Thank's everyone for your valuable help. I'm aware that the flexible diaphragm condition must be checked first and be designed accordingly. My doubt was about the accidental torsion for industrial buildings. How do you approach it.
Regards
Hello everyone,
I've tried to find a good reference to understand, if it is nedeed to consider accidental torsional moment in the seismic design of an industrial building, with flexible diaphragm.
Regardidng industrial buildings we do not consider any rigid diaphragm, instead we use roof...
I am very sorry if my comments promote confusion. I was trying to understand if footing below grade are really free to rotate and if OT check is required. But, as seen, there are other things to take into account. Sorry if I deviate from the topic, but some replies where very interesting...
Elaborate?? I already drew you a picture of it. If you need more than that, you'll have to ask me a more specific question.
I am sorry about that, at first I did not understand. Now is clear, thanks for your help!
Regards
2) Columns that land directly on footings with no intervening piers.
That is very interesting for me, could you please elaborate how piers participate?
Thank you.
Regards
Thank you all, now I am more confident on this.
phamENG :
I was talking about B. I agree with your explanation, for academic purposes, I will try to study a 3D model a see what happen.
1503-43:
That is a useful point of view. If uplift begins on one side, moment resistance is compromised...
Thank you all!
Yes, I am a bit confused, and I am not justifiying to pass overturning check, I would like to make it clear, the thing is:
I can't see a footing below grade be overturned, before that, soil mass mut be movilized and create a condition free to rotate, which involves that soil...
Celt83, I appreciate the reply! It is a moment. But, does the factor of safety against overturning, ensure fixed base? I think it does no, of course the FS indirectly give us more spread area and then more rotational rigidity, but I am not sure if that could be enough justification to end the...
Hello!
I am currently working on a PEER review for a steel moment frame building. In the past, I used to check isolated footings against overturning moment, no matter if they are below grade. At this time, there is a dicussion with the EOR, since he thinks that overturning only affects footings...
Hello Kpizzle, there is a software called: Sistema Viento based on CFE. It was developed by a goverment institute. I hope you find it useful. If any doubt applying the local code, you can send me an email to luisaguilarugarte@gmail.com, I will try to help, I am a mexican structural engineer...
Hello Everyone,
Imagine we have a steel primary beam running parallel to secondary beams. The floor system is a concrete-filled metal deck and is attached to the primary beam via shear studs. Under lateral loads, this beam will experience double curvature. If the beam was not attached to the...
Hello Everyone
I'm trying to find a plan configuration of real structures with extreme torsional irregularity Type 1a or 1b. Has any of you dealt with this problem, that could provide some information?
I'm starting to believe that is difficult to find structures with Type 1b in real world...
Hello Everyone
It is known that all of the tests for the prequalified connections were done using cantilever beam specimens. I'm currently studying the effect of weld restraints, and my concern is: will the behavior of a moment connection on a cantilver beam (free weld restraint in longitudinal...
Hello everyone
I'm designing a structures with a special moment frames system. One of the frames is coinciding on a basement wall (please see attachment), the question is:
Should I detail de basement wall for a base shear, including the omega overstrength factor of the special moment frame? I...
Hello everybody,
I'm currently on a proyect where there's a frame which coincide with a basement wall. We´re modeling the basement wall and providing pin supports, the thing is, should I dimension my piles for the reaction (shear force) obtained form that model? or should rely on the soil...
You might find helpful the attached paper. I think there is a good design criteria on the first page.
Regardshttp://files.engineering.com/getfile.aspx?folder=037d1bba-edcf-4223-86de-3bdb1b51922e&file=122011_dec11_si.pdf
KootK-
Thank you for your post, I'll make sure to take a look at that paper.
Now, something that led me to this post was:
Weeks ago I was told of a project where the contractor could not place the base plates correctly because he didn't know how to place them when they have a shear key...
Lion06
I think ACI 318 does not explain either, that the 0.8 reduction factor is to account for bending in rods, but that's what we understand. My idea is:
If we use STD holes and grout pads, the shear will be transferred through bearing within the base plate and grout thickness. But what...
JoshPlum-
That's right. But even if the base plate is grouted, I think we should consider bending stresses in rods because we still have a free space within the plate thickness due to the oversized holes, and that stresses could be significant. I understand that the reduction factor suggested...
