# Masonry Walls - LRFD for Slender Walls?



## McEngr (Feb 10, 2009)

I've been considering buying the Structural Reference Manual for the Civil PE exam by Williams. This is only because I'm studying for the SE II and I don't have the ACI 530-05 which includes the design of LRFD for slender walls. As some of you know, I'm not in a consulting firm that works with masonry anymore...laid off and in the telecom structural engineering realm of things...

Anyhow, I'm wondering if you think it's worth while to buy the Structural Reference for the Civil PE to cover this topic. It's only around $50.

http://www.ncees.org/exams/professional/pe...n_standards.pdf

Thanks,

McEngr


----------



## ARLORD (Feb 10, 2009)

McEngr said:


> I've been considering buying the Structural Reference Manual for the Civil PE exam by Williams. This is only because I'm studying for the SE II and I don't have the ACI 530-05 which includes the design of LRFD for slender walls. As some of you know, I'm not in a consulting firm that works with masonry anymore...laid off and in the telecom structural engineering realm of things...
> Anyhow, I'm wondering if you think it's worth while to buy the Structural Reference for the Civil PE to cover this topic. It's only around $50.
> 
> http://www.ncees.org/exams/professional/pe...n_standards.pdf
> ...



I have a masonry text book that discusses slender walls, LRFD design. Do you have a masonry text that may also discuss the topic. I don't have the new SERM4, I have the older SERM3. I actually didn't use the SERM at all on the SE II exam.


----------



## McEngr (Feb 10, 2009)

ARLORD said:


> I have a masonry text book that discusses slender walls, LRFD design. Do you have a masonry text that may also discuss the topic. I don't have the new SERM4, I have the older SERM3. I actually didn't use the SERM at all on the SE II exam.


The SERM4 is actually quite good. It goes through all of the p-delta methods of chapter c and appendix 7. It doesn't address masonry walls except for masonry shear walls. I have a really good concrete book that designs walls and shear walls, but I lack a decent masonry book - it's from like 1995.

What masonry book do you have?

Thanks ARLORD.


----------



## ARLORD (Feb 10, 2009)

McEngr said:


> The SERM4 is actually quite good. It goes through all of the p-delta methods of chapter c and appendix 7. It doesn't address masonry walls except for masonry shear walls. I have a really good concrete book that designs walls and shear walls, but I lack a decent masonry book - it's from like 1995.
> What masonry book do you have?
> 
> Thanks ARLORD.



My masonry text is by McGraw Hill. I got it over 6 years ago. See the following link for the title:

http://www.amazon.com/Design-Reinforced-Ma...a/dp/0070633665


----------



## kevo_55 (Feb 10, 2009)

McEngr,

I don't think that the SERM4 has the slender wall calculation for masonry in it. I've been looking in mine for a while now and just don't see it.

I learned my masonry &amp; concrete slender wall design in those Kaplan books. Have you looked into those?


----------



## McEngr (Feb 11, 2009)

kevo_55 said:


> McEngr,
> I don't think that the SERM4 has the slender wall calculation for masonry in it. I've been looking in mine for a while now and just don't see it.
> 
> I learned my masonry &amp; concrete slender wall design in those Kaplan books. Have you looked into those?


Hi Kevo,

Yeah. I suppose I was looking for the old h/t&lt;50 stuff that I studied for the first exam. I seem to have misplaced it. I think it was in the CERM. I have the kaplan books (2007 Problems and Solutions). It has only 1 example that I can tell. I'll look again.

Thanks.


----------



## MOOK (Feb 11, 2009)

The best reference for Masonry is

Design of Reinforced Masonry Structures, by Narendra Taly


----------



## McEngr (Feb 12, 2009)

MOOK said:


> The best reference for Masonry isDesign of Reinforced Masonry Structures, by Narendra Taly


God, I hope not. Taly is known for terrible typos and errors in his text. I have a prestressed book of his and I was very, very, very disappointed.


----------



## kevo_55 (Feb 12, 2009)

McEngr,

Those examples in Kaplan really opened my eyes to the P-delta effects of slender walls. I never really had a textbook in masonry as I had never taken it in college.

I can say that the 05 MSJC is pretty similar to the 02 version. I wouldn't worry too much if you don't have the 05 version.


----------



## McEngr (Feb 12, 2009)

kevo_55 said:


> McEngr,
> Those examples in Kaplan really opened my eyes to the P-delta effects of slender walls. I never really had a textbook in masonry as I had never taken it in college.
> 
> I can say that the 05 MSJC is pretty similar to the 02 version. I wouldn't worry too much if you don't have the 05 version.


Thanks kevo. As usual, very helpful.


----------



## kevo_55 (Feb 12, 2009)

No prob dude.

My pain is your gain. :thumbs:


----------



## MOOK (Feb 12, 2009)

I noticed that in All Allan Williams books (except SERM) he used SD method in Masonry Design. NCEES require SD method only for slender walls. In Kaplan books, Allan did not mention if these walls are slender or not. My question is how can we distinguish between the masonry slender wall from the non-slender one?


----------



## kevo_55 (Feb 12, 2009)

^^This was discussed some time ago. I think that the msjc states this in the back of the code.


----------



## ARLORD (Feb 13, 2009)

MOOK said:


> I noticed that in All Allan Williams books (except SERM) he used SD method in Masonry Design. NCEES require SD method only for slender walls. In Kaplan books, Allan did not mention if these walls are slender or not. My question is how can we distinguish between the masonry slender wall from the non-slender one?



You can use: walls are slender when h/t &gt; 30. See ACI 530 Section 3.3.5.4, that is the only location in the code that I know of that mentions a slenderness ratio. I have seen in text books where they give this ratio in the range of h/t&gt; 30-50.


----------



## Mcgill (Feb 13, 2009)

McEngr,

if you are preparing for SE 2 - I would recommend to buy 'seismic and wind design by Alan William (kaplan). I used this book and found very useful for my prep.

it covers slenderwall design for masonry, it has all masonry stuffs in SD- not good from exam point where you need ASD. But helpful for slenderwall design in SD.

My suggestion is don't worry about definition of slender wall - it should be clearly mentioned in exam if it appears.

thanks


----------



## MOOK (Feb 14, 2009)

Thanks Kevo 55 and ARLORD for the info. However, I do not agree about what you interpret from the code. To achieve the ratio h/t = 30, I need wall with 25ft height for 10" thick. I believe this has low chance to exist


----------



## McEngr (Feb 16, 2009)

MOOK said:


> Thanks Kevo 55 and ARLORD for the info. However, I do not agree about what you interpret from the code. To achieve the ratio h/t = 30, I need wall with 25ft height for 10" thick. I believe this has low chance to exist


Good point, but it never hurts to be prepared.


----------



## kevo_55 (Feb 16, 2009)

Mook,

I somewhat see your point but also see the other side of the coin. If you are using an 10" CMU to design a 30' wall, you sure better design it with LRFD. That's pretty slender!

See: A.3.5.5 (page C-62) of the '05 MSJC.

Like McEngr said, it's better to be prepared.


----------

