Auger Pile Reinforcement & Installation
Auger Pile Reinforcement & Installation
(OP)
I have 35 ft auger piles for a residential home I did the engineering for and the subcontractor is stating that they cannot run the #3 ties greater than 15 ft down the length of the 35ft required. Further more, they are saying that they bundle the bars together after 15 ft and only use half the number of bars. They state that if they don't bundle the bars together, they struggle to get them into the pile. I don't want to accuse someone of cutting corners, but it seems to me that they are. I have attached their detail so you can see what I am referring too.
Piles are 14" in diameter, and were used on this project because of a muck layer that was encountered on the property, so I am mostly relying on compression. 35 ft was the recommendation from the soils engineer on the pile length to develop the capacity needed.
Does anyone have any experience with this? Thanks in advanced.
Piles are 14" in diameter, and were used on this project because of a muck layer that was encountered on the property, so I am mostly relying on compression. 35 ft was the recommendation from the soils engineer on the pile length to develop the capacity needed.
Does anyone have any experience with this? Thanks in advanced.






RE: Auger Pile Reinforcement & Installation
I've seen many cages installed that were larger to similar depths.
The real question, in my mind, is why do you need a cage to such a great depth? You don't need a cage for compressive load, only lateral and/or uplift.
Mike Lambert
RE: Auger Pile Reinforcement & Installation
I have done some 55-ft piers (30" diameter) CFA piers (just think heavy duty auger cast) with respectable full length cages. It requires a mix with a lot of admixtures to get a high slump and some other chemicals to lower viscosity. Also needed the help of equipment to push the cage in the final 10-ft or so.
RE: Auger Pile Reinforcement & Installation
RE: Auger Pile Reinforcement & Installation
I've also done piles to this length with full cages before. While you don't necessarily need it for compression and your moment generally drops fairly low after the uppermost layer of soil, you'd still want it if you have seismic concerns or if you have non-competent material near the top and lateral forces.
RE: Auger Pile Reinforcement & Installation
I will assume you are in an area similar to the one in which I practice (Florida, USA). I surmise that because of the pile type and depth as recommended by the geotech.
If you are relying mostly on compression, as noted by GPT there is not much need for a rebar cage. That is mostly for loads other than compression.
Don't let the contractor rule the design. Tell him what you need and demand it. Just because it isn't the easiest approach for him is not your problem. He can place a cage to full depth if necessary by proper timing and concrete mix control.
RE: Auger Pile Reinforcement & Installation
RE: Auger Pile Reinforcement & Installation