悬臂浇筑连续梁墩旁临时固结计算分析研究

Calculation, Analysis and Study on Temporary Consolidation near Cast-in-Cantilever Continuous Beam Piers

摘要:

墩梁临时固结是保障连续梁悬臂浇筑施工安全的重要措施，结合实际工程中墩旁临时固结的设计，采用三种计算方法，分析计算结果的差异，提出悬臂浇筑连续梁墩旁临时固结的合理计算方法。结果表明：不考虑主墩作用的双链杆模型的计算结果与临时支墩实际受力状态差别较大；考虑主墩作用的三链杆模型虽然比双链杆模型接近实际受力状态，但忽略了零号梁段刚度的影响及节段施工过程中张拉预应力和主梁混凝土收缩徐变导致的主墩与临时支墩之间内力重分配的影响，其计算结果与临时支墩实际内力仍有30%左右的误差；而有限元正装模型能够准确地计算出临时支墩的受力状态。因此采用有限元正装模型计算的结果进行临时支墩的设计，可确保结构安全，降低工程造价。

Abstract:

Temporary consolidation of pier beam is an important measure to ensure the safety of cast-in-cantilever construction of continuous beam. Combined with the design of temporary consolidation near piers in practical engineering, three calculation methods are used to analyze the difference of calculation results, and a reasonable calculation method of temporary consolidation near the cast-in-cantilever continuous beam piers is proposed. The results show that the calculation results of the double-chain rod model without considering the action of the main pier are quite different from the actual stress state of the temporary pier. And the three-link rod model considering the action of the main pier is closer to the actual stress state than the double-link rod model, but it ignores the influence of the stiffness of 0# beam segment and the influence of the internal force redistribution between the main pier and the temporary pier caused by the tension prestress and the shrinkage creep of the main beam concrete during the construction of the segments. The error between the calculated result and the actual internal force of the temporary pier is still about 30 %. The finite element forward model can accurately calculate the stress state of the temporary piers. Therefore, the temporary piers are designed with the calculation result of the finite element forward model, which can ensure the structural safety and reduce the engineering cost.