Reinforced Concrete Columns - MCEER

Deformation Components:
Shear → Axial Failure (cont.)
Residual Axial Capacity (after shear failure) of damaged RC
column:
P N = tanθ*[(A ST *f YT *d C )/s]*[(1+µtanθ)/(tanθ-µ)]
..where f YT is yield strength of transverse reinforcement, d C is distance b/w
extreme longitudinal reinforcement., s is transverse reinforcement spacing, θ is
critical crack angle, µ is effective friction coefficient, A ST is transverse
reinforcement area
P N
= [tan65(0.01228in2)(70ksi)(4.5417in) / (4in)]*[(1+(8.28kip/10kip)*tan65) /
(tan65-(8.28kip/10kip))]
= 4.4 kips
!When gravity loads exceed shear-friction forces, axial failure occurs in
column (column loses ALL shear capacity) → total collapse of structure