Seismic behaviour of reusable column base connection with pinned energy dissipators

Abstract

A column base connection has been proposed to achieve reusability and self-centring after earthquakes. This proposed connection incorporates simple metallic yielding energy dissipators to effectively absorb seismic energy, while also employing pinned joints to facilitate the restoration of rocking behaviour in the column. To investigate the hysteretic behaviour of this innovative connection, a series of quasi-static tests were conducted on six groups of specimens. Among the parameters explored were the length, width, and limb number of the reduced section, activation angle, and material characteristics of the dissipative plate. During these experiments, the rocking mechanism was successfully demonstrated, and it was observed that the failure mode primarily involved concentrated plastic deformations of the dissipative plates. All of the specimens exhibited exceptional energy dissipation and self-centring capabilities. Furthermore, the repair process simply required the replacement of the damaged dissipative plates, which proved to be advantageous in terms of cost-effectiveness and efficiency. As a result, the repaired specimens regained their load-bearing ability and seismic performance to a comparable level as the original specimens. In the analysis of the test data, the changing patterns of dissipated energy, equivalent viscous damping ratio, and secant stiffness were determined in relation to the increasing target lateral displacement. The effects of various parameters on these aforementioned indexes were also preliminarily investigated. Additionally, based on the design concept, the relationship between moment and rotation angle of the column was described by an idealised curve. Consequently, the moment resistances of all test specimens were calculated, and the predicted results aligned well with the actual test results.