Strength of concrete cantilever 1

[ACE58]

A new truck maintenance building has a 183' long fiberglass trench drain with variable depth of 6" to 13" below fin. floor. The top of the trench drain is a attached to steel angles w/ Nelson studs that were cast into the thickened concrete floor. Due to improper bracing & over-vibration of the concrete during installation, the trench body is twisted out of vertical alignment by varying amounts along its length. In the worst instance, there is now a 1 1/2"H x 7"V triangular "lip" of concrete (rather than a vertical face) supporting the trench frame. The contractor won't warrantee the installation for more than 1 year & the owner wants it replaced because he expects this lip to crack off in the future (as do I). Besides finite element analysis programs (our company doesn't have that capability), what design procedures/standards/formulas are applicable to produce hard data (rather than empirical knowledge) that this installation will fail after repeated loadings? I've asked other engineers I know & they're stumped as well. Any advice would be appreciated.

 

[BAretired]

How would the concrete fail with heavy dynamic loads? I don't know for sure, but I believe it would fail in shear on a line more or less normal to the studs. The studs would have to burst out of the concrete to allow this movement.

The probable failure planes are shown in red on the attached sketch. The failure plane on the left is not significantly narrower on the left side of the trench than on the right side, nor is it significantly narrower than it would be if the trench had been constructed properly.

BA