(1) The construction environment is bad and the welding space is limited. The welding of the steel joint is carried out under the temporary water stop condition of Gina, and combined with the humid environment inside the chamber, without natural ventilation conditions, the net working space between the joint and the steel cap is o只有1米。
(2) The workload of the weld of the steel joint is large and the quality of the weld is high. The butt weld must be fully penetrated and 100% of the weld must pass UT/MT flaw detection.
(3) The construction period of steel joint welding must be as short as possible. The risk is too high because only GINA water stop is pushed by cylinder to isolate seawater before welding of steel joint is completed. Therefore, it is an effective guarantee for the safe penetration of immersed pipe engineering to complete the welding of steel joint and steel plate in the joint cavity as soon as possible.
(4) The workload of transporting components to the combined chamber is large, the labor intensity is high and the safety risk is high. We adjust the steel joint connection plate from the following aspects to effectively reduce the difficulty of on-site welding of the steel joint connection plate.
(1) Optimize the division of steel joint connection plates, reduce the length of field welding, and effectively reduce the difficulty of field welding.
(2) Hanging part of the connecting steel plate of the steel joint to the structure of the final joint (in the factory) can reduce the carrying capacity of the connecting steel plate on the construction site, greatly reduce the labor intensity and reduce the safety risk.
(3) Improve the structure of steel joint to enhance the stability and safety of the whole structure during the welding process.