QUANTITATIVE EVALUATION OF ESTIMATED RESIDUAL SETTLEMENT OF POORLY-GRADED CRUSHED STONE LAYERS BY USING DEM

Abstract

3D-DEM code was parallelized by using Open MP to decrease computing time and to improve the quantitative accuracy of estimated residual settlement of poorly-graded crushed stone layers. Ballast grain models are also elaborate to sharpen the angularity by adapting “Asperity” elements. Then the track stiffness after ballast renewal and initial settlement of ballasted layer during 70 trains passing are simulated by using above mentioned DEM codes and models. The computing time is reduced to one tenth at the case with 32 threads of supercomputer. The residual settlement calculated by DEM simulation fit into the range of mean value plus-minus standard deviation of measured data from real railway line.