RTRI REPORT September 2000

Reduction of Micro-pressure Wave and Generation of Pressure Waves by Branches in Tunnel

Takashi FUKUDA, Masanobu IIDA, Kaoru MURATA


  Pressure waves emitted from tunnel portals could be one of the environmental problems for high-speed railways. A micro-pressure wave and branch waves are representatives of such problems. Side branches in a tunnel have an effect to reduce the micro-pressure wave because they counteract steepening of the wavefront of the compression wave generated when a train enters a tunnel. However, when the train passes by the branches, other pressure waves (branch waves) are generated. This paper describes experimental, numerical and theoretical studies performed to clarify the effect of the branch to reduce the micro-pressure wave and the generation mechanism of the branch waves. A sort of check valves is proposed as a countermeasure to reduce both the micro-pressure wave and the branch waves.



Copyright (c) 2000 Railway Technical Research Institute