NEES11: Seismic performance of Column Splices

Seismic Performance of Column Splices with
Partial Joint Penetration Welds
S e a n S h a w, P h D , D e s i g n E n g i n e e r
Amit Kanvinde, PhD, Associate Professor
May 27, 2014
Acknowledgements
NEES@Berkeley
American Institute of Steel Construction
National Science Foundation
Herrick Corporation, Stockton, CA
Gayle Manufacturing, Woodland, CA
California Erectors, Benicia, CA
Overview
Background
Objectives
Research Scope
Results
Background
What is a PJP Weld?
Background
What is a CJP Weld?
Background
Northridge 1994– earthquake induced fracture in steel structures
Photo Acknowledgment - AISC
Background
Kobe 1995 – earthquake induced fracture in steel structures
Jarmai & Farkas
Background
Typical Pre-Northridge Column Splice
Background
2010 AISC Seismic Provisions
For most Seismic Force Resisting Systems
“Where welds are used to make the splice, they shall be
complete-joint-penetration groove welds.”
Background
Typical Post-Northridge Column Splice
Background
Inconvenient & Costly Field Welds
Interior groove weld
Background
Inconvenient & Costly Field Welds
back gouging
Background
Inconvenient & Costly Field Welds
exterior groove weld
Background
Excellent performance of tough, PJP
welded base plates and other details
Background
Excellent performance of tough, PJP
welded base plates and other details
Background
Can we use tough, PJP welded column
splices??
Objectives
Experimentally examine feasibility of PJP welded
column splices
Apply fracture mechanics to generalize finding
Examine implications for construction practice
Research Overview
frame analysis, testing protocol
Splice tests
synthesis, results,
implications
ancillary testing &
fracture mechanics
Research Scope
Research Scope
Test Setup - NEES@Berkeley
Research Scope
Specimens 24A&B
Specimen24A&B: Load vs. Displacement at Splice Location
2000
1500
Mp
My
Load (kips)
1000
Specimen 24A
Specimen 24B
500
0
-500
-1000
-1500
-2000
-2
-1
0
1
Displacement (in)
2
3
4
82% PJP External Flange Weld
87% PJP One-sided Web Weld
Specimen 24B – Post Test
Specimen 14B
Specimen14B: Load vs. Displacement at Splice Location
1500
Mp
1000
My
Load (kips)
500
0
-500
-1000
-1500
-2
-1
0
1
Displacement (in)
2
3
4
55% External Flange weld, 40%
Incomplete Internal Flange Weld
87% PJP One-sided Web Weld
Specimen 14B – Post Test
Specimen 14A
Specimen14A: Load vs. Displacement at Splice Location
3000
2000
Mp
My
Load (kips)
1000
0
-1000
-2000
-3000
-2
0
2
4
Displacement (in)
6
8
10
82% PJP Double Bevel Flange Weld
87% PJP One-sided Web Weld
Specimen 14A – Post Test
Specimen 14C
Specimen14C: Load vs. Displacement at Splice Location
500
400
Mp
My
300
Load (kips)
200
100
0
-100
-200
-300
-400
-500
-2
-1.5
-1
-0.5
0
0.5
1
Displacement (in)
1.5
2
2.5
3
89% PJP External Flange Weld
Bolted Web – No Weld
Results Summary
Implications
PJP welds with tough material performed very well
Fracture mechanics results (not discussed here) appear to
agree with these test results
The prohibition of PJP welded column splices appear to
be too restrictive
Questions???

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