Two-Way Cantilever Construction Control Techniques for Steel Box Girders of a Cable-Stayed Bridge Accommodating Road and Rail Traffic on Same Deck
The main bridge of Lingang Changjiang River Bridge in Yibin is a two-pylon steel box girder cable-stayed bridge accommodating the road and rail traffic on the same deck.The bridge has a main span of 522 m,two side spans of 203 m and two end spans of 72.5 m,and the stay cables are fanned out in double cable planes.The steel box girders on the two sides of the north pylon(pylon No.3)were erected by a balanced cantilever method,the steel box girders in the side span besides the south pylon(pylon No.4)were erected by the incremental launching method,and the steel box girders in the central span were erected by the one-way cantilever method.Following the control principles of the stress-free-state method,the finite element model of the main bridge was established in SCDS software for construction control calculation.During the balanced cantilever assembly of the steel box girder,the derrick cranes in the side and central spans worked in parallel in hoisting and adjusting the spatial locations of girder segments.The relative elevations of two adjacent segments were controlled for precise matching.The stay cable forces were controlled via the stress-free-length tensioning.The cantilever tips in the central span were temporarily counterweighted to facilitate the maneuver of the steel box girder segments on the top of auxiliary piers and resting on the top of transition piers via jacking.The construction control techniques ensured the success of the two-way cantilever assembly of the steel box girder segments and two times of jacking the steel box girders onto the top of piers.The configuration of the temporary vertical prestressing tendons in the pylons and main girders is effective,the loads on the bridge structure and pylon displacement did not surpass the limits,and the structural alignment and stay cable force errors reached the required levels.
cable-stayed bridgesteel box girderbalanced cantilever assemblystress-free-state methodcable length tensioningmaneuver across auxiliary pierjacking onto transition pierconstruction control
NETL
NSTL
万方数据
维普
