Pan Wei, Deputy general manager and chief engineer of 1st Bureau of Navigation, Deputy chief engineer of Bureau and head of Department of Science and Technology, representatives of Dalian Bay Undersea Tunnel Project Company, No.2 Company, Dalian Quality Safety Center, Dalian Maritime Safety Administration, design, supervision, Dalian Marine Environment Monitoring Center of State Oceanic Administration and other units participated in the whole process.
E15 pipe section is the first full-curve pipe section in the whole line. The immersed pipe axis is 148 meters long, 33.4 meters wide, 9.7 meters high, and weighs about 47,000 tons. The slope of pipe section reaches 0.65%, which is the largest in the curve section. Different from that of straight pipe joint, the parallel arrangement of gravel ridges is changed to parallel dislocation arrangement, which requires higher requirements for technicians and more stringent leveling conditions. Before the installation, the project team continued to optimize the leveling process and used the leveling ship automatic positioning and leveling system throughout the whole process, effectively guaranteeing the accuracy of the leveling operation and laying a solid foundation for the installation of E15 pipe joints.
Faced with such technical problems as large channel width occupied by curvy sections, asymmetric tugboat station position, and difficult coordination of ship pipe attitude control, the project team strictly regulated cable operation requirements, optimized installation and sinking steps, adjusted docking distance, strictly calculated the process of pipe sinking preparation for ballast, and controlled pipe attitude, thus creating conditions for accurate docking.
The installation of the floating transport was officially started at 6:00 AM. After the completion of tugboat formation, floating transport, mooring, sinking, drawing, hydraulic compression and other procedures, the docking with E14 pipe section was successfully completed at 19:26 on the same day, which took about 13.5 hours. The measurement and control system shows that the installation accuracy of E15 pipe section meets the design requirements.
After the E15 pipe section is installed, the construction of the submarine immersed pipe section of Dalian Bay Undersea Tunnel and Guangming Road Extension project will be accelerated. The project team will make every effort to promote the installation of the remaining three pipe sections and the final joint, so as to welcome the 20th Party Congress with outstanding achievements.
