Seismic Performance of Steel Moment-Resisting Frames Utilizing Dissipative Embedded Column Base Connections

Experimental and numerical studies on steel wide-flange columns as part of steel moment-resisting frames (MRFs) revealed that their seismic performance can be compromised when seismically compact, yet relatively slender cross sections are adopted. One aspect relates to the repairability of steel columns due to residual axial shortening. For this reason, the weak-base/strong-column design concept, which relies on the superior inelastic deformation capacity of the column base connections and keeps the steel columns intact, has gained attention. Along these lines, the authors have developed an innovative dissipative embedded column base (DECB) connection. Experiments and finite element analyses have demonstrated that the proposed DECB connections enjoy a stable hysteretic response without any residual axial deformations in steel columns. However, the influence of DECBs on the seismic performance of steelMRFs has not been examined. This paper numerically investigates this aspect. A component model that can describe the hysteretic response of DECB connections is first proposed. Nonlinear response history analyses of steel MRFs with DECB connections are then performed under a maximum considered earthquake. The simulation results suggest that the use of DECBs in steel MRFs effectively eliminated the risk of building demolition due to residual column axial shortening. Moreover, residual story drift ratios are not as high as those in their ideally fixed steel MRF counterparts.