Sondex
For Vertical Settlement Profiles
Data from the Sondex system can reveal the depths at which settle-
ment has occurred as well as the total amount of settlement.
The Sondex system consists of a probe attached to a cable or steel
tape, a cable reel with a built-in voltmeter, and a number of stainless
steel sensing rings positioned along the length of an access pipe. In
soft ground, rings are fixed to a corrugated plastic pipe and the ac-
cess pipe is installed inside the corrugated pipe for support. The cor-
rugated pipe slips along the access pipe and allows the rings to move
with the surrounding ground. In harder ground, sensing rings can be
attached directly to telescoping plastic pipe.
The operator draws the probe through the pipe. The meter on the
readout unit peaks and a buzzer sounds when the probe’s internal
coil is aligned with a sensing ring. The operator refers to cable
markings or the steel tape and records the depth of each ring. Later,
data from the current set of measurements is compared to the initial
set of measurements to determine changes.
Advantages
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Provides multiple measurements, indicating not only the total
settlement, but also the “incremental” settlement at the depth of
each magnet.
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Optical survey not required if bottom is fixed in stable ground.
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Can be combined with inclinometer in certain soils.
Limitations
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Interferes with site operations and cannot be automated.
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Readings are affected by operator’s technique.
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Installation can be difficult.
Borehole Extensometers
Rembco Geotechnical Contractors specializes in
slope stabilization,
soil nail wall,
foundation repair
and support,
grouting,
shoring,
micropile
construction,
rock drilling, and we remediate
sinkholes. We use a
problem-solving approach in the geotechnical portions of buildings, bridges, water plants, sewage plants, tunnels,
installing caisson bottom, and roads. We are experienced in these applications:
micro piles,
sinkhole repair,
permeation and
pressure
grouting,
soil nails,
cement grouting,
chemical grouting,
micropiles,
compaction grouting, and
rock anchors.
Rembco techniques apply when adding new structures: especially
rock anchor,
microfine cement,
soil nailing, and
micropile
installations for foundation support. Our specialties are
soil nails,
rock anchor,
chemical and
compaction grouting,
mini piles,
sinkhole repair,
micropiles, and
soil nailing.
