池州长江公路大桥施工控制关键技术

Key Construction Control Technology of Chizhou Changjiang River Bridge

池州长江公路大桥为主跨828 m的双塔双索面混合梁斜拉桥,采用将斜拉索分组集聚式锚固于塔间钢横梁上的新型锚固形式。钢箱梁施工采用悬臂拼装法,边跨预应力混凝土箱梁施工采用支架现浇法。针对大桥集聚式锚固和主梁不对称施工两个特点,应用几何控制法进行施工控制,采取了塔柱偏位和预抬量控制、塔柱应力控制、钢横梁预抬量控制、主梁制造线形及安装线形控制、斜拉索下料长度控制等诸多关键控制技术。成桥后对索塔偏位及应力、主梁线形、斜拉索索力进行了实测,并与理论值进行对比分析,结果表明:结构线形、应力、索力的实测值与理论值较吻合,均满足规范要求;大桥总体控制效果良好。

The Chizhou Changjiang River Bridge is a double-pylon double-plane composite beam cable-stayed bridge with a main span of 828 m. A new anchoring form of stayed cables anchored on the steel beam between the pylons in cluster type by groups is adopted. The steel box girders are constructed by the cantilever assembling method while the prestressed concrete box girders of side span are constructed by the support cast-in-place method. Aiming at two characteristics of the cluster-type anchoring and asymmetrical construction of the main girder, the geometrical control method is used to control the bridge construction. Many key control technologies of pylon offset and pre-lift control, pylon stress control, steel beam pre-lift control, main girder fabricating alignment and installing alignment control, and stayed cable fabrication length control are adopted. After the completion of the bridge, the pylon offset and stress, the main girder alignment and the stayed cable force are measured and compared with the theoretical values. The results show that the measured values of structure alignment, stress and cable force are in good agreement with the theoretical values, which all meet the specification requirements. The overall control effect of the bridge is good.