郑万铁路跨南水北调干渠特大桥钢管拱内混凝土灌注施工技术  

Concrete Injection Construction Technology for Steel Pipe Arch of Ultra-large Bridge of Zhengwan Railway Spanning the Main Canal of South-to-north Water Diversion

作　　者：许赛飞 XU Saifei(China Railway 18th Bureau Group Second Engineering Co.,Ltd.,Tangshan,Hebei 064099,China)

机构地区：[1]中铁十八局集团第二工程有限公司,河北唐山064099

出　　处：《建筑施工》2020年第3期420-422,共3页Building Construction

摘　　要：以郑万铁路跨南水北调干渠特大桥为例,从C55微膨胀混凝土配比设计、灌注压力、灌注施工工序选择、灌注注意事项以及工后检测评价5个方面出发,对钢管拱内混凝土灌注施工技术进行了全面分析。结果表明:采用水灰比0.37、微膨胀剂掺量为12%的C55微膨胀混凝土以"先上后下"的顺序匀速对称地灌注施工时,钢管和混凝土的应力和挠度均较小,对结构稳定性更有利,且灌注混凝土的平均密实度均大于96%,灌注效果良好。相关工程经验和分析理论可为类似特大桥钢管拱内混凝土灌注的设计和施工提供借鉴。Taking the ultra large bridge of Zhengwan railway spanning the main canal of South-to-North Water Diversion as an example, the concrete injection construction technology for steel pipe arch is analyzed comprehensively from five aspects: C55 micro-expansion concrete proportioning design, injection pressure, injection construction process selection, injection precautions and post-construction inspection and evaluation. The results show, when C55 micro-expansion concrete with water cement ratio of 0.37 and micro expansion agent content of 12% is used for symmetrical injection construction in the order of "top first, then bottom", the stress and deflection of steel pipe and concrete are smaller, which is more beneficial to the structural stability, and the average density of the injected concrete is greater than 96%, and the injection effect is good. The relevant engineering experience and analytical theory can provide reference for the design and construction of concrete injection in steel pipe arch of similar extra-large bridges.

关 键 词：钢管拱 C55微膨胀混凝土 灌注压力 灌注顺序 检测评价 

分 类 号：TU997[建筑科学—市政工程]