注胶与植筋对纵连板式无砟轨道受力变形的影响

针对采取维修措施后纵连板式无砟轨道在高温荷载下的受力变形问题，考虑轨道板与砂浆层间界面黏结应力-位移非线性本构关系、植筋结构应力-滑移非线性本构关系，建立了纵连板式无砟轨道力学行为分析有限元模型，并对其施加非线性高温荷载，对比分析了注胶、植筋与2种措施共用对纵连板式无砟轨道受力变形与结构损伤的影响规律。研究结果表明：对于轨道板两侧存在0.2 m层间离缝、一宽窄接缝存在破损的基本工况，注胶、植筋与2种措施共用情况下邻近破损接缝的轨道板端部层间离缝最大值分别为未采取维修措施时的63%、20%和18%，破损接缝混凝土受压损伤最大值分别为未采取维修措施时的51.0%、6.8%和5.5%；对于宽窄接缝结构状态较差的纵连板式无砟轨道，植筋措施的维护效果远好于注胶措施，而2种措施共用的效果更佳；注胶措施对纵连板式无砟轨道端部垂向位移、层间损伤和宽窄接缝受压损伤的限制作用随注胶深度的增加而增强；仅采用注胶措施情况下，若要达到2种措施共用情况下邻近破损接缝的轨道板端部层间损伤的幅值范围，注胶板块数需不小于2，且双侧注胶深度均需不小于0.9 m，建议在仅采取注胶措施时，充分保证注胶维修面积。

Effects of glue injection and reinforcement anchor installation on mechanical deformation of longitudinally connected slab-type ballastless tracks

For the mechanical deformation of longitudinally connected slab-type ballastless tracks under high-temperature load after maintenance measures were taken, the nonlinear constitutive relationship of bond stress-displacement at interfaces between track slabs and mortar layers and the nonlinear constitutive relationship of stress-slip in reinforcement anchor structure were considered, a finite element model for mechanical behavior analysis of longitudinally connected slab-type ballastless tracks was built, the nonlinear high-temperature load was applied to the model, and the influence laws of glue injection, reinforcement anchor installation, and 2 measures jointly used on the mechanical deformation and structural damage were compared and analyzed. Analysis results show that for the basic working condition with a 0.2 m interface seam on both sides of the track slab and a damaged wide and narrow joint, under the maintenance measures of glue injection, reinforcement anchor installation, and 2 measures jointly used, the maximum values of the interface seam at the end of the track slab adjacent to the damaged joint are 63%, 20%, and 18% of those before taking maintenance measures, and the maximum values of the compression damage of the damaged joint concrete are 51.0%, 6.8%, and 5.5% of those before taking maintenance measures. For the longitudinally connected slab-type ballastless track with a poor structural state of wide and narrow joints, the maintenance effect of reinforcement anchor installation is much better than that of glue injection, and the effect of using the two measures jointly is better. The effects of glue injection on limiting the vertical displacement at the end of longitudinally connected slab-type ballastless tracks, interface damage, and compression damage of wide and narrow joints increase with the increasing depth of glue injection. When only glue injection is taken, in order to reach the amplitude range of interface damage at the end of the track slab adjacent to the damaged joint when 2 measures are jointly used, the number of glue injection slabs shall not be less than 2, and the depth of glue injection on both sides shall not be less than 0.9 m. It is recommended to fully ensure the glue injection maintenance area when the glue injection is taken only.