Feb 17, 2021

SAAV Extend: How to monitor tailings dam lifts

Tyler Morency
3 years ago

SAAV Extend: How to monitor tailings dam lifts

Your project site is not static, so you need geotechnical instrumentation that can adapt. That’s why Measurand developed SAAV Extend to allow you to easily increase the length of your ShapeArray in the field as your needs change. SAAV Extend is ideal for situations such as increasing the height of a tailings dam while continuing to monitor for movement.

While a fixed-length instrument—either an in-place inclinometer or a SAAV model ShapeArray™—would have to be replaced entirely to accommodate the borehole’s increased length, SAAV Extend’s modular, connective design means scaling along with the dam raise is simple and more cost-effective. 

Anatomy of SAAV Extend

SAAV Extend makes it possible for clients to add sensorized lift extension segments between a top assembly and the existing sensorized segments from the initial installation, known as the base array.  

Clients don’t have to haul up the entire ShapeArray when to increase the total sensorized length. Just add the lift extension segments to the initial installation’s base array, along with the desired length of inclinometer casing. Re-attach the top assembly and the SAAV Extend is ready to continuously monitor deformation as the casing is back-filled.  

SAAV Extend Top Assembly
The top assembly is the brain of the SAAV Extend that locks the instrument into standard inclinometer casing with Measurand’s patented cyclical installation method.

SAAV Extend Top Assembly

SAAV Extend Base Array 
The base array refers to the sensorized segments at the bottom of the borehole after the initial installation.  

SAAV Extend Base Array

SAAV Extend Lift Extension Segments 
Lift extension segments added between the top assembly and base array connect to form the SAAV Extend’s total sensorized length. 

SAAV Extend Lift Extension Segment

Measurand Distributors on SAAV Extend

While SAAV Extend was developed to address the specific needs for clients concerned with tailings and mine waste management, Measurand’s trusted network of distributors see the instrument’s potential utility for other monitoring applications, specifically around mobility and re-usability.

“Large ShapeArrays are cumbersome and difficult to move around, so the possibility of shipping smaller sections and joining them together on-site will make life easier,” Dr. Andrew Ridley, Managing Director at Geotechnical Observations said. “I can also see a possible resurgence of work in the retaining wall sector because contractors will be able to reuse ShapeArrays. This is something that they already do but in the future, they will be able to add sections to make the right length.”

“We can use it for land reclamation, soil improvement—preloading, earth dam, dike, embankment or even offshore platform foundation monitoring,” Eric Hoe, Manager at Diagnostic Engineering Consultants Ltd, said. “Meanwhile it will be more cost-effective for repair or replacement concerned. Now we can move forward together to provide more flexible and precise monitoring service for clients.”

Monitor tailings dam lifts: Key takeaways

ShapeArray that grows with your monitoring strategy 
SAAV Extend will always have a sensorized length that is right for your needs. Individual sensor segments are 500 mm each and can be combined up to a total sensorized length of 200 m.

Simple installation in the field 
SAAV Extend’s hand-tight threaded connectors allow clients to easily add sections of lift extension segments without additional tools. Adding new lift extension segments is as simple as twisting, while keyed alignment marks on the connectors maintain the ShapeArray’s azimuth.   

A connectable ShapeArray design that is just as durable as SAAV 
Designed specifically for the rigours of tailings dam safety monitoring, SAAV Extend is submersible up to a depth of 200 m. SAAV Extend has the same 38-year MTTF as any ShapeArray that Measurand manufactures. It also has the same temperature tolerances and tensile strength, so clients can trust SAAV Extend in as wide a range of environments as existing SAAV models. 

Real-time measurements in real-world conditions 
You cannot guarantee pristine conditions in the field when you need to perform your ShapeArray installation. That’s why SAAV Extend’s connectors have a 300-psi open-face pressure rating. You can connect segments in the rain without worrying about damaging your instruments. 

Total control to monitor the zone of interest
Clients can use silent segments first introduced with SAAV, in addition to SAAV Extend’s lift extension segments to target the total sensorized length towards the geologic zone of interest.


  • 1993

    The Beginning

    Measurand is established in Fredericton, New Brunswick
  • 1994

    Bend sensor development

    Measurand develops and patents fiber optic bend and position sensors for the medical and automotive sectors

    U.S. Patent 5,321,257

  • 1995

    Canadian Space Agency

    Receives funding from the CSA to develop sensor technology that ultimately leads to invention of ShapeTape

    U.S. Patent 5,633,494

  • 1999

    Patent on fiber optic sensor

    Measurand receives patent for "Fiber Optic Bending and Positioning Sensor" issued June 29, 1999

    Canadian Patent 2,073,162

  • 2001

    ShapeTape & ShapeHand debut

    Measurand designs and develops innovative motion capture technology

    U.S. Patent 6,127,672, 6,563,107

  • 2002

    Measurand Attends the ICPMG

    First contact with the geotechnical sector at the International Conference on Physical Modelling in Geotechnics (ICPMG)
  • 2004


    Design patent application sent about a new product designed to meet the specific needs of the geotechnical industry

    U.S. Patent 6,127,672, 6,563,107

  • 2005-08


    Measurand debuts ShapeWrap motion capture technology for the film and animation industry

    U.S. Patent 7,296,363

  • 2006

    Malibu installation

    ShapeAccelArray installed for ground monitoring for the first time​ in Malibu, CA

    Canadian Patent 2,472,421

  • 2007


    Suite of instrumentation developed for motion capture within Magnetic Resonance Imaging (MRI) machines

    U.S. Patent 7,296,363

  • 2011

    SAAScan launched

    Built for rapid deployment and repeated use

    Canadian Patent 2,472,421

  • 2014

    SAAX launched

    Purpose-built for heavy-duty horizontal installation

    Canadian application 2,815,199 & 2,815,195

  • 2017

    SAAV launched

    The only geotechnical instrument with a patented cyclical installation method

    Cyclical Sensor Array, Canadian application 2,815,199 & 2,911,175