港珠澳大桥超大断面隧道混凝土裂缝控制技术

港珠澳大桥岛隧工程超大断面隧道混凝土包括预制沉管混凝土和人工岛现浇隧道混凝土,具有强度高、结构尺寸大、服役环境恶劣、控裂要求高且难度大等特点。其中预制沉管采用工厂法预制,全断面浇筑,采取片冰和制冷水拌合混凝土、喷雾养护等温控措施;人工岛隧道混凝土现场浇筑,采取合理分段分层、冷却水管、补偿收缩混凝土等温控措施。从施工现场情况来看,均未出现有害温度裂缝,温控效果良好,达到了预期的温控目标。

Crack control technology for concrete of super-large section tube of Hong Kong-Zhuhai-Macao bridge

As the high concrete strength,large size andsevere service environment for super-large section tunnel which includes the precast immersed tube and the cast-in-suit tunnel in the artificial island of Hong Kong-Zhuhai-Macao bridge,crack control of concrete is difficult.Harmful cracks can be controlled effectively by a series of treatment measures during the construction period such as precasting in the factory,one-piece casting,controlling concrete raw material temperature,mixing concrete with ice shavings and cooling water,setting up automatic curing system for the precast immersed tube and reasonable layered and segmented,water pipe cooling,compensating contraction concrete for the cast-in-situ tunnel.Moreover,the harmful crack does not appear in both the precast immersed tube and the cast-in-situ tunnel appear and the prospective objective of temperature control is achieved.