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Embankment Dams and Mine Tailings Testing

GDS Instruments designs and manufactures laboratory testing apparatus for the geotechnical characterisation of mine tailings and embankment dam materials, including cyclic simple shear, triaxial, bender element and consolidation systems.

Embankment Dams


Embankment dams are constructed primarily from compacted earth or rock fill, and their structural integrity depends on accurate characterisation of the strength, permeability and deformability of the materials used. The critical risk periods (end of construction, initial reservoir filling, and rapid drawdown) each demand material-specific laboratory data. GDS offers testing systems covering the full suite of design parameters required for embankment dam stability analysis; our equipment has been used in real-world failure investigations including the Cadia Valley TSF embankment slump (Australia, 2018). Download the Cadia Valley white paper from the GDS Learning Zone.



Mine Tailings Storage Facilities


Mine tailings storage facilities (TSFs) present geotechnical challenges that go beyond conventional embankment dam design. Tailings are raised incrementally, retain saturated fine-grained waste, and can be highly susceptible to static liquefaction  and rapid undrained failure, as demonstrated by the Fundão (Brazil, 2015) and Mount Polley (Canada, 2014) failures, both of which involved GDS equipment in the subsequent laboratory investigations. Since the launch of the Global Industry Standard on Tailings Management (GISTM, 2020), rigorous geotechnical characterisation of TSF materials is now a compliance  requirement for all major mining operators. GDS systems provide the laboratory data needed, from undrained shear strength and cyclic resistance ratio through to consolidation, permeability and interface friction testing.



GDS Products for Mine Tailings and Embankment Dam Testing 


Application / Test Type Recommended GDS Product(s)
Undrained/drained shear strength, monotonic & cyclic simple shear   EMDCSS, EMDCSS-CON
Cyclic resistance ratio (CRR), liquefaction susceptibility EMDCSS, EMDCSS-CON, ELDYN, DYNTTS
Small-strain stiffness, shear wave velocity (Vs) Bender Element System (BES)
Principal stress rotation, anisotropy Hollow Cylinder Apparatus (GDSHCA)
Cyclic/seismic direct shear, rapid drawdown DYNBPS
Drained/undrained direct shear, pore pressure control GDSBPS
Interface friction (tailings/geomembrane/liner) GDSIST
Consolidation, permeability, drainage GDSCTS, GDSCRS, GDSAOS
Stress path, incremental raising sequences GDSTTS

What test standards apply to embankment dam and mine tailings testing? 


The following internationally recognised standards are used for the laboratory characterisation of embankment dam and mine tailings materials. They apply across triaxial, direct shear, and direct simple shear test methods, and cover both total and effective stress approaches.

For mine tailings design programmes, these standards are typically applied alongside guidance from the Global Industry Standard on Tailings Management (GISTM, 2020), the Australian National Committee on Large Dams (ANCOLD) guidelines, and the Mining Association of Canada (MAC) framework. Where seismic hazard is a design consideration, cyclic test results from the EMDCSS or dynamic triaxial systems are used to supplement the parameters obtained under the standards below.


 Standard  Description 
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 fine-grained embankment materials at the end of construction.
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 useful for assessing the stability of permeable embankment materials.
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, can be used to assess stability at most critical stages of an embankment dam lifetime.
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 embankments, with the stress state imposed during the test representative of those directly beneath an embankment. This standard is also applicable to the direct simple shear testing of mine tailings, where it provides the undrained shear strength and cyclic resistance parameters required for liquefaction susceptibility assessment in tailings storage facility (TSF) design.
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, may be used to assess the stability of permeable embankment materials, or fine-grained embankment materials after reservoir filling.
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.
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, can be used to assess stability at most critical stages of an embankment dam lifetime.
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 fine-grained embankment materials at the end of construction.
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, can be used to assess stability at most critical stages of an embankment dam lifetime.

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 useful for assessing the stability of permeable embankment materials.
JGS 0521:Determination of the unconsolidated undrained shear strength of a saturated soil, in terms of total stress, via the triaxial apparatus.
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 fine-grained embankment materials at the end of construction.
JGS 0523:

Determination of the undrained shear strength of a saturated soil, in terms of effective stress, via the triaxial apparatus. These parameters, the angle of internal friction and cohesion, can be used to assess stability at most critical stages of an embankment dam lifetime.

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, may be used to assess the stability of permeable embankment materials, or fine-grained embankment materials after reservoir filling.
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 useful for assessing the stability of permeable embankment materials.

Products for Embankment Dams and Mine Tailings Testing

Each product shows its Embankment Dams application and its Mine Tailings application. Product names link to the full product page for general specifications.

EMDCSS - Electromechanical Dynamic Cyclic Simple Shear 

The EMDCSS runs cyclic and quasi-static simple shear tests on cylindrical soil specimens, from 0.005% to 10% shear strain amplitude.

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Embankment Dams Application

The specimen is subjected to principal stress rotation representative of the soil directly beneath a dam, and user-defined cyclic loading such as recorded earthquake acceleration time histories can be applied. The EMDCSS featured in the laboratory investigation of the Cadia Valley embankment slump (Australia, 2018).


Mine Tailings Application

The EMDCSS is the primary GDS instrument for tailings characterisation, delivering the cyclic resistance ratio (CRR) and undrained shear strength data required for liquefaction susceptibility assessment under static and seismic loading. It was used in the laboratory investigations of the Mount Polley breach (Canada, 2014) and the Fundão dam failure (Brazil, 2015). 

EMDCSS-CON - Electromechanical Dynamic Cyclic Simple Shear (Confined)

The EMDCSS-CON is the confined version of the EMDCSS, adding confining pressure and full effective stress control (saturation, B-check, drained and undrained testing) across the 0.005% to 10% strain range, in saturated or unsaturated states. Testing follows ASTM D-6528.

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Embankment Dams Application
The EMDCSS-CON tests core and shell materials under the repeated and seismic loading a dam sees during earthquakes and reservoir drawdown. Saturation, B-check and drained or undrained control let excess pore pressures and shear strength be measured at the dam's in-situ effective stress, so the potential for slope instability, softening or liquefaction can be assessed directly. Testing across saturated and unsaturated states covers material both below and above the phreatic surface.


Mine Tailings Application

The EMDCSS-CON reproduces the in-situ effective stress of a deposit before applying cyclic loading, so the cyclic strength and liquefaction potential of the material are measured under conditions that match the field. Because tailings sit both above and below the water table, testing saturated and unsaturated specimens gives a fuller picture of how a deposit behaves under seismic and operational loading. High stiffness and adaptive digital control keep the data accurate as specimen stiffness changes during failure, which is common in tailings materials. The EMDCSS-CON was used in the laboratory investigation of the Fundão tailings dam failure (Brazil, 2015) to obtain undrained peak and large-strain shear strengths and study cyclic resistance ratio (CRR) responses.

Bender Element System (BES)

The Bender Element System measures S-wave and P-wave velocities to give small-strain shear modulus (G₀) and stiffness at any point during a test.


Embankment Dams Application
The BES measures maximum shear modulus (Gmax) at very small strains, the stiffness that governs a dam's response to small deformations, dynamic loading and the onset of instability. It works on saturated and unsaturated specimens, covering material above and below the phreatic surface, and integrates with triaxial, consolidation and simple shear apparatuses. The BES was used alongside the EMDCSS in the Cadia Valley embankment slump investigation (Australia, 2018).


Mine Tailings Application
Bender element measurements give shear wave velocity (Vs) data used in liquefaction assessment and dynamic numerical modelling of TSF stability. The BES was used alongside the EMDCSS in the Mount Polley breach investigation (Canada, 2014).

GDSTTS - Triaxial Testing System

The GDSTTS is a fully automated stress-path triaxial system based on the Bishop and Wesley type cell, applying axial and radial stresses directly to the specimen.

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Embankment Dams Application
Stress paths that match specific construction and operational sequences can be applied to the specimen, letting the material response be observed and the design optimised.


Mine Tailings Application

Stress paths that follow the incremental raising sequences used in TSF construction can be applied, so the material response through each raising stage can be observed and the design optimised.

GDSHCA - The GDS Small-Strain Hollow Cylinder Apparatus 

The GDSHCA applies rotational displacement and torque to a hollow cylindrical specimen, giving control over the magnitude and direction of all three principal stresses so anisotropy and principal stress rotation can be studied.

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Embankment Dams Application
The GDSHCA suits investigations where principal stress rotation and anisotropy matter, for example the behaviour of foundation soils directly beneath an embankment crest.


Mine Tailings Application

The GDSHCA reproduces the rotating stress conditions imposed on tailings during incremental dam raising, where principal stress rotation and anisotropy effects are significant.

DYNBPS - The Dynamic Back Pressured Shearbox 

The DYNBPS performs static and dynamic direct shear testing on soil specimens with pore pressure control, so real-world drainage conditions can be modelled in the lab. It was initially designed for landslide testing.

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Embankment Dams Application
The DYNBPS provides shear strength parameters under controlled pore pressure for the stability assessment of existing and planned dams.

Mine Tailings Application

The DYNBPS is used for the cyclic and seismic testing of tailings, giving shear strength parameters under the dynamic loading relevant to earthquake stability and rapid drawdown scenarios in TSF design.

GDSBPS - Back Pressured Shearbox

The GDSBPS performs static direct shear tests on soil specimens with precise back pressure control, under constant volume or constant normal stress conditions.

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Embankment Dams Application
The GDSBPS recreates realistic slope failures and measures shear strength in core and shell materials. Controlling pore water and pore air pressures lets soils be tested at varying degrees of saturation, with effective stress, total stress and matric suction control for the unsaturated zones of a dam. This supports the assessment of stability and failure mechanisms under different hydraulic conditions.

Mine Tailings Application

The GDSBPS is used for the direct shear testing of tailings materials with precise pore pressure control, giving the drained and undrained shear strength parameters needed for TSF stability.

GDSIST - The Interface Shear Tester 

The GDSIST is a rotating-pedestal CRS consolidation cell whose internal load cell measures both axial force and torque, so it can define interface strengths between materials and the residual strength of soils.

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Embankment Dams Application
The GDSIST measures interface strengths between materials and the residual strength of soils as part of dam stability assessment.

Mine Tailings Application

The GDSIST quantifies the friction between tailings materials and containment structures (geomembranes, geosynthetic liners and embankment fill) to assess interface stability under static and dynamic loading.

GDSCTS - The GDS Consolidation Testing System (Rowe and Barden Type)

The GDSCTS is a fully-automated Rowe and Barden type consolidation system using GDS pressure/volume controllers for axial stress, axial displacement and back pressure control.

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Embankment Dams Application
The GDSCTS determines the consolidation and permeability parameters used to assess the performance of existing and planned dams.

Mine Tailings Application

The GDSCTS characterises the drainage behaviour and pore pressure dissipation of tailings materials, a critical input to long-term TSF stability assessment.

GDSCRS - The GDS Consolidation Constant Rate of Strain Cell (CRS in Load Frame Type) 

The GDSCRS is a constant rate of strain consolidation cell that shortens test times, fitting a new or existing load frame in place of a triaxial cell, with pore pressures measured up to 1MPa or 20MPa (high pressure).

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Embankment Dams Application
The CRS cell determines the consolidation parameters used to assess the performance of existing and planned dams.

Mine Tailings Application

The CRS cell determines the drainage and compressibility characteristics of tailings materials quickly and accurately.

GDS in Mine Tailings and Embankment Dam Investigations


Cadia Valley TSF Embankment Slump, Australia (2018)
Fundão Mine Tailings Dam, Brazil (2015)
Mount Polley Mine TSF Embankment Breach, Canada (2014)

A multi-apparatus GDS programme (including the EMDCSS, bender element system, triaxial apparatus and CRS oedometer) was carried out following the embankment slump at Cadia Valley Operations. GDS published a white paper summarising the geotechnical findings.

Following the Fundão failure, GDS published a technical note in Ground Engineering on the use of the cyclic direct simple shear apparatus in the investigation.

The EMDCSS with integrated bender elements was used on undisturbed samples from the failure zone, providing undrained shear strength and wave velocity data to help understand the failure mechanism.











Common questions about mine tailings and embankment dam testing


What laboratory testing is required for mine tailings storage facility design?
TSF design requires characterisation of undrained shear strength, cyclic resistance ratio (CRR), consolidation behaviour and permeability of both the tailings and foundation soils. Where seismic hazard is present, cyclic simple shear or cyclic triaxial testing assesses liquefaction susceptibility. Bender element measurements provide shear wave velocity (Vs) data used in liquefaction assessment and numerical modelling.

Which GDS products are used for mine tailings testing?
The most commonly used GDS systems in tailings applications are the EMDCSS (cyclic simple shear, CRR determination), EMDCSS-CON (confined cyclic simple shear, effective stress control), Bender Element System (S- and P-wave velocity), ELDYN and DYNTTS (cyclic triaxial, CRR determination), DYNBPS (cyclic/seismic direct shear), GDSBPS (drained/undrained direct shear with pore pressure control), GDSIST (interface friction with geomembranes and liners), GDSHCA (principal stress rotation and anisotropy), and GDSCTS/GDSCRS (consolidation and permeability). See the product table above for a full application map.

Has GDS equipment been used in major tailings dam failure investigations?
Yes, many times. Three examples include: The EMDCSS and bender element system were used in the Mount Polley breach investigation (Canada, 2014); the cyclic direct simple shear apparatus featured in the Fundão dam failure investigation (Brazil, 2015), with a case study available to download; and a multi-apparatus GDS programme was carried out following the Cadia Valley TSF embankment slump (Australia, 2018).

What is the difference between testing embankment dam materials and mine tailings?
Both require shear strength, consolidation and permeability testing, but tailings are typically fine-grained, hydraulically deposited and prone to static liquefaction, requiring greater emphasis on cyclic behaviour and CRR assessment. Tailings dams are also raised incrementally, so stress path testing relevant to sequential raising is often needed. GDS cyclic simple shear and stress path triaxial systems are designed specifically for these demands.

Product Applications