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Detailed field investigation of undrained shear strength
and sensitivity of soft and medium stiff clays.
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From 0 to 30 meters by hand jacks, even through hard
layers of clay, sand or silt.
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Two vane sizes: measurements from 0-60 kPa & 0-100 kPa.
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Two-level accuracy, results can be used for the design of
earth fill foundations and embankments.
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ISO 9001 Certified.
The field vane
shear test (FVST) is the most widely used method for measuring the undrained
shear strength and sensitivity of soft clays in-situ. FVST is a more
economic method than for example CPT, as its operation does not require a
drilling rig or highly qualified personnel.
Some criteria
have nevertheless to be respected if the choosen FVST equipment is to be
used as a professional, detailed investigation instruments:
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The instrument should allow
direct penetration boring, in order to avoid inaccuracy due to rod-clay
friction.
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The vane itself must be
protected against any bending due to stones or harder layers of soil.
The Geonor H-10
is a fully protected, pressure, push-in, field vane instrument. No rod-soil
friction is possible due to its tube-protected rods. There is not a need
either to check the vane, nor to clean it between each shearing (clay
adhering to the vane may increase its area ratio considerably). The
protection shoe of the Geonor H-10 not only protects the vane but also
cleans it automatically before each measurement. The shoe is particularly
useful for testing in stratified, sandy, stony, and marine sediment clay.
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Technical Characteristics:
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Installation:
Pressure push-in. no hammering. By hand with Geonor ground anchor jacking
system or with a hydraulic drill rig.
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Instrument:
Gear driven, of torque reading: +/- 0.5% of range.
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Measurement range:
From 0-60 kPa (0-6 T/m²) and 0-100 kPa (0-10 T/m²).
Lower part:
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Total length with the vane extended: 1430 mm.
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Max outer diameter: 77 mmWeight:15 kg
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Two different sizes of vanes: 55 mm x 110 mm and 65 mm x 130 mm.
Instrument:
Vane Borer, H-10 complete for 30 m depth, consists mainly of:
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Readout instrument complete
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Vane borer lower part with vanes
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Set of spare vanes and protection tube
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30 extension tubes and rods
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Preboring equipment complete
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Complete insertion/extraction with rack jack, ball cone clamp, anchoring
screws, etc.
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Steel transport cases.
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