@Greenalleycat
Somehow it all works out. I just have to do the underpinning.
@PEinc
Thanks for your response. Somehow it slipped my mind that you'd double the settlement risk with multilevel underpinning. And I agree with all the other points you made.
@LittleInch
Wow! I have not see that...
1) Building needs to be almost fully rebuilt but some walls are "historic" and need to be underpinned for lowering the basement.
2) Wall is holding up a couple of floors.
3) No, sorry.
4) How? What do you mean? If I excavate enough to support it then I might as well build the underpinning...
Yeah it's not exactly a rubble wall but I'm not sure what else to call it.
The brick wall seems ok, but not great. It is about 100 years old. The concrete on top of the rocks is about 2-3 inches thick (between the rock and brick).
Ok so removing the "rubble" is a possible option then. How...
Hello,
I have a job where we have to underpinning a wall that is resting on a single layer of rocks that are 1.5 - 2 feet in diameter. Looks like they just lined up the rocks next to each other, put concrete on top to create a level surface, and began laying bricks. It's only one layer of...
@Celt83 "Pretty much all of the structural software uses a winkler model"
I think that is the key. Software companies have not developed a more accurate model from a geotech point of view. It could be there isn't a better theory. I don't know. But this makes sense. Even if we all agree the...
@EireChch
That's exactly what I did. I'm glad to see I'm not the only one.
@milkshakelake
Yes, you need loading and also footing dimensions. I suppose in a pinch you could use various loads and give a range. I think the idea is that the geotech gives the structural a bearing capacity. Using...
Hello,
I'm a geotech engineer. From my side of the ground surface, the subgrade modulus, k, also known as modulus of subgrade reaction, is not used anymore for designing foundations. It is not really a property of the soil and depends on so many factors that getting an accurate value requires...
Thanks. It did seem like a claim with little basis. Otherwise it would also be said of tapered steel piles, which I've never heard.
I think if there's a concern with the the displacement needed to mobilize the shaft resistance vs. the end bearing, you could just design for side resistance using...
Piles might work depending on what's deeper down. If you think you'd have issues driving piles thorough the fill layer due to boulders and concrete pieces you could go nuts an remove/replace at the location of the piles but not everywhere! Piles would have the benefit that you would not need to...
Hello,
I'm doing a deep dive into some pile types. Regarding timber piles, I often hear that they are considered friction piles and their end bearing is ignored in capacity calculations. However, this is always just stated, but never justified. The best I could find was this quote from the 2015...
