Looks like it would involve determining the climatic loading and sizing rafters, joists, carry beams, etc. I did run this by my insurer and as expected they were less than thrilled. Sounds like I may need to decline on that basis alone. It is a shame, would be fun to work on something a...
Hi All,
Just got a request from a client to provide some engineering on a treehouse from a treehouse company here in the States. Curious if any of you have ever worked on anything like this. Seems like a lot of risk for very little $. Obvious concerns are the fact that it is going to be...
I do agree the full model joist is the most accurate and that is what I plan to use. I am just confused why the positive moment is not peaking higher over the vertical web members. Intuitively this does not make sense to me. I would have expected the two results to be a little closer...
I actually did have the top chord split into individual members at each panel point and they were defined as physical members in each model.
One of the things that seems suspicious to me about the entire joist model is how the negative moment is not fully developed over the verticals like...
Josh, are you aware of any way to get more accuracy out of the full joist model other than setting the internal sections to 200? That seems to be the max.
Thank you for all the responses. Let me try to address some of your questions/comments.
Yes, for checking the actual capacity of the components I am using the SJI specification along with the corresponding K values. I am only using RISA to obtain the forces in the members and not for the...
Hi All,
I am modeling a steel joist in RISA and I am curious about what is the correct and/or permissible way to analyze the top chord for bending moments. What I mean by that is that if I model the joist as a whole I am getting different moments for the top chord than if I would model the...
Thanks bones, yes, I had read that information. It is still not clear to me why ASTM E-1592 would state one allowable uplift value and then the Miami-Dade document would state an allowable value more than three times higher. I am not sure how to reconcile the two. Jed, are you saying that...
Can anyone explain to me what exactly a Miami-Dade County Notice of Acceptance is? A Client has asked me to design roof panels for a structure in a high wind zone (not in Florida) and provided this document for the allowable design values. It does contain a table with "Maximum Design...
I appreciate the input. There is no parapet on the lower roof and it is sloped but only at 1/2:12.
I had toyed with the idea of using an average separation distance rather than 1' for everything. Also perhaps reducing the leeward fetch by some amount since they are circular and not...
Hi All,
I would like to get some opinions on the following condition. We have a number of silos that are planned to go up near an existing building. The silos are going to be higher than the existing buildings low eave by about 11', they are about 12'-6" in diameter, and only off the low...
Yeah, I agree. If they are only going to give us the chart it would be nice if they could at least give us the flat line values. Then at least we could interpolate on the sloped portion.
