Seismic Performance of Pre-Northridge Welded Steel Moment Connections to Built-Up Box Columns

Abstract

Results of experimental and analytical investigations of the seismic response of fully restrained steel moment connections between deep W-shape beams and deep and square built-up box columns are presented. Prototype beam-column connections were selected from the steel moment-resisting frames in a building built before the 1994 Northridge earthquake. Two full-size, single sided, pre-Northridge box column connection assemblage specimens were fabricated using the prototype connection data. Pretest analyses showed that the responses of box column connections can be substantially different from W-shape column connections. Both specimens were tested using a standard connection prequalification test protocol and each failed by brittle fracture in the complete joint penetration (CJP) welds of the beam flanges at connection drift angles less than