Truss to Beam Connection
Truss to Beam Connection
(OP)
I've got steel trusses currently sitting on top of a concrete header. The trusses span 60 feet. The roof is curved. The bottom chords of the trusses are 4" channel oriented so that they are sitting on their 'legs'. The bottom chord currently rests on the concrete header - the two are not connected.
I had a SE design a new steel beam and column system, but he failed to address the connection of trusses to the beam. According to his numbers there is an approximate 7300 lb uplift reaction per truss while the deadload is about 5300 lb. Two-thousand pounds of force isn't much to counter. I figure I can just run a fillet weld down one side of the truss (the beam has a 10" flange)and be done with it - the only shear should be from thermal expansion.
Is there anything else to consider? What bothers me is the fact that the truss is not currently connected to the header. The building was constructed in 1927 and I realize they didn't have the same building requirements, but is there another reason why the truss would be allowed to 'float'?
I had a SE design a new steel beam and column system, but he failed to address the connection of trusses to the beam. According to his numbers there is an approximate 7300 lb uplift reaction per truss while the deadload is about 5300 lb. Two-thousand pounds of force isn't much to counter. I figure I can just run a fillet weld down one side of the truss (the beam has a 10" flange)and be done with it - the only shear should be from thermal expansion.
Is there anything else to consider? What bothers me is the fact that the truss is not currently connected to the header. The building was constructed in 1927 and I realize they didn't have the same building requirements, but is there another reason why the truss would be allowed to 'float'?






RE: Truss to Beam Connection
RE: Truss to Beam Connection
RE: Truss to Beam Connection
I also don't think it sees any lateral deflection. This is Florida, so there are no seismic conditions. I would therefore assume that lateral loading would be due to wind. The front and back of the building are constructed of concrete block which extends above the roof line by a couple of feet. I assume the walls take the lateral load and would be surprised if the trusses see any lateral deflection. But then, I'm a ME and not a SE, so I may not understand this quite right.
RE: Truss to Beam Connection
RE: Truss to Beam Connection
RE: Truss to Beam Connection
If there is not lateral deflection due to gravity loads, weld that sucker.
RE: Truss to Beam Connection
Will welding the "barrel trusses" to the beam be a cause for concern? If so, are there any suggested alternatives?
RE: Truss to Beam Connection
RE: Truss to Beam Connection
RE: Truss to Beam Connection
RE: Truss to Beam Connection
I'm a little concerned about the age of the steel, mostly for the same reasons you mentioned. Welding seems to be the most attractive option, though. I don't want to cut holes in the bottom chord for through-bolting, and I really don't want to design (and have fabricated) a unique hold down clamp that would bolt to the beam. If there's another (viable) option, I would like to hear it.
RE: Truss to Beam Connection
RE: Truss to Beam Connection