STUDY ON LATERAL RESISTANCE FORCE OF BALLASTED TRACK EQUIPPED WITH COUNTERMEASURES TO PREVENT TRACK BUCKLING DURING EARTHQUAKES

Abstract

Development of the seismic design and the seismic countermeasures of the structures supporting railroad ballasted tracks are progressing; development of them for ballasted tracks is also required. In this study, we conducted small-scale model tests to evaluate the mechanism of reduction of the lateral ballast resistance during shaking. The deformation behavior inside the ballast during shaking was photographed and image analysis by PIV was performed; then it was found out that a shear plane was generated in the loading direction from the depth of the bottom of the sleeper. Large shaking table tests were also conducted using a full-scale model to investigate the effect of the seismic countermeasures for ballasted tracks. It was confirmed that both the buckling prevention plates and the ballast retaining wall had high seismic countermeasure effect.