Study on micro-mechanical behavior of reinforced ballast under impact loading using discrete element method
In order to investigate the reinforcement effect of geosynthetics materials under impact loading from a micro view,the ballast particle model was established by the discrete element method,and the geogrid and geocell flexibility models were established by the parallel bond model.By comparing indoor impact tests on ballast and numerical simulation results,this study investigates the vertical cumulative settlement and lateral deformation of ballast from both macro and micro perspectives.The stress distribution,contact,and displacement of ballast are analyzed at a microscopic level.The simulation results show that,under the impact height of 250 mm,compared to unreinforced ballast,the vertical settlement and lateral deformation of geogrid-reinforced ballast were reduced by 24.4％and 12.7％respectively,while those of geocell-reinforced ballast were reduced by 33.5％and 24.0％respectively.Due to the cushion effect in the reinforced area,the contact numbers for geogrid and geocell reinforced ballast increases by 9.3％and 42.6％respectively,while the average contact force decreases by 5.6％and 16.7％respectively.In terms of average particle displacement,the geogrid and geocell reinforced conditions show reductions of 28.2％and 43.6％respectively compared to the unreinforced condition.The reinforcing effect of geocell is more significant than that of geogrid.
ballastgeocellgeogridimpact loaddiscrete element method
万方数据
维普
