来源：本站 时间：2019-03-27 11:09:03 浏览次数： 208
The hong kong-zhuhai-macao bridge undersea tunnel is composed of 33 immersed pipe joints and one final joint. Using floating crane hoisting in place, will eventually joint embedded hydraulic jack system startup, pusher trabecular structure to the ontology of direction, away from the final joint drive M water-stop tensioning, moved to a certain distance, pusher trabecular end of Gina water stop arrived in neighboring union steel cap, Gina water stop after compaction, namely realize union internal and external isolation, finally, the internal drainage pipe joint, forming a space of welds, the welding of steel joint is conducted in the space. The steel joint is composed of inner ring connection steel plate, outer ring connection steel plate, small stiffening and diaphragm system. On the tunnel cross section, the diaphragm is arranged at a distance of one gear. The connecting steel plates are made in pieces in the factory and shipped to the tunnel installation site. After the completion of the welding of the steel joint, the permanent closed interior is formed and filled with high fluidity concrete to complete the connection of the tunnel and realize the final penetration. There are a lot of overhead welding operations in the welding of connecting steel plates, and the working space is limited. There are no referential experiences at home and abroad, and the difficulties are as follows:
(1) poor construction environment and limited welding space. The welding of the steel joint is carried out under Gina's temporary water stop state, and combined with the damp internal environment of the cavity without natural ventilation conditions, the final working space between the joint and the steel cap is only 1 meter apart.
(2) the workload of steel joint welding is large, and the welding quality is required to be high. The butt welding must be fully penetration welding, and 100% pass UT/MT inspection.
(3) the steel joint welding cycle must be as short as possible. Before the completion of the welding of the steel joint, it is too risky to isolate sea water in the joint cavity only by pushing GINA water stop on the top of the oil cylinder. Therefore, it is an effective guarantee to complete the welding work of connecting steel plate with the steel joint in the cavity as soon as possible.
(4) it takes a lot of work to transport components into the bonding cavity, with high labor intensity and safety risk.
We from the following aspects of the steel joint joint steel plate to make adjustments, effectively reduce the steel joint joint steel plate site welding difficulty.
(1) optimize the division of steel joint connecting steel plate, reduce the length of on-site welding, and effectively reduce the difficulty of on-site welding.
(2) hang the connecting steel plates of some steel joints to the structure of the final joint (in the factory), so as to reduce the carrying amount of the connecting steel plates on the construction site, greatly reduce the labor intensity and reduce the safety risk.
(3) local improvements are made to the steel joint structure to enhance the stability and safety of the whole structure during the welding process of the steel joint joint plate.