Tel/Fax  01923 682300

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

Redevelopment of the Baltic Flour Mills (Newcastle) 02/1999 to 02/2001

In February 1999 CMCS Ltd designed and installed an automatic system to observe the shell of the 40 m high brick built Baltic Flour Mills, while the inside was removed and new internal structure fitted.
The system consisted of fixing 47 discrete electro- levels to the outside using abseilers. Movement of the more rigid corner pillars was monitored at one elevation by biaxial electro-levels mounted on the outside corners of each pillar. The photo opposite shows the structure with the inside silos removed and the retained walls supported by an external steel frame. The view is from the East and shows the top section of the East wall, which was retained and fitted with three ELs to monitor its movements.

The diagram opposite shows the computer screen display of the data from the electro-levels. The changes in slope along each of the vertical strings of ELs were converted into vertical deflection profiles. The profiles were displayed in the 3-dimensional format as shown. The seven deflection profiles representing the wall movements could be viewed in animated mode so that relatively large volumes of data can be scanned and interpreted quickly by the engineers responsible for demolition work. A feature of the software allows the view angle to be moved so that you can fly around the structure. The profiles could also be viewed in 2-dimensions showing the movements against a horizontal scale. The red bar charts on the edge of the simplified structure show the change in temperature at the top of the electro-level lines. The natural movement of the structure due to temperature proved invaluable in observing the changing stiffness of the structure.

Objectives of the monitoring system: To give early warning of movements outside those allowed with the frame, i.e. 60 mm. Maximum movements observed less than 20 mm.

Redevelopment of the Royal Courts of Justice

Keeping our heritage while satisfying the need for modern working practices has meant keeping the shells of our important buildings suitably propped while demolishing their internal fabric. The picture opposite shows the Royal Courts of Justice under such circumstances.

G Price and I Wardle (while at the Building Research Establishment) designed and installed a monitoring system that used 60 electro-levels fitted in vertical lines at ten sections along the 26m high outside walls that were to be retained.

The system was to warn of any excess horizontal movements of the walls during the removal and subsequent replacement of the internal floors and walls to make the interior more suitable to its present day functions.

Monitoring the effect of new construction on existing infrastructure requires the monitoring system to be installed in advance of any work carried so that the normal movements of the structure due to diurnal and seasonal changes can be established. These normal envelopes of movement can then be used to assess the effect of the new work.

As well as the major projects outlined above, CMCS have installed smaller systems comprising of only a few instruments and a logger to monitor the effect of repairing damaged structure in domestic properties.

The software display shown opposite warned of excessive movements of any of the retained walls. The magnitude, location and the level at which the maximum movement occurred were easily identified by the display. The display could be animated to show the trends of any wall movements. The fixed sensors gave early warning of potential problems with the supports.