桥梁排架结构地震破坏机理及损伤控制方法

发布时间：2018-07-18 15:36

【摘要】：美国Loma Prieta地震、日本Kobe地震、中国汶川地震及集集地震中的桥梁震害,均证实了桥梁排架结构的抗震薄弱性。为研究桥梁排架地震破坏机理并发展排架地震损伤控制方法,本文基于OpenSees数值分析平台,建立了考虑弯曲、剪切和纵筋粘结滑移变形的钢筋混凝土桥墩抗震数值分析模型,通过与试验结果对比,验证了模型的正确性。提出了设置延性系梁和防屈曲支撑(Buckling Restrained Brace, BRB)对钢筋混凝土排架进行损伤控制的抗震措施并进行了数值验证。本文主要工作和结论如下：1.为研究纵筋粘结滑移变形对钢筋混凝土桥墩地震反应的影响,基于OpenSees中的非线性梁柱单元、零长度转动弹簧单元和零长度剪切弹簧单元,建立了8个考虑弯曲变形、粘结滑移变形和剪切变形的桥墩抗震数值分析模型。将模拟得到的滞回曲线,墩顶弯曲、粘结滑移和剪切变形等成分与试验结果进行对比。结果表明,所建模型对各桥墩的滞回曲线、各变形成分、初始刚度和残余位移有较好的模拟效果。且粘结滑移变形占墩顶总位移成分比例较大,约为20-50%,在数值模型中不可忽略。2.为研究OpenSees中的非确定参数对数值模型中残余位移模拟的敏感性问题,建立了考虑弯曲变形和粘结滑移变形的数值分析模型,对桥墩进行动力时程分析,在关键参数可以根据试验和试件设计确定的基础上,通过改变软件中的7个非确定参数,对非确定参数进行残余位移模拟的敏感性分析,并与试验结果进行对比,以验证影响效果。结果表明,非确定参数对多条地震动中残余位移最大值影响较为明显,且通过调整,可以获得较好的残余位移模拟精度。3.为研究高强箍筋高强混凝土墩柱抗震性能,基于Elwood建立的普通强度钢筋混凝土墩柱变形能力计算公式,对22个高强箍筋高强混凝土柱拟静力试验进行分析,验证了Elwood剪切破坏面对高强箍筋高强混凝土墩柱的适用性。使用Elwood模型模拟6个发生弯剪破坏的高强箍筋高强混凝土柱,将模拟与试验滞回曲线进行对比,结果表明,滞回曲线吻合较好,修正模型对高强箍筋高强混凝土柱的强度、刚度退化、残余位移等具有较好的模拟精度。4.为提高桥梁排架横桥向抗震能力,减少桥墩地震损伤破坏,提出在排架中设置延性系梁的设想并给出了设计构造措施。建立了无系梁排架和设置延性系梁排架抗震数值分析模型,通过拟静力和增量动力分析(IDA)手段讨论了延性系梁设置对减少排架地震反应的效果。结果表明：延性系梁提高了桥梁排架横桥向的强度和刚度,地震作用下,系梁先于排架桥墩发生屈服,形成塑性铰并耗散地震能量,延缓了桥墩的破坏过程,并减少了桥梁排架的变形需求。5.为研究BRB对桥梁排架的损伤控制效果,提出了设置BRB提高排架横桥向抗震能力的设想,以一个桥梁排架抗震拟静力试验结果为依据,建立了无BRB排架和加BRB排架抗震数值分析模型,并进行拟静力分析和增量动力分析(IDA)。结果表明：BRB核心段长度的选择是影响排架屈服顺序的关键,合理设计的BRB先于桥梁排架构件发生屈服并消耗地震能量,延缓了排架本身的屈服过程,提高了桥梁排架的抗震性能。
[Abstract]:The earthquake damage of the Loma Prieta earthquake in the United States, the Kobe earthquake in Japan, the Wenchuan earthquake in China and the bridge earthquake in the gathering earthquake proved the seismic weakness of the bridge frame structure. In order to study the seismic failure mechanism of the bridge arrangement and develop the method of controlling the seismic damage of the frame, this paper is based on the OpenSees numerical analysis platform to consider the bending, shear and longitudinal reinforcement. The seismic numerical analysis model of reinforced concrete bridge pier with bond slip deformation is compared with the test results to verify the correctness of the model. The seismic measures for the damage control of the reinforced concrete frame with the ductile beam and the Buckling Restrained Brace, BRB are put forward and the numerical verification is carried out. The results are as follows: 1. in order to study the effect of the bond slip deformation on the seismic response of the reinforced concrete bridge pier, based on the nonlinear beam column element in OpenSees, the zero length rotating spring element and the zero length shear spring element, 8 numerical models for seismic analysis of bridge piers with bending deformation, bond slip deformation and shear deformation are established. The simulated hysteresis curve, the pier top bending, the bond slip and the shear deformation are compared with the experimental results. The results show that the model has a better simulation effect on the hysteretic curve, the deformation components, the initial stiffness and the residual displacement of the pier, and the proportion of the total displacement of the pier top is about 20. -50%, in the numerical model,.2. can not be ignored to study the sensitivity of the non deterministic parameters in OpenSees to the simulation of residual displacement in the numerical model. A numerical model is established to consider the bending deformation and bond slip deformation, and the dynamic time history analysis of the piers is carried out. The key parameters can be based on the basis of test and test design. By changing the 7 non deterministic parameters in the software, the sensitivity analysis of the residual displacement simulation of the uncertain parameters is analyzed and compared with the experimental results to verify the effect. The results show that the influence of the undetermined parameters on the maximum residual displacement in the multiple ground motions is more obvious, and a better residual position can be obtained through adjustment. In order to study the seismic performance of high strength reinforced concrete pier columns with high strength stirrup,.3. is based on the formula for calculating the deformation capacity of ordinary strength reinforced concrete pier column based on Elwood. The pseudo static test of 22 high-strength reinforced concrete columns with high strength stirrup is analyzed, and the applicability of Elwood shear failure surface to high strength concrete pier columns with high strength stirrup is verified. The Elwood model is used to simulate 6 high-strength concrete columns with high strength stirrup and shear failure. The simulation and experimental hysteretic curves are compared. The results show that the hysteresis curve is in good agreement. The modified model has a better simulation precision of the strength, stiffness degradation and residual displacement of the high-strength stirrup high strength concrete column.4. to improve the bridge frame cross section. The seismic capacity of the bridge is reduced and the seismic damage and damage of the pier are reduced. The idea of setting the ductile beam in the frame is proposed and the design construction measures are given. The seismic numerical analysis model of the unsupported beam row and the ductile beam frame is set up, and the ductile beam setting to reduce the frame earthquake is discussed by means of the pseudo static and incremental dynamic analysis (IDA). The results show that the ductile beam increases the strength and stiffness of the cross bridge direction of the bridge frame. Under the earthquake action, the girder is yielding to the pier before the pier, forming plastic hinge and dissipating the seismic energy, delaying the failure process of the pier, and reducing the change requirement of the bridge row frame.5. to study the damage control of the bridge arrangement by BRB. The effect is proposed by setting up BRB to improve the aseismic ability of the horizontal bridge. Based on the results of the pseudo static test of a bridge frame, a numerical model of the anti earthquake resistance of the BRB frame and the BRB frame is set up, and the pseudo static analysis and the incremental dynamic analysis (IDA) are carried out. The results show that the selection of the length of the core section of the BRB is to affect the arrangement of the frame. The key of order is the rational design of BRB before the bridge frame members yield and consume seismic energy, delay the yield process of the frame itself and improve the seismic performance of the bridge frame.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55

【参考文献】