Resilient Modulus Testing System (RMTS)
The GDS Resilient Modulus Testing System (RMTS) enables the resilient modulus and permanent deformation of unbound base/sub-base pavement materials to be determined. The system, based around the GDS ELDYN, uses an axially-stiff load frame with a beam mounted electro-mechanical actuator to apply dynamic cyclic axial loads, with a GDS triaxial cell used to confine the test specimen.
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Hydraulic Resilient Modulus Testing System (HRMTS)
The GDS Hydraulic Resilient Modulus Testing System (HRMTS) enables the resilient modulus and permanent deformation of unbound base/sub-base pavement materials to be determined. The system, based around the GDS ELDYN, uses an axially-stiff load frame with a beam mounted hydraulic actuator to apply dynamic cyclic axial loads, with a GDS triaxial cell used to confine the test specimen.
ST-RTS - Static Triaxial Rock Testing System
The Static Triaxial Rock Testing System enables axial load application up to 2MN, with triaxial cellsrated up to 100MPa used to confine test specimens of maximum 200mm diameter.
AT-RTS - Triaxial (Active Cell) Rock Testing System
The Active Triaxial Rock Testing System allows an axial load application up to 2MN via a hydraulically-actuated triaxial cell. Confining pressures up to 64MPa are available for a maximum 150mm test specimen diameter.
DT-RTS - Dynamic Triaxial Rock Testing System
The Dynamic Triaxial Rock Testing System can apply axial loads of up to 1.5MN at dynamic frequencies of 20Hz and below. Dynamic loading is achieved using a servo-hydraulic actuator system.
GDSAE - Acoustic Emissions transducer
The Acoustic Emissions transducers enable micro-fractures occuring within a rock specimen during testing to be recorded. The submersible transducers may monitor fractures continuously, or only when triggered.
Acoustic Velocity (GDSAV) transducers measure the P- and S- wave velocities within a test specimen. Sensors and sources can be mounted in either the pedestal and top-cap, or both sides of the specimen in some cases, enabling acoustic velocities to be measured in multiple directions. Such small-strain information is often required when designing and constructing new underground spaces.
GDSHC - Instrumented Hoek Cell
The Instrumented Hoek Cell is a highly sophisticated version of the traditional Hoek cell, which can be fully instrumented with acoustic velocity and/or acoustic emission transducers.
GDSLADS - Large Automated Direct Shear (300mm)
The Large Automated Direct Shear system is an electro-mechanical direct shear testing device for specimens of up to 300mm square in size.
HPBPS - Back Pressure Shearbox - High Pressure
The High Pressure Back Pressure Shearbox is a high pressure version of the GDSBPS. Normal and shear loads of up to 100kN may be applied to the test specimen, with a back pressure of up to 10MPa available.
GDS Resonant Column Apparatus
For many years the resonant column apparatus has been used in research and commercial laboratories to estimate values of the shear modulus, G, and damping ratio, D, for soil specimens across the small to medium strain range (< 1 %).
The variation in these parameters with increasing strain magnitude allows engineers to conduct dynamic response analyses, such as those using finite element and non-linear analytical methods, which enable performance assessment of natural and engineered structures subjected to dynamic and cyclic loadings.