武汉二七长江大桥主桥结合梁施工技术

武汉二七长江大桥主桥为(90+160+2×616+160+90)m三塔双索面结合梁斜拉桥,其2～6号墩主梁为钢-混结合梁,采用预制拼装施工。4号(中塔)墩墩顶节间梁段采用无托架技术施工,3号、4号墩两侧梁段采用架梁吊机双悬臂对称架设法施工;5号墩上塔柱施工时采取塔梁同步施工技术,5号墩至4号墩跨中部位梁段采用单悬臂架设法施工;5号、6号墩间梁段采用钢管支架法施工。钢梁采用主动合龙技术,先合龙武昌侧梁段,再合龙汉口侧梁段。

Construction Techniques for Composite Girder of Main Bridge of Wuhan Erqi Changjiang River Bridge

The main bridge of Wuhan Erqi Changjiang River Bridge is a steel and concrete composite girder cable-stayed bridge with three pylons,double cable planes and with span arrangement(90+160+2×616+160+90) m.The main girder on Piers No.2～6 of the bridge is the composite girder that was constructed by prefabricating and assembling.The girder segments atop Pier No.4(pier of the intermediate pylon) were erected by the technique of not utilizing brackets and the segments on the both sides of Piers No.3 and No.4 were erected by the girder erection cranes by the free balanced two-side cantilever method.At the time the upper pylon columns on Pier No.5 were constructed,the technique of concurrent construction of the pylon and girder was applied.The segments at the midspan from Pier No.5 to Pier No.4 were erected by the one-side cantilever method and the segments in between Piers No.5 and No.6 were erected on the steel pipe supports.The part of the steel girder was closed by the active closure technique in the sequence of the girder section on Wuchang side first and the girder section on Hankou side late.