The Study On Runoff Control Performance Of New Permeable Pavement System For Weakly Permeable Soil

As a technical measure of sponge city construction,permeable pavement has been widely used in urban construction.However,the application of conventional permeable pavement is not good in the weak soil infiltration area.This topic focuses on the application of permeable pavement technology in weak permeable soil area,through research and development of two permeable pavement-the new permeable(perforated pipe)pavement and the new permeable(gravel pipe)pavement compared and analyzed the control effect of new permeable pavement on rainfall runoff,water quality and the effect of initial scouring,which can provide reference for the application of pervious pavement in weak pervious soil area.(1)Experiments on runoff control were carried out and compared with ordinary and conventional permeable pavements.The results show that: in the weak pervious soil area,the water control effect of the new permeable(perforated pipe)pavement and the new permeable(gravel pipe)pavement is obvious.compared with conventional permeable pavement,the runoff yield time increased 50% ~ 200% and 55.5% ~ 212.7% respectively,and the total amount of runoff reduced by 19% ~ 34% and 15% ~ 31%,the reduction of runoff height were reduced by 20.83% ~ 66.67% and 16.67% ~ 55.56%,the largest base water level also decreased from 21.6% to 43.5% under different return period.(2)Compared with conventional permeable pavement,runoff water quality control were studied.The research shows that: new permeable pavement has good effect on reducing rainfall pollutants,the surface runoff pollutants SS,COD,TN,TP Cu,Zn,Pb concentration decreased to 54.96,52.16,5.63,0.41,0.49,0.47 and 0.17mg/L at the end of rainfall duration,decreased by 20.77%,19.23%,21.26%,8.89%,22.22%,17.54% and 10.53%.the new permeable(gravel pipe)pavemen is better than the new permeable(perforated pipe)pavement in removal runoff pollutants,surface runoff pollutants SS,COD,TN,TP,Cu,Zn,Pb concentrations were reduced by 15.85%,24.37%,17.94%,12.2%,8.16%,6.38% and 5.88%.(3)The initial erosion effect of pollutants on different roads was tested and simulated,the results shows that: the initial erosion strength of the new permeable pavement is weakest and the process is similar,It can better control the initial scour intensity of rainwater and alleviate the excessive concentration of pollutants at the initial stage of runoff.Pollutant indicators of initial scour from strong to weak is: SS>Zn>COD>Pb>Cu>TP>TN.Overall,the new water(perforated pipe)and the new permeable(gravel pipe)pavement can well apply to the weak permeable soil area.It has a good control effect on runoff,water quality and first flush effect,thus reducing the pollution to the surrounding environment.