Transcript Steel Concrete Composite (SC) Modular Construction for

Steel Concrete Composite (SC)
Modular Construction for SafetyRelated Nuclear Facilities
Codes and Standards
Future Work
Appendix N9 for AISC N690
• N9A – General requirements
– Materials, welding, etc.
• N9B –Minimum requirements for SC sections
– Reinforcement ratio and plate thickness
– Concrete thickness
– Plate slenderness
– Tie system requirements
– Shear connector spacing and size
Appendix N9 for AISC N690
• SC specific failure modes
– Prevented from governing design
– N9B4 - Plate slenderness ratio to ensure yielding
before local buckling (non-compactness)
– N9B5 - Stud spacing and size to prevent
interfacial shear failure from governing design
strength
– N9B6 - Tie system spacing and strength to
prevent splitting failure of the composite section
Appendix N9 for N690
• N9C - Analysis Recommendations
– Stiffness as a function of concrete cracking
– In-Plane shear stiffness (pre and postcracking)
– Flexural stiffness (pre and post- cracking)
– Cracked stiffness for accident thermal loading
combinations
– Recommendations for finite element modeling
– Calculation of Design Demands
Appendix N9 for N690
• N9D – Design for axial tension demands
• N9E – Design for axial compression
demands
• N9F – Design for flexural demands
• N9G1 – Design for in-plane shear
demands
Appendix N9 for N690
• N9G2 – Design for out-of-plane shear
– Four cases:
– (1) Tie system yielding or non-yielding
– (2) Spacing less than thickness/2 or more
– Account for size effects
Appendix N9 for N690
• N9H – Design for combined forces
– Interaction equation for two out-of-plane shears
– Interaction equation for tie systems acting in
interfacial shear and axial tension
– Interaction surface for SC walls subjected to
combined in-plane forces and out-of-plane
moments
Appendix N9 for N690
• N9J – Connection Design
– Full strength connection design
• Designed so that connection is stronger than
weaker of connected walls
• Ductile behavior ensured
– Over strength connection design
• Designed for 200% of seismic forces in
combinations with other demands
• Relies on overstrength to achieve HCLPF of 1.67
SSE
Appendix N9 for N690
• Connections can be designed using
connector elements that are widely used
– Rebars, dowel bars
– Welding, base plates
– Shear studs, shear lugs etc.
Future Work
• Experimental evaluation of full-strength
connections
– SC wall-to-basemat connections
• Experimental confirmation of joint shear
strength
– SC wall-to-wall joints
• Experimental confirmation of SC wall to
slab connections
SC Wall-to-Wall Joint
• Experimental setups developed,
specimens being designed
SC Wall-to-Wall Joint
SC Wall-to-Wall Joint Analysis
• Nonlinear analysis benchmarked to
experimental results, and used to conduct
parametric studies
SC Wall-to-Basemat Connections
• Full strength connection will develop strength
of SC wall, no failure in connection elements
• Setup designed and built, specimen being
designed
SC Wall-to-Basemat Connection
• Specimens being designed, and different
options being evaluated analytically
Baseplate
5 - #6 @ 3.5”
O.C. Rebar
Lenton Rebar
End Anchors
Future Research Needs
1. Effects of accident thermal loading on
connection behavior and design
2. Effects of tornado and hurricane missile
impact on SC walls (two-way shear strength)
3. Concepts, designs, and tests of SC floors.
4. Fire resistant design of SC floor slabs
5. Effects of penetrations and pipes on SC wall
design strength
Future Research Needs
6. Benchmarked analytical approaches for
evaluating behavior of complex SC designs
7. Evaluation of green options for concrete in
SC walls
8. Effects of fabrication, erection, and
construction related imperfections and
tolerances on SC wall design
9. Inspection and monitoring plans
10. Damping ratios for SC systems