【作者】 王立峰；

【导师】 贾艳敏；

【作者基本信息】 东北林业大学 ， 林区交通工程， 2013， 博士

【摘要】 梁式桥是具有悠久历史的桥梁结构体系。按承重结构的静力体系划分,梁式桥包括简支梁、悬臂梁以及连续梁桥。近年,在建筑材料、设计理论、施工工艺水平大幅提高的基础上,以传统梁桥理论为基础进行桥梁结构形式的创新层出不穷,V撑蝶形拱式连续梁桥正是在此背景下出现的新型结构之一。其中,V撑(即V墩)的出现丰富了桥梁的艺术造型,同时彰显了增大整体刚度、减小跨径、改善主梁受力性能等优点。蝶形拱即拱肋向桥外侧有倾角,从远处观望,犹如振翅欲飞的蝴蝶。此桥型外观新颖,富有空间曲线美及力度感,具有明显的艺术造型与技术创新的特点,但V撑蝶形拱的构造复杂,设计和施工难度均相对较高。因此,准确的分析其结构的受力特征、了解结构破坏形式、开展其极限承载力的研究、获取结构在特定荷载工况下的安全储备能力,为今后同类桥型的设计、施工、监控提供可靠的参考和指导,具有重要的现实意义。本文结合黑龙江省黑河市大黑河岛蝶形拱式连续梁桥建设项目,该桥的V撑结构具有大夹角和双向V形的特点,为国内首例。通过理论分析、数值模拟、施工现场监测、神经网络等研究方法,研究了大角度V撑蝶形拱式连续梁桥对不同结构参数的敏感性规律、应力传感器埋设的合理位置的确定、明确风险分析的目标并确定结构失效风险最大阶段。主要工作内容包括结构的理论分析、现场应变传感器的埋设、数据的测试与分析、结构的数值模拟以及多参数敏感性规律的归纳总结。主要研究内容与成果如下：(1)通过数值模拟分析与现场实测相结合的方法,进行大角度V撑蝶形拱式连续梁桥不同参数的敏感性分析,通过人工神经网络技术与参数敏感性分析的结合,根据一个特定的系统和一个给定的基准状态,识别出对系统状态产生影响的参数,从而分析参数变化对系统状态的影响程度。总结了桥梁结构施工阶段及运营阶段的敏感性参数,为同类桥梁设计、施工提供理论支持。(2)应用有限元分析理论和大型有限元分析程序,建立了大黑河岛蝶形拱式连续梁桥的整桥静力分析模型并展开分析研究。通过结构内力的分布情况,选择结构受力不利、受力情况难以明确或重点关注的位置进行传感器的埋设,初步确定传感器的布置形式,并通过现场检测得出测试数据与模型分析的结果的对应关系,进行分析研究,提出了可全面而精确的获得结构受力信息的传感器布置方案,提高同类桥型施工监控与结构分析的工作效率及准确性,从而保障桥梁施工安全。(3)V撑蝶形拱式连续梁的动力性能研究。通过动力分析的基本方法和建模原则,建立了Midas/civil2010建立V撑蝶形拱式连续梁桥抗震分析模型,进行桥梁的自振特性分析。分别建立了考虑桩-土效应的分析模型和不考虑桩-土效应的分析模型,对两种模型前10阶自振特性进行研究,讨论了桩-土效应对结构振动响应的影响,分别应用反应谱法和时程分析法进行抗震分析,明确了动力分析中考虑桩-土效应的必要性,为同类型桥梁的结构优化提供参考。(4)建立了V撑结构的ANSYS空间有限元模型,通过局部应力的理论求解与振弦式传感器实测数据的对比分析,得到不同阶段V撑结构的应力分布状态。利用数据分析程序MATLAB(?)寸测试数据进行数值回归,结合人工神经网络技术,对影响结构破坏、失效的内部、外界风险因素进行预测,开展结构失效的风险分析。提出了基于层次分析—灰度理论—蒙特卡洛—有限元—神经网络(AHP-Gray theory-Monte Carlo-FEM-ANN)的风险分析综合方法。解决了以往风险决策多依赖于决策者经验和定性分析的问题,从而更具可靠性和可操作性。根据影响桥梁施工阶段的风险因素,提出了蝶形拱式连续梁桥施工阶段风险因素的防范对策。本文的研究工作为了解大角度V撑蝶形拱式连续梁桥结构提供了较为实用的研究方法与成果,为设计、施工、监控以及风险评估管理体系的建立起到一定的借鉴作用。更多还原

【Abstract】 Beam bridge is a structural system with a long history. On the basis of static system, it can be classified into three types:simply supported beam, cantilever beam and continuous beam bridge. In recent years, with the development of building materials, design theory and construction technology, the innovation of bridge structures which is based on traditional bridge theory is endless. V-shaped pier of butterfly arch continuous girder bridge is just one of the new structures created under this background. Besides, V-shaped pier enriched the art forms of bridge. At the same time, it highlights the advantages of increasing the overall stiffness, reducing the span and improving the mechanical properties of the main beam. Ⅴ-shaped butterfly arch has lateral angle of the bridge, which, watched from a distance, is like a butterfly that spreads its wings to fly. The type of bridge has novel appearance, space curves and strength feeling and features of artistic design as well as technical innovation. But the structure of Ⅴ-shaped butterfly arch is complex; the design and construction are relatively difficult. Therefore, it has important practical value to analyze the stress characteristics of the structure accurately, master the forms of structure damage, carry out the study of the ultimate bearing capacity and obtain its secure reserve capacity under specified stress conditions. And it can provide reliable reference and instructions for the similar bridges’ design, construction and monitoring.This paper refers to the Heihe Island butterfly arch-continuous beam bridge project in Heihe City, Heilongjiang Province. Its Ⅴ-shaped pier has characteristics of large angle and bidirectional Ⅴ-shaped, which is the first case in China. By some research methods such as theoretical analysis, numerical simulation, construction site monitoring and neural network, we study the regularity of large angle Ⅴ-shaped pier butterfly arch-continuous beam bridge’s sensitivity to different structural parameters and the reasonable buried position of strain sensors, determine the biggest stage of the risk of structural failure. The main work includes the theoretical analysis, burying the strain sensors, data testing and analysis, numerical simulation of the structure, as well as concluding the regularity of multi-parameter sensitivity. The main research contents and results are as follows:(1) By combining the numerical simulation analysis with testing at the construction site, we analyze the large angle V-shaped pier butterfly arch-continuous beam bridge’s sensitivity to different parameters. And by combining the artificial neural network technology with the parameter sensitivity analysis, we identify the impact on the state of the system parameters, and analyze the impact of parameter changes on the state of the system, after which we can identify the parameters that have impact on the system state according to a specific system and a given reference state. Parameters sensitivity at the construction and operation stage is summarized to provide theoretical support for similar bridge design and construction.(2) Set up the static state analysis finite element of Heihe Island butterfly arch-continuous beam bridge and carry out analysis and researches. Select the position which is unfavorable for structure stress, the position where the stress is not clear and the position focused on to bury the sensors. Then preliminary determine the layout form of the sensors and put forward optimization scheme of the layout form of the sensors that can offer comprehensive and accurate force information of the structure according to the correspondence relationship of the testing data at the construction site and model analysis results, which improving the efficiency and accuracy of similar bridge construction monitoring to ensure the safety of bridge construction.(3) Dynamic property research on V-shaped butterfly arch-continuous beam bridge. By the basic means and modeling principle of dynamic analysis, Midas/civil2010seismic analysis model of V-shaped butterfly arch-continuous beam bridge is set up to analyze the self-vibration characteristics of the bridge. Heihe Island Bridge models of both considering and not considering the pile-soil effect are established and analysis on the two models’self-vibration characteristics in the first10phases is carried out. The influence on pile-soil effects on vibration characteristics of the structure is also discussed. Response spectrum method and time history method are used to discuss seismic analysis of the bridge; it’s clearly showed that taking pile-soil effects into consideration in the dynamic analysis is rather necessary. Methods above provide reference material for similar bridges in structure optimization.(4) Set up ANSYS space finite element model of V-shaped structure. By contrastive analysis on local stress theoretical results and vibrating wire transducer measured data, stress distribution of V-shaped structure in different phases can be obtained. MATLAB, a data analysis program, is used to carry out regression analysis on testing data. Combined with Artificial Neural Network, both the influence on the structural damage and the failure of internal and external risk factors can be forecast. Moreover, the venture analysis on structure failure can be carried out. In this paper, we propose a theory based on AHP.Gray-Monte Carlo-FEM-neural network synthesis methods for risk analysis, which can solve the problem that previous risk decision was relied on experience and qualitative analysis of decision makers. As a consequence, that makes it more reliable and operable. On the basis of the risk factors that has an impact on bridge construction phase, preventive measures for construction phase risk factors of Heihe Island butterfly arch continuous beam bridge are put forward.This article provides not only practical research methods and achievement to understand large angle V-shaped butterfly arch-continuous beam bridge deep but important references for building design, construction, monitoring and the establishment of risk evaluation system as well.更多还原