底部加强型工字形钢管混凝土柱抗震性能研究

Study on seismic behavior of bottom strengthened I-section concrete filled steel tube columns

提出了工字型截面钢管混凝土柱,同时提出了一种在柱底部区域翼缘贴焊钢板的底部加强型工字形截面钢管混凝土柱。进行了3个不同构造的工字形钢管混凝土柱模型的低周反复荷载试验,模型1为普通工字形钢管混凝土柱,模型2为工字形截面两翼缘外侧贴焊钢板的钢管混凝土柱,模型3为工字形截面两翼缘周边均贴焊钢板的钢管混凝土柱。分析了各模型的破坏特征、承载力、刚度及退化过程、延性和滞回耗能特性。给出了工字形钢管混凝土柱正截面及斜截面承载力计算公式,计算结果与实测符合较好。研究表明:所提出的底部加强型工字形钢管混凝土柱与普通工字形钢管混凝土柱相比,承载力明显提高,延性和抗震耗能能力显著提高。

The I-section concrete filled steel tube （CFST） column and the bottom strengthened I-shaped cross section CFST column, in which the column flange was welded with steel plates, were proposed. Three columnmodels with different constructions were tested under horizontal low cyclic loading. Model 1 was a conventional I-section CFST column;model 2 was an I-section CFST column with its outer part at the bottom of flange weldedwith steel plates; model 3 was an I-section CFST column with its surrounding part at the bottom of flange welded with steel plates. The failure characteristics, load-bearing capacity, stiffness and degradation process, ductility andhysteretic energy dissipation capacity of the models were analyzed. The calculation formula for cross section and oblique section load-bearing capacity of bottom strengthened I-shaped cross section CFST column was given, and theresults obtained from the calculation are in good agreement with those from the experiments. The study shows that the load-bearing capacity, ductility and seismic energy dissipation capacity of the bottom strengthened I-sectionCFST column are improved obviously compared with the conventional I-section CFST column.