基于概率的合肥城市高架桥抗震性能评估

发布时间：2018-05-07 08:48

本文选题：城市高架桥 + 基于性能的地震工程学　；参考：《合肥工业大学》2014年硕士论文

【摘要】：地震作用会导致桥梁结构的易损性及其破坏的严重后果，现役的大量桥梁，有一部分还是根据旧的桥梁抗震设计规范进行设计，在抗震设计方法和抗震构造措施等方面都存在着一定的不足，迫切需要进行抗震性能评价，并根据评价结果进行不同程度的抗震加固。同时，城市高架桥具有多跨、曲线匝道多、高低墩不齐等特点，使得桥梁的抗震评估更为复杂。欧美日等发达国家的结构抗震设计规范已经全面转向基于概率的抗震设计方法，其中应用最为广泛的就是基于性能的地震工程学理论，是未来结构抗震设计的发展方向。合肥市处于地震带上，随着城市交通基础建设的发展，城市高架桥的地震安全性评定日益严峻。本文将以全概率理论为基础、基于性能的地震工程学理论，进行合肥市城市高架桥的抗震评估。根据工程场地地震危险性分析，选择合理的地震波，进行非线性动力时程分析；对不同地震危险性水平下的特定工程需求参数（EDP）进行预计，并建立起相应的概率地震需求模型和EDP危险性曲线。对算例桥梁的破坏状态进行了详细的量化定义，通过基于概率的能力需求比法进行了概率地震破坏分析，得到了各主要构件的地震易损性曲线，充分显示了基于概率的城市高架桥抗震性能评估方法的优越性。论文的主要工作包括： 1.详细介绍了基于概率的抗震性能评估框架（PBEE），并给出了具体实施步骤。 2.讨论了概率地震危险性分析（PSHA）的计算过程，通过PSHA方法，获得了合肥市包河大道工程场地在四种超越概率水平下的目标谱和地震危险性模型。在此基础上，，选择了合理地震波作为输入地面运动，为下一步概率地震需求分析打下基础。 3.采用所选择的四组不同超越概率的地震波，以合肥市包河大道某桥为对象，进行非线性动力时程分析，获得桥梁在不同强度地震作用下的地震响应。采用“Stripe”方法建立桥梁的地震需求模型（PSDM）和地震需求参数（EDP）概率危险性曲线。 4.对算例桥梁的桥墩、支座和落梁等破坏状态进行了详细的量化定义，并根据概率地震需求分析的计算结果，进行了概率地震破坏分析，得到了各主要构件的地震易损性曲线。
[Abstract]:Earthquake will lead to the vulnerability of bridge structure and the serious consequences of damage. A large number of existing bridges are still designed according to the old seismic design code. There are some shortcomings in seismic design methods and seismic structural measures. It is urgent to evaluate the seismic performance and carry out seismic reinforcement in different degrees according to the evaluation results. At the same time, the urban viaduct has many characteristics, such as multi-span, curve ramps and uneven high and low piers, which makes the seismic evaluation of the bridge more complex. The codes for seismic design of structures in developed countries, such as Europe, America and Japan, have turned to probabilistic seismic design methods. The most widely used seismic engineering theory is performance-based seismic engineering theory, which is the development direction of seismic design of structures in the future. Hefei is located on the seismic belt. With the development of urban traffic infrastructure, the seismic safety assessment of urban viaducts is becoming more and more serious. Based on the theory of full probability and the theory of seismic engineering, the seismic evaluation of Hefei city viaduct is carried out. According to seismic hazard analysis of engineering site, reasonable seismic waves are selected to carry out nonlinear dynamic time-history analysis, and the parameters of specific engineering demand under different seismic hazard levels are predicted. The corresponding probabilistic seismic demand model and EDP hazard curve are established. In this paper, the failure state of bridge is defined in detail, and the probability seismic failure analysis is carried out by means of the probability-based capacity requirement ratio method, and the seismic vulnerability curves of the main components are obtained. The superiority of the probabilistic method for evaluating the seismic performance of urban viaducts is fully demonstrated. The main work of the thesis includes: 1. The probabilistic seismic performance evaluation framework is introduced in detail, and the concrete implementation steps are given. 2. The calculation process of probabilistic seismic hazard analysis (PSHAA) is discussed. By using PSHA method, the target spectrum and seismic hazard model of Baohe Avenue project site in Hefei under four levels of transcendental probability are obtained. On this basis, the reasonable seismic wave is selected as the input ground motion, which lays the foundation for the next probabilistic seismic demand analysis. 3. Using four groups of seismic waves with different transcendental probabilities, the nonlinear dynamic time-history analysis of a bridge in Baohe Avenue, Hefei City, is carried out, and the seismic response of the bridge under different earthquake intensity is obtained. The probabilistic hazard curves of bridge seismic demand model and seismic demand parameter (EDP) are established by "Stripe" method. 4. The failure states of bridge piers, supports and falling beams are defined in detail. According to the calculation results of probabilistic seismic demand analysis, the probabilistic seismic failure analysis is carried out, and the seismic vulnerability curves of the main components are obtained.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55

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