One thing to be careful of with a 2.5" x 2.5" tube and the deck running parallel to that tube is that there is no guarantee that the bottom of a deck flute will line up over the tube and allow an attachment. Wouldn't a wider tube than 2.5" be better? For a type B deck, the flutes are 6" o.c.
I am using a W27x146 for a tall column. It's web is slender for compression. However, when I go through section E7 of the AISC manual, I find that there is no reduction (Qa=1). E7.2 is kind of confusing since they don't tell you what to do when b/t is less than 1.49x(E/f)^0.5. Am I missing...
I'm running into a problem with a moment connection and I was wondering if anybody could shed some light. I have a W18x119 beam (25'long) framing into a W18x143 column. It's designed to be an OMF. These sizes were picked to meet drift. I want to use a bolted connection to avoid alot of full pen...
This question is for anybody that is familiar with the massachusetts state building code. It does not appear that the current edition allows you to take R=3 for steel design of buildings. So you would need to design and detail all buildings to meet AISC seismic requirements even if they fall...
I graduated a while ago. This is a real world problem for a real world job that I have to stamp. I'm trying to determine the seismic deflection of a rigid frame to determine if it meets code. In the past, for moment frames supported by spread footings, I've used a deflection that is the...
Given a spread footing and a soil subgrade reaction modulus, does anybody know how to calculate the amount of rotation (degrees) a footing will rotate under a moment reaction from a fixed column base plate?
Would welding flat 1/4" x 4" bars to the top of the bar joists be a good solution? The grating wouldn't be exatly level though. The only other option I am thinking about would be creating a horizontal truss system under the joists out of tee's or angles.
Yes. Its 1 1/2" x 3/16" galvanized bar grating. My problem is that I have a large elevated platform (200' x 100') with bar joists at 4'-0" o.c. The bar grating sits on top and is clipped to the top chord of the joists. The lateral bracing is at the perimeter of the platform. I'd like to make the...
Well, let me try to explain. The top of steel of the platform is about 4' to 5' above the top of steel of the roof. The platform is rectangular in plan (32' x 45') with six posts up from the roof. 4 of the posts are on the corners and 2 are centered on the 45' long side of the platform. These...
I'm designing a mechanical platform sitting on top of a roof. It's in seismic design category D. I was planning to use kickers to transfer the lateral load down to the roof diaphragm. Are these kickers considered an eccentrically braced frame and do they have to be designed and detailed as...
Hi. I am designing a fairly large elevated platform to support heavy mechanical equipment. The platform falls into design category D. Because the platform is less than 35' tall, I am using ordinary concentrically braced frames for vertical bracing. However, the platform does not really have a...