摘要：Recently heavy rainfall have caused inundations in urban areas of Koera. Especially, inundation of undergroudn stairs makes people's evacuation difficult. In this study, inundated flow condition of stairs are simulated numerically using commecial 3 D CDF model(FLOW 3D). From the results, critical evacuation conditions are evaluated according to flow depth and slopes of stairs. It is found that flow depth only over the 20cm could cause the danger in the evacuation along stairs. In the flow depth over 0.36cm, every people including young male, could not escape alone without any help. Inlet flow depth is more important factor than stair slopes. Inundation depth to underground stairs should be managed to keep below 0.2 m.
