Research on Mechanical Characteristics of Railway Ballast Bed Based on Micro-mechanical Model
The ballast bed is a kind of granular structure composed of crushed stone ballasts.The interaction between ballast particle affects the mechanical properties of ballast bed structure.In order to study the laws of load transfer and settlement within the ballast layer,and explore the mechanisms of service state evolution of ballast bed during train oper-ation,the Chang-Hicher model was developed by means of internal subroutine based on the finite element ABAQUS plat-form software.The numerical simulations of the conventional triaxial compression tests of ballast aggregates and the dy-namic characteristies tests of ballast bed were carried out,to expound the feasibility of using meso-analytic constitutive model to simulate the mechanical properties of ballast from the static and dynamic perspectives.Further,the dynamic mechanical behavior of ballast bed under moving high-speed train loads was studied using this model to discuss the set-tlement characteristics of different areas of ballast bed from the macroscopic level,and analyze the distribution and change law of the contact force between ballasts by using the rose diagrams from the microscopic level,and discuss the influence of speed and axle load on contact force and displacement.The results show that during the operation of the train,the contact force of the ballasts below the load position is the highest,followed by the contact force of the ballasts below the center of sleeper box,and the contact force of ballasts below the center of sleeper.However,the vertical dis-placements of the ballast bed in these areas are basically the same.Besides,there are positive correlations between the train speed and axle load on the ballast contact force and ballast bed settlement.
万方数据
维普
