Retrofit of Pre-Northridge Moment-Resisting Connections
Publication: Journal of Structural Engineering
Volume 126, Issue 4
Abstract
An experimental program was undertaken to evaluate methods to retrofit existing steel moment connections for improved seismic performance. Six full-scale subassemblages were tested under cyclic loading. Typical pre-Northridge connections were retrofit by the addition of either a bottom flange dogbone or a welded bottom flange haunch. Retrofitted specimens were tested both with and without a composite floor slab. The tests showed poor performance of the bottom flange dogbone retrofit when the existing low toughness welds were left in place. Somewhat improved performance was observed when the bottom flange dogbone was combined with replacement of beam flange groove welds with higher toughness welds. The welded bottom haunch retrofit showed excellent performance on specimens with a composite slab, even though the existing low toughness beam flange groove welds were left in place. The presence of the composite slab appeared to help prevent fracture of the existing top flange weld in the haunch retrofit. This paper provides a summary of the complete experimental program.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 126 • Issue 4 • April 2000
Pages: 445 - 452
History
Received: Jul 1, 1999
Published online: Apr 1, 2000
Published in print: Apr 2000
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