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Landslides Testing

Landslides are a serious geologic hazard that affects many parts of the world. Landslides occur in all 50 U.S. states and territories for example, causing an estimated $1-2 billion in damages and more than 25 fatalities on average each year (USGS, 2014). Falling rocks, rotational slides and debris flows are some of the most common and sometimes deadly hazards relating to slope failures, yet there is still much to learn about how and why they occur.

Understanding what triggers a slope to fail, and how a soil mass will respond once physical conditions change, are key to managing risk. GDS have worked with some of the leading researchers in the slope stability field to develop and manufacture testing systems that enable slope failures to be better understood. The systems allow often complex field conditions and slope response to be modelled in the laboratory, which in turn can be used to assess the risk to infrastructure from various types of landslide hazard.



Test Standards for Landslide Testing

  • ASTM D-2850-03a:
 Determination of the undrained shear strength of a saturated soil, in terms of total stress, via the triaxial apparatus. This parameter can be used to assess the stability of a slope against sliding.
  • ASTM D-3080:
 Determination of the drained shear strength parameters of a soil via the direct shear apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.
  • ASTM D-4767:
 Determination of the shear strength parameters of a saturated soil, in terms of total and effective stresses, via the triaxial apparatus. These parameters, the angle of internal friction and cohesion, are used to assess the stability of a slope.
  • ASTM D-6528:
 Determination of the shear strength parameters of a soil via the direct simple shear apparatus. These parameters, the angle of internal friction and cohesion, are used to assess the stability of a slope.
  • ASTM D-7181:
 Determination of the drained shear strength parameters of a saturated soil, in terms of effective stresses, via the triaxial apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.
  • BS 1377-7:
Determination of the drained and undrained shear strengths of a soil, in terms of total stress, via the direct shear and triaxial apparatuses. These parameters can be used to assess the stability of a slope against sliding.
  • BS 1377-8:
Determination of the drained and undrained shear strengths of a saturated soil, in terms of effective stress, via the triaxial apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.
  • CEN ISO/TS 17892-8:
Determination of the undrained shear strength of a saturated soil, in terms of total stress, via the triaxial apparatus. This parameter can be used to assess the stability of a slope against sliding.
  • CEN ISO/TS 17892-9:
Determination of the drained and undrained shear strength parameters of a saturated soil, in terms of effective stresses, via the triaxial apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.
  • CEN ISO/TS 17892-10:
Determination of the drained shear strength parameters of a soil via the direct shear apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.
  • JGS 0521:
Determination of the unconsolidated undrained shear strength of a saturated soil, in terms of total stress, via the triaxial apparatus. This parameter can be used to assess the stability of a slope against sliding.
  • JGS 0522:
Determination of the undrained shear strength of a saturated soil, in terms of total stress, via the triaxial apparatus. This parameter can be used to assess the stability of a slope against sliding.
  • JGS 0523:
Determination of the undrained shear strength of a saturated soil, in terms of effective stress, via the triaxial apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.
  • JGS 0524:
Determination of the drained shear strength parameters of a saturated soil, in terms of effective stresses, via the triaxial apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.
  • JGS 0560:
Determination of the constant volume (undrained) shear strength parameters of a soil via the direct shear apparatus. These parameters, the angle of internal friction and cohesion, are used to assess the stability of a slope.
  • JGS 0561:
Determination of the constant pressure (drained) shear strength parameters of a soil via the direct shear apparatus. These parameters, the effective angle of internal friction and cohesion, are used to assess the stability of a slope.


Products for Landslide Testing



GDSTAS – Triaxial Automated System

The Triaxial Automated System (GDSTAS) is a load frame based triaxial testing system. The system is configured by choosing from a range of load frames, triaxial cells, pressure controllers and software. The system can be configured as a multi-station commercial testing apparatus right through to high range rock testing at research level. If an existing triaxial system requires upgrading, parts of the TAS system can be incorporated with existing equipment (including those from other manufacturers) to perform the upgrade. Typical drained and undrained shear strength parameters, such as the angle of internal friction and cohesion, can be obtained from the TAS to enable slope stability assessments to be made when considering landslide hazards.


The Shearbase System (GDSSS) is an electro-mechanical shear testing device that can be configured as either a direct shear or direct simple shear test apparatus. The benefit of this apparatus is that the conversion between direct shear and direct simple shear is straightforward, and therefore if both options are not supplied at time of build the missing option can be supplied at a later date. Note slow cyclic loadings may also be applied to test specimens using the SS, allowing multi-reversal tests to be automated and the residual strength of a soil at large strain to be estimated.


The Back Pressured Shearbox (GDSBPS) is used to perform static direct shear tests on soil specimens with precise back pressure control. This enables slope failures to be studied by applying realistic field conditions to the test soil, including the ability to assess the effect of changing water table elevation. The static BPS range includes a saturated version providing control of pore water pressure, and an unsaturated version providing control of pore water and pore air pressures.


The Dynamic Back Pressured Shearbox (DYNBPS) is used for the static and dynamic direct shear testing of soil specimens with control of pore pressures. The control of pore pressure allows fully saturated specimens to be tested, and loadings in the normal and shear directions may be cycled at up to a maximum frequency of 5 Hz. The ability to apply dynamic cyclic loadings to soil specimens in the DYNBPS enables the stability of slopes to be assessed when subjected to hazards such as earthquake shaking and other natural or man-made dynamic loadings. Note user-defined cyclic loading patterns can also be applied to the test specimen when using the DYNBPS.

GDSLADS - Large Automated Direct Shear System 

GDS Large Automated Direct Shear System (GDSLADS) is an electro-mechanical direct shear testing device for large specimens, up to 300mm square or round. Different specimen sets can be used to monitor the response of geo-membranes and rock specimens under direct shear deformation. These options make the GDSLADS a useful tool when assessing the stability of slopes, be them natural or man-made, where larger aggregates or rock may be present.

EMDCSS – GDS Electromechanical Dynamic Cyclic Simple Shear Device 

The GDS Electromechanical Dynamic Cyclic Simple Shear Device (EMDCSS) is for simple shear testing only. It is capable of carrying out dynamic cyclic tests from small strain (0.005% shear strain amplitude) to large strain (10% shear strain amplitude), as well as extremely accurate quasi-static testing. This is the choice for a no-compromise simple shear machine with the greatest range of testing capability. The perfect choice for advanced commercial testing or academic research, allowing strength and deformation parameters required for slope stability assessments to be determined.

VDDCSS – Variable Direction Dynamic Cyclic Simple Shear system 

The variable direction dynamic cyclic simple shear system (VDDCSS) allows simple shear to be performed in two directions, rather than the standard single direction. This is achieved by having a secondary shear actuator that acts at 90 degrees to the primary actuator. When used as a variable direction machine, the secondary shear axis can be used independently or in conjunction with the other shear axis. Therefore, simple shear may be performed in any horizontal direction. Such features allow strength and deformation parameters required for slope stability assessments to be determined.

GDSIST – Interface Shear Tester 

The Interface Shear Tester is a CRS consolidation cell with the additional ability that the base pedestal may infinitely rotate. The internal load cell measures both the axial force on the specimen as well as the torque generated. The system is designed to test the shear interface between the specimen and the top-cap.  Users may bond specific materials to the top-cap for testing. Such features allow the GDSIST to define interface strengths between materials, as well as determine the residual strength of soils as part of slope stability assessments.

ST-RTS  – Static Triaxial Rock Testing System


The Static Triaxial Rock Testing System enables axial load application up to 1MN, with triaxial cells rated up to 70MPa used to confine test specimens of maximum 50mm diameter.


DT-RTS Dynamic Triaxial Rock Testing System



The Dynamic Triaxial Rock Testing System can apply axial loads of up to 400kN at dynamic frequencies of 20Hz and below. Dynamic loading is achieved using a servo-hydraulic actuator system.


DGSAV - Acoustic Velocity transducers


The Acoustic Velocity transducers allow P- and S-wave velocities to be measured within a rock specimen. The transducers are mounted in the pedestal and top-cap, or in some cases the sides of the specimens.

HPBPS - Back Pressure Shearbox High Pressure


The High Pressure Back Pressured Shearbox is a high pressure version of the GDSPS. Normal and shear loads of up to 100kN may be applied to the test specimen, with a back pressure of up to 10MPa available.


Product Applications