EXPERIMENTAL VALIDATION OF INTERACTION MODEL AT STORM DRAIN FOR DEVELOPMENT OF INTEGRATED URBAN INUNDATION MODEL

Recently, there have been a lot of numerical models for prediction of urban inundation damage due to heavy rainfall by using the combined drainage system. Although it is important to estimate inlet and overflow discharge through the storm drain, calculation method and formula are not clarified. Hence, in this study, the numerical model of storm water interaction between the ground surface and drainage system we have previously used is improved and validated based on physical experiments. From the comparison, they showed agreement in all the cases of steady state condition. In the unsteady state cases, it was found that simulation results agreed well with experimental results of the ground inundation start time and the maximum inundation depth as well as the water level increase process. However, piezometric head reproduced small differences when the downstream water level was decreased. It was judged that was caused by inadequate consideration of exit and entrance head loss between the tank and pipe.