PC斜拉式桁架梁桥敏感参数分析

为了准确地把握PC斜拉桥在各施工阶段及营运阶段内力及线形变化情况,以某PC斜拉式桁架梁桥为例,借助大型有限元计算程序,建立了三维空间有限元模型。运用仿真分析方法,对该结构受力特性进行了相应的研究,得出混凝土收缩徐变、温度变化、非线性等敏感参数对该桥内力及线形的影响规律。结果表明:混凝土收缩徐变、非线性及刚度误差对结构内力影响较小,对结构挠度的影响较大,挠度变化值自中跨跨中向两侧呈线性递减趋势;温度与自重误差对结构的内力及线形影响相对较小,挠度变化值自跨中对称向两侧呈抛物线变化,而轴力变化值在全桥范围内分布较为均匀。

Sensitivity Parameters Analysis of PC Oblique-pulling Truss Bridge

In order to accurately grasp variation situations of inner force and deflection for PC cable-stayed bridge during construction and running stage and study the mechanical characteristics of this type bridge,a PC oblique-pulling truss bridge was taken as the studying case.A three-dimensional space finite element model was built with the large-scale finite element calculation program.The related researches were carried on the structure by computer simulation analysis method.The influence rules and levels of the bridge static characteristics were obtained,which were affected by the sensitivity parameters,such as shrinkage and creep of concrete,changing of the temperature,nonlinearity and so on.The results indicate that shrinkage and creep of concrete,nonlinear and rigidity deviation have a less affection on inner force of bridge,while they have a greater affection on deflection of structure,and changes of deflection value linearity decrease from middle span to two side spans.But temperature and self-weights deviation have a smaller affection on deflection and inner force than the other sensitivity parameters and changes of deflection of them are taken as parabolic distribution from middle span to two side spans,while changes of inner force don't have much variation on the whole bridge.