PC连续刚构桥长期下挠参数敏感性分析

Sensitivity Analysis of Long-term Deflection Parameters of PC Continuous Rigid Frame Bridge

随着交通强国建设的不断推进,PC连续刚构桥以其出色的跨越能力和耐久性,广泛用于多样化的桥梁建设中。然而,这种桥梁结构在长期使用过程中可能出现的下挠问题,对其稳定性和使用寿命产生了重大影响。基于全桥有限元仿真模型,分别选取了自重、徐变、预应力损失以及刚度折减四个主要参数,对其下挠表现的敏感性展开研究。结果表明:混凝土的超重增幅、初始加载龄期过短、成桥时间、预应力的损失以及刚度的折减均会对桥梁长期下挠产生不利影响,有针对性的采取相应措施可以有效避免长期下挠的持续发展。以便在设计、施工和运营中科学决策,为同类桥梁建设提供理论支持和技术指导。

With the continuous promotion of the construction of a transportation powerhouse,PC continuous rigid frame bridges are widely used in diversified bridge construction due to their excellent crossing ability and durability.However,the possible downward deflection issues that may occur during long-term use of this bridge structure have a significant impact on its stability and service life.Based on the finite element simulation model of the entire bridge,four main parameters,namely self weight,creep,prestress loss,and stiffness reduction,were selected to study the sensitivity of their downward deflection performance.The results indicate that the increase in overweight of concrete,short initial loading age,bridge completion time,loss of prestress,and reduction in stiffness can all have adverse effects on the long-term deflection of the bridge.Targeted measures can effectively avoid the sustained development of long-term deflection.In order to make scientific decisions in design,construction,and operation,and provide theoretical support and technical guidance for the construction of similar bridges.