【作者】 陈强；

【导师】 刘沐宇；

【作者基本信息】 武汉理工大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 温(州)福(州)昆阳特大桥为连续梁拱组合结构桥。本文以正在建造的昆阳特大桥为工程背景,应用有限元理论建立了该桥的计算模型,进行了主要施工阶段的静力分析、受力复杂的梁拱结合部空间应力分析和主要设计参数对成桥阶段内力及稳定性的影响分析,揭示了铁路大跨度连续梁拱组合桥的受力及稳定性特点。具体地说,本文主要进行了以下几个方面的工作:1.运用MIDAS软件对昆阳特大桥整个施工过程中的结构内力、应力和变形进行了模拟计算,并将理论计算值与施工控制过程中的实测值进行了对比分析。结果证明采用先梁后拱,主梁为挂篮悬臂对称施工,各个施工阶段主梁及拱肋截面的应力均满足规范要求,施工方法比较合理。2.根据圣维南原理,采用平面杆系结构分析和三维实体结构分析相结合的方法,运用ANSYS对受力复杂的梁拱结合部采用实体单元进行了空间应力分析。对于受力复杂的梁拱结合部,除应力集中区域外,该部位的应力均处于较合理的范围,本桥设计所采用的拱座外形及局部构造总体上是一种受力比较适宜的方案,能确保该桥拱座受力与传力的功能。3.在连续梁拱组合桥的设计参数中,拱轴线线型、矢跨比和刚度比对结构内力的影响最为显著。通过改变桥梁的设计参数(拱轴线形式、矢跨比及刚度比),比较了不同设计参数对梁拱组合结构内力分布的影响,并得出合理的取值范围,为设计人员选取结构参数提供参考。4.探讨了横撑及拱肋布置形式等因素对该桥型稳定性的影响。结果表明:拱肋横撑布置形式和数量对连续梁拱组合桥稳定性有较大影响,吊杆非保向力能提高整体稳定性大约10%,拱肋内倾角变化对该类桥型的稳定型影响不明显。更多还原

【Abstract】 Kunyang Bridge on Wenzhou-Fuzhou Railway is a combined structure composed of prestressed concrete continuous box beam and concrete-filled steel tubular (CFST) arch. Based on the bridge under construction and the finite element theory, the calculating model for the bridge was built. This dissertation focuses on static analysis of the bridge in the main construction phases, a space-stress analysis for the connection area of the beam and arch with complicated structural stress, the influence of the main design parameters on the internal force and the stability. Specifically speaking, this dissertation has dealt with the following respects:1. The internal forces, stress and deformation throughout the construction process of Kunyang Bridge have been calculated by MIDAS software. Comparison and analysis are made between the results of the theory analysis and the measured datum in the construction control. It is demonstrated that the sectional stress of the main girder and the arch ribs can meet the requirements of the standards in each construction stage by erecting the continuous girder prior to that of the arches and using cantilever casting construction. The construction method is also proved to be reasonable.2. According to Saint-Venant principle, the finite element space model for the connection area of the beam and arch was built in order to simulate the stress characteristics by ANSYS software adopting the method of combining the plane bar structure analysis with three-dimensional finite element analysis. The stress of the connection area of the beam and arch are within a reasonable range with the exception of the stress concentration regions. The shape and the local structure of the arch abutment which have been adopted in this bridge design are basically a reasonable design scheme, which can ensure the function of the structural force and the force transferring.3. Among the design parameters of the continuous beam-arch composite bridge, the arch axis, the ratio of the rise to span and the stiffness ratic have more obvious influence on the structural internal force. Through changing some design parameters(arch axis, ratio of the rise to span, stiffness ratic), the influence to the internal force distribution of the continuous beam-arch composite bridge is compared under different design parameters. The optimal range of these parameters is pointed out and some advances are also given.4. The factors influencing buckling eigenvalues of the bridge, such as the number and the the type of the transverse brace, the arch rib obliquity etc., have been discussed. The results showed that the number and the the type of the transverse brace have great influence on the sability of the bridge and non-directional force of suspender can improve global stability about 10%, but the change of the arch rib obliquity has no obvious influence on the global stability.更多还原