Ledges analysis is done following PCI 8th Edition or PCI 7th Edition. Limitations on this methodology, as listed in 5.6.1, are not checked and the engineer should verify the methodology is valid. When performing the calculations present in section 5.6 the following assumptions are made:
The bearing with, bt, is assumed to be 4 inches.
Only supports the following geometry types: Inverted Ts, Spandrels, L Beams
Loads are assumed to be located at the center of the ledge.
Loads assumed to be centered on ledge.
If using the 8th edition of the PCI Design Handbook and transverse reinforcement is not input by the user, the Vn used to compute R is assumed such that the factored shear capacity is not below the required demand. This in tern sets a maximum value of R (from shear) to be 0.75. For a more accurate analysis shear reinforcement must be input.
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