Research on Regulation Method of Rainfall Infiltration Intensity Based on Water Gas Two-phase Flow Theory
Rainfall infiltration intensity is a key index in the construction of a sponge city,which is jointly controlled by soil permeability and driving force.In the past,more attention has been paid to the former,but less research has been done on the control method of driving force.In this paper,combined with soil column rainfall infiltration model test and numerical simulation,the driving effect of pore air on rainwater infiltration was explored.By pumping and injecting gas at the bottom of the model to control the internal gas pressure of soil,it is found that the infiltration intensity of rainwater has a significant dependence on the pore gas pressure.When the bottom gas injection is pressurized,the gas pressure gra-dient is opposite to the infiltration direction,which blocks the infiltration of rainwater.When pumping air and reducing pressure,it is the same direction as the infiltration,driving rainwater infiltration.Furthermore,by simulating the infil-tration process under different pressure conditions at the bottom boundary,the relationship between the infiltration inten-sity and the gas pressure at the bottom boundary is linear.Therefore,changing the pore gas pressure can regulate rainwa-ter infiltration,especially the rainfall infiltration intensity increases significantly under pumping conditions,which pro-vides a new idea for the construction of sponge cities and urban waterlogging control.
pore gas pressureinfiltration intensitypore gas pressure gradientmodel testnumerical simulation
万方数据
维普
