Truss chord connections
Truss chord connections
(OP)
Truss top and bottom chords are WT sections. Truss web members connect to the WT webs. Is there any code restriction of connecting the truss web members directly to the WT web without using gusset plates? In this case the web members are double angles. If it is okay to connect directly to the WT webs are there any specific checks that are required.
A scan of the truss drawing is attached.
Thanks very much.
A scan of the truss drawing is attached.
Thanks very much.






RE: Truss chord connections
RE: Truss chord connections
So you need to check for all the issues that are dealt with gusset plate connections, some may be alleviated, but you might to also consider specifics of the situation not present tor the alternative gusset plates, even when this may seem unlikely; and not being within the expectancies of codes and texts, you may end having to imagine the correct answer to your derived questions.
RE: Truss chord connections
RE: Truss chord connections
Example II.C-4 Truss Support Connection
RE: Truss chord connections
If the geometry of the connections b/t the web members and the top and bot chord allows for enough room for all members and clearances for welds and enough material to satisfy the connection desing than why add gussets?
RE: Truss chord connections
BA
RE: Truss chord connections
RE: Truss chord connections
RE: Truss chord connections
I don't think transportation is too difficult, but there is no reason why they cannot use a bolted splice at midspan if they wish to reduce the length for trucking.
BA
RE: Truss chord connections
i just had some VERY simlilar trusses built last summer that were 80' long and those took special permits.
I agree...shop weld and splice the two halves...63' is just over a normal 55' truck.
RE: Truss chord connections
There will be a couple of bolted splices. The fabricator wants to use bolted connections only. He doesn't want any welding. He would rather cut a W530 into a WT265 instead of welding on gusset plates etc.
For the bolted splice connections can one use 2 continuous plates instead of one continuous L to bridge over the butting truss chords?
Ipetu
RE: Truss chord connections
You can do a number of solutions, as long as you comply with the specs, i.e.min edge distance and spacing for bolds, ultimate limit states for connecting elements and bolts, ultimate limit states for connecting and supporting members, etc. I would suggest to follow the recommendations of the AISC manual 13 (the one that includes LRFD and ASD) in the chapter regarding connections.
Greetings
RE: Truss chord connections
The type of splice I have used in the past for large trusses is end plates welded to the chords and bolted together in the field. This puts the bolts in the tension chord into tension. For the compression chord, unless you have a stress reversal, the bolts are not stressed at all.
BA
RE: Truss chord connections
Ipetu
RE: Truss chord connections
I would stay far, far, far away from splicing in the middle where the tension/compression forces are the greatest.
Just my 2 cents
RE: Truss chord connections
As for staying far, far away from midspan, the benefit is illusory. Assuming 35', 55', 35' truss sections, the moment at splice points is 81% of the midspan moment. Considering the reduction in truss depth, the tension in the bottom chord at splice points is 86% of the midspan tension. Compression in the top chord is of no importance as it does not have to be carried by bolts. Thus, two splices requires 72% more bolts than one splice.
BA
RE: Truss chord connections
Can you really just rearrange the diagonals independent of where the truss is being loaded?
I mean, i can only assume that the diags and verticals are there because that is where the roof purlins land.
RE: Truss chord connections
You are quite right. Panel points of the truss should correspond with purlin spacing. However, it would be preferable to have the center two diagonals meeting at the top chord instead of the bottom chord to avoid a vertical member at the splice.
BA
RE: Truss chord connections
BA