京张高铁隧道衬砌混凝土智能式养护成套技术实践

通过分析隧道衬砌养护期裂缝的形成机理,找到养护期衬砌裂缝控制的3个要素:湿养天数、环境相对湿度、衬砌内部与表面温度差和衬砌表面与隧道内环境温度差,进而提出混凝土养护期控制要求,包括养护时间、养护湿度控制方法、养护期温度控制要求及结构强度控制要求等。2016年开工建设的京张高铁八达岭隧道,采用添加粉煤灰和石粉的现浇高性能混凝土二次衬砌。现浇混凝土衬砌养护使用养护台车结合自粘式节水养护膜进行养护,同时采用充气式帆布气囊对养护中的隧道衬砌进行保温,取得了良好效果。结合京张高铁八达岭隧道衬砌智能式养护经验,介绍包括智能式养护设备、自粘式节水养护膜及保温充气式帆布气囊等智能式养护成套技术的使用情况。

Engineering Practice of Intelligent Maintenance of Beijing-Zhangjiakou High-Speed Railway Tunnel Lining

Through the analysis of the formation mechanism of cracks in tunnel lining during maintenance period, 3 control factors, such as the duration of moisturizing maintenance, the environmental relative humidity and the ambient temperature difference between the lining interior and surface and between the lining surface and the tunnel internal, are found out and control requirements for concrete maintenance, including maintenance duration, relative environmental humidity, temperature control during maintenance period and structural strength, are proposed. In the construction of Badaling Tunnel on Beijing-Zhangjiakou High-speed Railway since 2016, new maintenance equipment and materials, such as intelligent maintenance equipment, self-adhesive water-saving maintenance film and thermal insulation inflatable canvas air bag are used and good maintenance effects are achieved.