Study On New Structure Of Seepage Rainwater Well And Its Design Method In Sponge City

There are many old communities in modern cities.The reconstruction of old communities in cities is an important aspect of promoting the construction of sponge cities.In this paper,a new type of permeable rainwater well is proposed,which not only has the function of water collection and drainage,but also has the function of water infiltration.The rainwater collected on the ground during rainfall can be infiltrated to the ground in whole or in part through the new type of permeable rainwater well.Under the benign permeable sand layer,this not only enhances the city’s own drainage capacity,but also can supplement the city’s groundwater,which can be described as killing two birds with one stone.In this paper,a new structure of infiltration well is proposed and its infiltration condition is analyzed.The calculation model of rainwater infiltration in permeable sand layer is established.Combined with the control equation and initial boundary value conditions,the analytical solutions of plane radial transient seepage and steady-state seepage of rainwater in the underground sand layer are obtained.Based on the analytical solutions,the corresponding calculation program is compiled in MATLAB,and the pore water pressure and seepage are obtained.The evolution law of the quantity and the analysis of the relevant parameters show that the time from the beginning of rainwater infiltration to the steady-state infiltration is very short.Based on the complex function theory and superposition principle,the basic relationship for calculating the well group infiltration flow is obtained.The typical arrangement of the well group infiltration flow is calculated,and the well group infiltration flow is analyzed.The results show that the inter well interference is the main factor affecting the infiltration flow of the well group.The infiltration flow of each well group and the total infiltration flow of the well group increase with the increase of the distance between the wells.When the number of wells in a well group is the same and the arrangement is different,the infiltration flow of each well and the total infiltration flow of the well group will be different.When the number of wells in the cluster is arranged in the same way,the infiltration flow of each well and the total infiltration flow of the cluster will be different.On the premise of certain arrangement and spacing between adjacent wells,the total infiltration flow of the well cluster increases with the increase of the number of wells,and the average infiltration flowof each well in the well cluster decreases with the increase of the number of wells.At the end of this paper,the calculation of a sponge city community in Shijiazhuang is taken as an example.The results show that the application of the new seepage rainwater well can make the rainwater infiltration of the reconstructed community meet the requirements of sponge city construction,and it has the application prospect in the reconstruction of the old community rainwater well in the sponge city.