Global stiffness matrix is singular until you remove the rows and columns associated with redundancies/reactions. The kinematic submatrix should be invertible.
I find fire-damaged concrete comparatively more fun to evaluate. I’ve probably done more of that than for steel buildings. I’m sure @TRAK.Structural will report back with any concrete question marks. We can whip ourselves up into a frenzy, then.
Why wouldn’t the usual lateral dowel capacities apply? There’s 4 limit states, two of which are further split between main member and side member (for a total of 6). You could consider the plywood to be the main member and the strap to be the side member. There is also supplementary info on...
Thanks for the photo. I’ve seen similar issues. You’re right that I’m not familiar, so I appreciate your insights. Gotta learn somehow, and better here to start than with an occupied building.
@XR250 is basically describing what my prospective client’s previous engineer did. Definitely no...
I remember watching some webinar recently discussing what it would take to completely protect the deck members and fasteners from this type of corrosion. The consensus was a veritable jungle of flashing details that would be completely impractical. Even if you use zinc-magnesium hangers or...
The helical pier is not installed directly below the footing. It's screwed down off to the side, hence the eccentricity.
Absurdly common in Texas. Ask me how I know...
Yeah, none of that happens here. I've spent a good bit of time this week trying to get a building official on the phone to explain why. The contractor has shown me permits issued on the basis of their napkin sketches and the previous engineer's report. It's not like we're in a rural area, either.
I'll lastly point out that we as engineers have a tendency to rely on calcs and tests to even our own detriment at times. It's no coincidence that fresh engineers say things like, "but the model told me that the building would do this..." Let the building speak for itself.
I’m skeptical that a survey could aid in parsing minor fire-related deformation from original erection misalignment, thermal movement, and foundation movement beyond what you could discern visually to begin with. Fire-related movement will generally be obvious and spatially correlated with heat...
Incredible responses...thank you everyone. I have some more questions, please.
All the load? The footings are already doing that and haven’t experienced a local/general bearing failure. Thank you for sharing your experience btw.
I have his reports but no calcs. Can’t tell what he checked (or...
We do this a lot. You end up paying less attention to the steel and more attention to everything else. You can get a good spatial idea of how hot the fire burned by examining all involved materials. Cable jacketing melts at one temperature; concrete can turn pink at another. There have been...
Local contractor sells underpinning services to homeowners. Jurisdiction requires a sealed engineering report before issuing a permit for the work. Their last guy retired; I’ve seen his work. Enter me: seems like a good potential source of revenue, low hanging fruit. Totally new line of work for...
Assembly uses are specifically exempted from live load reduction, per 4.7.5 and Table 4.3-1, which I’m assuming you knew since the uniform live load is from the same table. To address the later question: I really wouldn’t fiddle with the 100 psf. You cannot reason the same mean and coefficient...
A variation of this detail is extremely common in DC; the new retaining wall is usually inboard of the existing foundation wall, which isn’t deepened. Only way to get more space out of an 1800s rowhome.
Up to the client and their wallet.
For a house in Tennessee: we showed our fairly sophisticated client the different statistical windspeeds broken down by return period to include/exclude thunderstorms and compared that to ASCE’s curve (right column). Then we showed them how that turned into...
