A STUDY ON IMPROVEMENT OF MAINTENANCE FOR RAILWAY BRIDGE PIER FOUNDATIONS AGAINST FLOODS

Abstract

 Due to frequent heavy rains in recent years, disasters caused by flooding occur almost every year on railway river bridges in Japan. In this paper, we proposed methods for improved maintenance for pier foundation of river bridges, based on the experience of disasters so far, in order to prevent trains from serious events such as the inclination of piers caused by scouring around the foundation due to flooding. First, we proposed a method to set the highest water level in the past as an approximate water level for timely inspection after floods, and confirmed its effectiveness through actual flood cases. Furthermore, regarding the impact vibration test, which is generally performed as a detailed inspection for bridge piers, we examined advanced method that also focuses on the damping constant in addition to the natural frequency. We have confirmed through the impact vibration test of railway bridges crossing river, that it is possible to grasp more detailed situation of scouring of the pier foundation for the railway river bridge with this method.