Geotechnical News • June 2016
29
GEOTECHNICAL INSTRUMENTATION NEWS
complete geotechnical investigation
and analysis. Instrumentation also
plays a role in monitoring the long-
term stability of the slope after reme-
dial measures have been taken.
Summary of instruments that can
be considered for helping to provide
answers to possible geotechnical
questions
Table 5 lists the possible geotechnical
questions that may lead to the use of
instrumentation for landslides in soil,
together with possible instruments
that can be considered for helping to
provide answers to those questions.
Cut slopes in rock
General role of instrumentation
The general role of instrumentation
is identical to the role for cut slopes
in soil, as discussed above. However,
when planning to monitor the stabil-
ity of rock slopes, it is important to
recognize that if the slope is subject to
a brittle failure mode, movement will
be sudden. In such cases, geotechnical
instrumentation may not be appropri-
ate to forewarn of instability. It may
be more appropriate to develop an
area-wide correlation between rainfall
intensity and slope instability, and to
use rainfall measurements to warn of
potential problems.
Summary of instruments that can
be considered for helping to provide
answers to possible geotechnical
questions
Table 6 lists the possible geotechnical
questions that may lead to the use of
instrumentation for cut slopes in rock,
together with possible instruments
that can be considered for helping to
provide answers to those questions.
Landslides in rock
General role of instrumentation
The general role of instrumentation is
identical to the role for landslides in
soil, as discussed above.
Summary of instruments that can
be considered for helping to provide
answers to possible geotechnical
questions
Table 7 lists the possible geotechnical
questions that may lead to the use of
instrumentation for landslides in rock,
together with possible instruments
that can be considered for helping to
provide answers to those questions.
Table 5. Some instruments that can be considered for monitoring landslides in soil
Possible geotechnical questions
Measurement
Some instruments that can be considered
What are the post-landslide conditions? Pore water pressure
Surface displacment
Subsurface displacement
Open standpipe piezometers
Vibrating wire piezometers installed by the fully-
grouted method
Flushable piezometers
(Pneumatic piezometers)
Conventional surveying methods
Remote methods
(Tiltmeters)
(Fiber-optic instruments)
Inclinometers
In-place inclinometers
(Time domain reflectometry)
(Fiber-optic instruments)
Is the slope stable in the long term?
As for “What are the post-
landslide conditions?”
Rainfall, for possible
correlation with any
displacement
Load in tiebacks
As for “What are the post-landslide conditions?”
Rain gauges
Load cells
