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1. Index
2. CMCS at BRE
3. Development of AMS
4. Non-destructive testing of Marine Jetties
5. Fixed sensor monitoring of Diaphragm walls
6. Monitoring Buildings during Redevelopment
7. Tunnel Monitoring
8. Embankment Systems
9. Loggers
10. Tunnel Distortion Monitoring
11. In-place tilt monitoring system
12. Tunnels Interaction System
13. Re-Development of Small Properties
14. Viaducts
15. DLR at Mansion House
16. Tunnel Monitoring System (Discrete beams)
17. CTRL 240
18. Dams
19. Electro-levels
20. Movement indicators
21. Results of Charing Cross Load Cells
22. Non-destructive testing of concrete structures
23. Radio in Construction Monitoring
24. Settlement Reducing Piles
25. Land Surveying and Total Station Monitoring
26. Vibration Monitoring
27. Monitoring the complete strain history of concrete elements
28. Past CMCS Projects

CMCS's Radio Storage Units (RSU) are providing easier recording of strains developed in concrete tunnel lining segments from manufacture of the segments to after they have been installed as a ring in a tunnel lining. With inbuilt storage as well as interactive radio is powered by 4 x 'C' cell batteries. The sensors and recording unit can be built into each segment at manufacture and will record the strain history for up to 12 months, i.e. during the casting, storage, transport and installation as part of a tunnel. The various stages are shown in the photographs below.

Data from the systems can be recovered at any time using a hand held radio transceiver. During the installation when strain can be significant and physical access to the segments around the tunnel is limited the radio system allows easy transfer of data from each of the six segments forming one complete ring of the tunnel lining. If recording is required indefinitely then the batteries in the transmitter storage unit can be changed provided the lid of the transmitter unit is cast against an accessible surface.

The unit can be set any where within 100 to 400 metres of the transmitters to recover the data either automatically or on command. Since the units have internal storage then even if the transceiver is not on site then no data is lost because it can be recovered when the transceiver is brought to site.

The above photograph shows a segment, with the RSU already cast in it being moved at the casting yard close to Vesuvius (Naples). CMCS RSU were used in conjunction with SISGEO vibrating wire strain gauges as part of a project overseen by Professors Russo and Viggiani of Naples University.

The photographs above show the sequence of event involved in installing the RSU. The strain gauges (5 in the above installation) are attached to the reinforcement cage of the segments and connected to the RSU, also fitted to the cage. The RSU is positioned so that it can be accessed from inside the tunnel to change the batteries or attach a recharging system for long-term recording of data. The casting moulds can be seen behind the cages in the photograph on the left. The centre photograph shows the RSU outer case and the photograph on the right shows the finished segments with their RSU cast inside.

The CMCS RSU have also been used in London Underground tunnels to record data from VW piezometers inserted in the soil behind the cast iron linings. Where the installations are within 150 m of the platforms data can be recovered with need to access the running tunnels during engineering hours.