Hank,
I'll give you 50% on the garden hose answer.
You can compact SAND very well with a garden hose. The water turns the sand to
quick sand, and the vibration of the water is similar to a vibratory roller.
When the water pore pressure is allowed to dissipate, you end up with very
dense sand. (This is similar to using a vibrator in wet concrete)
This method doesn't work at all in CLAY soils. For SILTS - depends if it SANDY
or CLAYEY.
If you have ever walked or driven on the beach you know that the wet sand near
the water has been compated by the surf. Sand has another property, when it
dries out it bulks or increases in volume (less dense). You can see that by
trying to drive or walk on the dry part of the beach.
Tower2sell@aol.com
In a message dated Wed, 21 Mar 2001 1:05:06 PM Eastern Standard Time,
"Lonberg, Hank" <Hank.Lonberg@Harrisgrp.com> writes:
<< John:
Actually as someone mentioned previously, OHSA and most states require
shoring for excavations more than 4 feet deep if someone is to be in the
excavation. My previous discussion does not condone being in an excavation
without shoring if it is deeper than 4 feet or at a minimum benched per OSHA
requirements.
IF you are going to backfill please do not just use a hose to compact the
soil with water. This usually decreases the density of the backfilled soil
including the undisturbed soil adjacent to the backfill material. This is
opposite of what you want to do. IF you know the optimum water content of
the soil then wet it to that point, place it and mechanically compact in 8
inch lifts. This will give you the maximum density for the soil. This is
what you want. If you use too much water then the water is in the voids of
the soil,reducing the density of the soil and acts like a lubricant to allow
the soil to flow, i.e., quick sand. Dampen the soil and compact, is the rule
of thumb, don't place and water like a garden.
73
Hank Lonberg / KR7X
>>>
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