填充长度对部分填充混凝土钢桁梁桥力学性能的影响分析

Analysis of Influence of Concrete-filled Length on Mechanical Property of Partially Concrete-filled Steel Truss Girder Bridge

部分填充混凝土钢桁梁桥作为一种新型桥梁结构形式,在大跨度组合钢桁梁桥中得到了实际应用。以天津某部分填充混凝土钢桁梁桥为研究对象,利用大型有限元软件ANSYS建立其有限元模型,定义填充长度与中跨跨度之比为混凝土填充系数,系统讨论了填充系数对钢桁梁桥位移、应力和动力特性等力学性能的影响。结果表明,部分填充混凝土能减小钢桁梁桥的竖向位移,减小钢桁梁桥下弦杆的应力,增加钢桁梁桥的刚度,提高其承载力;填充系数对桥梁位移、应力和动力特性的影响不尽相同,设计时应综合考虑选择填充长度。

As a new form of bridge structure,partially concrete-filled steel truss structure is used in composite large span steel truss girder bridge.In this paper,taking the partially concrete-filled steel truss girder bridge across Haihe river in Tianjin for instance,the large finite element software ANSYS is used to establish the model of steel truss girder bridge.The concrete-filled coefficient is defined as the ratio of concrete-filled length to mid-span length.The influence of concrete-filled coefficient on the displacement,stress and dynamic characteristics of steel truss bridge are systematically analyzed.The results show that partially filled concrete can reduce the vertical displacement of steel truss bridge and the stress of bottom chord,and increase the stiffness and carrying capacity of the steel truss girders.The influences of concrete-filled coefficient on the displacement,stress and dynamic characteristics are different,therefore the concrete-filled length should be chosen with comprehensive considerations in the design of the bridge.