耗能型辅助墩抗震性能数值研究

NUMERICAL INVESTIGATION OF SEISMIC PERFORMANCE OF ENERGY DISSIPATION SUBSIDIARY PIERS

耗能型辅助墩可以有效地实现大跨度斜拉桥的地震损伤控制。刚度和强度是耗能型辅助墩的关键设计参数,因此,该文对安装剪切型连梁和屈曲约束支撑两种耗能构件的双柱墩进行理论分析,推导了耗能型辅助墩的刚度和强度的简化计算公式,能够快速准确地估算其弹性刚度和屈服强度。通过有限元模型,仿真分析了其滞回性能,可以准确地模拟耗能型辅助墩的非线性行为,为大跨度斜拉桥的整体弹塑性分析提供了可靠的依据。与试验结果对比,验证了简化公式和有限元模型的准确性。对比研究了安装耗能构件的双柱墩试件和拆除耗能构件的裸双柱墩试件的性能差异,结果表明耗能构件能够显著提高辅助墩的抗震能力。最后,对安装屈曲约束支撑的辅助墩抗震性能进行了参数分析。

Seismic damage control for long span cable-stayed bridges can be achieved by adding energy dissipation subsidiary piers. The stiffness and strength of energy dissipation subsidiary piers are key design parameters, so theoretical analyses for energy dissipation subsidiary piers with shear links(SLs) or buckling restrained braces(BRBs) are conducted. Then simplified formulas are developed to calculate the elastic stiffness and yielding strength of energy dissipation subsidiary piers fast and accurately. The finite element models are developed to replicate the hysteretic behavior of specimens. The numerical results accurately capture the nonlinear behavior of energy dissipation subsidiary piers and provide reliable models for the global elasto-plastic analysis of long span cable-stayed bridges. Compared with experimental results, the simplified formulas and finite element models are verified. The differences in behavior between the twin-column piers with and without energy dissipation elements are investigated. The results show that energy dissipation members can improve the seismic capacity of energy dissipation subsidiary piers significantly. Finally, parametric analyses for energy dissipation subsidiary piers with BRBs are performed.