Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
(OP)
Hello everyone,
I would like to know what types of small equipment are available to drill 3 ft diameter drilled pier foundations to a depth of 10 ft within an existing structure? Is there anything on the market that can fit through a standard door width? Drilled piers will extend through a concrete slab, after saw cutting and demolition of the slab. Which of the two details do you think is easier to construct in an existing building, and why? Please provide photos of similar jobs and equipment if you have any.
Thank you
I would like to know what types of small equipment are available to drill 3 ft diameter drilled pier foundations to a depth of 10 ft within an existing structure? Is there anything on the market that can fit through a standard door width? Drilled piers will extend through a concrete slab, after saw cutting and demolition of the slab. Which of the two details do you think is easier to construct in an existing building, and why? Please provide photos of similar jobs and equipment if you have any.
Thank you






RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
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RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
If you have to drill can you take out the wall? Can you go with micropiles on a pier cap? 3' diameter holes requires a machine with some B@!!$. There are very small rigs but they don't fit through doors. How much head room is available, at least 8'?
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
Dave
Thaidavid
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
for spread footing you would excavate a wide area (footing area and some). so you have all those dirt around waiting specially if footing is not poured monolithic with pedestal.
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
The truck was maybe 12-30ft from the caisson holes, they just added hose sections where needed. Was pretty easy to thread the hose through obstructions.
Word of caution, the truck was very loud and disorienting.
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
The project location actually is in a shop with 12 ft tall roll up doors, and vehicle bays. So a small drill rig should be able to back into the locations. Sorry for confusion. I intentionally left out some details to see if anyone had some ideas on innovative excavation/construction techniques for tight access areas without a drill rig, backhoe, or equipment access (such as basements). Arp32's vacuum truck excavation is an interesting solution I've never seen or heard about.
The soils are stiff clays, with a very deep water table. Geotechnical engineer says either foundation system will work with the existing foundation system, and has designed for induced stresses, and consolidation. This thread is purely a constructability/cost comparison between the two options. Either designed system should work.
Undermining the slab for the verification of existing spread footing depth for the spread footing option was of concern. The spread footing requires someone to climb into the excavation and tie-wire a cage together (shallower then OSHA requirements for shored excavation), also requires compaction of fill under an existing undermined slab, and has (risk) assumptions made on existing foundation system, without as built verifications.
The temporary stability of the existing strip footing for a drilled pier excavation depth below the bottom of the wall strip footing, was of concern for this option. In lieu of the new information I provided with access for a small drill rig, it is my opinion that the drilled pier is a better/faster construction technique, maybe shore the wall first (damages during construction is contractors responsibility). Casing the hole doesn't make sense for such a shallow pier, in clay, in my opinion. This option just drops a reinforcement cage in place.
RE: Drilled Pier Foundation Vs Spread Footing Constructability in Tight Access Areas.
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