Construction Technique for Central Span and Side Span Closure of Steel Box Girder Cable-Stayed Bridge of Xiamen-Zhangzhou Sea-Crossing Bridge

The construction technique for closure of the central span and side spans of steel box girder cable-stayed bridge was introduced,against the background of the main bridge of the north bridge of Xiamen-Zhangzhou Sea-Crossing Bridge,which is a five-span continuous steel box girder cable-stayed bridge of half-floating system with a main span of 780 m,and with span arrangement of(95+230+780+230+95) m.The bridge accommodates six traffic lanes and the full width of the box girder is 38 m.In the closure construction of the girder sections over the auxiliary pier and the transitional pier in the side spans,the closure method of cantilever assembling construction was adopted,which made it possible to reduce the difficulty of the closure.During the closure of the central span,the match-cutting closure method with incremental launching assisting measures was used,considering the effects of temperature and incremental launching force.In the construction process of the whole bridge,the unstressed state control method was adopted to do construction monitoring and control.