收缩徐变作用下铁路连续刚构桥-轨道系统受力特性

Interaction Between Tracks and Continuous Rigid-frame Bridge Carrying Railway Under Action of Shrinkage and Creep

通过建立(72+128+72)m高速铁路大跨度连续刚构桥-双线无砟轨道系统仿真模型,揭示收缩徐变作用下大跨度连续刚构桥与轨道相互作用规律,分析收缩徐变模式、混凝土养护条件等主要设计参数对系统受力和变形的影响,探讨采用整体升温代替收缩徐变效应计算的可行性。研究表明:随着服役时间的延长,收缩徐变作用下系统的受力与变形逐渐增大;采用梁体降温30℃计算的钢轨应力和竖向位移无法包络收缩徐变效应引起的钢轨应力和位移,《高速铁路设计规范》中建议采用整体降温10℃来模拟收缩徐变的方法并不适用于梁-轨相互作用分析。

Based on a simulation model for （72＋128＋72） m large-span continuous rigid-frame bridge and double-line ballastless track system, the interaction between large-span continuous rigid-frame bridge and track was revealed under the action of shrinkage and creep. Following the analysis on the influence of the main design parameters, such as shrinkage and creep model, concrete curing condition, on system force and deformation, the feasibility of adopting thermal effect to replace calculation of shrink and creep effect was discussed. The study showed that the system force and deformation under the action of shrinkage and creep effect gradually increased with the extension of service time. The rail stress and vertical displacement generated by shrinkage and creep cannot be completely contained by those calculated from 30 ℃ temperature drop of the beam. The method that shrinkage and creep can be simulated by beam temperature dropping of 10℃ recommended by the ＂Code for Design of High Speed Railway＂ is not applicable to track-bridge interaction analysis under the action of shrinkage and creep.