The amount of fines that water can carry is determined by the speed that it is flowing. Why not make the trench a little wider or less of a slope to reduce piping and plugging of the filters.
Usuall there isn't anything at the surface of geothermal wells(I'm assuming your talking about ground source heat pumps) and the line to the structures are usually buried below the frost line so the depth could vary according to your area. The only issue I see is that local or state regulations...
A little of both, no one grout mix will work in every situation, I have even used pea gravel and bentonite chips in certain situations. Throw regulators into the mix and it can get even more interesting.
Those mmixes are pretty thick, most standard geotech drill rigs with a moyno pump probably wouldn't be able to pump anthing with less water without bringing in a grout pump.
Something we do alot is drill as small of a hole as possible (4"in dia. for 2 3/4") casing and use the grout valve that...
Your right it wont set. Any more than 10% bentonite by weight is too much. Check with Slope Indicator They reccommend a couple of different mixes one with bentonite, the other with lime. One of them should work or at least give you a good starting point.
CME or Diedrich Drill both make tracked geotechnical drills. I would trust them over trying to modify another type of drill. Check out either www.cmeco.com or www.diedrichdrill.com
You might want to go back and look at the samples from the test borings again, if possible, and maybe do some lab tests on the ones classified as silty clay they may actually be clayey silt especally if the person doing the logging had less than 15 or 20 years experience logging borings. I've...
Sounds like you have more than one problem.
You said your site is seaside which probably means the groundwater is either salty or brackish. Straight bentonite won't work. You may be able use a polymer enhanced bentonite but if you grout and redrill the cement will breakdown the polymer...
Jastan,
As far as Loose sands underlying dense sands, that is a relatively common phenomenon, and it can happen with any soil or rock type, especially if there is groundwater or faulting invovled.
I would have to agree with Focht3 and BigH, you do need to get some good samples of the...
Sounds like a compaction issue. Many of the builders there will compact their fill by running over it a few times with a front end loader and call it good. This was going on 15 years ago when I moved from the Atlanta area, and I noticed a builder doing it his past winter when I went back to...
I'll through my 2 cents worth in on this one too.
If I'm not mistaken the US government offically adopted the metric system over 100 years ago. Its the US businesses that are dragging their feet. Most of us here would be willing to accept the change, except for the cost. I personally prefer...
