预应力混凝土曲线连续梁桥施工及使用过程时效仿真分析

根据BP-2理论,考虑混凝土的收缩徐变、预应力及其损失等因素的影响,采用按龄期调整的有效弹性模量法和有限单元步进法,编制预应力混凝土曲线连续梁桥的时效仿真分析软件,计算结构在整个施工过程及投入使用后任意时刻任意位置的内力和变形,实现对预应力混凝土曲线连续梁桥施工过程进行实时控制的目的。应用该仿真分析软件对1座3跨曲线连续梁桥的分析表明,混凝土的收缩徐变和预应力对桥梁结构的内力和变形均有较大的影响,而且某些截面的控制内力往往发生在施工过程中而非成桥后。因此对于分阶段施工的预应力混凝土曲线连续梁桥,应该结合实际的施工过程进行相应阶段的内力计算,以确保各个施工阶段的内力值在安全范围内。

Time-Dependent Emulation Analysis on Prestressed Curved Continuous Concrete Bridges during Construction and Open to Traffic

According to the BP-2 theory,taking into account many influencing factors such as shrinkage and creep of concrete,the prestressing force and its loss of reinforcement,using the age-adjusted effective modulus method and step by step finite element method,a time-dependent emulation program of follow-up analysis of the curved bridges has been compiled.With it the internal forces and deformations of the curved continuous bridge at any position and at any period of time during the whole construction course can be analyzed,the whole sequences time-dependent emulation analysis and the control of the engineering construction can be carried out.Through analyzing a three spans prestressed concrete curved bridge with this program shows that the shrinkage and creep of concrete and the prestressing force both have great influence on the internal force and deformation of the bridge structure.Moreover,the control internal forces of some position are produced during the construction course sometimes.For the prestressed curved continuous concrete bridges constructed in stages,the actual construction course should be taken into account to ensure the internal forces at each building course are all in the safe ranges.