My presentation at the International Course on Geotechnical and Structural Monitoring, entitled: Real-time monitoring of sewer tunnel deformations

1. 13-14-15 June, 2017 – ROME, Italy
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Session NT.1: Real-time monitoring
of sewer tunnel deformations
By Gábor Patassy
Making FBG sensing user-friendly

2. Making FBG sensing a common technology
• FBG systems – commercial contact monitoring
solutions for 20+ years
• Why is everybody afraid of FBG technology?
• Proven track record of VW vs FBG
• Cost of the system
• Biggest challenge – user-friendly + plug-and-play
• FBG is the only applicable technology for certain
applications
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3. Monitoring structural integrity of existing tunnels
• Development impulse – Sewer monitoring in London
• Existing sewers need to be instrumented while new
tunnels are being dug
• Those old sewers date back hundreds of years
• All equipment needs to be ATEX rated
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4. Development of a new sensor
• FBG is ideal for the project
• Reduced cabling
• ATEX compliance
• Amount of sensors
• Requirements: modular, simple and robust
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5. The Tideway project
• The Tideway project is a “super-sewer” that is:
• 25km long
• 7.2m in diameter
• Running from Acton down to Abbey Mills
• A construction project valued at £4.2 billion
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6. Defining the problems
• A cofferdam will be built directly opposite the sewer
• Such works are likely to cause displacements
• FEA analysis have been conducted
• 5 cross sections – each with 8 strain segments
• Simplified segment replacement
• 24/7 online data access
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7. Installation
• The system has been verified through a real-life
installation
• Quick and easy anchoring in confined spaces
• Each segment is specially protected
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8. Expected results
• Obtaining strain baseline well before the works
• During the works – 24/7 monitoring is required
• On-site data collection
• Cloud-based remote data access
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9. Benefits of the system
• An easy-to-install FBG strain sensing system
• Plug-and-play cabling
• Rigid sensor body
• Easy transportation into confined spaces
• The design can be adapted to any sewer diameter
• Simple transportation
• Online data access through cloud based monitoring
software
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10. This system has been developed in collaboration of
companies Getec UK and Sylex
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Questions