Study On Design And Construction Technology Of Precast Immersed Tube Concrete For Tunnel Project Of Hong Kong-Zhuhai-Macao Bridge

Acrossing the Lingdingyang sea,Hong kong-Zhuhai-Macao(HZM)bridge across the sea cluster project consists of immersed tunnel,artificial island and bridge,construction scale and complex structure,difficult corrosion harsh environment.Immersed tube tunnel which is immersed tube tunnel worldwide yijianhuzaijian in total length,the buried depth of the deepest,most wide,single span single flexible pipe section of the longest and largest sea highway engineering total immersed tunnel,but also the history of the submarine pipeline transportation construction the most technically complicated tunnel in China,the highest standards of super engineering.Therefore,on the basis of HZM brige island tunnel project,the first detailed survey to collect the HZM brige island tunnel project overall project location,natural climate condition,immersed precast plant general layout and distribution analysis as far the construction difficulties and characteristics of the world's largest offshore construction engineering sinking Island tunnel project;Then,in view of the large volume concrete prefabricated immersed tube,large section,large label,the characteristics of bad environment,put forward the principle of selection of concrete raw materials and optimize the selection of raw materials,set mix design requirements and principles to carry out small-scale model tests and full-scale model test to optimize the initial mix ratio of the immersed tube construction properties,mechanical properties and durability,determined the construction of three seasonal immersed precast concrete mix;Again,the construction method and process of the factory prefabricated immersed tube prefabricated water production line,and calculate the factory prefabricated immersed tube prefabricated structure size,grasp the concrete construction technology in production,transportation(immersed tube prefabricated full section partition pouring and vibrating,wall connection construction,special parts of the vibration plate pound);After that,the maintenance method and precautions of the precast immersed tube concrete were put forward,and the different curing systems were designed according to the maintenance place and the maintenance time;Finally,in order to strictly control the immersed precast concrete cracking,is proposed based on finite element simulation analysis of concrete crack control technology of prefabricated immersed tube,and the calculation results are given concrete construction standards and requirements of stage temperature control according to the simulation,and put forward the comprehensive coverage of the whole process of prefabricated link,visual monitoring and warning system in order to better implement the immersed precast site monitoring.The design of prefabricated immersed tube concrete for the island tunnel project of Hong Kong Zhuhai Macao Bridge and the construction of the core technical system of the concrete construction technology are studied in this paper,which will provide some experience and reference for similar Island tunnel projects in the future.