内嵌加劲耗能钢板的箱形钢墩柱拟静力试验及数值分析

Pseudo-Static Test and Numerical Study on the Box Steel Pier with Built-in Stiffened Energy-Dissipating Steel Plates

地震作用下钢桥墩根部易发生屈曲破坏且震后难以快速修复。基于可恢复功能理念与钢桥墩的受力特征,提出一种具备震后易恢复功能的新型箱型钢桥墩。此新型桥墩通过设置可更换的加劲耗能壁板以增强结构的耗能与变形能力,且震后能够快捷更换受损的耗能壁板以恢复桥墩力学性能。为研究设置加劲耗能壁板的箱型钢墩柱的抗震性能,选取耗能壁板上加劲肋的布置形式、轴压比及耗能板强度等作为影响参数进行拟静力试验,且通过有限元数值模拟,综合探讨此类新型试件在地震作用下的力学性能;并对比分析新型桥墩的受力特点和破坏机理,为此类钢墩柱的数值仿真提供理论基础。结果表明,增设内嵌耗能钢板后,试件的抗震性能得到较大改善;提高耗能板强度后,试件的水平承载力得到较大提高,但其延性与变形能力下降;有限元模拟结果验证了新型钢桥墩良好的抗震性能。在试验研究、理论分析与数值仿真的基础上提出此类新型钢桥墩承载力建议公式,并应用试验结果验证了公式的准确性。

The steel piers are prone to buckling destruction at the root and difficult to repair after the earthquake.Based on the recoverable function and mechanical characteristics of steel piers,a novel box steel piers with easy recoverable function after earthquake is proposed.The new piers can enhance the energy dissipation and deformation capacity of the structure by setting replaceable energy-dissipating plates.The damaged energy-dissipating plates can be quickly replaced after the earthquake to restore the mechanical properties of the piers.To clarify the seismic performance of box steel piers with built-in stiffened energy-dissipating steel plates,the layout of stiffeners,the axial compression ratio and the strength of energy-dissipating plate are selected as parameters to carry out pseudo-static tests.A finite element numerical model is generated to analyze the mechanical properties of the specimens under seismic action.The mechanical characteristics and failure mechanisms of the new piers are compared and analyzed as a theoretical basis of the numerical simulation.The results indicate that the seismic performance of the specimens is improved significantly by embedding the energy-dissipating steel plate.The energy-dissipating plate greatly enhanced the horizontal bearing capacity of the specimens,but it reduced the ductility and deformation capacity.Finite element simulation results are verified on the seismic performance of the new steel piers.Based on the experimental research,theoretical analysis and numerical simulation,a formula is proposed on the bearing capacity of the new steel piers,and the accuracy of the formula is verified by comparing to the test results.