12 m depp excavation
12 m depp excavation
(OP)
Hello , i would like your help for the support of a 12 m deep excavation in urban area. The soil layers from top to bottom consist of :
1) 3 m fill ( with construction debris ) .
2) 2.5 m Sandy silt with gravel .
3) 0.5 m mollasse ( its a local French term here )
4) 2 m marly clay
5) Marl til the end of the borehole at 20 m.
The site is fairly small and the geological layers reminds the same , since there are 4 underground parking lot the total excavation depth will (4x3m = 12) we add to it 0.5 m for the raft foundation. Our piezometers detected water at 3 m in summer time , now we are thinking of using Berlin or Paris type walls for the support of the excavation as no company in my country work with slurry walls. Thing is i am currently inexperienced for this kinds of foundations same thing cause with the tiebacks that we should use too .
My question is can we use Berlin or Paris type walls in this case ? I can assume that there will be no water flow from under the walls ( marl ) .
Also what are the typical stiffness values for tiebacks ?
1) 3 m fill ( with construction debris ) .
2) 2.5 m Sandy silt with gravel .
3) 0.5 m mollasse ( its a local French term here )
4) 2 m marly clay
5) Marl til the end of the borehole at 20 m.
The site is fairly small and the geological layers reminds the same , since there are 4 underground parking lot the total excavation depth will (4x3m = 12) we add to it 0.5 m for the raft foundation. Our piezometers detected water at 3 m in summer time , now we are thinking of using Berlin or Paris type walls for the support of the excavation as no company in my country work with slurry walls. Thing is i am currently inexperienced for this kinds of foundations same thing cause with the tiebacks that we should use too .
My question is can we use Berlin or Paris type walls in this case ? I can assume that there will be no water flow from under the walls ( marl ) .
Also what are the typical stiffness values for tiebacks ?





RE: 12 m depp excavation
RE: 12 m depp excavation
RE: 12 m depp excavation
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: 12 m depp excavation
RE: 12 m depp excavation
I agree with hokie66 that a secant pile wall would be a good option.
RE: 12 m depp excavation
RE: 12 m depp excavation
RE: 12 m depp excavation
guys if a soldier beam wall is constructed according to standards and knowing that the marl underneath the wall is impermeable of course , i think there will be no seepage water toward the excavation
RE: 12 m depp excavation
The design methodology is no different than designing for openings in wall and slabs to begin with. The formwork and reinforcing aspect is slightly more difficult from a labour perspective but still manageable.
RE: 12 m depp excavation
www.PeirceEngineering.com
RE: 12 m depp excavation
RE: 12 m depp excavation
RE: 12 m depp excavation
You will need to dewater the perimeter or you will need to use steel sheet piling to retain the water. You have to determine if steel sheet piling can be driven through the cohesive soils to the required depth below subgrade.
www.PeirceEngineering.com
RE: 12 m depp excavation
RE: 12 m depp excavation
@PEinc : how can i judge the ability to penetrate the cohesive soil using sheet piling
RE: 12 m depp excavation
RE: 12 m depp excavation
RE: 12 m depp excavation
You could do some reading about pile hammer selection, talk to a local pile driving contractor, and talk to an equipment supplier that rents pile driving equipment. You will need to show the contractor and supplier the soil borings/geotech report.
www.PeirceEngineering.com
RE: 12 m depp excavation
We did conduct DCPT tests that showed for the most part a max depth of 12 m