Well, we used to do that for negative bending resistance. Which we still could do. Personally, I preferred to look at whatever negative moment could exist and provide 4/3 As required for it.
What would often happen for thicker slabs, we'd start with 4/3 As required in the bottom of the slab...
Close, but not quite. The minimum steel requirements merely ensure that the ultimate strength of the slab is greater than the cracking strength. So, if you were to go from an uncracked state to a cracked state you could get brittle failure. The steel would still yield, but it would be during...
So, there is a flaw (IMO) with the ACI code for minimum slab reinforcement when compared to beams.
When you have reinforcement in a slab, you are required to meet the same flexural minimums that were developed for beams. These insure that there is enough steel to avoid a brittle failure when...
Depends on who the "they" are that you are asking about?
a) The new world order types who are trying to take over our economies and assert more and more power over what we are allowed to do and how we are allowed to live? I agree that they will never admit their faults.
b) If the "they" is...
My starting point for any dynamic equipment pad / foundation is the ACI document on the subject. ACI 351.3-R Foundations for Dynamic Equipment.... That will give the basic guidance for dynamic equipment and foundation modeling.
I would say the work sounds good.... But, I think you may want to review their standard caveats on their contract documents. The key is what the contractor is promising. Is it to repair a settlement issue. Or, are they promising more than you would feel comfortable signing off on.
Also, of...
I don't know.... I don't think 100 psf is unreasonable. Remember we're probably talking about an event that takes place once in the design life of the building.
I think it's pretty common for restaurants to rent out their spaces for weddings or such. The dance floor at a wedding can be...
To be honest, Spain's attempt to use 100% renewable energy for a full day is beneficial. Probably stupid, but beneficial.
What I mean by that is these attempts are necessary to hash out the flaws in their plans. I think we (meaning those of us who live in countries that can afford the...
There's still OMF requirements to be followed:
a) The connection still needs to be designed to the "probable plastic moment". And, the shear strength requirement based on developing that probably plastic moment.
b) Alternatively (as discussed in the code commentary) you can design the...
Absolutely. I was nit-picking the reference to coal in particular. FWIW, here is the breakdown of electricity production for the USA (and California further down):
And, for California which appears to hardly use any coal at all:
First, I'm curious what you hope to accomplish by modeling the foundation with the superstructure.
My thinking is this:
1) When we model the superstructure separately we generally go with some basic assumptions that the foundation provides rigid support to the structure. This is not...
I wouldn't say that "most" electricity (at least in California) is produced by burning coal. In CA, we use relatively little coal. We have Natural Gas, Hydro power, Nuclear. But, very little coal.
Certainly, in locations that heavily lean towards coal, electric cars don't make as much sense...
So, usually the structural model includes the superstructure and there is a separate model for the foundation. That's generally good practice in my opinion.
If you are not REALLY experienced in modeling concrete structures and foundations, I would strongly discourage you from including the...
Yeah, I never really understood this either. We did the same thing with Earthquake loads back in the 90's. That made a little more sense because we were factoring an "event" level force down to a service level force then scaling it back up to a strength level force.
Maybe the wind guys wanted...
I saw this drivel in the news today:
https://www.usatoday.com/story/news/nation/2025/04/23/earth-climate-tipping-points-study-warning/83209239007/
My issue with the article is mostly about the use of a new "buzz word" to create fear. There are 16 climate related "tipping points" that...
It's just being able to communicate effectively. There is nothing wrong with saying something like:
"This structure does not meet the current code requirements for snow loads in your area. For such a load condition, the structure is 30% 'overstressed'. Keep in mind that this includes safety and...
Thank you EngDM and PhamENG. I think the idea of thru bolts is probably the way to go. I helped another engineer with extending a deck / balcony a few feet. This was a few years ago when I was helping a friend with a side project when he was swamped.
I have to see what he did for the...
I struggle for words about this post of yours. For a very short post, it seems to have plethora of ridiculousness.
a) What's "diminishing quickly", the context of previous posts would suggest that China's coal usage is diminishing quickly. I don't believe this is factually correct. If that's...
One thing that helped me is reviewing other people's work. Like being a second set of eyes on a friends project. Especially if it was a project that I had limited experience in. I've only done that a couple of times though. Call this a "peer review" if you want a formal name for it or if you...
I should also mention that I attended code meetings (AISC mostly) twice a year for 10 years. And, I can attest that there is a lot of effort made to listen to everyday engineers. However, relatively few of them are involved in the code writing process. In general, I'd say that there are a few...
