Experimental and numerical studies on the hysteretic behavior of linked column frame with uplifted column feet

In order to reduce earthquake damage of structures and lowering corresponding repair costs, this paper proposes an uplifted column foot with springs for linked column frame (LCF). Firstly, two 1:3 scale pseudo-static tests have been conducted to investigate the hysteretic behavior of LCF with uplifted column feet. The results indicate that when LCF is subjected to horizontal loads, springs are compressed axially, and then the column moves upwards in vertical direction. Meanwhile, in the link beam, it occurs a small vertical displacement. Consequently, the frame rotates like a rocking structure. The link beam, in which most damage is concentrated, is proved as the first earthquake fortification line of LCF system. In other words, link beams can be replaced rapidly following moderate earthquakes, so that the performance level of a building can return to its functionality. Furthermore, the web configuration of link beams can greatly influence the hysteresis performance of whole LCF system. Secondly, the finite element software Abaqus was used to carry out a numerical validation. The result shows that the hysteretic curves of FEM are roughly consistent with those of the test. A parametric study on the influence of spring ultimate deformation capacity Δsu and length of link beam l was carried out. Eventually the results suggest that Δsu has a significant influence on the seismic response of LCF system. More specifically, Δsu can change the yielding mechanism of LCF system, whereas the length of link beam l has little influence on the hysteresis performance of LCF system.