Splay rod install on pre-eng building
Splay rod install on pre-eng building
(OP)
I have a pre-engineered steel building 100'x50' and i have done a fast foundation design for it. However i'm not sure if the building requires splay rods or not. I have design the columns to sit on concrete piers and the piers are tied into the surrounding foundation wall. Does anybody know where to get info on the design of splay rods?






RE: Splay rod install on pre-eng building
Are you talking about embedded hairpins in the slab to take the lateral kick of the mainframes?
Mike McCann
McCann Engineering
RE: Splay rod install on pre-eng building
RE: Splay rod install on pre-eng building
During our search we learned about a book that Butler Manufacturing published in the mid 80s. It was a design guide on pre-engineered building foundations. It contained some test data and good 'rules of thumb'...so I am told. It is out of print for liability reasons.
If you find it let me know where to get it!
I would say that if you are in doubt and it is a rush job, do a thickened slab from column to column and embed cross ties. Then there is no question.
cldea8
RE: Splay rod install on pre-eng building
Still do not know what he meant by "splay rods" though.
Mike McCann
McCann Engineering
RE: Splay rod install on pre-eng building
RE: Splay rod install on pre-eng building
I have a copy of the Butler Manufacturing Foundation Design and Construction Manual, although I have no idea how to get it out there for you. Any ideas?
RE: Splay rod install on pre-eng building
It is good to know it does exist anyway...
RE: Splay rod install on pre-eng building
RE: Splay rod install on pre-eng building
Hair pin rebars uses the principle as tie rods, and in this system hairpin relies on the floor slab to function as the tie. Concrete itself cannot take much tension but the steel reinforcement within slab would. By lap splicing the horizontal loads are transfered to the floor slab.
to design a hairpin, divide the horizontal column reaction by an allowable tensile stress of the reinforcement (24 for Grade 60 steel, ) and you will get the area of steel to be used. The length of bar depends on the slab area to be engaged, it should be long enough for the assumed failure plane to intersect the desired number of slab rebar and to allow for their proper development.
Do keep in mind that for these hairpins your flooring should be reinforced. and not PCC. it would be a Slab on grade.
hope this helps