道砟胶固化道床力学特性的离散元分析

Discrete element analysis on mechanical properties of ballast curing track bed

为探究道砟胶的使用对有砟轨道道床的影响规律,采用镶嵌式组合颗粒单元构造道砟颗粒,根据相关文献确定道砟胶的黏结模型和刚度模型,利用单轴压缩试验和三点弯曲试验确定道砟胶固化道床的细观力学参数,基于离散元法对道砟胶固化道床开展数值模拟,系统分析道砟胶用量和加胶深度对道砟胶固化道床力学特性的影响。模拟结果表明:随着道砟胶加入量的增大,道床的累积沉降量减小且累积沉降量的振幅减小,道床的刚度逐渐增大且增大趋势逐渐趋于平缓;当道砟胶加入量为48 kg/m^3时,道床的累积沉降量最小且刚度最大;随着道砟胶加入深度的增大,道床的累积沉降量减小且累积沉降量的振幅减小,道床的刚度与道砟胶加入深度呈线性关系;道床全部加入道砟胶时道床的沉降量最小且刚度最大。

To study the influence of ballast glue on ballast track bed,the ballast glue curing track bed is simulated using discrete element method,and the influence of the consumption and depth of ballast glue on the mechanical properties of ballast glue curing track bed is analyzed.The ballast particles are constructed with mosaic composite particles.The bond model and stiffness model of ballast glue are determined according to relevant literature.The micromechanical parameters of ballast glue curing track bed is determined by uniaxial compression test and three-point bending test.The simulation results show that,with the increase of ballast glue consumption,the cumulative settlement of track bed decreases,and the amplitude of cumulative settlement decreases,and the rigidity of track bed increases gradually and its increasing trend tends to be slow;the cumulative settlement is minimum and the track bed rigidity is maximum when the consumption of ballast glue is 48 kg/m^3;with the increase of ballast glue depth,the cumulative settlement of track bed decreases and the amplitude of cumulative settlement decreases,and there is a linear relationship between the rigidity of track bed and the depth of ballast glue;the settlement of the track bed is the minimum and the rigidity is the maximum when whole track bed are added with ballast glue.