铁道建筑
鐵道建築
철도건축
RAILWAY ENGINEERING
2014年
11期
152-156
,共5页
道床%道砟%裂纹扩展%破裂%离散单元法
道床%道砟%裂紋擴展%破裂%離散單元法
도상%도사%렬문확전%파렬%리산단원법
Ballast bed%Ballast%Crack propagation%Breakage%Discrete element method
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。
為瞭研究道砟外部接觸狀態變化對其靜態壓碎行為的影響,建立單顆粒道砟離散元模型,模擬道砟靜態壓碎過程,比較不同位置加載對道砟抗壓彊度、壓碎過程以及破碎形式的影響。結果錶明:加載位置的變化對道砟單軸抗壓彊度影響顯著,併有可能改變道砟破壞形式;噹上下方有穩定的受力平麵時,道砟單軸抗壓彊度較大,壓碎破壞形式為拉伸破壞;噹道砟在稜角處受載時,單軸抗壓彊度較小,壓碎破壞形式變為單斜麵剪切破壞;道砟上下加載位置中心連線與加載方嚮有較大夾角時,道砟單軸抗壓彊度很小,容易髮生單斜麵剪切破壞。
위료연구도사외부접촉상태변화대기정태압쇄행위적영향,건립단과립도사리산원모형,모의도사정태압쇄과정,비교불동위치가재대도사항압강도、압쇄과정이급파쇄형식적영향。결과표명:가재위치적변화대도사단축항압강도영향현저,병유가능개변도사파배형식;당상하방유은정적수력평면시,도사단축항압강도교대,압쇄파배형식위랍신파배;당도사재릉각처수재시,단축항압강도교소,압쇄파배형식변위단사면전절파배;도사상하가재위치중심련선여가재방향유교대협각시,도사단축항압강도흔소,용역발생단사면전절파배。
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.