Column Cracking

This model assumed that the columns supporting the roof were cracked based on an analysis of the cracking moment. Accordingly, the moment-of-inertia was assumed to be 0.5 Igross.

Time-Dependent Effects

The time-dependent effects of creep and shrinkage in concrete were modeled using the ACI Committee 209 effective modulus approach (ACI 209, 1997) as follows:

E

^t=28days

1+Ф

Et=x = long-term modulus of elasticity Et=28 days = 570°0f ф = time- factor; this case equal to 1.5