Strap Footing vs. Combined Footing
Strap Footing vs. Combined Footing
(OP)
A long time ago when I was designing larger buildings, I had to design a lot of combined footings. One time however, I had to design a strap footing. I can't remember why I had to use a strap instead of a combined footing. Can anyone explain when it is appropriate to use a strap footing over a combined footing? I also forgot the simple design of the strap footing. Can anyone refresh my memory?






RE: Strap Footing vs. Combined Footing
A strap footing is a beam that is supported by two spread footings, cantilevering over one of them. The column near the property line or existing building sits at the tip of the cantilever.
DaveAtkins
RE: Strap Footing vs. Combined Footing
I designed many combined footings where the exterior column was next to the property line but I guess I was always able to get the pressures to work so I never had to ask what happens when they don't. The only time I designed a strap footing was on a project where I was working with a 70 year old engineer. (We started the same day. I was 23. He was 70. He liked to travel around the world.) Anyway, it was a column for a long span truss over an atrium that was part of an addition to a hosptial. He must have known by experience or by running a quick number that a combined footing wouldn't work. I can't remember if he ever explained why or I forgot to ask. It was a VERY fast track project.
RE: Strap Footing vs. Combined Footing
RE: Strap Footing vs. Combined Footing
RE: Strap Footing vs. Combined Footing
RE: Strap Footing vs. Combined Footing
RE: Strap Footing vs. Combined Footing
Isn't that what a strap footing is? A grade beam cantilevering over one footing, with the back span going to another footing (preferably with a column on top of it)?
DaveAtkins
RE: Strap Footing vs. Combined Footing