On January 6, with the completion of the pouring of the last section of roof concrete, the tunnel in the weir section of the main line of the East artificial island of the deep middle channel was officially capped, marking a key step in the construction of the tunnel in the weir section of the main line of the project. Shenzhen China channel is a world-class cross sea cluster project integrating "bridge, island, tunnel and underwater interconnection", which adopts the scheme of East Tunnel and West Bridge. Among them, the weir section tunnel of the main line of dongrengong island is the transition intersection point between the underwater interchange and the project immersed tunnel in the island, with a total length of 480m. The construction area is located in the sea land interactive sedimentary stratum, with complex geological and hydrological conditions. It is greatly affected by the 35m aviation height limit of Shenzhen Bao'an airport, high construction technical requirements and great difficulty in on-site construction organization, The safety risk of cross operation and underwater operation is high. The main structure of the weir construction section of the main line of the East artificial island of the deep middle channel is divided into 26 structural sections. A total of 270000 cubic meters of concrete needs to be poured, and the maximum single concrete pouring volume is nearly 4000 cubic meters. It needs to be poured and formed at one time. It has the characteristics of a wide variety of reinforcement, large weight of single reinforcement, difficult erection of rigid skeleton, and high requirements for crack control of high-performance marine concrete. In order to ensure safe and efficient construction, the project technical team uses the existing open space to organize operators and technicians to carry out the construction of equal scale full-scale model test block, timely summarize, optimize and adjust, and stabilize the relevant parameters of main structure construction, Construction standardization systems such as the construction guidance album of main structure and the special construction scheme for cast-in-situ tunnel mass concrete in weir construction section have been prepared successively to continuously improve the construction management level of the project. At the same time, the project scientifically plans the construction organization, reasonably plans the human, machine, material and other resources, forms a high-intensity and efficient flow operation production, and sets up a full-time safety officer to monitor the whole process, so as to realize closed-loop management. After 520 days, the main structure of the weir construction section of the main line of the East artificial island of the Shenzhen middle channel was poured and capped. At present, the tunnel construction on the East artificial island of the project has been fully launched. The follow-up project department will continue to adhere to the high-quality construction concept of weir construction section and spare no effort to promote the tunnel construction on the island. (Xinhua News Agency)