某高墩大跨连续刚构桥主墩优化设计研究

Research on Optimization Design of Main Pier of a High-pier Long-span Continuous Rigid Frame Bridge

摘要:

选择合理的桥墩型式是降低高墩大跨连续刚构桥造价的有效措施。以瓦厂特大桥的设计为背景，将原设计主墩采用的组合墩墩型，优化成单肢空心薄壁墩，通过建立各墩型的空间有限元模型，进行对比分析。结果表明：两种主墩墩型的梁部应力水平相当；单肢空心墩稳定性优于组合墩；在最大双悬臂施工状态下，采用单肢空心薄壁墩强度安全系数较组合墩小，但成桥后安全系数相当；采用单肢空心薄壁墩经济性优于组合墩，能大幅节省造价，在施工质量与工期方面具有明显的优势。研究结果可为今后山区同类的桥梁提供一定的借鉴和参考意义。

Abstract:

The selection of reasonable pier type is an effective measure to reduce the cost of high-pier long-span continuous rigid frame bridges. Taking the design of the Wachang Grand Bridge as the background, the composite pier type used in the original design of the main pier will be optimized into a single-limb hollow thin-walled pier. By establishing a spatial finite element model, the comparison and analysis are carried out. The result shows that the stress levels of the beams of the two main pier types are equivalent. The stability of single-limb hollow piers is better than that of composite piers. In the maximum double-cantilever construction state, the strength safety factor of using the single-limb hollow thin-walled piers is smaller than that of composite piers, but the safety factor is equivalent after completion of the bridge. The economy of using single-limb hollow thin-walled piers is better than that of composite piers, which can greatly save the costs and have the obvious advantages in construction quality and duration. The research results can provide certain reference and significance for similar bridges in mountainous areas in the future.