The total length of Longhu inner ring road crossing North water conduit Bridge is 210m, the bridge is a cable-stayed bridge with single tower and double cable planes (95m+20m+95m), total bridge width is 53m, adopts two-way six-lane motor way, on both side set bicycle lane and sidewalk.
Main girder adopts double main girder structure plus overhanging beam system,all-steel structure,roof width is 53m,top surface set bi-directional 1.5% horizontal slope,within the scope of overhanging beam set reverse 1.5% horizontal slope,girder height in the center line of bridge is 3m.
A single main box girder width is 5.8m,overhanging beam box girder width is 9.9m,standard spacing of main girder diaphragm plate is 3.0m,between two main girder, main girder and overhanging beam there are steel beam connections,standard spacing just like diaphragm.
The bridge deck of motor way,bicycle lane and sidewalk adopt orthotropic steel deck,roof plate thickness is 16mm, the part of plate which close to tower increase to 20mm thick,motor way adopts U-shape stiffening rib,sidewalk and bicycle lane adopts I-shape rib,thickness of box girder bottom plate is 20-25mm,thickness of ventral plate is 14-30mm.
1.Three direction adjustment of main girder
2.Incremental launching for main bridge steel box girder
As showed in the picture,during the process of lowering steel box girder to the bed-jig, there will be displacement error between south and north, so there will be a correction before pulling the girder to incremental launching platform, put 4 pcs 3D jack on position B2 and B1, by adjustment on X,Y,Z direction to correct the position of steel box girder.
As showed in picture 1, put ILS cylinders on the extended foundation of A1,A2,A3, connect cylinders and hydraulic pump station with PLC system, to realize synchronization. During incremental launching process,monitoring the linearity all the time, in order to timely correction, and reach designed position. And, before incremental launching for main girder, also need to consider the position alignment of girder segment during assembly.