山区窄钢桁加劲梁悬索桥施工暂态抗风安全性研究

发布时间：2018-03-26 20:21

本文选题：大跨度窄悬索桥　切入点：钢桁加劲梁　出处：《兰州交通大学》2015年硕士论文

【摘要】：本文就山区窄钢桁加劲梁悬索桥抗风问题这一风工程领域的难点问题,探讨了一个涉及窄钢桁悬索桥的静风稳定、动力特性、颤振稳定等多方面的研究课题。另外,还侧重于该种桥型施工暂态抗风的这一大跨度桥梁施工中的重、难点问题。窄钢桁悬索桥在施工过程中风环境比较复杂、工期较长、结构刚度较低,很可能出现成桥时不会发生的风效应;再者,考虑到施工期人员的安全性和舒适性以及工作时间,因此,施工暂态风致稳定的重要性非同小可。本文以刚刚建成的刘家峡特大悬索桥为依托,详细阐述了该桥型处于施工暂态期间结构抗风的安全性问题。具体所做的工作如下:首先,简要陈述了桥梁风工程的发展以及现状。简述风致静风稳定和颤振稳定国内外的研究情况及其发展方向。其次,简明介绍了悬索桥静风稳定性分析理论和方法,包括如何描述非线性静风荷载。建立了刘家峡大桥成桥状态的三维有限元模型,采用Newton Raphson迭代数值计算法在ANSYS中对其进行了非线性静风稳定性的全过程分析,同时验证了刘家峡大桥静风稳定性。第三,以刘家峡大桥为例,对窄钢桁加劲梁悬索桥成桥及施工过程中动力特性进行了研究分析,给出成桥状态动力特性结果及各典型施工暂态之间动力特性的变化趋势,得到了该桥施工过程中动力特性变化的一般规律。最后,利用APDL参数化程序并基于ANSYS有限元工具,探究了刘家峡悬索桥施工暂态颤振性能及吊装方案对悬索桥施工暂态颤振稳定性的影响。利用颤振时域分析方法将得到的结果与试验结果进行对比。同时,验证了方法的可行性及正确性。对该桥分别采用几种吊梁方案以及非对称吊装方案,对比各种情况下施工暂态颤振稳定性结果,从而获得了施工阶段颤振临界风速的递变趋势和有效提高窄加劲梁悬索桥施工期颤振稳定性的措施。
[Abstract]:In this paper, the wind resistance problem of narrow steel truss stiffened girder suspension bridge in mountainous area is discussed, and a study on static wind stability, dynamic characteristics and flutter stability of narrow steel truss suspension bridge is discussed. The paper also emphasizes on the heavy and difficult problems in the construction of this kind of long-span bridge, which is transient wind-resistant. The narrow steel truss suspension bridge has complicated stroke environment, long construction period and low structural stiffness during construction. It is likely that the wind effect will not occur when the bridge is completed; furthermore, considering the safety and comfort of the personnel during the construction period and the working hours, therefore, The importance of transient wind-induced stability in construction is not trivial. Based on the newly built Liujiaxia suspension bridge, this paper expounds in detail the safety of the structure during the transient construction period. The specific works are as follows: first of all, The development and present situation of bridge wind engineering are briefly described. The research situation and development direction of wind-induced static wind stability and flutter stability at home and abroad are briefly described. Secondly, the theory and method of static wind stability analysis for suspension bridges are briefly introduced. Including how to describe nonlinear static wind load, a three-dimensional finite element model of the bridge state of Liujiaxia Bridge is established, and the full process analysis of nonlinear static wind stability is carried out by using Newton Raphson iterative numerical method in ANSYS. At the same time, the static wind stability of the Liujiaxia Bridge is verified. Thirdly, taking the Liujiaxia Bridge as an example, the dynamic characteristics of the suspension bridge with narrow steel truss stiffened beam and during construction are studied and analyzed. The dynamic characteristics of the bridge and the variation trend of the dynamic characteristics among the typical construction transient are given, and the general law of the dynamic characteristics during the bridge construction is obtained. Finally, using the APDL parameterization program and the ANSYS finite element tool, the dynamic characteristics of the bridge are obtained. The effect of construction transient flutter performance and hoisting scheme of Liujiaxia suspension bridge on the transient flutter stability of suspension bridge is investigated. The results obtained by time-domain flutter analysis are compared with the experimental results. The feasibility and correctness of the method are verified. For the bridge, several kinds of hoisting schemes and asymmetric hoisting schemes are adopted, and the results of transient flutter stability under various conditions are compared. The trend of flutter critical wind speed in construction stage and the measures to improve flutter stability of narrow stiffened girder suspension bridge during construction are obtained.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445;U448.25

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