Design of Concrete Moment Frames.ppt - School of...
Transcript of Design of Concrete Moment Frames.ppt - School of...
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Design of Concrete Moment gFrames
Anindya Dutta, Ph.D., S.E.
Topics to be Covered
• Preferred Lateral Mechanisms
•Code Provisions for Member Design
•Shear Design of Beams
•Column Confinement Design
•Joint Design
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Structural Behavior of Frames
Undesirable Desirable
Story Mechanism
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Code Provisions
Chapter 21 deals with members resisting earthquake loads
Performance Objectives of ACI 318
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Code Provisions
Beam Design
Code Provisions
Beam Design
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Code ProvisionsBeam Design-Reinforcement
Code ProvisionsBeam Design
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Code ProvisionsBeam Design-Splice Requirements
Code Provisions
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Code Provisions
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Code ProvisionsBeam Design-Lateral Reinforcement
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Code Provisions
Code Provisions
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Code Provisions
Column Design
Code Provisions
Note:
Column Design
c1 is the dimension in the direction of framing and c2 is the perpendicular dimension
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Code Provisions
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Code Provisions
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Code Provisions
Column Longitudinal Reinforcement Design
Code ProvisionsColumn Longitudinal Reinforcement Design
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Code Provisionsem
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Code Provisions
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Code Provisionsem
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Code Provisions
emen
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Code Provisions
emen
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Code ProvisionsColumn Confinement Requirements
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Code ProvisionsColumn Spiral Hoop Requirements
Code ProvisionsColumn Supporting Discontinuous Stiff Members
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Code Provisions
Undesirable Desirable
Code ProvisionsHysteretic Behavior of Well Confined Concrete Columns
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Moment Frame Example
Moment Frame Example
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Moment Frame ExampleReinforcement Layout
Shear Design of Beams
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Shear Design of Beams-Example
Shear Design of Beams-Example
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Shear Design of Beams-Example
Shear Design of Beams-Example
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Shear Design of Beams-ExampleBeam Reinforcement Layout
Total 6-#8
Total 6-#8
Shear Design of Beams-Example
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Shear Design of Beams-Example
Special Moment Resisting Frame Joints - Design intent -
Vcol For seismic design, beam yielding defines demands
Beam
wMpr
Mpr
Vp
Mpr
Vp
lc
defines demands
Beam Section
lnbVp
VpVp
MprVcol
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Joint demands C2 = Ts2
Ts1 = 1.25Asfy
Vcol
Vb1 Vb2
(b) internal stress resultants acting on joint
Ts2 =1.25Asfy
C1 = Ts2
Vcol
Vcol
(a) moments, shears, axial loads acting on joint
(c) joint shear
Ts1 C2
Vu =Vj = Ts1 + C1 - Vcol
Joint shear strength
γ = 20 γ = 20γ = 20
hbfVV jcnu'φγφ ==
d) RoofInterior B.1
e) Roof Exterior B.2
f) RoofCorner B.3
ACI 352
φ = 0.85
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Joint Details - Interior
hcol ≥ 20db
ACI 352
Joint Details - Corner≥ ldh
ACI 352
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Code-conforming joints
Joint failures
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Joint Design-ACI Requirements
Joint Design-ACI Requirements
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Joint Design-ACI Requirements
Joint Design-ACI Requirements
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Joint Design-ACI Requirements
Joint Design-ACI Requirements
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Joint Design-ACI Requirements
Column Transverse Reinf. Design
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Column Transverse Reinf. Design
Column Transverse Reinf. Design
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Column Transverse Reinf. Design
Column Transverse Reinf. Design
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Column Transverse Reinf. Design
Column Transverse Reinf. Design