[Towertalk] Water in hole update
David
k4zzr@bellsouth.net
Tue, 09 Jul 2002 14:05:04 -0400
First of all....thanks to everyone with an opinion or suggestion regarding
water in the hole for my tower base. Here's how things went......
I rented a mini backhoe and dug the majority of the 5'x5'x6.5' hole with it.
A friend and myself used shovels to finish and square it off. I hit ground
water at a little over 5' and a very slow trickle. I used the backhoe to
lift and place the rebar cage into the hole and secured the T-base to the
2x4 above-ground form.
Sunday morning I go out to look at the hole and it's got just over a foot of
water in it! I run to the local marine supply house and pick up a bilge
pump and switch for $20 and attach them to a piece of 1/4" plywood and a
scuba diving weight. I attach the pump wires to a portable 12v jumpstart
battery I happend to have and lower the little pump into the hole. It took
awhile but it finally pumped all the water out, except for a little less
than an inch in the very center of the hole. It worked all night long and
when I checked it Monday morning, it was still pumping fine.
The concrete truck was scheduled for 10am, but thunderstorms were heading my
way so I called and asked them to try to get there early. The truck and a
very light rain arrived simultaneously around 9:45. The truck backed up to
the hole (big tire ruts!) and we started slowly pumping in the concrete.
Because there was that little bit of water in the hole, the concrete driver
put less water in the first couple feet of mix (he said that's always the
way they do it). I used a concrete vibrator throughout the pour and it
really did help making the concrete level out. One hour later, the job was
complete, having used 6.15 cu yrds of 3,000psi concrete. About 3 hours
later, I trowled and edged the concrete, and see that I've got a low area
right in the middle where some water is standing (dang it). Not sure if I
should just mix up a bag of concrete and level it out, or use a thick layer
of grout? One way or the other, I'll be grouting up around the base bolts,
so I don't know if it really matters or not.
I've got wet burlap bags and a plastic tarp covering the concrete. Now I
just have to wait for a month (or more) for my tower to arrive. At least
the hard (and dirty) part of the job it done. Hooray!
Thanks again and 73 to all,
David, K4ZZR