Soil Nail Wall?
Soil Nail Wall?
(OP)
I am looking at a project that requires some deep excavations next to an existing building. My client is expanding his business and wants to put an addition on that requires a basement. He wants to maximize his space, therefore, he wants to locate his basement as close to his original building as possible.
My question is to the use of a soil nail wall. Who is responsible for the design of this wall system, the structural engineer, the geotechnical engineer or is this something the contractor would typically do?
My question is to the use of a soil nail wall. Who is responsible for the design of this wall system, the structural engineer, the geotechnical engineer or is this something the contractor would typically do?






RE: Soil Nail Wall?
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Soil Nail Wall?
RE: Soil Nail Wall?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Soil Nail Wall?
RE: Soil Nail Wall?
RE: Soil Nail Wall?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Soil Nail Wall?
If the existing building will not be underpinned, then the new basement foundation wall needs to be designed for the surcharge load from the existing building. If the underpinning or other type of retaining wall is not a permanent wall with corrosion protection, then the new foundation wall also needs to also be designed for the lateral earth pressure.
www.PeirceEngineering.com
RE: Soil Nail Wall?
This was a job where soil nailing was designed to support an adjacent building instead of using underpinning. The building collapsed as soon as the first lift of excavation was made for the soil nail wall.
www.PeirceEngineering.com
RE: Soil Nail Wall?
But don't over proscribe this or it might be your turn in the barrel. I've done these (the contractor chose soil nails and shotcrete) and was scared ever minute the silly thing was up. But it worked.
RE: Soil Nail Wall?
I will say that the existing building is a single story 10ft eave height metal building so the loads should not be that large. This is the third addition that he has done in similar fashion...... But with the SOG elevation change stabilization of the existing gets worse as we move down the building.
RE: Soil Nail Wall?
The way I was mentored is that we, as the EOR document what we want as the final condition (e.g. Basement wall next to adjacent building) and how the contractor gets there is his Means and Methods. Trying to dictate how the contractor builds will inevitably lead to discussions about the EOR costuming the job money because the contractor can come up with a better or faster method. With that said, it's incumbent upon the EOR to ensure that he believes there is a realistic way to build what he wants.
You should require in the spec and General Notes that shop drawings and calculations be submitted for review.
RE: Soil Nail Wall?
RE: Soil Nail Wall?
RE: Soil Nail Wall?
RE: Soil Nail Wall?
So, would you be using the micropiers at the top of the wall to resist the lateral loads produced by the unbalanced soils.... sort of a "propped" retaining wall?
This will be the second addition they have done in a similar fashion. I believe they said they used sheet piling while constructing the last addition. However, only 8'-10' of undermining/underpinning was required. They also reverenced "dead men" that were installed inside the existing building. I was too busy looking at other items in the building to hear if the dead men had been installed during construction of the addition.
RE: Soil Nail Wall?
I've had to design shoring a few times, a couple times you could tell the EOR thought about the shoring first and the design was easy, there was enough room to install shoring. Everything was seamless on those jobs. The other jobs the EOR just wrote shoring by others without giving a second thought to whether it was possible or not. Those jobs were friggen headaches to no end. One of them in fact we never arrived at a feasible shoring solution (24' excavation with no room for rakers and deadman, and no allowance to put in soil anchors).
RE: Soil Nail Wall?
RE: Soil Nail Wall?
They use sheet piles before when the depth of excavation was only 12' (8' below bottom of footing). Now their excavation will be 24' (20' below bottom of footing). Slightly different than what was used before.
RE: Soil Nail Wall?