大尺度现浇暗埋段隧道裂缝控制关键技术

摘要

The maximum height of 11.4 m, the maximum width of 72.2 m of cast-in-situ buried tunnel main structure of east artificial island of Hongkong-Zhuhai-Macao Bridge, which is the largest structure section size of pipe gallery box of mass concrete structure for the domestic and foreign similar engineering, and restricted by sea island operation, to section and pouring step by step. According to the project research, theoretical calculation analysis and finite element simulation analysis, we researched on the crack control technology of cast-in-situ buried tunnel, put forward some key technologies for crack control, such as moving the construction joint to the top of the side wall, making the floor and side wall as a whole for one-time pouring, and controlling the section length, shortening the step-by-step pouring time interval, and temperature control of mass concrete, which can solved the key parts' cracking problems of side wall and floor in the cast-in-situ buried tunnel.%港珠澳大桥东人工岛现浇暗埋段隧道主体结构最大高度为11.4 m，最大宽度为72.2 m，为国内外同类工程中结构断面尺寸最大的管廊箱型大体积混凝土结构，受外海孤岛作业限制，需分段分步浇筑。通过工程调研、理论计算分析和有限元仿真计算分析对现浇暗埋段隧道的裂缝控制展开研究，提出将施工缝移至侧墙上部，底板和侧墙作为整体一次性浇筑，以及控制分段长度、缩短分步浇筑间隔时间及大体积混凝土温控等裂缝控制关键技术，解决了现浇暗埋段隧道关键部位侧墙和底板的裂缝问题。