Steel Detailing 101 Questions - Bolted Double Angles
Steel Detailing 101 Questions - Bolted Double Angles
(OP)
Some of you will think these are pretty funny questions, but I'll ask it anyway. I've been wondering about these for a while.
Say I have a bolted-bolted dougle angle connection with bolts in-line rather than staggered. Folks often use L4x4x5/16 with a 2-11/16" angle gage in each leg of each angle. This is no good according to the 13th Ed. Table 7-16 with "no good" being defined ask not being able to get a socket on either bolt.
So what's the deal here? Do erectors just use a wrench for these situations, so it doesn't matter if Table 7-16 is violated? If that's the case, then what's the use of Table 7-16?
While I'm at it: What are the common angle sizes and gages that you guys see for this type of connection?
When this kind of connection is made to a girder, I've heard it referred to as a "suicide connection" because the first installed beam must somehow be supported without bolts while hte second is installed. Is there a standard procedure for dealing with this issue? I've seen people show temporary seats at some connections, but don't know if this is mandatory. Commentary on this would be appreciated.
Thanks in advance.
100000e
Say I have a bolted-bolted dougle angle connection with bolts in-line rather than staggered. Folks often use L4x4x5/16 with a 2-11/16" angle gage in each leg of each angle. This is no good according to the 13th Ed. Table 7-16 with "no good" being defined ask not being able to get a socket on either bolt.
So what's the deal here? Do erectors just use a wrench for these situations, so it doesn't matter if Table 7-16 is violated? If that's the case, then what's the use of Table 7-16?
While I'm at it: What are the common angle sizes and gages that you guys see for this type of connection?
When this kind of connection is made to a girder, I've heard it referred to as a "suicide connection" because the first installed beam must somehow be supported without bolts while hte second is installed. Is there a standard procedure for dealing with this issue? I've seen people show temporary seats at some connections, but don't know if this is mandatory. Commentary on this would be appreciated.
Thanks in advance.
100000e






RE: Steel Detailing 101 Questions - Bolted Double Angles
RE: Steel Detailing 101 Questions - Bolted Double Angles
RE: Steel Detailing 101 Questions - Bolted Double Angles
Regarding the "suicide connection", it is normal practice to provide one extra row of bolts on one of the beams, so that row can be used to temporarily secure the first beam.
RE: Steel Detailing 101 Questions - Bolted Double Angles
My copy of the AISC Manual shows 'g' as 2-1/2 inches for a 4 inch angle.
I presume this has to do with minimum clearances needed to get the hardware in place, not the tool. In many connections, the opposite face is open so the tool can enter from that side and a wrench used on the difficult side.
My copy of the AISC Manual also offers guidance on staggered holes for tight situations as you describe. Maybe a good detail would follow these guidelines. Or as you suggest, a larger angle might be the best solution.
For myself, I have always found the information in the AISC manual to be of very high quality, bringing attention to aspects I might have overlooked, and amazingly free of typographical errors by contemporary standards.
RE: Steel Detailing 101 Questions - Bolted Double Angles
RE: Steel Detailing 101 Questions - Bolted Double Angles
RE: Steel Detailing 101 Questions - Bolted Double Angles
JAE, the problem with the "suicide connections" and OSHA is avoided if one of the angles is extended longer and an extra bolt added, as Spats described.
RE: Steel Detailing 101 Questions - Bolted Double Angles
Vincent,I'd say that the fabricators I've worked with are about half and half when it comes to the conn you described and bolted-bolted. In this case, I've just been asked by a pal to take a look at some bolted-bolted ones.
RE: Steel Detailing 101 Questions - Bolted Double Angles
RE: Steel Detailing 101 Questions - Bolted Double Angles
The OP was only partly about "suicide" connections. The other part was about clearance for tightening in bolted-bolted angle connections.