Do you consider ice loads on large mechanical equipment like cooling towers? If so, how? ASCE 7 Ch 10 doesn't seem to address it very well. SPX has a white paper on icing, but doesn't indicate how to consider it.
In my experience, utility racks are typically designed using a deflection ratio of L/240 for beams between supports using the collateral + operating load. This can vary based on what's being conveyed in the pipes and to address specific loading conditions (e.g. - if the pipe rack is outside, you...
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Historically, ACI has explicitly exempted footings from the minimum shear requirements. In ACI 318-14 the chapters were rearranged and minimum steel requirements were put into chapter 7 (one-way slabs) and 9 (beams). Foundations are in chapter 13.
Foundations says to design one-way shallow...
So ponding analysis is covered in AISC K2 and SJI has a direct ponding analysis tool, but there are limitations to both. For instance, they're only applicable to rectangular bays with evenly spaced framing.
I understand that ponding stability is iterative for an exact solution, but why can't...
I was looking at typical steel joist to masonry connection showing 2 shear studs welded to a bearing plate. ACI 530 doesn't allow studs per se, so I went in search of the ESR to see allowable values...there wasn't one. Concrete only.
So is this configuration technically not allowed in masonry...
There is a large rooftop unit going on a building with a metal roof deck and steel joists. Wind has been considered for overturning loads on the joists. How do you account for the horizontal load from the wind into the diaphragm? Do you just include the horizontal load when your calculating the...
I have a masonry elevator shaft, where the elevator manufacturer has requested that the rough opening be the full length of one shaft wall (~12ft). This is much wider than the finished door widths. How is the infill supposed to work? Dowel into the masonry above and below and fit the blocks in...
Steel roof and floor deck capacities are typically presented as a function of span condition. Most calculations I've seen assume a 3 span condition to get the most out of the deck; however, if you don't have supports in multiples of 4, wouldn't you be required to design some of the deck to a...
We've noticed that our partially grouted walls end up containing more grout than we would like. It looks like the stretcher block may be part of the issue.
Issue #1: ACI 530.1 3.3B 3d says, "Vertical cells to be grouted are aligned and unobstructed openings for grout are provided in accordance...
A contractor has decided to switch from ready-mix grout to field mix grout. No problem...except it took a whole day to pour one lift (<5') in a wall 30 ft long. I know that there is a maximum batch time of 90 minutes on a batch, but I could not find any guidance on a single lift. It seems like...
Should Class 1 or 2 bar supports be used for galvanized metal deck / composite slabs? Class 3 bars seem inappropriate since the idea is to protect the steel. Also, if the deck is vented, the bottom surface is more exposed. From a cost standpoint, it seems like plastic chairs would be the...
I'm sure this question has been asked, but I did not find an answer that was satisfactory in the threads.
In a doubly reinforced concrete beam that is a part of a moment frame, does ACI 12.2 govern the length of splice of the top reinforcement or 12.3. The building is already built and uses...
Without getting into the debate a few posts below, I am interested in how your companies delegate connection design. Currently, we design shear type connections and provide loads for moment connections. For a variety of reasons, I would like to see us delegate more of this to the fabricator...
