悬索桥扁平钢箱梁顶推施工受力分析

某3跨地锚式悬索桥加劲梁为扁平钢箱梁,钢箱梁跨径组成为(40+430+40)m,采用多点临时墩顶推施工。为了确保钢箱梁在顶推施工过程中结构安全,建立有限元计算模型对顶推施工过程进行整体和局部受力分析。计算结果表明临时墩支点高程设置形式、滑道支承形式和横向偏位等对钢箱梁受力影响较大。根据计算结果提出了钢箱梁顶推施工过程线形控制、临时墩反力控制及局部应力施工控制等参数以及相应控制措施。实际顶推施工结果表明钢箱梁受力及线形控制较好。

Analysis of Force Conditions of Flat Steel Box Girder of a Suspension Bridge in Incremental Launching Erection

The stiffening girder of a 3-span ground anchored suspension bridge is the flat steel box girder with span arrangement(40+430+40) m and was constructed by the multi-point incremental launching erection by the aid of temporary piers.To ensure the structural safety of the girder in the process of the incremental launching erection,the finite element calculation models were established to analyze the global and local force conditions of the girder.The results of the calculation and analysis showed that the elevation setting of the temporary piers and the bearing ways and transverse offsetting of the slipway had considerable influence on the force conditions of the girder.In accordance with the calculation,the corresponding parameters and measures for control of the geometric shape of the girder,reaction forces of the temporary piers and local stress in the erection were put forward and in the actual erection,the control of the force conditions and geometric shape was quite good.