论文部分内容阅读
基于OpenSees数值分析平台的纤维梁柱、剪切弹簧和转动弹簧单元,建立了考虑桥墩剪切破坏的不规则桥梁排架抗震数值分析模型.其中纤维梁柱单元模拟桥墩、盖梁弯曲变形,剪切弹簧单元模拟桥墩剪切变形,转动弹簧单元模拟纵筋拔出变形.基于圆形截面桥墩抗震试验结果,并结合数值分析手段建立了桥墩剪切破坏时塑性铰区转角计算公式.并以此公式为基础,监测数值模型中桥墩剪切破坏,剪切破坏前桥墩以弯曲反应为主,剪切破坏后桥墩侧向强度和刚度发生显著退化.最后以3座实际不规则桥梁排架为工程背景,进行了排架横桥向地震作用下的滞回性能分析.研究表明,所建立的抗震分析模型可有效模拟由于桥墩剪切破坏造成的强度和刚度退化,为不规则桥梁结构抗震性能分析提供了依据.
Based on OpenSees numerical analysis platform, the beam-column, shear-spring and rotating-spring units are used to establish the numerical analysis model of the seismic response of irregular bridges with considering the shear failure of bridge piers. The shear spring was used to simulate the shear deformation of the piers, and the rotating spring unit was used to simulate the longitudinal deformation of the longitudinal reinforcement.According to the results of the seismic tests on the pier with circular cross-section and the numerical analysis, the formulas for calculating the rotational angles of the plastic hinge were established. Based on the formula, the shear failure of the bridge piers in the numerical model is monitored, and the bending response of the piers is mainly dominated by the shear failure. The lateral strength and stiffness of the piers are significantly degraded after the shear failure. Finally, three actual irregular bridges are used as the engineering Background, the analysis of hysteretic behavior under cross-bridge seismicity is carried out.The research shows that the established seismic analysis model can effectively simulate the degradation of strength and stiffness due to shear failure of pier, which is the seismic performance analysis of irregular bridge structure Provided the basis.