I have no experience with pier drilling at all.
But, it bothers me to see three or four feet of water at the bottom of the hole. What should be done if anything about the water?
It was dry when the soil tests core drill was done, no water found then. But, it has rained a LOT since then. The foundation contractor decided it was dry enough today to drill the piers, hope the rain holds off (50% chance this afternoon, 30% tonight), and pour cement tomorrow afternoon. The foundation engineer and city inspector are supposed to look at the piers tomorrow morning. Do I just wait and see what they say?
Where the garage will sit, there is up to 5′ of fill. The deeper the fill, the more water at the bottom of the hole, so I guess there is some chance it will drain out over night, but that is quite likely wishful thinking on my part.
Replies
I have heard of adding some hydro-cement to the mix when pouring in wet conditions. You have to work fast though. But I have no first hand knowledge of this.
I have sucked it out with a ShopVac; had 16 to do; about one would fill up the vac to the float. Dump, go to the next while FIL filled that one.
Sandy soil on Chesapeake Bay
Don't know if I needed to our not.
Felt better
Forrest
If the water is a problem I use the sump pumps, but for piers, I can pour and the water will float right out.
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By "fill" I hope you mean crushed rock or sand, or some other competent structural fill material. And, I hope your piers are drilled to bedrock or undisturbed mineral soil.
Anyway, concrete (you are not pouring "cement") will displace water quite nicely. If I were doing your pour I would talk to the batch plant and tell them what I was doing--the owner of the plant here is quite fluent will his chemistry and would send me the best possible mix for that. You may not need anything exotic at all. I would also see what the engineer and inspector say.
You could also send your contractor to the rental yard for a trash pump, which will evacuate most of the water in each hole and allow concrete placement before too much water gets back in.
The piers are drilled down to rock, or "auger refusal" as the foundation engineer calls it.
Most of the holes for the piers are dust dry at the bottom.
The fill is well packed clay dirt. My understanding is that the slab for the garage was designed to be supported by the piers and not by the fill.
Thanks for the feedback though, it makes things less scary.
paul42,
Here I would have to pump the water out and then probe the bottom of the hole to determine how soft the soils have become. Inspectors take the phase " Undisturbed Soil" and "Solid Bearing" seriously here. Some very highly expansive clay content soils in this area."Poor is not the person who has too little, but the person who craves more."...Seneca
Since Portland loves water, it's not a huge problem and your foundation contractor should know what to do about it.
IOW, I wouldn't worry.
I have been around pier pours 20' deep x 3' dia, that were water filled to 1' from the top at the beginning of the pour. I don't know if the super ordered special mix or not, but as the mud went down the water came out.
SamT
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