Masonry Block
Masonry Block
(OP)
There is a formula to height of masonry block wall, ratio of Block width dimension; i.e. 4" block, maximum 6' height. I've forgotten the formula and can't find note within my reference materials for maximum height of 6",8", 12". Can you help?






RE: Masonry Block
RE: Masonry Block
Undfer the "new" masonry codes, that provision was basically removed. However, most people still use it.
RE: Masonry Block
RE: Masonry Block
If you are really concerned about P-delta effects on the wall, you could try the UBC slender wall design method and see what you get, Enercalc has it.
RE: Masonry Block
THEY ARE VERY USEFUL AS A GUIDEINE EVEN FOR ENGINEERED DESIGNS
RE: Masonry Block
RE: Masonry Block
RE: Masonry Block
Reinforced masonry walls under the NCMA Code were limited to h/t of 36, unless "evidence by a qulaified person showing the wall met all the other requirements".
As I previously ststed, the MJSC no longer limits the height of the "engineered" walls. Walls are designed based on the h/r ratio, where r is the radius of gyration = sq. root of (I/A).
If you are "designing" a masonry walls based on the EMPIRICAL DESIGN methodilogy of Chapter 5, the h/t ratiuoa are still used. The h/t ratios are different than the "old" NCMA limits but not significantly. The "new" h't ratios classify the walls as bearing or non-bearing walls, interior or exterior.
RE: Masonry Block
It is interesting that they give and h/t ratio of 20 for an unreinforced nonbearing exterior wall. If you were to engineer a wall like this, particularly with a small dead load to reduce the tension bending stresses, it would never work out under most wind loadings.
RE: Masonry Block
RE: Masonry Block
RE: Masonry Block
http://www.ncma.org/etek/homefrm_map.cfm?spdm=cemexusa.com