高速铁路无砟轨道混凝土动态性能及其评价方法综述

Dynamic Performance and Evaluation Method of High-speed Railway Ballastless Track Concrete

高速铁路无砟轨道是高速列车运行的直接承载结构。在高速列车动荷载的持续作用下,无砟轨道内部发生动态损伤,导致宏观服役性能衰减,影响高速铁路结构耐久性和运营安全性。根据高速铁路无砟轨道混凝土正常服役条件下承受高频疲劳荷载,轨道不平顺时还要承受冲击荷载的服役特征,本文总结了无砟轨道混凝土承受动荷载的作用特点,从标准层面梳理了高速铁路无砟轨道混凝土疲劳性能和冲击性能的技术要求,指出了无砟轨道动态性能评价方法的适用性和局限性,以期为高速铁路无砟轨道混凝土动态性能评价及长寿命无砟轨道设计提供参考。

Ballastless track concrete structure is the key position for bearing the dynamic loads induced by high-speed running train.With the continuous effects of periodic dynamic loads,internal damage occurs and service performances of ballastless track structure are decreased,leading to the durability issue of ballastless track and insecurity risk of the running train.According to the service characteristics of ballastless track concrete,high-frequency fatigue loads are the main types of dynamic loads under normal service state,however,impact loads cannot be ignored when the track is irregular.This paper summarizes the characteristics of dynamic loads,and then illustrates the requirements for both fatigue and impact performances of ballastless track concrete.Meanwhile,the applicability and limitations of the dynamic performance evaluation method of ballastless track are further elaborated,aiming to provide certain suggestions and directions for the evaluation of service performances and long service life design of ballastless track.