寒区铁路隧道衬砌抗冻主要设计标准与施工技术探讨  

Discussion on Main Design Standards and Construction Techniques for Frost-resistance of Railway Tunnel Linings in Cold Regions

作　　者：张弛 ZHANG Chi(China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]中国铁路设计集团有限公司,天津300308

出　　处：《铁道标准设计》2024年第3期185-191,共7页Railway Standard Design

基　　金：中国铁路设计集团有限公司科研开发课题(2020YY340627)。

摘　　要：受长期低温环境作用,寒区铁路隧道衬砌易出现开裂、剥落等病害,影响结构的安全耐久性。通过梳理分析寒区隧道衬砌抗冻设防相关建设标准现状及存在问题,从设计和施工方面提出需要研究完善的主要内容,并结合具体工程实例,进一步探讨抗冻设防段衬砌的配筋参数、伸缩缝设置等主要设计标准和保温层防水施工工艺,提出寒区隧道衬砌模段长度计算方法。结果表明:(1)抗冻设防段衬砌的纵筋宜采用“细而密”的配置方式,有利于提高结构的抗裂性能;(2)“零缝宽”伸缩缝在一定条件下能够消减寒区隧道温度应力作用;(3)“喷涂式”聚氨酯保温板防水处理施工工艺可有效提高保温性能;(4)隧址区的年平均气温应作为寒区隧道衬砌环境温差的重点考量因素,计算结果表明,当最冷月平均气温-3~-8℃,年均温12~8℃时,12 m的衬砌模段长度亦可满足季节性温差要求。Under the effect of long-term low temperature environment,the railway tunnel lining in the cold regions is prone to cracking,peeling and other diseases,which effects the safety and durability of the structure.This paper analyzes the current situation and existing problems of relevant construction standards for frost-resistance and protection of tunnel lining in the cold regions,and puts forward the main contents that need to be studied and improved from the aspects of design and construction.Combined with engineering examples,this paper further discusses the main design criterion of the reinforcement parameters,expansion joint setting and waterproof construction technology of insulation layer of the tunnel lining in the cold regions,and puts forward the computing method for the length of formwork of the tunnel lining in cold regions.The results show that:(1)the longitudinal reinforcement of the lining in the frost-resistant section should be“fine and intensive”to improve the anti-crack ability of the structure;(2)“Zero joint width”expansion joint will reduce the temperature stress of tunnel in cold region under certain conditions;(3)The waterproof construction technology of“spray type”polyurethane insulation board can effectively improve the insulation capacity;(4)The annual average temperature of the tunnel zone should be taken as an important consideration factor for the temperature difference of the tunnel lining environment in the cold regions.The calculation results show that when the average temperature of the coldest month is-3~-8℃,and the annual average temperature is 12~8℃,the length of the lining formwork with a length of 12m can also meet the seasonal temperature difference requirements.

关 键 词：寒区 铁路隧道 衬砌抗冻性 温度伸缩缝 保温层 模段长度 

分 类 号：U25[交通运输工程—道路与铁道工程] U459.1[建筑科学—桥梁与隧道工程] U455.91