I have a 2.5m deep steel truss made out of HSS members and spanning 32m. It is connecting to a W14x233 column. Any special things I should be taking into consideration, the shear load for the connection will be about 500kips.
Posted Nov 28, 2019, 3:16 PM UTC
Perhaps you could tell us which things you have already considered so it is not just a guessing game
[deleted]
Apologies, so the connection will be a shear end plate with 1.5in bolts and a 2in plate. Checks for the bolts would be bolt shear, shear and tension. For the plate, bolt bearing, shear yielding and rupture, and block shear. The HSS will be CJP welded to the end plate. For the column the check will be bolt bearing. Due to the significant mass, the column deflects about half an inch in analysis, which puts me off a bit. I fear it's the significant mass and size that has me a bit hesistant in my thinking.
If you must do this setup then limit the depth if you can. 6 heavy bolts in single shear spaced as close together as possible will make the connection most like a pin. Stabilize the bottom chord but don’t connect it vertically. This way you’ll not impose rotation restraint to the end of the truss.
are you implying to use slotted holes for the bottom chord?
At least. I prefer guides with no bolted connection.
You should check all the basics of truss design. Deflection, floor vibrations (it supporting occupied floors), strength, bracing points, connections and splices, truss type (Warren, Pratt, Howe) and how that affects member size and connections), and end support conditions (tracing load path back into supporting members including any eccentricities).
It is a pratt truss to a shear endplate, so at the end the will be shear and tension for the connection correct? And i've been told to simply CJP the members together for the splicing and bracing points.
Assuming you've done all the design checks, how are you planning on getting it into position?
I'm thinking it will need to be constructed on-site and craned into position. There is room on the site.
32m is not a small lift. I'd definitely make sure that your lifting scheme and erection plan are feasible before going too far.
thank you I will keep this as a major consideration
Bearing, bearing, bearing. You always want to bear a long span truss.
If you doubt this look at typical bar joist and joist girder connection details from Vulcraft or Canaam
how would this be configured for members of this size and load magnitude, the HSS is the same width as the column at present.
Cap plate on the column. Run the tube over the cap plate. A shop welded bearing plate on the tube that would then bolt to the column cap plate. Bolts should be able to resist 5% of the vertical load and 100% of any horizontal load (axial or transverse to the truss).