Proposal for seismic retrofit of beam-to-column connection by the addition of H-section haunches to beams using bolt connection

This Paper proposes a method to improve plastic deformation capacity of the welded wide flange beam-to-column connections in existing steel buildings by using supplemental H-section haunches jointed by high-strength bolts and welding which expected to secure construction quality. By attaching supplemental haunches to upper and lower flanges of the beam end, the critical section is moved from the beam end to the beam cross-section corresponding to the tip of the supplemental haunch. As a result, it could prevent the fracture of beam flange initiated from toe of weld access hole. Cumulative plastic deformation capacities of retrofitted specimens were 1.5 to 2.0 times larger than that of un-retrofitted specimen.