连续刚构桥施工监控计算要点分析

Calculation Points for Construction Monitoring of Continuous Rigid Frame Bridge

连续刚构桥一般采用挂篮悬臂施工,在施工阶段随着节段的增加和挂篮的移动,各截面的内力和位移不断变化。在施工期间布置位移、应力、温度测点,监控桥梁状态,设置合理的预拱度确保使用期间的性能。以某预应力混凝土连续刚桥为实例,建立有限元模型,综合考虑挂篮、收缩徐变、预应力张拉、温度变化等多种因素的作用,对该桥在施工阶段的内力位、移作了分析,计算得到了桥梁施工阶段立模标高及成桥预拱度,通过和施工监控测试数据做比较分析,指导施工顺利实施。

Basket cantilever construction is commonly used in the construction of continuous rigid frame bridge. The internal forces and displacements of each section are constantly changing with segment increasing and basket shifting. During the construction measurement points for displacement, stress, and temperature are applied to monitor the state of the bridge, meanwhile a reasonable camber is required to ensure performance during service. A prestressed concrete continuous rigid bridge is taken as an example, so the finite element model is applied to analyze the internal forces and deflection, considering the basket, shrinkage, creep, prestress, temperature and other factors. The bridge elevation in construction phase and camber during service is got. The comparative analysis of monitoring and test data is helpful to successful implementation and construction.