tailings dams

Tailings Dams Solutions

Background

Recent catastrophic tailings dam failures and subsequent ecological devastation have resulted in the requirement for real-time dam integrity monitoring. ConVue (a digital technologies division of Geotesta P/L) offers a complementary range of digital

solutions to achieve early detection of dam movement, slope stability, heave, subsidence and in-situ stresses. Data from these digital technologies can be stored locally or in the cloud for the convenience of multi-stakeholder access and the generation of real-time alarm events.

ConVue’s technologies are comprised of the following:

tailings dams services

InSAR

Interferometric Synthetic Aperture Radar (InSAR) is a radar method that can measure the ground movements of the Earth’s surface using satellite imagery.

Subsidence and heave of dam walls and construction phase earthworks

  • Measures the extent of the deformation over a period of time
  • Measure subsidence when groundwater extraction occurs
  • This measures the difference in radar photos from different time frames
  • This also measures the movement and change in the surface of the Earth through time series
  • Easier to identify the timing of failure about one month before it actually occurs
  • Displacement maps can be produced to showcase the change in position with associated graphs

Tailings Subsidence

  • Identify patterns of subsidence using millimetre accuracy vertical displacement measurements
  • Monitor the ground movements using deformation maps

Capabilities of image analytics

  • Feature extraction such as extracting features using machine learning
  • Change detection include pixel-based image change detection
  • Vector analysis such as neighbourhood, intersection and overlay
  • Linament extraction such as extraction of linear features from a photo
  • An object-based classification that utilises advanced machine learning algorithms

InSAR Capabilities

  • Deformation Analysis which can do ground deformation measurements to a millimetre accuracy
  • Differential SAR is used to identify slow-moving landslides as well as identifying surface deformations
  • 3D DEMs (digital elevation models) can be extracted with SAR photos
  • Change detection
InSAR

Aerial Photogrammetry/Imaging using Drones/UAV

Leak Detection

  • Thermal imaging drones are used to measure the differences in temperature in tailings dams
  • Thermal imaging drones can be used to detect temperature differentials of the tailings surface and within dam walls caused by tailings leakage
  • Thermal contrasts can be generated by comparing thermal images

Structure from Motion Photogrammetry

  • Measures the subsidence and the surface displacement using ground control points
  • Erosion, tailings settlement and compaction of peat layer are causes of these surface displacement
  • RTK/PPK correction can increase accuracies to 2.5cm, removing the requirement for ground control points3D models can be created from 2D drone photos which can be used to measure the topography of the tailings dams and structure
  • DEMs of Difference can be used to measure the settlement of tailings and subsidence of dam walls
  • Point clouds can be developed to form 3D models as well as to measure the point-to-point distances for the subsidence

 

Orthomosaics

  • Used to compare the progress of the tailings dams from one-time frame to another
  • Digital Elevation Models can be produced High-resolution georeferenced drone imagery can be produced
  • Aerial survey management of the stockpiles
    Minimises the necessity for as well as risks associated with manual survey measurements in tailings dams management
  • Identify hazards and minimise them using drone imagery

Time Lapse for Environmental Monitoring

Embankment slope monitoring

  • Can measure the subsidence of the embankment, compare images for overtopping erosion and foundation stability
  • Targets would be implemented on the slope to measure the displacement of the slope and the extent of slope instability
  • The photogrammetric system used to monitor and measure the deformation consists of commercially available high-resolution cameras
  • CSattAR uses digital image correlation or close-range photogrammetry
    The accuracy is at 0.1mmThis can be used to measure the horizontal movement and settlements

ConVue Cloud Data Hosting System

ConVue Cloud Data Hosting Platform
  • Remotely administer a network of data loggers and their sensors
  • Interpret the type of data with live visualisations
  • Customisable reporting with configurable alarms for real-time notifications
  • Incorporate manually read instruments
  • Easily set up and administer multiple projects with intuitive GUI
  • Integrate third-party systems into ConVue Cloud Data Hosting System such as SCADA

Data Acquisition Systems

Convue can supply, install, program and commission a wide range of data acquisition systems, utilising several communication technologies.

Application-specific, off-the-shelf or bespoke data logging solutions can be deployed remotely to achieve scheduled status and real-time alarm monitoring of sensors.

Common applications include:-

  • tilt, crack, strain and deformation of infrastructure
  • ground subsidence and heave
  • downhole monitoring of lateral movement within boreholes load and stress monitoring of earthen masses, structures
  • groundwater and pore water pressure monitoring
  • water level and flow rate
  • environmental & vibration

4G/Radio, Solar Backed, Battery Powered Multi-Level Vibrating Wire, Extensometer Data Loggers

4G/Radio, Solar Backed, Battery Powered Multi-Level Vibrating Wire, Extensometer Data Loggers

Low Powered Wireless LAN Data Acquisition System

Low Powered Wireless LAN Data Acquisition System

Field Installed Customised Data Acquisition Systems

Field Installed Customised Data Acquisition Systems

Geotechnical Instrumentation

Thermistor Strings

Measures temperature: resistance in thermistor decreases as temperature increases

Applications: seepage/leak detection

Thermistor Strings

Vibrating Wire Piezometer

Measures: Pore water pressure and water level through the diaphragm, electromagnetic coil and tensioned steel wire

Applications: Foundation & embankment, pore water pressure, water level sensing

Vibrating Wire Piezometer

Total Earth Pressure Cells

Measures: Amount of stress against plane/steep surfaces

Applications: pipelines, earth dams/embankments, tunnel linings

In-Place Inclinometers

Measures: displacement by calculating the difference between current and previous readings, which is installed in a borehole

Applications: Identifying slopes and landslides, as well as their lateral deformations, Assess the stability of the slope, Identifying shear and slip zones, Assessing dams, Assess monitoring walls

In Place Inclinometers

Shape Accelerometer Arrays

Measures under-surface movement to identify where the share planes are as well as causes of instability. Also measures the subsidence in tailings dams and deformation monitoring

Shape Accelerometer Arrays

Tilt Sensors

Measures the tilt in a reference plane, and can measure the inclination of the slopes

Applications: Slope stability and Structural movement