长大坡道铺设无缝道岔可行性分析

基于有限单元法建立无缝道岔非线性阻力计算模型,分析不同工况条件下的钢轨纵向力及位移。计算结果表明:坡度对无缝道岔的受力及变形是不利的;随着阻力减小区段距道岔距离增加,钢轨纵向力、最大位移增加,尖轨相对基本轨的位移减小。道床捣固不密实引起的道床纵向阻力减小,会显著增大道岔各部分受力和变形。建议:(1)在大坡道地段,宜采用全长淬火钢轨或高强度钢轨;(2)在进站道岔前列车频繁制动地段、无缝道岔尖端、辙跟、叉心处宜布置观测桩,随时观测无缝道岔的爬行情况;(3)加强无缝道岔防爬锁定;(4)加大上坡方向道床的堆积厚度,并加强捣固。

Feasibility Analysis of Seamless Turnout on Long Steep Grade

Based on the finite element method,this paper establishes a nonlinear resistance calculation model of the seamless turnout and analyzes rail longitudinal force and displacement under different working conditions. The results show that slope is negative to stress and deformation of seamless turnout.With the increase of the distance from the resistance reduced section to the turnout,the rail longitudinal force and the maximum displacement increase,and relative displacement between the point rail and the stock rail decreases. The decrease of track bed longitudinal resistance caused by insufficient tamping of track bed may significantly increase stress and deformation of each part of the turnout. Recommendation:( 1) in a long steep grade area,the full-length quenched rail or high strength rail should be adopted;( 2) observation pile should be arranged to look for turnout creeping where frequent braking is applied in front of the approach turnout,at the point of the seamless turnout,the frog heel and frog center;( 3)anti-creeping of seamless turnout should be strengthened;( 4) the thickness of the track bed in uphill direction should be increased and tamping reinforced.