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为优化无背索曲塔曲梁斜拉桥施工顺序,对桥梁施工进行全过程模拟,确保桥梁在施工过程中的安全及正常使用状态下受力合理,以无背索曲塔曲梁斜拉桥——东莞水道桥为工程背景,采用MIDAS/CIVIL空间有限元分析软件,分析在钢主梁悬臂施工前拆除支架,同时,钢主梁节段与对应主塔节段同步悬臂施工的情况下,对施工工期、造价、主塔应力及变形、主梁的应力及变形、拉索初拉力的影响。结果表明:(1)优化施工顺序后,结构传力更明确,能有效缩短工期,节省工程投资。(2)优化前后主塔应力分布规律一致,应力影响小;优化后内、外弧侧主塔位移不对称性明显,对主塔x方向位移影响较大。(3)优化后对钢主梁受力有所改善,对混凝土主梁受力影响小;主梁z方向位移影响较大,发生在主跨3/4跨径处,需要调整施工预拱度。(4)优化施工顺序后,2#~5#拉索初拉力均有所增大,拉索安全系数均满足设计规范要求。
In order to optimize the construction sequence of the cable-stayed bridge without back-bending curved-beam girder, the whole process of bridge construction is simulated to ensure that the bridge is under the normal conditions of safety and normal operation. Bridge - Dongguan waterway bridge as engineering background, the use of MIDAS / CIVIL space finite element analysis software, analysis of steel girder before the cantilever construction demolition of the stent, while the main girder section and the corresponding pylon segment cantilever construction , On the construction period, cost, stress and deformation of the main tower, the main beam of the stress and deformation, the impact of cable tension. The results show that: (1) After optimization of the construction sequence, the structure transmission force is more clear, which can effectively shorten the construction period and save the project investment. (2) The stress distribution of the main tower before and after the optimization is consistent and the influence of stress is small. The asymmetry of the displacement of the main tower inside and outside the arc is obvious after the optimization, which has a great influence on the displacement of the main tower in the x direction. (3) After optimization, the stress on the steel main girder is improved, and the influence on the stress of the concrete main girder is small. The displacement of the main girder in the z direction is greatly affected, which occurs at the span of 3/4 of the main span. (4) After the construction sequence is optimized, the initial tensile force of 2 # ~ 5 # cable increases, and the safety factor of the cable meets the design specifications.