實尺寸三層樓鋼構架二元系統於2022池上地震下之振動台試驗：中等韌性箱型鋼柱、全鋼型夾型挫屈束制支撐及滑動樓版之耐震性能

Abstract

本研究討論中等韌性斷面箱型鋼柱、全鋼型夾型挫屈束制斜撐及新型滑動樓版系統在振動台實驗中之耐震性能，製作一組三層樓實尺寸二元系統試體，鋼材使用CNS SN490B，箱型柱斷面寬厚比為20.5及21.1，滿足美國鋼結構耐震規範AISC 341-22之中等韌性斷面要求，以全鋼型夾型挫屈束制支撐作為試體中之斜撐，而試體樓版採用鋼筋混凝土預鑄樓版，樓版與構架間在不同階段中分別以全鋼型夾型挫屈束制支撐及T型軸力桿件連接。使用2022池上地震玉里測站東西向之地震紀錄作為實驗輸入之加速度歷時，實驗由小規模地震開始進行，逐次提高至最大規模為台面加速度達1.05 g。實驗結果顯示使用中等韌性斷面箱型鋼柱在初始軸力0.1Py下於層間位移達0.038 rad時仍能有良好耐震行為，箱型柱可發展至Mp及軸壓0.28Py且不發生局部挫屈。全鋼型夾型挫屈束制支撐作為試體中的斜撐，在實驗中最大軸向變形達2.6%，累積韌性容量達到749以上，表現出極佳的韌性及遲滯消能行為，可作為挫屈束制斜撐構架中良好的斜撐消能桿件。新型滑動樓版系統在實驗中被證實可以在地震時降低地震側向力，滑動量越大則慣性力降低比例越高，而使用全鋼型夾型挫屈束制支撐作為水平連接桿件能比使用T型軸力桿件提供額外消能，實驗中觀察到此機制可使樓版加速度降低25%，進一步降低地震力。

This study discusses the seismic performance of moderately ductile box columns, all-steel sandwiched buckling-restrained braces, and a new sliding slab system in shake table tests. A full-scale three-story steel dual system specimen was constructed, with CNS SN490B steel used as the material. The box column sections had width-to-thickness ratios of 20.5 and 21.1, satisfying the requirements of the American Institute of Steel Construction (AISC) 341-22 for moderately ductile members. The specimen utilized all-steel sandwiched buckling-restrained braces as diagonal bracing, and the slabs consisted of precast reinforced concrete slabs. The slabs were connected to the frame using all-steel sandwiched buckling-restrained braces and T-members in different phases. The input acceleration history for the experiments was obtained from the 2022 Chishang earthquake Yuli seismic station in the east-west direction. The experiments started with small-scale earthquakes and gradually increased to the maximum scale with a table acceleration of 1.05 g. The experimental results demonstrate that the moderately ductile box columns exhibited good seismic behavior even when the story drift reached 0.038 rad under an initial axial force of 0.1Py. The columns were capable of developing plastic moment and resisting axial compression up to 0.28Py without experiencing local buckling. The all-steel sandwiched buckling-restrained braces used as diagonal bracing in the specimen achieved a maximum axial deformation of 2.6% and cumulative plastic ductility exceeding 749, demonstrating excellent ductility and hysteretic energy dissipation behavior. They can serve as effective energy dissipation elements in buckling-restrained brace frames. The new sliding slab system was proven to reduce seismic lateral forces during earthquakes. The larger the sliding displacement, the higher the reduction in inertial forces. Additionally, using all-steel sandwiched buckling-restrained braces as horizontal connecting elements provided additional energy dissipation compared to using T-members. It was observed during the experiment that this mechanism can reduce floor acceleration by 25%, resulting in further reduction of seismic forces.