(I received by mail a request and a beautiful story of Frank. That's why I asked him if I could post it in the forum. Maybe there anyone can ever lash out useful tips, or add.)

Dear Hugo,

diggingwellsUntil 1997 I lived in Brazil for seven years and have still a house there in Nova Timboteua, Para, Brazil, 140 km from Belem, Para.

In one corner of the area of ​​4 ha. the water level is just below the soil surface and within the same area we had 15 years ago used an artesian well that was 30 meters deep and from which we pumped a lot of water from 15 meters deep. That well is polluted after not being used and kept clean for a long time.

The pumps of the village stand on an adjacent site.

We have recently dug a well, with a brick ring of about 1 meter in diameter.
We are at a depth of about 5 meter stumbled on a kind of quicksand and the pit fills itself as quickly with new quicksand, as there is dug and lifted.

After now 1,000 liters is sucked with a pump to a 1,000 liter water tank, there must be a while to wait until the water level has risen in the pit again. I want to pump water faster, so we should probably have to go deeper.
And deeper fails. We do not know how thick the layer of quicksand is. Within 100 meters and within the plot was also a well that without this problem had a water level at 3 meters below the surface.

Do you have experience with this problem and do you know what to do in our case?
The well has so far costed € 700 approx. on labor and material,

Frank Day,

I have little experience with quicksand. I have 1x a shallow pit (about 3m) dug of which the lower part (about 50 cm) was quicksand.
That could still because we could immediately put a concrete ring. But dig a pit in quicksand really is dangerous. There are disappeared already people as well as concrete rings just like that.

For large projects, it happens that, to get through to the quicksand, locally and temporarily the soil is frozen. But I suspect that such is almost priceless.

Drilling seems more appropriate than digging. Goes through quicksand itself.
Since you do not know the thickness of the layer of quicksand you should always hold the drill well, so she will not sink and become lost.

If you put a drainage tube in the sand, and then connect a pump, then you do not get enough flow?

If it has to be a dug well it seems to me that you should concatenate concrete rings from above and lower them. Loose rings can tilt or flush. You have in advance, to fix them above ground together. Lower it a part, and again (above ground) mount a new. Could by using 'staples'. Rebar mounted in 4 holes in the top of the lower ring, and 4 in the bottom of the top ring. Rebar through the holes, folding and the two loose ends welding or bonding.
On the outside you can use these staples to hang and to lower the tubes with hooks to levers (First on 6 and 12 hours, then at 3 and 9 o'clock.) (This cannot past from the inside, because so you can no longer get new ring on top.)
A tough job. And it works only as long as the rings still can be hold with levers, and as long as they do not get pinched in solid ground.
Metal would be a lot lighter: an iron (rust!) or stainless steel silos lowering, and then welding pipes on top.

Drilling thus seems more realistic, and less dangerous and expensive.

Are there any similar cases that have already found a solution?
I wonder if you can do something with this, and if it succeeds.
Success, greetings

Hello Hugo,

How nice that you send such a comprehensive answer to my question!
In our case we masonry along when the column sinks in the hole and we make sure that the column remains one meter above the ground, the interior is plastered. When you dig scoop sand from under the brick column away. So there is no danger of tipping. The danger is that in our case there is a hollow space at the bottom besides the column, as sand is removed and thus may collapse, which may constitute a risk to the person who is digging.
Indeed, I am considering to drill next to the water tower which stands next to the dug well, so that is still usable. The well should we considered as lost. The rainy season is coming, maybe even a miracle happens and the situation improves.

Interesting site though. I have some principles applied in Brazil that you deal with. First at an agricultural cooperative, where we learned these techniques to members. After my contract as
development worker expired, I myself am going to farmer. The cooperative went bankrupt. I've tried everything in the field of organic, then self - and green manure. We used bean types and
leguminous shrubs, we pruned and as green manure around the planted fruit trees let perish. In addition, cow manure and I have used a test load of dried pig manure pellets from the Netherlands. For irrigation we used rolled, perforated tubing. We also utilize soil and light / shadow by different types of plants such as banana, coconut, and cupuacu together. During the planting of fruit trees, we first have planted melons and beans so that the bottom was covered and gave an additional crop yield. The bananas were used for shade and would disappear as soon as the coconut trees would produce. However, the bananas I had bought in another state from another farmer, turned another, non-commercial type. I 'm more or less gone bankrupt. (it was 5,000 banana trees) and later returned to the Netherlands.


I got in the car on the way some thoughts about it. If you have the time, perhaps there is another solution.
If you make with a mold concrete wedges ¼ of the tube circumference, about 25 cm high, with a tooth above and right; and bottom, and left a groove, then you can put the rings from the inside to move up and down under. Given the quicksand resists, you may press the last two segments of a ring too far outwards, and then as a double door, back (tongue and groove) pull them inside closing.
With a mold you can make all identical pieces. And concrete hardens even under water further (even better than dry). Possibly using fast curing concrete and testing after how many hours it can out of the formwork.
Due to the pressure of the propellant sand around the segments, they are pressed firmly against each other. In order to shorten the lead time may it be necessary to make several molds.
And secure the installer / digger always with a sturdy rope under the arms around the chest and keep him under constant surveillance.
We might make it so in a reasonably safe manner...
Success, greetings

Day Hugo,

I do not understand well what advantage working with concrete circular segments yields compared to the way we do it.
We worked the way you describe with a rope so that the digger can be lifted in case of emergency so therefore were always two man upstairs.

Hei Frank,

You must assess the course, in practice, on the spot. Benefits can include:
- The whole structure should not slide down, like concrete rings,
- It depends on how fast it flows in quicksand. If it is relatively quick and powerful masonry is pushed. Readymade pie slices would be just pressed tightly together.
- You can continue digging, masonry must harden before you can dig further.

You should see what is workable and appropriate.
Maybe you can occasionally show some pictures? I'm curious how it goes and evolves.
Kind regards


Well with rings


I have discovered an ancient well with concrete rings in my court.
Probably two rings, but the bottom ring is completely silted

How do I make that usable again? Scoop with a bucket? Can I go into that hole without danger?



I have done it 2 x in the past with an old well.
2 rings is not so deep, probably you can find a third.
Your nose can tell you whether you can.
You can also lower a candle. If there is too little oxygen, she will go out and you keep better out.
There may also be flammable or explosive methane gas in it, but you had already smelled then normaly. So still be careful.
If you decide to go there, make sure that you are never alone.
Place a narrow ladder into the pit so you can also get out again. And tie a sturdy rope under your arms that above anywhere is attached properly.
You helper can pick up the gunk that you put in a bucket, and therefore keep an eye on you.

Another option is to use a waste water pump. Take plenty of water with mud from the pit content, and pump it out. Maybe you can settle a few basins or tubs for reuse (water pumping and dump settled gunk. )
If the job is done, wash the walls, the dirty water pumping or scooping, and lay a layer of pebbles in the bottom.
(Let's know how it went?) Be careful, and good luck!