John- The ASCE 7 committee has not done serious evaluation of garage loading requirements since 2002 when the load was reduced from 50 psf to 40 psf. However, Cole Graveen who heads the ASCE 7 Live Loads Subcommittee indicates that he has received a number of questions of this type recently,...
I’m writing to inquire about the live load minimums in ASCE 7 for parking garage structures in light of electric vehicle weights. With the EV demand appearing to not slow down, is ASCE reviewing any impact the EV industry may have on the current parking garage design live load minimums. ...
Hello Justin, I always consider a moving load to be live, but to James's point I would be hesitant to take advantage of a reduction for a live load that will be present concurrently with a full design floor or roof load. For the 0.75 reduction, are you referring to ASD load combination 4 in...
In the early pages of ASCE 7 you find text that says "ASCE does not intend, nor should anyone interpret, ASCE's standards to replace the sound judgment of a competent professional, having knowledge and experience in the appropriate field(s) of practice, ... ." In my professional opinion,...
I was hoping to connect with someone when considering the Dead Load vs Live Load cases and get more clarity on items not expressly stated in the two designations. I often come across having a moving load that is almost always present, and I'm trying to get clarity on the code intent of whether...
Ah, I see. I tend to think of the ASCE 7 as a balancing act between ease of implementation and economy of design, but you make a great point about the importance of transparency. I would argue that the current live loads are very easy for engineers to use (aside from those pesky load...
While I understand the pros and cons of ASD & LRFD, once AISC combined them into one manual, the differences began to disappear to all that remains is a conversion between the two. What is the load and what is the capacity? Well, that depends... the public (or client) demands a clear answer...
Ron, I appreciate the thorough explanation, and I'm sorry for not responding sooner. In fact, I wish this timeline was part of my undergrad curriculum. Only after entering practice did I realize how little I knew about ASD, and how much my understanding of design loads and limit states...
James, Thanks for the response. You make a good point, but for environmental hazards, the safety factor lives in the return period to establish uniform risk. For example, I'm told that snow loads in ASCE 7-16 and earlier resulted in dramatically different probabilities of failure across...
Chad, Thanks for the thoughtful response. It's certainly true that we wrap a lot of big questions into our floor loads, and it may be true that the public cares more about minimizing risk from human-imposed loads than minimizing risk due to external hazards like earthquakes. That's hard to...