BadgerPE
Structural
- Jan 27, 2010
- 500
I am working on analyzing an existing exterior two-way slab (circa 1968) with drop panels and am looking to determine the design moments and capacities of the slab based upon current code requirements. This slab has been subjected to some significant weathering effects and most likely some deterioration so reduction in capacity from the original design is likely. However, the architect is pursuing options to reduce the live load requirements on the slab.
Since this is new to me, I am looking to do the analysis by hand using the equivalent frame method. Direct design method was ruled out because adjacent spans are less than 1/3 of the max span, which is a requirement in the DDM. I have read up on the EFM quite a bit and have replicated design example 20.1 from the PCA Notes on 318-08 up until the frame moments are adjusted to the face of the support. I am unsure how the shear diagram was calculated in the attached example. I suspect it has to do with unbalanced column moments, but I am unsure. Any guidance on how to obtain these values?
Since this is new to me, I am looking to do the analysis by hand using the equivalent frame method. Direct design method was ruled out because adjacent spans are less than 1/3 of the max span, which is a requirement in the DDM. I have read up on the EFM quite a bit and have replicated design example 20.1 from the PCA Notes on 318-08 up until the frame moments are adjusted to the face of the support. I am unsure how the shear diagram was calculated in the attached example. I suspect it has to do with unbalanced column moments, but I am unsure. Any guidance on how to obtain these values?
