SOME CONSIDERATIONS ON UNSTEADY FLOWS IN UNDERGROUND CHANNELS

Hydraulic transients in the underground channel system such as the underground flood way and the sewer network are investigated experimentally and numerically. The typical features of unsteady flows induced by the inflow discharge into the underground channel are clarified by the fundamental hydraulic experiments. It is also shown that the hydraulic transients with the propagation of an interface between the open channel flow and the pressurized pipe flow can be reproduced by using the numerical model. Numerical model is extended to predict the hydraulic transients with the interaction between the overland surface flow and the underground channel flow, considering the inflow and outflow discharge through manholes.