Abstract: In the aim of improving the utilization rate of rainwater in the construction and operation of sponge city, a rainwater infiltration device was proposed and its effect on increasing infiltration was verified. The rainwater infiltration device was formed via digging an infiltration well in clayey soil ground and filling the well with coarse sand. The seepage in the infiltration well was measured through in-situ test device, and the saturation degree of soil at different times during infiltration was obtained. In the meantime, the original clay site and the clay ground equipped with sand well were simulated in ABAQUS, which provided us the simulated values of saturation degree of soil at different instances in the process of infiltration. Moreover, the test values and simulation values were compared, and the simulated values between original clay site and clay site equipped with infiltration well were further compared. Results demonstrated that sand infiltration well could augment the infiltration capacity of soil by a large margin, and the average growth rate of water infiltration of soil near the infiltration well reached 67.21%. In addition, the effect of infiltration was increased along with the decrease of depth and the distance from the axis of infiltration well.

Key words: sponge city, rainwater infiltration device, closed pores, in-situ tests, infiltration well, seepage field