Key Construction Techniques for Whole-Hole Lifting and Erection of Long-Span Steel Girders of the Hong Kong-Zhuhai-Macao Bridge

The steel box girders for the non-navigable bridge sections in the Contract Section CB03 of the Hong Kong-Zhuhai-Macao Bridge's deep-water zone， along with those of the Yacheng 13-1 gas-field pipeline bridge， comprise a total of 68 spans. All of these were constructed using an integrated lifting scheme. Among these， 66 spans were individually lifted using a 4000 t floating crane. The other two spans， which are large segments of the Yacheng gas-field pipeline （with lengths of 152.6 m and 151.15 m， respectively）， were lifted using a combination of 4000 t and 2600 t floating cranes. To minimize the frequency of assembly and disassembly of the equipment， and to meet the lifting requirements for steel box girders of various specifications， a specially designed lifting rig was developed. This rig features a single-layer， straight-truss beam structure and is capable of lifting all types of non-navigable bridge girders. Prior to hoisting， computational analysis was performed on the box girder reinforcement at the pier-top adjustment locations and the bull leg adjustment points. During the actual lifting process， the maximum stress observed in the steel box girder was 231 MPa， resulting from localized stress concentration. This value remained below the allowable stress limit of 250 MPa. Internal reinforcements within the girder also satisfied the construction technical requirements. The positioning and adjustment of the steel box girder during hoisting were achieved using an initial alignment system， a pier-top adjustment system， and a corbel adjustment system. The achieved alignment accuracy reached 2 mm horizontally and 1 mm vertically， meeting the stringent installation precision requirements for the steel box girders of the Hong Kong-Zhuhai-Macao Bridge.