Factors Affecting the Choice of Instruments
Critical Parameters Each project presents a unique set of critical parameters. The designer
must identify those parameters and then select instruments to mea-
sure them. What information is required for the initial design. What
information is required for evaluating performance during and after
construction. When the parameters are identified, the specification
for instruments should include the required range, resolution, and
precision of measurements.
Ground Conditions Ground conditions often determine the choice of instrument. For
example, a standpipe piezometer is a reliable indicator of pore-water
pressure in soil with high permeability, but is much less reliable in
soil with low permeability. A large volume of water must flow into
the standpipe to indicate even a small change in pore-water pressure.
In soils with low permeability, the flow of water into and out of the
standpipe is too slow to provide a timely indication of pore-water
pressure. A better choice in this case would be a diaphragm-type
piezometer, which offers faster response since it is sensitive to much
smaller changes in water volume.
Complementary Parameters &
Redundant Measurements
The behavior of a soil or rock mass typically involves not one, but
many parameters. In some cases, it may be sufficient to monitor only
one parameter, but when the problem is more complex, it is useful to
measure a number of parameters and to look for correlation between
the measurements. Thus it is common practice to choose instruments
that provide complementary measurements.
For example, inclinometer data indicating increased rate of move-
ment may be correlated with piezometer data that shows increased
pore pressures. The load on a strut, calculated from strain gauge
data, should correlate with convergence data provided by inclino-
meters behind a retaining structure.
Another benefit of selecting instruments to monitor complementary
parameters is that at least some data will always be available, even if
one instrument fails.
Purpose & Choice of Instrumentation
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.
