基于汶川地震震害的公路桥梁易损性研究
发布时间：2018-09-06 09:12
【摘要】：随着综合国力迅速提升,我国进行了大规模的公路网络建设,兴建了数以万计的公路桥梁,为整个经济社会的可持续发展提供了有力支撑。然而,国内外历次大地震中有大量公路桥梁发生破坏,这会极大地降低公路交通的通行能力,严重阻碍应急救援工作和城市日常生活。我国是受地震灾害最多的国家之一,因此,在我国开展公路桥梁地震易损性研究具有重要现实意义。本文在对汶川地震公路桥梁调查数据深度挖掘整理和全面归纳总结之基础上,采用多种方法比较系统地研究了当代公路桥梁的地震易损性,还开展了基于公路桥梁震害评定地震烈度的研究,旨在更好地服务于公路桥梁的震害预测和损失评估、震后可恢复性研究、交通系统的地震风险分析,以及应急救灾决策的制定和完善抗震设计理论等工作,从而达到减轻桥梁震害和提高救援效率之目的。论文主要完成了以下工作:1.针对低烈度区公路桥梁调查数据不完备,遗漏大量基本完好桥梁的实际情况,按照烈度区面积与调查桥梁数量相近的原则对低烈度区的调查数据进行了补充估计,利用常见的几种经验分布函数拟合了破坏概率直方图,对公路桥梁的易损性矩阵进行了改进,还分析了地震地质灾害的影响。2.合理地估计了桥址处的PGA数值,基于补充后的调查数据建立了一系列“桥梁-破坏等级-桥址处PGA”样本对,采用最大似然估计法确定了易损性函数中的待定参数,给出了汶川地震公路桥梁的经验易损性曲线,比较分析了拱桥与梁桥之间的易损性差异,并探讨了桥梁规模对易损性的影响。3.基于SAP2000建立了9种工况下的连续梁桥有限元分析模型,选取36条典型地震动记录为输入,考虑支座和桥墩的非线性行为,进行了桥梁非线性时程分析,在此基础上首先建立了支座和桥墩两种构件的易损性曲线,随后利用一阶界限法合成了整座连续梁桥的易损性曲线,并讨论了不同支承方式对地震易损性的影响,同时验证了桥梁规模对地震易损性的影响规律。4.通过统计整理近2000座公路桥梁的详实震害资料,分别得到了拱桥和梁桥的主要震害类型,探讨了它们的发生概率与不同地震烈度的对应关系,分析了关键构件的破坏程度随地震烈度的变化规律。最后,以桥梁破坏等级和典型震害的形式分别提出了评定地震烈度的建议指标,并进行了对比分析和验证。
[Abstract]:With the rapid improvement of comprehensive national strength, China has carried out large-scale highway network construction and built tens of thousands of highway bridges, which provides a strong support for the sustainable development of the whole economy and society. However, a large number of highway bridges have been destroyed in the past major earthquakes at home and abroad, which will greatly reduce the capacity of highway traffic and seriously hinder the emergency rescue work and daily life of the city. China is one of the countries most affected by earthquake disasters. Therefore, it is of great practical significance to study the seismic vulnerability of highway bridges in China. On the basis of deep mining and summing up the survey data of highway bridges in Wenchuan earthquake, this paper systematically studies the seismic vulnerability of contemporary highway bridges by using various methods. In order to better serve the earthquake disaster prediction and loss assessment of highway bridges, the research of earthquake intensity assessment based on highway bridges is also carried out, and the research on recoverability after earthquake, the analysis of seismic risk in traffic system is also carried out. In order to reduce the earthquake damage of bridges and improve the efficiency of rescue, it is necessary to formulate the decision of emergency relief and perfect the theory of seismic design. The thesis has accomplished the following work: 1: 1. In view of the fact that the survey data of highway bridges in low intensity area are not complete and a large number of basic intact bridges are missing, according to the principle that the area of intensity area is close to the number of investigated bridges, the survey data of low intensity area is estimated by supplementary estimation. The damage probability histogram is fitted by using several common empirical distribution functions, the vulnerability matrix of highway bridges is improved, and the influence of seismic geological hazards. The PGA value at the bridge site is reasonably estimated, and a series of "bridge damage grade-bridge site PGA" sample pairs are established based on the supplementary survey data. The undetermined parameters in the vulnerability function are determined by the maximum likelihood estimation method. The empirical vulnerability curves of highway bridges in Wenchuan earthquake are given, the differences between arch bridges and beam bridges are compared and analyzed, and the influence of bridge size on vulnerability is discussed. Based on SAP2000, the finite element analysis model of continuous beam bridge under 9 working conditions is established. 36 typical ground motion records are selected as input, and the nonlinear behavior of support and pier is considered, and the nonlinear time history analysis of bridge is carried out. On the basis of this, the vulnerability curves of two kinds of components, bearing and pier, are first established, then the vulnerability curves of the whole continuous beam bridge are synthesized by the first order limit method, and the influence of different supporting modes on the seismic vulnerability is discussed. At the same time, the influence of bridge size on earthquake vulnerability is verified. Based on the detailed earthquake damage data of nearly 2000 highway bridges, the main damage types of arch bridge and beam bridge are obtained, and the corresponding relationship between their occurrence probability and different earthquake intensity is discussed. The variation law of the damage degree of key components with earthquake intensity is analyzed. Finally, in the form of bridge damage grade and typical earthquake damage, the suggested indexes for evaluating seismic intensity are put forward, and compared and verified.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U442.55
，
本文编号：2225875
[Abstract]:With the rapid improvement of comprehensive national strength, China has carried out large-scale highway network construction and built tens of thousands of highway bridges, which provides a strong support for the sustainable development of the whole economy and society. However, a large number of highway bridges have been destroyed in the past major earthquakes at home and abroad, which will greatly reduce the capacity of highway traffic and seriously hinder the emergency rescue work and daily life of the city. China is one of the countries most affected by earthquake disasters. Therefore, it is of great practical significance to study the seismic vulnerability of highway bridges in China. On the basis of deep mining and summing up the survey data of highway bridges in Wenchuan earthquake, this paper systematically studies the seismic vulnerability of contemporary highway bridges by using various methods. In order to better serve the earthquake disaster prediction and loss assessment of highway bridges, the research of earthquake intensity assessment based on highway bridges is also carried out, and the research on recoverability after earthquake, the analysis of seismic risk in traffic system is also carried out. In order to reduce the earthquake damage of bridges and improve the efficiency of rescue, it is necessary to formulate the decision of emergency relief and perfect the theory of seismic design. The thesis has accomplished the following work: 1: 1. In view of the fact that the survey data of highway bridges in low intensity area are not complete and a large number of basic intact bridges are missing, according to the principle that the area of intensity area is close to the number of investigated bridges, the survey data of low intensity area is estimated by supplementary estimation. The damage probability histogram is fitted by using several common empirical distribution functions, the vulnerability matrix of highway bridges is improved, and the influence of seismic geological hazards. The PGA value at the bridge site is reasonably estimated, and a series of "bridge damage grade-bridge site PGA" sample pairs are established based on the supplementary survey data. The undetermined parameters in the vulnerability function are determined by the maximum likelihood estimation method. The empirical vulnerability curves of highway bridges in Wenchuan earthquake are given, the differences between arch bridges and beam bridges are compared and analyzed, and the influence of bridge size on vulnerability is discussed. Based on SAP2000, the finite element analysis model of continuous beam bridge under 9 working conditions is established. 36 typical ground motion records are selected as input, and the nonlinear behavior of support and pier is considered, and the nonlinear time history analysis of bridge is carried out. On the basis of this, the vulnerability curves of two kinds of components, bearing and pier, are first established, then the vulnerability curves of the whole continuous beam bridge are synthesized by the first order limit method, and the influence of different supporting modes on the seismic vulnerability is discussed. At the same time, the influence of bridge size on earthquake vulnerability is verified. Based on the detailed earthquake damage data of nearly 2000 highway bridges, the main damage types of arch bridge and beam bridge are obtained, and the corresponding relationship between their occurrence probability and different earthquake intensity is discussed. The variation law of the damage degree of key components with earthquake intensity is analyzed. Finally, in the form of bridge damage grade and typical earthquake damage, the suggested indexes for evaluating seismic intensity are put forward, and compared and verified.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U442.55
，
本文编号：2225875
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