Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1] 2 3 Next   Go Down
  Print  
Author Topic: Dug Hole for Tower WET  (Read 7514 times)
KC4MOP
Member

Posts: 741




Ignore
« on: September 11, 2012, 02:40:32 PM »

Hello
I finally got around to getting a hole dug for my tower. 3X3X3 feet deep. Guy did it with a backhoe in 5 minutes. $25. Nice job.
It seemed like nice and dry in the bottom for almost a week (middle of August). I threw some rocky type gravel down there.
Then we go into a rainy period. The hole was half-assed covered and possible water go into it.
I got the Shop-Vac and sucked out 3 shop-vacs worth of water down to a mud. Several hours later checking and it looks like water still seeping in from bottom.
I'll keep checking the next few days as, we are in a nice dry period with low humidity.
If water keeps seeping in, from somewhere, do I give up on this location? It seemed like it was dry as a bone down there and I delayed too long to pour concrete. And now that it is a hole, the water that was flowing from underneath has decided to start filling my hole.
What thoughts are here about this possible dilemma?
Thanks

Fred
Logged
N7EKU
Member

Posts: 78




Ignore
« Reply #1 on: September 11, 2012, 04:04:39 PM »

Hi Fred,

Do you know at what level the water table is in your area?  You might try giving a call to your local health department and talk to one of their septic inspectors.  They should know quite a bit about the soils in the area.  You could also try you local septic guys.

Once the hole is more dry, clean of a side of the hole from top to bottom and look at the soil layers.  If you have a repeated high water table, it might show there e.g. you may have clay where the soil is often wet or mineral deposits or some other obvious change in the soil profile.

I doubt is another hole in the same area and elevation will be much different until the soil dries.  If it a hole that you need strong and stable, I would make it deep and wide for a good sized concrete block.

Mark.
Logged
KC4MOP
Member

Posts: 741




Ignore
« Reply #2 on: September 11, 2012, 04:52:03 PM »

Thanks Mark,
I shudda ordered the concrete and poured the base while we were in a dry spell.
Looking every couple of hours in the hole, shows me no additional water is accumulating. It might be worth going in there with my boots on, and digging up the muck and try to get back down to something less saturated and retry the vigil to see if water is seeping back in.
That darn hole was dry on the bottom when first dug and then I put off calling the concrete company to deliver.
The company said they would recommend that the hole be almost dry before delivery. There was quite an accumulation in there until 3PM today.

Fred
Logged
N7EKU
Member

Posts: 78




Ignore
« Reply #3 on: September 11, 2012, 05:06:34 PM »

Sure Fred,

I don't think it was the hole filling up with surface water unless you had a channel going in there or it was a big low spot in the yard.  Of course you might have had a serious rain (many inches?) and that might do it anyway.  Where I live we never really have any "exciting" weather so sometimes I forget about how big rains can be in other places.

From what you say though, it sounds like your local water table may be a bit high.  As long as the weather holds, I would just wait another day or two till the water stops seeping.  Clearing it out some more like you say might speed it up a bit too.

Oh and when I re-read your post I see the hole is a 3' cube -- that is a lot of concrete!  I think it would hold your tower pretty well as long as its guyed.

Mark.
Logged
KD0UN
Member

Posts: 56




Ignore
« Reply #4 on: September 11, 2012, 06:53:03 PM »

Check your water bill.

Seriously, remember that the strongest concrete is poured underwater.
Logged
W8JI
Member

Posts: 9296


WWW

Ignore
« Reply #5 on: September 12, 2012, 03:44:31 AM »

Fred,

Water seeping into the hole is NOT an issue.

The WORSE thing you can do is try to pump the hole over and over. When you pump the hole, you will disturb the soil by allowing more water to flow through the walls and bottom into the hole. This will just drag more loose soil into the hole. Like your mama used to tell you, stop squeezing those zits.

If you pull into the hole by pumping, and plug the stones up with mud so the tower legs don't drain, you will have a leg splitting or rusting problem. Be SURE the legs can drain. Stop messing with that hole.

When you get ready to pour, you can pump the hole, position the base, and then just pour right into the hole. I wouldn't even worry about a little water, myself. I'd pour right into it with a thick mix. You will eventually find the water all floats out the top.

73 Tom

   
Logged
KC4MOP
Member

Posts: 741




Ignore
« Reply #6 on: September 12, 2012, 07:00:00 AM »

Ok guys thanks for the reassuring replies.
As of this morning at 9AM 9-12, there is no additional water seeping into the hole. It must be the saturated muck at the bottom. I'll try to scoop some of the saturated mud out and get a layer of the gravel going again. I definitely want to make sure about tower legs draining.
Looks like some rain coming our way Friday and I now have a 3/4 inch plywood board to completely cover the hole and a tarp to keep things dry 4 feet beyond the hole to prevent any water going back in.
And I forgot about concrete being able to cure even under water!!
I have a 3' tower base arriving to place into the hole.

Fred
Logged
N7EKU
Member

Posts: 78




Ignore
« Reply #7 on: September 12, 2012, 11:03:12 AM »

Hi Fred,

Sounds like a good plan.  Good luck!

It's exciting to hear about your tower.  I can't put up a big one here, so it's fun to hear of an op getting a new tower.  What are you planning to put up on top of it?  I would put up a nice tribander and maybe a half-sloper or inverted-v for 80M if it was tall enough, or... so many options once you have a nice tower!

73,

Mark.
Logged
WN2C
Member

Posts: 453




Ignore
« Reply #8 on: September 12, 2012, 11:41:59 AM »

Only one square yard of concrete?  How tall is this tower and what part of the country do you live in?  Are you guying it or free standing

wn2c Rick
Logged
AJ4RW
Member

Posts: 568




Ignore
« Reply #9 on: September 12, 2012, 12:04:41 PM »

Fred, I just finished a tower job for myself putting a US Tower HDX 572 up.  Myself and a couple of teenagers dug the hole 6.5' x 6.5' x 7.5' with re bar webbing in place in June and the hole was dry but bordering on the water table level and then came TS Debby.  The day I was scheduled to pour it rained and rained, more than 12" in 24 hours.  I had the hole covered but the water table rose so much that it washed the sides out due to a sandy soil.  I went to Harbor Freight and bought a dirty water sump pump (about $80) and it did the trick for keeping the constant influx of water out from the encroaching water table.  In the mean time I disassembled the re bar webbing and dug the hole out and finally poured 3 weeks later.  The sump pump was the best investment I made and as soon as I was ready to pour it was poured.  The sump pump ran quite a bit till the cement was finally poured.  By the time I was finished the hole was 7' x 7' x 7', big hole.  Don't waste any time on pouring, even if it's raining.  Just cover the concrete after pouring so as to have a finished looking slab, rain will wash away the fine cement on the top and leave it looking porous.
Randy AJ4RW
Logged
WA2CWA
Member

Posts: 298


WWW

Ignore
« Reply #10 on: September 12, 2012, 02:59:28 PM »

Are you going to put a re-bar frame in the hole before you pour the concrete?

Pete, wa2cwa
Logged
AJ4RW
Member

Posts: 568




Ignore
« Reply #11 on: September 12, 2012, 03:47:37 PM »

Hi Pete
Yes, it was a massive project doing the re-bar and by the way it's already poured, set up for 45 days, then refurbished the tower with cabling and some new sheaves, transferred the quad and using it as I write this reply.  What a difference 75' makes.  Took in excess of 3 months from started digging the hole to getting it up in the heat of Florida summer.
73 de Randy AJ4RW
Logged
KC4MOP
Member

Posts: 741




Ignore
« Reply #12 on: September 12, 2012, 05:40:14 PM »

Yes I will also put in some rebar on my small project. There was a YouTube vid that some guy had a way to assure draining of the tower legs once they were in concrete.
I have two fans running on high speed pointing into the hole and it is finally drying out. I'll drop a couple more 50 lb bags of rock type gravel in there to re-establish a strong foundation. A 3 foot tower base will be in the concrete pier
The antennas will be a 3 element 6M antenna and my Magnetic loop antenna for RX.
The tower can be extended and guyed later, but for now I am looking at 40 feet. I want to get my feet wet on 6M.
I presently have a 65 foot utility pole with an A3S tri-bander on top and a dipole arm and pulley for one end of my 240 foot long dipole fed with OWL.
Logged
WA2CWA
Member

Posts: 298


WWW

Ignore
« Reply #13 on: September 13, 2012, 12:55:38 AM »

Very good Fred. Will look for you on 6 meters.

And, Randy, I can relate to your project. I have an EZ-Way RBZ-75 crankup/tilt-over tower which I had to dig the base and then fabricate the re-bar frame. Took about 7 yards of concrete which me and 2 other guys had to wheel barrow to the hole because the truck couldn't get to the back of my yard.  Also dropped a ton or two of bluestone ballast rock first into hole before the concrete was poured. Previous owner of the property thought the rock was better then grass so he covered the entire rear of the property with it. Too big to rake or shovel, so each piece had to picked up by hand. Took me several years to do that and I needed some place to get rid of some of it so the tower base hole seemed like a good place.

It's been up for 34 years and gone through numerous bad storms and hurricanes. Just finished replacing all the tower cables and installing a new motorized tilt-over winch. Antenna work on beams is the next project. Here's a picture at roughly the 45 to 50 foot height: http://amfone.net/Amforum/gallery/25_08_10_07_11_24_00.jpg The tower can handle roughly 28 square feet of antenna without guys.

Pete, wa2cwa
Logged
NA4IT
Member

Posts: 876


WWW

Ignore
« Reply #14 on: September 13, 2012, 04:22:11 AM »

Pete, your picture link says "Error 403 - Forbidden You tried to access a document for which you don't have privileges."
Logged
Pages: [1] 2 3 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!