Experimental Study on Validation of Stormwater Interaction Model between the Ground Surface and Sewerage System

摘要

For prediction of damage extent caused by heavy rainfall disasters, a lot of numerical models for inundation simulation considering the effects of urban drainage system have been developed. However, it is difficult to estimate how much of stormwater on the ground surface is drained into sewerage system. Numerical estimation method of that is different depending on research groups. In this study, numerical model of stormwater interaction between the ground surface and drainage system we have ever used (step-down and overflow formula) is validated based on physical experiment. This experimental setup consists of a rainfall simulator, a surface flood plain with buildings, a sewer pipe and connecting pipes between them. From the comparison between experimental and simulation piezometric heads of the sewer pipe, they have good agreement in all the cases of steady state. However, in the cases of unsteady state, it is found that coefficient values ever used can not express stormwater interaction process and much smaller values are recommended to be used.