明洞隧道衬砌环向非受力裂缝分析及控制技术

目前国内对明洞隧道拱墙衬砌浇筑过程中出现的环向裂缝研究较少,该类裂缝由于是非受外力作用产生,没有引起足够的重视,但该类裂缝会引起隧道渗水、甚至影响结构耐久性。为了解决明洞隧道拱墙衬砌环向裂缝问题,依托京张高铁东花园明洞隧道工程实例,对明洞隧道衬砌环向非受力裂缝宽度影响因素进行了深化研究,通过对环境温度、配筋率、每版衬砌长度、底边墙的约束度等不同工况进行理论分析,提出明洞隧道衬砌混凝土非受力裂缝关键影响因素,并对裂缝的宽度和长度进行理论量化计算,提出该类裂缝控制关键技术,研究结果可为其他类似的明洞隧道衬砌设计、施工提供借鉴和参考。

Analysis and Control Technology of Non-Stressed Ring Cracks in Open Tunnel Lining

At present, there are only a few researches on the ring cracks in the lining of the arch wall of the open-excavated tunnel. The cracks are not affected by external forces and have not attracted enough attention. However, such cracks may cause tunnel seepage and even affect the structural durability. In order to solve problem, the influencing factors of the non-stressed crack width are studied intensively, and the ambient temperature, the reinforcement ratio, the length of each lining and constraint of bottom wall are analyzed theoretically with reference to the East Garden open cut tunnel construction on the Beijing-Zhangjiakou High-speed Railway. Key factors affecting the non-stressed cracks are identified, theoretical quantum calculation of the crack width and length is conducted, and key control technology is proposed. The research results can provide some references for the design and construction of other similar open-excavated tunnel lining.