Etsuo Sekine

Cyclic deformation of granular material subjected to moving-wheel loads

This paper describes a new testing method to examine the mechanical behavior of railroad ballast subjected to repeated train passages on ballasted track. Two types of cyclic loading tests, namely a single-point loading test and a moving-wheel loading test, were performed with small-scale models of ballasted track. Next, a “multi-ring shear apparatus” was developed as a type of torsional simple shear apparatus, and the applicability of a newly proposed multi-ring shear test to an element test of railroad ballast subjected to moving-wheel loads was examined by comparing the results of multi-ring shear tests with those of small-scale model tests. As a result, it was recognized that cumulative strain obtained from multi-ring shear tests is almost equivalent to the one derived from small-scale model tests. Moreover, it was revealed that the difference between loading methods has a considerable influence on the cyclic plastic deformation of railroad ballast because settlement in a moving-wheel loading test was ...

Development and Practical Use of Paved Track for Revenue Line

In recent years, the destructive force acting on the ballasted track is on the increase with the speed-up of trains and the increase in the number of trains, requiring more labor and expenditure to maintain the track in good condition. On the other hand, it is increasingly difficult to obtain maintenance manpower, because Japan is quickly shifting to a society of elders, and people tend to hate tough works such as manual track maintenance work. Under these circumstances, the Paved Track which is to be laid during the midnight interval on existing line has been developed and improved in order to reduce the maintenance work of the ballasted track on subgrade. This paper describes the track structure and the results of the performance tests of this track.