公铁合建段公路大跨度钢箱梁施工技术

Construction Techniques for Long Span Roadway Steel Box Girders of Rail-cum-Road Section of Tongling Changjiang River Bridge

合福铁路铜陵长江大桥公铁合建段公路引桥(47.35+80+47.35)m三跨连续钢箱梁位于铁路桥面以上,分上、下游2幅,单幅采用单箱单室结构,顶板宽16.5m,腹板间距8.5m,两侧挑臂宽各4m。钢箱梁离地面高度约52m,为超高空作业。在上游幅铁路梁面上设置拼装平台和滑移支架,钢箱梁在工厂分块制造,经水路运输、工地码头上岸和陆上运输至墩位,再通过墩位固定式架梁吊机起吊梁块至拼装平台上组拼成节段梁,经滑道纵移与前一梁段对接,下游幅钢箱梁经整体横移就位,将钢箱梁落于支座上,完成钢箱梁施工。该桥钢箱梁整个施工过程工序简便、安全可控。

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, un- loaded 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 down- stream side was later on integrally and transversely shifted in place, lowered down onto the bear- ings 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.