On September 12, after the Hong Kong-Zhuhai-Macao Bridge, the second full-bridge prefabricated sea-crossing bridge in Fujian Province after the Hong Kong-Zhuhai-Macao Bridge - Xiamen No. ) The main bridge closed successfully.
Xiang'an Bridge is a key pilot project of the first demonstration project in Fujian, a country with strong traffic. It is the "one vertical" in the "six vertical and ten horizontal" planning expressway network in Fujian Province and an important part of Xiamen's "two rings and eight shoots" expressway network. Xiamen Bridge, Haicang Bridge, Jimei Bridge, Xinglin Bridge, Xiang'an Tunnel, and Haicang Tunnel are the seventh sea-crossing passages entering and leaving the island bridge and tunnel.
The Xiang'an Bridge project starts from the intersection of Fangzhong Road and Jinshang Road in the west, and crosses the sea on the east side of Xiamen with a continuous beam bridge in the east, and ends at Xiang'an Avenue, with a total length of about 12 kilometers, of which the cross-sea bridge is about 4.5 kilometers long. The cross-sea bridge is a single-width variable-height variable-section continuous girder bridge. The main line is constructed according to the standard of a two-way 8-lane expressway, with a design speed of 80 kilometers per hour and a designed service life of 100 years. The prefabricated assembly rate of bridge piers and steel box girders in the sea is 100%. There are 35 prefabricated piers and 36 steel box girders on the whole line, all of which are prefabricated and hoisted by prefabrication. Among them, the prefabricated piers and abutments adopt the vertical dry joint matching prefabrication method, which is the second in China after the Hong Kong-Zhuhai-Macao Bridge and the first in Fujian Province to be used in sea-crossing bridges.
CCCC Second Aviation Bureau undertakes the construction of the Xiang'an Bridge A2 section, with a line length of 3,300 meters. The main construction contents include the inter-connection project of Huandao East Road, the pile foundation, substructure and steel box girder transportation and hoisting of the cross-sea bridge. Among them, the sea bridge in the A2 bid section has a total length of 2190 meters, including 23 piers and abutments and 24 steel box girders, and the overall hoisting capacity exceeds two-thirds of the entire line.
In order to solve the hoisting problem of large-section steel box girder, CCCC Second Aviation Bureau independently developed and manufactured a special hoisting tool suitable for the hoisting of the entire large-section steel box girder of the variable-width curve. It weighs 560 tons and is used in the same type of domestic bridges Maximum spreader. The spreader adopts modular design, adding or reducing inserting sections on each beam, and horizontally opening and closing through 3 hydraulic cylinders and guiding devices, which can be freely retracted and suitable for various types of steel box beam section changes, shaped like an offshore "transformer". ". At the same time, some node components of the spreader adopt flexible connections, which can effectively shorten the hoisting time and reduce construction risks.
The steel box girder at the closing point of the main bridge is 72 meters long, 53 meters wide, 3.5 meters high, and weighs about 2,197 tons. It is the widest steel box girder section of the whole bridge. It has high safety risks and complex process connections, which is not conducive to the balance and safety of hoisting. , and accuracy are put forward higher requirements.
Before closing, the project team carried out the optimization and transformation of the spreader based on the special structure of the steel box girder in the closing section, and added adjustment blocks to balance the stress state of the steel box girder; organized the desktop deduction of the hoisting of the steel box girder in advance, closely tracked the transportation dynamics of the steel box girder, and deployed the transport beam. Ships and cranes are anchored and positioned, and more than 10 large-scale equipment such as a 4,000-ton floating crane and a 10,000-ton steel box girder transport barge can be operated in an orderly manner in the same sea area; at the same time, the operation "window" is accurately selected according to the tidal characteristics of the sea area. period”, which provided the necessary conditions for the precise hoisting of the steel box girder.
After the steel box girder of the Helong section is located on the top of the pier, the project adopts a three-way hydraulic jack, and integrates the position adjustment data in the information platform through the intelligent sensor and the position adjustment control system, and finally realizes the millimeter-level error closing.
The closing of the Xiang'an Bridge has achieved the completion of all bridges in the Haizhong District of the bridge, and further promoted the opening of the entire line to traffic. After the completion of the Xiang'an Bridge, it will further improve the road network of the Haixi Economic Zone and the urban road network of Xiamen, narrow the gap between inside and outside the island, promote the integrated development of the regional economy on the west coast of the Taiwan Strait, and accelerate the construction of the "Belt and Road" national logistics new channel and It is of great significance to be an international comprehensive transportation hub city.
