Odd offset masonry pier design in existing structure
Odd offset masonry pier design in existing structure
(OP)
I've been called out to a building where the architectural drawings were not very good. I attached a picture. There are a bunch of offset piers with cantilevers. I'm not worried about the actual sizes of the beams. I've sized those. What I'm worried about is the size of the piers. The first floor piers are made of 4" CMU and limestone stackbond. I should also mention that this is under construction and they're at the top of the first floor. They have all these problems because they never hired a structural engineer. Now they need repair details. I'm concerned about the lateral resistance of the pier. The pier doesn't have to be designed for seismic, building is in Chicago (code states this). Drawings show the channels bearing on the piers, I'm going to splice all steel together to give some continuity. I think this will help the lateral capacity at the front. I am trying to figure out a solution to avoid telling the owner to rebuilding the first floor piers with reinforced 8" block. Thoughts?






RE: Odd offset masonry pier design in existing structure
But that's just what I've seen. The last time we had to come in after the fact and check 4" CMU we ended up attaching channels along the full height of the CMU to provide any out of plane resistance.
RE: Odd offset masonry pier design in existing structure
BA
RE: Odd offset masonry pier design in existing structure
Regardless of the code outs available to you, I wouldn't disregard seismic, especially for your connections. You've got the New Madrid fault in the vicinity. I'd hate to see one of those piers fly off and crush one of our fellow humans.
Can you share any more detail about the building?
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Odd offset masonry pier design in existing structure
RE: Odd offset masonry pier design in existing structure
RE: Odd offset masonry pier design in existing structure
In the ‘windy city’ you don’t have to design for wind loads on a bldg. either? “(code states this)”? You’ve got a soft story at the second level, two piers in their weak direction. And, damn little in the way of lateral restraint structure ( two piers?) at the first and third levels. Two 4' screening piers which are not continuous, at levels 1 & 3, just won’t cut it. That you’ve asked this question, the way you have, suggests that you should find a local mentor to help you with this problem. You and the Arch. are in way over your heads on this one, and I don’t mean in Lake Michigan either.
RE: Odd offset masonry pier design in existing structure
RE: Odd offset masonry pier design in existing structure
BA
RE: Odd offset masonry pier design in existing structure
RE: Odd offset masonry pier design in existing structure
RE: Odd offset masonry pier design in existing structure
RE: Odd offset masonry pier design in existing structure
BA
RE: Odd offset masonry pier design in existing structure
RE: Odd offset masonry pier design in existing structure