弯剪相互作用下钢筋混凝土桥墩抗震非线性数值分析模型

发布时间：2018-03-15 05:12

本文选题：桥梁抗震　切入点：钢筋混凝土桥墩　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：钢筋混凝土桥墩在地震荷载作用下,遭受弯剪耦合作用而导致严重震害,发展此类构件抗震数值分析模型,是揭示桥梁地震破坏机理、认识桥梁抗震能力的前提和保证。本文在总结国内外历次大地震中钢筋混凝土桥墩震害及桥墩抗震数值模型研究进展的基础上,进一步发展了弯剪耦合作用下钢筋混凝土桥墩抗震非线性数值分析方法,基于OpenSees数值分析平台,建立了考虑弯曲效应、剪切效应和纵筋拔出效应的数值模型,通过对比试验结果,证明了模型的准确性,最后通过该模型,对不规则排架桥墩进行了抗震性能分析。本文主要工作和认识如下： 1.为了研究纵筋拔出对钢筋混凝土桥墩抗震性能的影响,基于OpenSees软件中的纤维梁柱单元和零长度截面单元,建立了弯曲破坏为主的钢筋混凝土桥墩抗震非线性数值分析模型,通过修正模型中零长度截面单元内的钢筋纤维和混凝土纤维的本构关系,以合理考虑试件弯曲与纵筋拔出变形的耦合作用,最终通过对Lehman完成的试件滞回曲线、各变形成分的模拟分析,验证了模型的准确性,为合理评估弯曲破坏桥墩抗震能力提供了依据。 2.搜集整理了36个以弯剪破坏和剪切破坏为主的,且截面为圆形的钢筋混凝土桥墩抗震拟静力试验数据,基于OpenSees数值分析平台并结合试验获得的滞回曲线,进行了目标位移下的循环Pushover推覆分析,从而分离了桥墩发生剪切破坏时塑性铰区墩底转角,并通过多元线性回归分析的方法,建立了圆形截面桥墩发生剪切破坏时墩底转角计算公式。最后通过OpenSees数值分析平台建立了考虑桥墩弯-剪-轴力耦合效应的数值分析模型,以12个剪切效应控制的圆形截面桥墩拟静力试验结果为依据,对数值模型的准确性进行了验证。 3.在完成的拟静力试验基础上,基于OpenSees分析平台建立了无粘结预应力钢筋混凝土桥墩抗震数值分析模型,采用非线性纤维梁柱单元模拟桥墩的弯曲变形,采用修正的压力场理论计算试件剪切变形并通过剪切弹簧模拟,通过零长度转动弹簧模拟纵筋拔出变形,三者共同考虑试件在地震下的弯-剪-轴力耦合作用。将模拟得到的试件滞回曲线、骨架曲线、预应力筋应力和残余位移等与试验结果进行了对比,同时将模拟得到的墩顶弯曲变形、纵筋拔出变形和剪切变形进行了分离。结果表明该模型可对竖向配置无粘结预应力筋钢筋混凝土桥墩的抗震性能进行准确的模拟分析。 4.以云南省大理-丽江高速公路水东瓜山2号大桥工程为背景,从工程实践应用角度(不考虑剪切效应)和基于前述数值模型角度(考虑剪切效应),基于OpenSees分析平台,建立了不规则排架桥墩的数值分析模型,进行了抗震性能分析和非线性静力分析,研究了排架桥墩墩柱中轴压比变化情况、荷载-位移关系、以及桥墩塑性铰形成时刻等。为此类桥墩抗震性能评估提供工程可接受与精细化分析手段。
[Abstract]:Reinforced concrete bridge piers under earthquake loading, subjected to shear bending coupling effect and cause serious damage, the numerical analysis model of the development of this component is to reveal the bridge seismic, earthquake damage mechanism, the premise and the guarantee of understanding the bridge seismic capacity. Based on the summary of previous research progress at home and abroad based seismic design of reinforced concrete pier and pier seismic numerical model of earthquake on the further development of the method of numerical analysis of nonlinear bending shear of reinforced concrete bridge pier seismic coupling, analysis platform based on OpenSees numerical model considering the effect of bending, shear and pull-out effect of longitudinal reinforcement effect numerical model, by comparing the test results, the accuracy of the model was proved by the model, finally, the earthquake the performance analysis of irregular bent pier. The main work of this paper are as follows:
1. in order to study the longitudinal pull-out effect on seismic performance of reinforced concrete bridge piers, OpenSees software in fiber beam column element and zero length section unit based on a nonlinear analysis model of bending failure of reinforced concrete bridge pier seismic numerical based, the constitutive relation of steel fiber concrete and fiber length zero correction model in section unit. The reasonable consideration to the specimen bending and longitudinal reinforcement pullout coupling deformation, finally on the hysteretic curves Lehman, simulation analysis of the deformation of the components, verify the accuracy of the model, provides the basis for assessing bending seismic capacity of pier damage.
2. collect 36 in bending shear failure and shear failure of reinforced concrete bridge piers and seismic quasi-static test data for circular cross-section, OpenSees numerical analysis platform and combined test hysteretic curves are analyzed based on the target displacement under cyclic Pushover nappe, and pier shear plastic hinge of pier bottom corner separation, and through the method of multivariate linear regression analysis, circular cross-section pier shear pier bottom angle calculation formula is established. Finally, through the numerical analysis of OpenSees platform to build the pier bending shear - numerical analysis model of coupling effect of axial force, with circular section piers control 12 shear effect the pseudo static test results as the basis, the accuracy of the numerical model is verified.
3. in the quasi static test based on the OpenSees analysis platform for the establishment of the unbonded prestressed reinforced concrete bridge pier seismic numerical analysis model based on the nonlinear bending deformation of fiber beam column element to simulate the pier, calculating the shear deformation and the shear spring is simulated by the modified compression field theory, through the simulation of longitudinal zero length spring rotation pull out the deformation of three joint specimens under earthquake considering bending shear and axial force coupling. The hysteretic curves, skeleton curves obtained by simulation, reinforcement stress and residual displacement were compared with the experimental results, and the simulation results of the pier top bending deformation, longitudinal reinforcement pull the deformation and shear deformation were isolated. The results show that the simulation analysis of the accuracy of the seismic performance of the model of unbonded prestressed tendons reinforced concrete piers on the vertical configuration.
4. in Yunnan Province, Dali Lijiang Expressway East Mountain No. 2 bridge project as the background, from the perspective of application engineering practice (without considering shear effect) and the numerical model based on the angle (including shear effect), on the basis of OpenSees, a numerical analysis model for bent pier irregular, analyzed the seismic performance analysis and the nonlinear static, study frame bridge pier column axial compression ratio, load displacement relationship, and pier form plastic hinge moment. Acceptance and fine analysis method can provide engineering properties of this kind of bridge pier seismic evaluation.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55

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