高海拔大断面隧道衬砌混凝土质量控制

Concrete Quality Control of Large Cross Section Tunnel Lining in High Altitude Area

兰新铁路客运专线祁连山、大梁隧道设计为大断面双线隧道,两座隧道均处在平均海拔为3 500~4 345 m的祁连山高原,高寒缺氧,气候恶劣,特别是祁连山地区集高原、高寒、冻融等特殊气候条件于一体,沿线合格混凝土原材料匮乏,给隧道衬砌混凝土质量控制带来极大难度。本文针对现场施工实际,对高海拔大断面双线隧道衬砌混凝土防寒措施、原材料质量、混凝土配合比设计与优化、混凝土拌和、混凝土浇筑、脱模、养护及现场管理等质量控制技术进行了分析总结,具有一定参考价值。

Qilian Mountain Tunnel and Daliang Tunnel in Lanzhou-Xinjiang High-speed Railway were designed into large cross section double-line tunnel,the two tunnels located at Qilian Mountain plateau with an average altitude of 3 500 m to4 345 m,the special climate conditions such as cold,hypoxia,awful weather,and especially the Qilian Mountain areas owning an integration of high altitude and freezing-thawing,with lack of qualified raw materials of concrete along the line,it brought huge difficulty for concrete quality control of tunnel lining. In connection with the construction practice,the coldproof protection measures for double-line tunnel concrete lining of the high altitude,quality of raw materials,design and optimization of concrete mix proportion,the concrete mixing,pouring,demoulding,maintenance and site management,and other quality control techniques were analyzed and summarized,which had certain reference values.