Tilt-Up Wall Nominal Moment Capacity vs Cracked Moment Capacity
Tilt-Up Wall Nominal Moment Capacity vs Cracked Moment Capacity
(OP)
In ACI 318-11 Section 14.8.2.4, it gives a requirement that the nominal moment capacity of a concrete wall shall be greater than the cracking moment of that wall. My question is that if all of my factored loads (Pu, Mu, Vu) are all lower than the allowable nominal values (Pn, Mn, Vn) and my combined axial and flexural calculations are sufficient, and the only thing that doesn't check out in my calculations is the Mc<Mn, is it unreasonable to say that the panel is sufficient? I'm trying to understand the theory behind the Mc<Mn equation and why it requires me to put more reinforcement into my panel when I am at a Mu/Mn ratio of less than 0.15 for all cases. Worst case scenario is that my nominal moment is 15% larger than my cracking moment. Can someone explain to me the importance of this check??
Thanks in advance!
Thanks in advance!






RE: Tilt-Up Wall Nominal Moment Capacity vs Cracked Moment Capacity
I consider this less important, and might be willing to waive the requirement, for a wall panel where the bending loads are mainly the result of transient environmental effects (Wind/EQ). Another option, for complete code compliance, might be to treat the panel as plain concrete.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Tilt-Up Wall Nominal Moment Capacity vs Cracked Moment Capacity
RE: Tilt-Up Wall Nominal Moment Capacity vs Cracked Moment Capacity
RE: Tilt-Up Wall Nominal Moment Capacity vs Cracked Moment Capacity
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Tilt-Up Wall Nominal Moment Capacity vs Cracked Moment Capacity