多振型组合的钢管混凝土拱桥Pushover分析

发布时间：2018-02-28 17:02

本文关键词： 拱桥 Pushover分析钢管混凝土抗震性能高阶振型　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：钢管混凝土拱桥的抗震性能一直备受关注，本文以基于结构性能的抗震设计理念为应用背景，对钢管混凝土拱桥进行研究。目前基于结构性能的抗震设计理念分析主要采用两种方法：非线性时程分析和静力弹塑性分析(Pushover)。时程分析虽然是较精细分析方法，但对地震动记录非常敏感且计算量大、耗时多；然而，Pushover方法因为简单有效而成为基于性能设计的热点课题，该方法可以避免非线性时程分析的复杂性和不确定性。本文尝试将Pushover分析方法应用于钢管混凝土拱桥的抗震性能评估，对促进基于性能的桥梁结构设计和评估的研究与实践，有着重要的理论价值和现实意义。本文以实际工程潮白河大桥为研究对象，首先建立了该钢管混凝土拱桥的空间有限元分析模型，并对其进行了模态分析，获得了前60阶模态参数，为进一步的Pushover分析准备数据。之后，，研究分析了拱桥Pushover分析方法的基本原理、基本假定、影响因素以及传统的Pushover分析方法。与传统方法不同，本文中直接获得等效单自由度体系equivalent-single-degree-of-freedom(ESDOF)的恢复力Q与位移x，直接建立ESDOF的能力曲线，从而既实现了三维加载模式，又符合理论推导。其次，基于拱桥Pushover分析方法理论，选取按振型Φ加载的方式加载，并考虑高阶振型的影响，按横向振动有效质量系数和达到90%以上为原则选取振型向量Φ1和Φ5加载，直接获得相应的等效单自由度体系ESDOF1和ESDOF5。对原结构度多自由度体系muti-degree-of-freedom(MDOF)和ESDOF1、ESDOF5分别进行了天津地震动、EL Centro地震动和阪神地震动这三条地震动下的弹塑性时程分析，将MDOF分别与考虑多振型组合的ESDOF、以及仅考虑振型1的ESDOF的地震响应峰值进行对比分析。结果表明考虑多振型组合的Pushover分析方法与原结构MDOF响应峰值吻合的较好，误差都在20%以下；然而不考虑多振型组合的Pushover分析方法与原结构MDOF吻合的很差，误差都在20%以上，不满足实际工程精度要求，从而验证了基于多振型组合的Pushover分析的钢管混凝土拱桥抗震性能评估方法的可行性，且精度满足实际工程需求。最后，将Pushover分析方法和增量动力分析IDA结合起来，尝试用多个等效单自由度体系的恢复力模型近似代替原结构进行IDA分析，这样不仅计算代价小，而且结果吻合较好，误差都在20%以内，将考虑多振型组合的Pushover分析方法与IDA方法结合在一起，从而实现了对钢管混凝土拱桥全面的抗震性能评估，对基于结构性能的桥梁设计和评估的研究与实践，有一定的参考意义。
[Abstract]:The seismic performance of CFST arch bridge has been a concern, based on the seismic design of structure based on performance as the application background, research on CFST arch bridge. The seismic design analysis of structural performance mainly uses two methods based on nonlinear time history analysis and pushover analysis (Pushover). Although the time history analysis more sophisticated analysis methods, but the record is very sensitive and large amount of calculation, time-consuming; however, because the Pushover method is simple and effective and has become a hot topic in performance-based design, this method can avoid the complexity of nonlinear time history analysis and uncertainty. This paper will try to evaluate the seismic performance of Pushover analysis method is applied to concrete filled steel tubular arch bridge and to promote the research and practice of bridge structure design and performance evaluation based on, has important theoretical value and practical significance.
Taking the actual engineering of the Chao Bai River Bridge as the research object, the spatial finite element analysis model of the CFST arch bridge is built first, and the modal analysis is carried out. The first 60 order modal parameters are obtained, which will prepare data for further Pushover analysis.
After the research and analysis of the basic principle, the basic assumption of arch bridge Pushover analysis method, the influence factors and the traditional Pushover method. Different from traditional methods, direct access to the equivalent single degree of freedom system in equivalent-single-degree-of-freedom (ESDOF) Q restoring force and displacement x, direct build capacity curve of ESDOF, so as to implement the three-dimensional loading model, and are consistent with the theoretical results.
Secondly, the Pushover analysis method based on the theory of arch bridge, select the loading mode according to the diameter of loading, and considering the effects of higher modes according to the transverse vibration of the effective mass coefficient and more than 90% for the principle of choosing the mode vector Phi 1 and phi 5 loading, direct access to the corresponding equivalent single degree of freedom system of ESDOF1 and ESDOF5. muti-degree-of-freedom the original structure of multi degree of freedom system (MDOF) and ESDOF1, ESDOF5 were carried out in Tianjin earthquake, EL Centro earthquake and the Kobe earthquake processanalysis the three earthquake bombs, MDOF respectively and considering the multi modal combination of ESDOF and ESDOF mode 1 only consider the comparative analysis of earthquake response peak. The results show that considering the Pushover analysis method of multi mode combined with the original structure of MDOF response peak in good agreement, errors are below 20%; however, without considering the analysis of multi modal combination Pushover The method is very consistent with the original structure MDOF, and the error is over 20%, which does not meet the requirements of actual engineering accuracy. It verifies the feasibility of the seismic performance evaluation method of CFST Arch Bridge Based on multi mode combination Pushover analysis, and the accuracy meets the actual engineering needs.
Finally, the Pushover analysis method and incremental dynamic analysis IDA together, try to use a single degree of freedom system of multiple equivalent restoring force model instead of the original structure was analyzed by IDA, which not only has lower computational cost, and the results are in good agreement, errors are less than 20%, the test method of Pushover analysis and multiple mode combination the IDA method together, so as to realize the evaluation of seismic performance of CFST arch bridge comprehensively, research and practice of the performance of bridge structure design and evaluation based on a certain reference value.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.22;U442.55

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