双块式无砟轨道裂纹对结构受力特征的影响分析

Analysis on Effect of Bi-block Ballastless Track Cracks on Mechanic Behavior of Structure

建立了含初始裂纹的CRTSⅠ型双块式无砟轨道空间有限元实体模型,对无砟轨道的受力特性进行研究,为无砟轨道的优化设计及其养护维修提供一定的理论基础。综合考虑列车荷载和温度应力的共同作用,求出了裂纹张开量和道床板纵向钢筋应力,并分析了裂纹深度和道床板配筋率对裂纹张开量和道床板纵向钢筋应力的影响。得出结论:(1)在列车荷载和整体温降共同作用下,无砟轨道道床板裂纹深度对裂纹张开量和裂纹处道床板下层纵向钢筋应力的影响不明显;(2)在满足最小配筋率的前提下,道床板配筋率对无砟轨道道床板裂纹张开量没有影响;在列车荷载和整体温降共同作用下,道床板配筋率对裂纹处道床板下层纵向钢筋应力的影响也不明显。

The space finite element model of the CRTSⅠbi-block ballastless track with initial cracks is established first, then the mechanical behavior of the ballastless track is studied, thus certain theoretical basis is provided for the optimum design and maintenance of the ballastless track. Based on overall consideration of combined action of the train load and the temperature stress, the crack opening and longitudinal reinforcement stress of trackbed slab are obtained, and the effect on the crack opening and the bar stress of the crack depth and the reinforcement ratio of trackbed slab is analyzed. We can get the conclusion from the above analysis：（1）Under the combined action of the train load and the overall tem-perature drop, the impact of crack depth of trackbed slab on crack opening and the longitudinal reinforcement stress of trackbed slab under layer at the crack is not obvious. （2）in the premise of meeting the minimum reinforcement ratio, re-inforcement ratio of trackbed slab does not obviously affect the ballastless trackbed slab crack opening. Under the com-bined action of train load and the overall temperature drop, the influence of reinforcement ratio of trackbed slab on the longitudinal reinforcement stress of track bed slab under layer at the crack lower is not obvious.