客运专线路基地段铺设无碴轨道有关问题的探讨

与传统有碴轨道相比,客运专线路基地段铺设无碴轨道后,对路基工程的沉降变形控制、基床结构、过渡段设置及铺设前的综合评估有明显的差别。本文在调研分析国内外资料的基础上,针对路基地段铺设无碴轨道的关键技术问题,包括沉降变形控制中工后(残余)沉降的概念、标准、组成及控制方法,路基基床承受的动应力水平及传递规律,不同工程类型衔接处过渡段的设置形式、长度及设置方法;无碴轨道铺设前的沉降观测分析方法及评判标准进行了系统的分析和探讨,并参照客运专线工程设计国际咨询成果资料,结合我国多条客运专线前期工作的不断深入,提出了指导客运专线路基地段无碴轨道设计与施工的建议。

DISCUSSION ON THE PROBLEMS ABOUT CONSTRUCTION OF BALLASTLESS TRACK IN THE PASSENGER DEDICATED RAIL-WAY LINE

Different from traditional ballast track, there are significant differences in the control of subgrade settlement, the structure of subgrade bed, the construction of transitional section, as well as general pre-evaluation when constructing ballastless track. In this paper, after investigating the techniques of the ballastless tracks used in the world, several key technical problems about constructing ballastless track under subgrades discussed, which includes the concept of residual settlement, the constitution of subgrade settlement, the standard and the measures on the control of subgrade settlement, the transmission of dynamic stress on subgrade bed, the design patterns and the length of transitional section, as well as the construction techniques on connecting different types of structures for the ballastless track. Besides, the evaluation standard and the approach to analyze subgrade settlement before construction studied in detail. Combining with previous work on several existing passenger dedicated railway line and referred to the data from international consultation about the design of transportation line, some helpful suggestions are proposed to guide the design and the construction of the ballastless track in the passenger dedicated railway line.