Geotechlab The site of the Geotechnical Lab
Geotechlab

Facilities

Meso-scale chute / channel / box  for physical modelling of geotechnical problems

The layout of the box used for the loading tests on a granular slope (Box size: ~180x40x70 cm).

Example of application with seepage in a sandy-clayey slope .
Example of application with a footing on a granular slope .

The box is equipped with a

  1. motorized hopper for the soil deposition by pluviation
  2. hydraulic jack for controlling the box inclination
  3. motorized loading system apparatus
  4. hydraulic circuit for seepage modelling and water recirculation
  5. photographic monitoring system
  6. load cells, displacement transducers, strain gauges and micro-pore water pressure transducers

High-resolution Micro-CT scanner

SkyScan 1172 Micro CT.
Example of 3D tomographic reconstruction of a wet granular material (glass beads) .

The device has the following characteristics:

  1. X-ray source: 20-100kV,10W,<5µm spot size or 20-80kV, 8W, <8µm spot size
  2. X-ray detector: 11Mp, 12-bit cooled CCD fiber-optically coupled to scintillator;
  3. Maximum object size: 27mm in diameter (single scan) or 50mm in diameter (offset scan);
  4. Detail detectability <0.8µm at highest resolution.

Schneebeli apparatus

Schneebeli 2D apparatus made of wooden dowel pins.

High-speed digital cameras

Casio EX-F1 Exilim (6.6 Mpx, 2816×2112, max 60 frame/s as camera and 1200 frame/s as video).
2x Sony Cyber-shot DSC-RX100 V (up to 1000 fps).

DSLR cameras

2x Canon EOS 400D Digital Rebel XTi
(10.1 MP, max res. 3888×2592).
2x Canon EOS 550D Rebel T2i
(18 MP, max res. 5184×3456).
3x Canon EOS 1300D
(18MP APS-C, max res. 5184 x 3456).

Depth camera

2x Azure Kinect DK

GNSS receiver

Trimble R1 GNSS receiver

Labview

Chassis and modules

Chassis NI cRIO-9074
Chassis NI cDAQ-9188
Module NI 9237
Example of application for the seepage control in the slope model .
Module NI 9234

Arduino

Arduino UNO R3

Raspberry

3x Raspberry Pi High Quality Camera
3x 6mm Wide Angle Lens for Raspberry Pi HQ Camera
3x 16mm Telephoto Lens
3x Raspberry Pi4 8Gb Ram

Equipment

USB Oscilloscope Owon VDS1022 (2 channels, 25 MHz, 100MS/s)
Example of reading for 1 m of a 50-ohm cable. Note the shift of the reflected signal by some nanoseconds.

Sensors

GE Druck PDCR81 miniaturized pressure transducers with high air-entry filter (350 mbar g; 0-3.5 m H20)
1x Onset Hobo water level U20L-04 (0-4m)
2x Onset Hobo water level U20-01 (0-9m)
https://i.ebayimg.com/images/g/cHsAAOSwQMVfLHG1/s-l500.jpg
x Onset Hobo water level U20-001-01-TI (0-9 m) Titanium
Example of reading with Hobo transducer: pressure, temperature and battery level data.

For a glossary in the field of force measurement have a look here

Load Cell TCA.315.R3 (compression and tension) 10 kg
Load cells (1kg-20kg) and HX711 module
Strain gauges Tokyo Sokki Kenkyujo Co., Ltd.
Gauge types: FLK-6-23 (gauge factor 2.15), FLK-6-17 (gauge factor 2.13)
2x shear force sensor Kistler 9144B21
SlimLine, Fy = -1.7 … 1.7 kN
2x normal force sensor Kistler 9134C21
SlimLine, Fz = 0 … 26 kN
1x 3-component force sensor Kistler 9027C Fx,Fy = -4 … 4 kN; Fz = -8 … 8 kN
1x 8-channel Laboratory Charge Amplifier Kistler 5167A80KH1 LabAmp , quasi-static, signal: Charge

Important video instructions on the functioning and the use of 1-component Piezoelectric force sensors:

Servo accelerometer inclinometer probe
Phreatimeter – water level meter OTT KL010-100 (100 m)
Water level indicator BFK100 (cable length 100 m, probe diameter 1 cm) (PASI)
1x Green (520 nm) and 5x Red (650 nm) Laser module diode.

Granular materials

Glass ballotini of different grain-size (0.1 mm; 0.75-1 mm; 1.5 mm; 2.0 mm; 3.0 mm; 5.0 mm)
Calcium carbonate particles (800-1180, 1180-1410, 1410-2000, and 2000-2830 μm)
Adige sand ($latex D_{50}$ =0.42 mm)
Fontainebleau sand

Micro-stages

2x XYZ-axis 40×40 LD40-LM fine tuning Microstages and 2x XYZ-axis 40×40 LD40-RM fine tuning Microstages

Alluminium extruded profiles

References

Gabrieli, F., Cola, S., & Calvetti, F. (2009). Use of an up-scaled DEM model for analysing the behaviour of a shallow foundation on a model slope. Geomechanics and Geoengineering, 4(2), 109–122. https://doi.org/10.1080/17486020902855688
Gabrieli, F., Grigoletto, E., & Cola, S. (2010). Physical modeling of a drainage system on a layered sandy-clayey slope. Physical Modelling in Geotechnics - Springman, Laue & Seward (Eds), 2, 1107–1112.
Santomaso, A. C., Volpato, S., & Gabrieli, F. (2018). Collapse and runout of granular columns in pendular state. Physics of Fluids, 30(6), 63301. https://doi.org/10.1063/1.5030779
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