group's experimental work takes place in three adjoining laboratories,
plus field! Below is a list of our tools for research.
pieces of triaxial apparatus with each own complete driving and
monitoring system. Many of them are driven by a Megatorque Motor; a
motor which allows an extremely fine and accurate control through a
servo-system. They operate on Windows-based software in fully automated
manners. Optional devices such as LDTs (Local Displacement Transducers)
and bender elements may be mounted to the specimen to measure
Hollow Cylinder Apparatus
HCA permits complex
stress conditions to be applied to a soil specimen. With clever loading
schemes, the direction of the three principal stresses and their
individual magnitudes can be manipulated at our will. This is a unique
advantage in investigating soil's anisotropy, for example.
Characterisation of soil behaviour under general stress conditions
through HCA testing is arguably one of the most advanced mechanical
studies in geotechnical laboratory.
Direct Shear Apparatus
pair of direct shear
apparatus also have Megatorque Motors for horizontal loading. The
vertical loading is also computor-operated via EP regulators, allowing
either constant-stress or no volume change condition. Recently we
have added an optional set of confining rings to achieve more uniform
shear deformation modes. A newly designed pedestal allows installing a
suction probe when testing unsaturated soils (this project has been
undertaken in collaboration with Dr. Apiniti Jotisankasa of Kasetsart
Five oedometers in our laboratory all have a Megatorque Motor for Constant-Rate-of-Strain (CRS) loading. They are
capable of achieving extremely slow rates of compression, which are
comparable to those observed in field. One of the oedometers has a
chamber in which the temperature may be controlled between -30 and +80oC. These
features of the oedometers are useful in investigating loading rate
effects and thermal effects on soil's consolidation behaviour.
Our arm-type geotechnical
centrifuge, with its effective radius of 1.5m, is just the right size
for routine testing. The maximum attainable acceleration is 150 G.
Introduced less than 10 years ago, new capabilities have been added for each new projects.
We have a suite of field
testing tools. They include an electric cone, seismic cone,
conventional Dutch cone, field vanes, penetration balls of two different sizes. Our
portable rig allows our team to reach depth of 30m in soft
clay on our own, without hiring specialist machines.
X-Ray Diffraction machine
is capable of indentifying mineral compositions of soils. By
scanning a soil sample, fundamental information concerning the soil's
physical properties and geological origin is obtained.
And, there are lots more of bits and pieces!