| In this paper,the problem of permeability attenuation caused by the permeable pavement clogging in the construction of sponge cities and the poor effect of frequent floods and floods in urban waterlogging disasters were analyzed by indoor experiments.Contrasting and analyzing the permeability timeliness of permeable pavement with various structural variations;The numerical simulation method was used to study the effect of natural and artificial factors in the process of rain and flood infiltration.Through the optimization analysis of the rain and flood infiltration effect,the control plan of the rain and flood infiltration of the sponge city construction in the test area was determined.The main conclusions of this article are as follows:(1)Through the analysis of the factors affecting the permeability of the permeable pavement and the results of the experimental study on the permeability attenuation,it is shown that the self-configured suspension of the permeable pavement will have obvious permeability attenuation after the infiltration process.The content and type of suspended matter have a significant effect on the permeability attenuation rate of permeable pavement.The siphon method is used to simulate the high-pressure water washing and vacuum dust removal method to remove the sediment on the surface of the brick body,and the effect of restoring the permeability of the brick body is not obvious.Therefore,it is necessary to restructure the permeable pavement.(2)According to the permeation attenuation mechanism and influencing factors in the process of permeable pavement,this paper studies and designs five types of permeable pavement structures such as uniform structure,corrugated surface,multi-particle size combination,embedded PPR and backwashable.The experimental research results of the permeability attenuation law of permeable pavement show that the wave-shaped permeable pavement has no obvious effect on permeability attenuation,and the combination of multi-particle size permeable pavement and embedded PPR permeable pavement has a significant effect on permeability attenuation,which can be backwashed Permeable pavement has significant effect on permeability recovery;(3)This paper uses GEO-STUDIO to establish a numerical simulation model of rain and flood infiltration,and analyzes the results of rain and flood infiltration under the influence of natural and human factors.The results show that when the rainfall intensity increases to a certain value,the infiltration amount is less than the rainfall,The surface runoff is generated,and the runoff coefficient increases with the increase of rainfall;the lower the lithologic permeability of the aerated zone,the larger the surface runoff coefficient;the thicker the stratum with weak permeability,the greater the surface runoff coefficient;The control works such as permeable pavement,replacement of weakly permeable strata in the aerated zone,and connectivity of the weakly permeable stratum in the aerated zone significantly increase the effect of rain and flood infiltration under the same rainfall intensity and rainfall duration.In the case of rain and flood infiltration schemes,engineering measures for replacing weakly permeable strata in the aerated zone should be adopted.In the case of thicker aeration zones,the engineering measures for connection of weakly permeable strata in the aerated zone should be adopted.(4)According to the hydrogeological conditions of the planned test area,the SEEP/W module in GEO-STUDIO is used to establish a rain flood infiltration numerical simulation model to determine two rain flood infiltration control schemes: Scheme 1 is a pavement permeable on the surface On the basis,the silty clay layer with a thickness of 3 m on the surface is excavated and replaced with sand and gravel with a saturated permeability coefficient of 50 m/d;the second option is to establish a communication well with an interval of 8 m on the basis of permeable pavement on the surface,and fill the well Grit with a permeability coefficient of 50 m/d. |
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