To rapidly restore the seismic behaviour of a portal steel bridge column after an earthquake, the installation of replaceable tubular steel piers at the root of a portal steel bridge column is proposed herein. In this study, various tubular steel piers with different structural measures were designed; an axial compression test and a numerical simulation of the newly designed tubular steel piers were performed. The effects of parameters such as the structure of stiffening rib, the strength of LYP steel plate, the size of low-yield-point (LYP) steel plate, and the size of outer constrained steel plate were discussed. The results indicate that local buckling of steel tubular plates is likely to occur at the upper or lower end of those specimens, which belong to type II-A specimens with stiffened LYP steel tubular plates or type III-A specimens with T-shaped LYP steel plates, respectively. This led to the LYP steel plate cannot fully display its function. For type III-B and III-C specimens with embedded LYP steel plates and constrained steel plates on both sides, when the outer steel tubular plates buckle, the internally constrained LYP steel plates provide support for the outer steel tubular plates. The plastic deformation of the specimens is sufficient, and the deformation performance is good. For type IV-A specimens with LYP steel tubular plates and constrained steel plates on both sides, the mechanical behaviour of the new tubular steel piers is significantly improved, and increasing the height of the constrained LYP steel tubular plate can improve the compressive behaviour of the new tubular steel pier. Considering the effect of the steel plate thickness on bearing capacity and deformation performance, the thickness t_w of the outer constrained steel plate should be equal to the thickness t of the common steel tubular plate, and the thickness t_f of the LYP steel tubular plate should satisfy t ≤ t_f ≤ 2t. Finally, a design formula is proposed to calculate the axial bearing capacity of newly designed tubular steel piers with constrained LYP steel plates.

中文翻译：

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新型可更换管状钢管墩的抗压性能

为了在地震后快速恢复门式钢桥柱的抗震性能，本文提出在门式钢桥柱的根部安装可更换的管状钢墩。在这项研究中，设计了各种具有不同结构措施的管状钢管墩。进行了新设计的管状钢管墩的轴向压缩试验和数值模拟。讨论了加劲肋的结构，LYP钢板的强度，低屈服点（LYP）钢板的尺寸以及外约束钢板的尺寸等参数的影响。结果表明，在这些样品的上端或下端可能会发生钢管的局部屈曲，分别属于带有加强LYP钢管板的II-A型试样或属于T形LYP钢板的III-A型试样。这导致LYP钢板无法充分发挥其功能。对于在两侧均嵌入LYP钢板和受约束​​钢板的III-B和III-C型试样，当外部钢管板弯曲时，内部受约束的LYP钢板为外部钢管板提供支撑。试件的塑性变形充分，变形性能良好。对于在两侧都带有LYP钢管板和受约束​​钢板的IV-A型试样，新的钢管墩的机械性能得到了显着改善，增大受约束的LYP钢管板的高度可以改善新型管状钢管墩的抗压性能。考虑钢板厚度对承载力和变形性能的影响，厚度吨_瓦特外约束钢板的应等于厚度吨普通钢管状板的，并且厚度吨_˚F的LYP钢管板的应满足吨 ≤ 吨_˚F  ≤2吨。最后，提出了一个设计公式来计算新设计的约束LYP钢板的管状钢管墩的轴向承载能力。