PSN-L Email List Message

Subject: Re: Help with self leveling Lehman
From: meredithlamb meredithlamb@.............
Date: Wed, 20 Nov 2002 00:16:24 -0700

Hi all,

The "worst possible helpful reality resolution" (ha), to frequent
horizontal seismometer adjustments is to actually get down and
dirty and make a large/thick isolated ground pier out of concrete
and house it all with a surrounding insulated box/vault/building.

For the "physical work allergic" members....I'd suggest you
somehow get your wife, kids, (someone else) to do all the
digging, mixing of concrete (yea....sure!!...."you say"...ha).

Their will still be house influenced tilt when its made
underneath such; even in loose soil, but it should yield
considerably less need for set screw adjustments in the long term.

I'd even suggest that the pier be made over thick insulation
pliable plastic sheet/s, to keep the ground moisture/water
out of the concrete pier itself.  A surrounding covering "vault"
thats well insulated will also help somewhat.  I used to use
concrete patio squares on loose dirt and that required
several adjustments a week (for a horizontal).  With the
present "vault" and pier, its now ~ once a month.

A vertical is not very influenced by "ground" tilt of course ......
but....they tend to be much more temperature sensitive, where a
coiled or flat spring is involved....hence adding ALOT of insulation
"R factor" is quite helpful.  Without insulation and on a simple
dirt/concrete paver, I used to have to adjust it ~ once a day....
but with a insulated vault, its ~ every 6 months or so.

Take care, Meredith


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