Abstract
At locations where the bearing capacities of roadbeds are insufficient, settlement of ballasted tracks become large and they should be repaired at short maintenance intervals. At such locations, the improvement method to replace weak roadbed material with strong material such as cement treated soil is occasionally applied. However, since it is necessary to make sufficient compaction of those materials by vibration rammer, it is difficult to execute sufficient extension of improvement length, restricted by the short working-time during the night when trains are not in operation. Therefore, in this study, we have developed a method to improve sufficient length of roadbed with short time by reusing the ballast mixed with grout. In this research, we evaluated the effectiveness of this method by elemental tests, realscale tests and FEM analysis.
