Abstract
Recently, a localized torrential downpour was happened frequently as a heavy rain, and rain-water was leaking out of gutter installed in roofed rail station. As the mechanism of drainage through drain pipe has not been clarified, the drainage capacity could not be predicted. In this paper, the mechanism of drainage has been discussed on the basis of experimental works by using 14 prototype models for the arrangement of drain pipes, and the prediction of drain capacity has been proposed. Systematical measurements yield that the length of vertical drain pipe connected to gutter is most significant to keep drainage capacity in gutter by focusing on the relationship between water depth in gutter and the existence of water level in the vertical drain pipe. The drain capacity can be predicted by applying Torricelli’s and Bernoulli’s theorems supported discharge coefficients for all experiments, loss factor due to bending, and friction factor for roughness bed.
