds and green areas have been decreasing,rainwater runoff has increased,and storage and infiltration have been decreasing,which has aggravated the risk of urban floods and rainwater disasters.At the same time,the rapid urbanization construction has led to the over-exploitation of water resources,and the traditional rainwater control model has not met the requirements of urban development.Therefore,the construction of sponge city has become the product of the times.It is necessary to make the city like sponge absorb water,seep water,purify water and store water when it rains.When it needs water,it can recycle the stored rainwater and make the city have good "flexibility"in adapting to environmental changes and coping with natural disasters.This paper mainly studies the road construction in sponge city,and carries out low-impact development and design of roads.Through the evaluation and analysis of low-impact development measures suitable for roads,a series of combined measures are selected to intercept and impound the rainwater runoff from the source,reduce the total amount of runoff and peak flow,lag the peak time,which has certain guiding significance for solving the rainwater and flood problems in the process of urbanization.Through discussing the goals,principles and methods of Sponge City Road design,this paper analyses the low-impact development and design of motor lane,non-motor lane,sidewalk and road green belt,which provides a reference for different road requirements,soil forms and objectives to be achieved.On the basis of theoretical research,taking Sino-German Eco-Park Line 9 as the research object,through the analysis of its construction environment,site status quo and the design concept and strategy of sponge city road,the low-impact development rainwater system of sponge city road of Line 9 is constructed.According to the design scheme,the SWMM simulation of its design effect and current situation in different recurrence periods is carried out.The simulation results show that compared with the current road,the road development model designed by LID has obvious effect on reducing rainwater runoff and lagging behind the peak runoff.With the increase of the recurrence period,the amount of runoff reduction and flood peak reduction increases gradually.Through the establishment of scale model,the design scheme is verified in practice.The section between two permeable catchment wells is selected as the test object,and the scale is reduced according to the ratio of 1:10.Different rainfall intensity is selected to carry out the rainfall test.The experimental results show that the rainwater runoff coefficients in the design scheme are 0.4,0.42 and 0.46 respectively,which correspond to the runoff coefficients in the simulation and meet the design requirements,and the proportion of permeability and storage obtained by the experiment is similar to the simulation results.From this,it can be concluded that the feasibility and validity of the low-impact development and design scheme of Sponge City Road Line 9 are verified from both simulation and test directions.It provides a reference basis for road construction in sponge city and has a certain guiding significance for solving the problems of rain and flood in the process of urbanization in China.