Catering to increased demand for accurate geotechnical monitoring instruments, civil and mining geotechnical service provider GeoGroup and its subsidiary Terra Monitoring showcased the ShapeArray automated inclinometer at Electra Mining Africa 2026.

The ShapeArray automated inclinometer is an instrumented chain of rigid segments and flexible joints containing micro-electromechanical system (MEMS) accelerometers that measure 3D changes, such as deformations in geological and manmade structures, explains Terra Monitoring operations manager Schalk Prinsloo.

The inclinometer plays a vital role in complementing current monitoring instrumentation, as it ensures that clients can access more data to facilitate better planning and execution, particularly from a safety perspective.

He adds that the ShapeArray is primarily used in two applications: tailings storage facilities (TSFs), where it monitors soil and structural deformation to comply with the Global Industry Standard on Tailings Management; and infrastructure and slopes, where it tracks lateral movement, ground settlement and structural displacement in unstable slopes, retaining walls, tunnels and rail lines.

Inner Workings

“Each ShapeArray segment contains MEMS accelerometers that measure tilt relative to gravity, and these measurements are combined with the known segment lengths to reconstruct the position and overall shape of the instrument,” says Prinsloo.

In a vertical installation, this provides deformation information in two horizontal directions, as well as the vertical position of the array.

The main advantage over simpler or point-based systems is not simply the three axes, but the ability to obtain a continuous deformation profile along the length of the installation.

This enables engineers to identify where deformation is occurring, the direction in which it is developing and how the deformation profile changes over time.

It is worth noting that the exact dimensional representation depends on the installation configuration – vertical ShapeArrays can be modelled in 3D, while horizontal installations are generally treated as 2D, Prinsloo adds.

Tried and Tested

With some installation sites, including mines in the Thabazimbi area and the Steelpoort region, ShapeArray technologies have proven to be effective.

The raw X, Y and Z sensor readings are processed through Measurand’s Raw2Data software into Cartesian engineering units, with multiple software adjustments available to optimise this process.

For critical applications, it is important that the data-processing methodology and assumptions are understood and that the raw data remains available for verification.

Moreover, conventional or automated in-place inclinometers, remain “very capable deformation-monitoring systems” and can be configured with different sensor spacings and segmented lengths, depending on the application.