"O",

Have you or the contractor considered that this tunneling might go down far enough to hit water? I know when I lived in
Jupiter (FL), the water table was only 2.5-3 feet below the floor level of our house.

I have a feeling that if the tunnel went down to the level of the water table, things could get (even more) complicated real
fast.

Eric Law

"orangetrader" wrote in message news
I need to have someone come dig a tunnel to access a "Y" connection in the
sewer line that needed to be replaced. Access from above is too problematic
and messy.

The quote I got is $187 per foot of digging. They will need to dig down
several feet beyond the footing, then dig a horizontal tunnel six feet over
to the location of the pipe. Because we are in Miami and near the beach,
the soil is all sandy, I guess when they tunnel, the compacted sand above
the tunnel will fall? This means more dirt will be removed from the tunnel.
Now when they finished repairing or replacing the drain line, they told me
they can just throw the dirt back into the tunnel and all will be ok.

I wonder how you will throw the dirt back into the tunnel to fill the space
below the slab and above the footing? Can this really be done? Does it not
require some sort of a sand/dirt pump? Even if this is doable it will not
be compacted right?

Will this cause the line to be "suspended" and not resting on dirt and will
that cause future failure - possibly the weight of water going through may
create a back pitch? Will the foundation settle as a result of this dig?

Thanks for any comments,

O