无砟轨道下沥青混凝土层与支承层层间关系研究

Research on interlayer relationship between asphalt concrete layer and support layer under ballastless track

为研究温度荷载下全断面铺设沥青混凝土层与无砟轨道支承层之间的层间关系及破坏过程,首先采用基于表面的黏聚力模型(CZM)描述沥青混凝土层与支承层的层间关系,分析不同温度、不同支承层长度下二者的层间相互作用;然后分析低温条件降温工况(最不利工况)下,沥青混凝土层与支承层的层间破坏全过程。结果表明:沥青混凝土层与支承层层间剪应力在端部最大,向内逐渐减小;最不利工况下沥青混凝土层与支承层的层间剪应力最大;支承层长度的增加使其与沥青混凝土层的层间剪应力增大,发生层间破坏的可能性增大;沥青混凝土层与支承层的层间损伤及破坏先从板端位置开始,随着温度降低,破坏范围逐渐向内扩展。

In order to study the interlayer relationship and failure process between the full-section asphalt concrete layer and the support layer of ballastless track under temperature load,a numerical model is established for analysis.The surface-based CZM was used to describe the interlayer relationship between asphalt concrete layer and support layer.The interactions of different temperature and different support layer lengths were analyzed.Then,the interlayer damage of asphalt concrete layerand support layerwas analyzed throughout the process by choosing the most unfavorable working condition.The results show that the shear stress between the asphalt concrete layer and the support layer is the largest at the end and gradually decreases inward.The interlayer shear stress is the largest under the condition of low temperature and cooling,which is the most unfavorable condition.The increase of the length of support layer increases the interlayer shear stress and the possibility of interlayer damage.The interlayer damage of the asphalt concrete layer and the support layer starts from the position at the end of the plate,and the damage range gradually expands inward as the temperature decreases.