加载位置对道砟静态压碎形式的影响研究

Simulation study on influence of load position on static crushing form of ballasts

为了研究道砟外部接触状态变化对其静态压碎行为的影响,建立单颗粒道砟离散元模型,模拟道砟静态压碎过程,比较不同位置加载对道砟抗压强度、压碎过程以及破碎形式的影响。结果表明:加载位置的变化对道砟单轴抗压强度影响显著,并有可能改变道砟破坏形式;当上下方有稳定的受力平面时,道砟单轴抗压强度较大,压碎破坏形式为拉伸破坏;当道砟在棱角处受载时,单轴抗压强度较小,压碎破坏形式变为单斜面剪切破坏;道砟上下加载位置中心连线与加载方向有较大夹角时,道砟单轴抗压强度很小,容易发生单斜面剪切破坏。

In order to study the effect of external contact states on the static crushing behavior of railw ay ballast,this paper established the discrete element models of single particle ballast to simulate static crushing processes and compare the influence of different loading position on ballast compressive strength,the crushing process and the breakage mode. T he results showed that the loading position has a remarkable influence on the uniaxial compressive strength and may change the ballast breakage mode,the ballast has a larger uniaxial compressive strength and crushing damage mode is tensile failure when ballast top and bottom has a steady force plane,the ballast has a smaller uniaxial compressive strength and crushing damage mode is single bevel shear failure when ballast loading position is at sharp edge or corner,the ballast has little compressive strength and single bevel shear failure is prone to happen w hen there is a larger angel betw een center connection line of ballast top and bottom loading position and loading direction.