Abstract
At a tunnel portal of a high-speed railway, a hood is build to reduce a micro-pressure wave generated by a train entering into a tunnel. A conventional hood has a rectangular cross-section larger than that of a tunnel, and in order to minimize the construction costs, we have developed a porous round hood with the same cross-section as the tunnel. In this study, we examine the effect of this round hood on a micro-pressure wave and other pressure waves. The result of an experiment with a scale model shows that the round hood can reduce a micro-pressure wave as much as the conventional rectangular hood. Then, the round hood is constructed at the Yamanashi Maglev test line, and a field measurement is conducted. The result agrees with the experimental result and shows that the round hood can reduce both a micro-pressure wave and a pressure wave at a tunnel portal enough for the environmental standard criteria.
