QUASI-STATIC TESTS OF WALLED CONCRETE-FILLED STEEL TUBULAR COLUMNS WITH BINDING BARS

To avoid column protruding from the infill wall in multi-story steel structure buildings, a walled concrete-filled steel tube column with binding bars and with a section height-to-width ratio of 3.0 is proposed. To study the seismic behavior of the walled concrete-filled steel tubular column with binding bars (WCFT-B Column), the quasi-static experiments were conducted on two full-scale specimens. The test results show that: the binding bars can effectively restrain the local buckling of the column walls on both sides; the specimens fail in the local buckling of steel plates, and the longitudinal welds tear between steel plates at the bottom of the column; the hysteresis curves of the specimen are relatively plump without significant pinching effects; the yield drift ratios of the specimens vary 1/147 rad to 1/121 rad and the ultimate drift ratios are between 1/51 rad and 1/41 rad; the displacement ductility coefficient is about 2.61 to 3.11 and the bearing capacity degradation coefficients of the specimens are between 0.86 and 1.04; upon the failure of the specimens, the equivalent viscous damping coefficients are above 0.3. Based on the quasi-static experiments, the finite element (FE) model of the specimens was developed; The FE results are in a good agreement with the test ones, which verify the correctness of the FE model and provide a reference for the numerical simulation of such components. The research results enriched the types of rectangular concrete-filled steel tube composite components and promoted the development of fabricated steel structure buildings.