SE Practice Exam Vertical Forces Breadth #26

[nicculusreadicculus]

May someone please help me find these equations that NCEES just magically pulled out of a hat? There is no reference to them anywhere in TMS402-16 or 22

 

[Rabbit12]

Find yourself a masonry textbook or design guide. Amrhein is really good. We still use an old version of his book in our office.

 

[Celt83]

They are geometric formulas

Here is a derivation for k:


If I recall correctly j is the moment arm between the steel reinf. and the center of the triangular compression block with d factored out.

 

[nicculusreadicculus]

They are geometric formulas

Here is a derivation for k:
View attachment 1479

If I recall correctly j is the moment arm between the steel reinf. and the center of the triangular compression block with d factored out.

This looks good, but where did you get the f_m and f_s equations from? Why is f_m a triangular block? I only took reinforced concrete design in school. I don't think many universities teach Masonry design anymore. I recall the Whitney stress block being a rectangle like you did for f_s

 

[YC611]

The PE handbook has a section that gives those formulas.

 

[lexpatrie]

Conversationally, I think LRFD uses a rectangular stress block, but ASD is legacy and uses triangular.

 

[YC611]

Conversationally, I think LRFD uses a rectangular stress block, but ASD is legacy and uses triangular.

I agree and I believe most still stick with ASD for masonry.

Below is the screenshot of the strength illustration from the PE handbook.