This guide outlines the things that you will need to think about before you order a ShapeArray (SAA). It is presented in the form of questions that you should be asking prior to ordering a ShapeArray. If you have any questions, contact firstname.lastname@example.org.
Step 1 - What type of ShapeArray do I need?
The type of ShapeArray required depends on the application. Questions you should be asking include the following:
- What are you planning to monitor with the ShapeArray?
- What are you trying to determine using ShapeArray?
- What is the geotechnical reason for monitoring?
- Is the installation horizontal, vertical, or in the cross section of a tunnel?
- How much deformation are you expecting?
The following table summarizes the common monitoring applications for ShapeArrays and the product best suited to meet the monitoring goals.
|Horizontal Deformation||SAAV installed vertically|
|Vertical Deformation||SAAV or SAAX installed horizontally|
|Convergence (Tunnel Deformation)||SAAV installed along the circumference|
|Borehole Shape or Deviation||SAAScan|
Step 2 - How is a ShapeArray built?
All ShapeArrays are composed of a series of rigid segments separated by flexible joints. Their constructions differs slightly to fulfil a variety of monitoring requirements.
- SAAV segment lengths can be either 250 mm or 500 mm. SAAVs with 250 mm can be installed horizontally or for convergence monitoring. SAAVs with 500 mm segments can be installed vertically, horizontally, or for convergence monitoring.
- SAAX segments are 1000 mm in length. SAAX can only be installed horizontally.
- SAAScan segments are 500 mm in length. SAAScan's rugged construction allows for repetitive insertions and removal from boreholes.
Step 3 - How do I connect to a ShapeArray?
A single 18 AWG communication cable extends from the top of every ShapeArray providing both power and communication to the sensors inside. Every ShapeArray has 15 m of cable attached as standard, but this can be lengthened as required. For maximum cable lengths, refer to the following articles from our manuals:
If you are extending the communication cable, consider the use of an SAA Surge Protection Device (SAASPD) to provide surge protection from nearby lightning strikes.
Step 4 - What length of ShapeArray should I order?
The length of the ShapeArray should be outlined in the project specifications. Measurand cannot specify what length is required for your project. The overall length of the ShapeArray includes the sensorized segments, and unsensorized components such as the PEX tubing. For more information, refer to the following articles from our manuals:
For deformation monitoring, make sure that one end of the ShapeArray is installed into stable soil to ensure a stable reference point. Alternatively, measurements can be made to one end of the ShapeArray via surveying techniques to guarantee a stable reference.
Step 5 - How do I collect data?
Manual data collection can be done using a PC running SAARecorder, or smartphone or tablet running SAADroid. This requires the use of an SAA Field Power Unit (SAAFPU).
Automated measurements can be done using a Campbell Scientific data logger. Supported data loggers include the following:
- CR300 - this logger is limited to five SAAs consisting of no more than 300 segments total
Step 6 - How do I do automated data collection on a remote site?
Automating data collection on a remote site requires the use of a data acquisition system which includes the following:
- A data logger
- Solar panel and power regulator
- An SAA232 or SAA232-5
Data acquisition system components are housed in enclosures to protect them from the elements. These items can be purchased from Measurand or Campbell Scientific, or other third-party system integrators, such as RST.
Step 7 - How do I get data transferred remotely to my office?
Transferring data remotely to an office requires the use of a remote communications device, such as one of the following:
- cellular modem
- satellite modem
- wireless modem
Measurand does not sell these devices. You should contact your local Campbell Scientific representative for help sourcing the appropriate modem for your application or geographic area.
Step 8 - Does Measurand do installations?
Measurand can provide on-site training and assistance for a fee, but we do not perform any of the physical installation of the ShapeArray.
Step 9 - Where do I obtain the casing required for ShapeArray installation?
Casings are required for long term monitoring with SAAV and SAAX.
SAAV can be installed vertically inside a 27 mm inside diameter (ID) PVC conduit or in any casings with IDs from 47 mm to 100 mm. The best source of 27 mm casing is local home improvement stores. Appropriately sized conduit is typically found in the electrical conduit department in North America and in the plumbing conduit section in Europe. For larger sized conduits, Measurand recommends standard inclinometer casings with 70 mm or 85 mm outer diameter (OD).
When installing SAAX or SAAV horizontally, at least 2" Schedule 80 trade dimension PVC conduit (approximately 49 mm ID)must be used. However, the conduit requirements for horizontal installations will vary based on the expected loading. Pipe ovalization must be considered when purchasing conduit. More information is available in the SAAX Manual and the SAAV Manual.
NOTE: Measurand does not sell or supply conduit. Conduit must be sourced locally.
Step 10 - How many times can I re-use a ShapeArray?
SAAV, SAAX, and SAAScan have hydraulic hose joints which are resistant to twist. These can be re-used indefinitely as long as the joints are intact and the segments are straight.