I've searched the internet for a long time and can't find an answer:
I am wondering if I should include a portion of live load in calculating component seismic forces on an egress stair (ASCE 7-05). I know seismic forces don't usually include live load, but ASCE doesn't define "component...
Josh,
Let's say an elastic structure would see the equivalent of 10000 kips lateral. It is designed for 1667 kips, so it first experiences inelastic behavior at 1667 kips (ideally). Then a certain part is designed for extensive inelastic deformation, protecting the elastic members, which I...
So, correct me if I am wrong, but what I am seeing is that assuming I=1, R=6, and Ωo=3, I may put all braces in one direction, so long as they are designed to take a load reduced by 6x and then increased by 3x. So I am seeing all braces buckling at 1/2 the actual expected seismic forces. I...
Nevermind the definition - it is in there, but for some reason is not italicized. On another note, is it possible to edit these posts so I don't end up posting over and over and over again?
I am looking through AISC documents, in particular the Seismic Specifications. It says:
"Along any line of braces, braces shall be deployed in alternate directions such that,
for either direction of force parallel to the braces, at least 30% but no more than 70%
of the total horizontal force...
Hi, I am a month and a half out of school, and am modeling a 3 story, 340,000 sqft building in high seismic zone. In grad school, my professor skipped SCBFs altogether, saying in essence that they suck and to always use BRBFs instead. The owner and another PE are planning on using - as a...
Well, I still don't know why the warnings were showing up, but if I close the program and reopen it, they are gone. I guess maybe it's just one of those pesky bugs.
I am learning RAM Structural System on the job, and am currently modeling a 3 story building for gravity loads. Due to the ridiculously un-intuitive modeling user interface, I modeled the floors in CAD and imported the first 2 floors so far. Floor one has no problems, but floor 2 gives a...
I have nine grids about 220 feet long. That's about 2000 feet of girders. Comparing strength sizing for Lb= 6 ft (our joist spacing) and Mu=600 k-ft vs. 720 k-ft (20% higher), I get W21x68 (or 24x68) vs W24x76. 8 lbs times 2000 ft = a possible 16,000 lbs extra weight in girders.
In reality...
Hi all, I have been trying to find out a good way to design a steel roof system in RAM for snow loads for some time.
Problem:
RAM treats snow loads as live loads, and creates a "worst case" scenario by "skip loading" - applying all or nothing on cantilevers/backspans. However, according to...
I have a question similar, so I'll just put it here:
In general, should different snow loads be combined in general? For instance, should drift loads be applied with partial loading? Or should they be considered separate cases?
- Aaron
