I am working on an existing structure from the 80's which used steel tube columns and doubled light wood trusses designed for end moments. The columns have big flag plates welded to the top, and the top and bottom chords of the trusses are bolted to it.
We have to modify this structure. We are...
Is it possible for principals of a firm to be considered liable for errors or unethical activity of another principal?
I’ve got a situation where I believe a principal is practicing outside of his expertise (and encroaching on mine).
On the one hand, surely he is solely responsible since he is...
msl - Yes, that's what we have in hand. Although it's deficient - no mention of seismic loads.
brent - That's great to know, thanks for sharing. The SE we have on the foundation is from Iowa, so probably the same firm. Musco did tell me today that they are looking to get a me "calculations," so...
msl - Your experience is similar to mine. I was expecting a few pages of shop drawings with details, design notes, reactions, and a stamp. My understanding of the UL is the same, more about broad conformance to electrical codes rather than specification conformance to site-specific design...
I've got a project at a sports field which includes some 70' - 80' light poles. The electrical engineer spec'd Musco poles, and I have received some submittals from the contractor. In my specs, I asked for stamped pole shop drawings showing that they meet the project design criteria (I assumed...
This is a follow up to a previous post I made about pre-engineered metal building modifications.
This building is in SDC D. I am replacing existing rod bracing with a portal frame. The building was built in the 90s. Does the new frame need to meet current seismic detailing requirements? In...
@kootk - I agree, that's the frame that would see an increase, but only in a rigid diaphragm scenario. I'm just being too conservative about the 10% under a particular load case. Thanks for the insight, it's appreciated.
Thanks also everyone else. I've just about got this thing whipped.
@bones - I modeled them the same. I'm running that model alongside another model of the portal frame and comparing the stiffness of each. H/60 may the be the spec'd minimum, but no way these X braces are allowing that kind of deflection. I'm proceeding with a 1/2" max. That keeps me a little...
@pham - rods. Yes, I can come up with that and have already modeled the frames. But that's really only applicable to situation where the rods are tightened. The rods are typically left loose, so I assume that has a big effect on the amount of deflection that would occur at service levels.
@bones - H/60? Wow, I didn't realize they went so low. Do they typically use a maximum limit? H/60 would take me to 3" of allowable deflection. I also don't think I have a good way to approximate the existing X bracing stiff. I bet the deflection required to get the sag out of the rods would be...
This ship's already sailed, no chance of turning down the project now. I don't sell them, I just design them. I'm actually not too worried about it. As far as the legality goes, I have no idea - no one knows who made this building. A local contractor built it in the 90s. It's a very rural area...
Hi all.
I've been asked to provide a design allowing a PEMB owner to remove X bracing for new doors. I've done this before with chevron bracing and new beam, but this time the openings are going to be quite large and I don't have enough room for that.
So I'm going with a new portal frame...
Hi all.
I'm working on a small residential renovation project. This is a late 19th c. brick building. The project is on the interior of the building, and a lot of the walls are covered with gypsum board or painted. I've worked on similar buildings, but none with this much involvement with the...
It turns out I do have enough space for a multi-ply LVL underneath the damaged valley. Since the valley is deflected, I'm going to have shims installed between it and the top of the LVL to provide the vertical load transfer. I also want to put some steel flat bars on the sides to provide a...
Maybe some of you have been in this boat before. I am currently working alongside an architect as part of a design firm. We have been invited to give a proposal in a neighboring state (IL) for a small building. He has a license there, but I do not have the SE (PE only). However, reading the...
It's about 18'. 375lb/ft DL and 750lb/ft LL over the two plies, but not uniformly distributed of course due to the nature of a valley rafter. The original slate roof was replaced with a much thicker clay tile roof. Slate is back on the roof now. It seems to me that the rafters were originally...
HouseBoy - Yes, I agree the channel might not be stiff enough. I could add some some angles. As for your other idea, it sounds like you're talking about building a sort of knee wall supported by a new beam in the plane of the floor joists. It would have to use the existing supports. One is a...
IFR - I don't think in this application, but thanks for sharing! That's a good one to know about.
XR250 - Ah, got it. Space is a concern, I am not able to access or make new bearing points for something like this. My channel idea would work like a flitch plate, where the end fasteners would...
There is about 1/2" to 3/4" , I haven't been out to measure yet.
Yes, the spacer idea is on my mind. That would provide a load path for the rafter thrust, because as it stands now there isn't much.
And yes, if I settle on a repair like this I will have it progress from one end to the other to...
