Construction Techniques for Right Line Bridge of the Second Xiangfan-Chongqing Railway Crossing Zhuxi River

The Right Line Bridge of the Second Xiangfan-Chongqing Railway Crossing Zhuxi River is a three-span prestressed concrete continuous rigid-frame bridge with span arrangement(72+128+72) m.The main girder of the Bridge is a single cell single box structure and the piers supporting the girder are the rectangular ones with variable cross sections.The piers rest on the foundations socketed in the ground,are built by the turnover formwork and the anti-cracking construction measures for the massive concrete of the piers are accordingly taken.The construction of the girder proceeds from segments No.0 that are cast on the pier-top brackets and the further more segments of the girder are cantiveredly cast in symmetry by the lightweight form travelers from both sides of the segments No.0 to finally form two T-frames.At the same time,the side spans are cast on the scaffoldings at the two abutments.The central span is closed first and the side spans are closed late to make the girder a complete continuous rigid-frame system.In the prestressing construction,the vacuum grouting technique is applied to grouting of the prestressing ducts and the geometric shape of the girder has also been monitored and controlled in the whole construction process.