Construction techniques for long span roadway steel box girders of rail-cum-road section of Tongling Changjiang River Bridge

The three-span continuous steel box girders arranged in (47.35+80+47.35) m of the roadway approach bridge of the rail-cum-road section of Tongling Changjiang River Bridge on Hefei-Fuzhou Railway are located over the railway decks and are separated into two parts of the girders of the upstream and downstream sides. A part of the girders is the single-cell single-box structure. The width of the top plate of the structure is 16.5 m, the spacing between the webs is 8.5 m and the width of the cantilever of the top plate on each side is 4 m. The height of the steel box girders from the ground is about 52 m and the construction of the girders is therefore a kind of the work done very high above the ground. In the construction of the girders, the assembling platform and movable scaffoldings were arranged on the upstream side railway deck. The girders were manufactured in blocks in the workshop, transported to the construction site by water, unloaded at the wharf at the site and again transported on land to the pier sites. The blocks of the girders were lifted onto the assembling platform by the fixed deck crane at the pier site where they were assembled into the incomplete girders and the girders were longitudinally shifted on the slipway and connected with the previously installed girders. The patr of the girders on the downstream side was later on integrally and transversely shifted in place, lowered down onto the bearings and thus far, the construction of the girders was completed. The working procedures of the whole construction process of the steel box girders of the roadway approach bridge are simple and the safety of the construction is controllable.