TWO TOPCON total stations are being used to monitor movement in neighbouring buildings during construction of a 13m deep basement car park in a congested residential area of Knightsbridge, London.
The high value of the surrounding buildings means an accurate monitoring system was needed.
The GTS 800A stations were positioned on the roofs of a nearby hotel and a garage. They are programmed to take a set of measurements every 30 minutes, 24 hours a day, and are linked via radio modems to the site office computer.
Information has been recorded for almost a year and the system is set to stay in place until the foundation work is finished early next year.
Topcon was called in by Cementation Foundations Skanska when monitoring equipment was showing unlikely levels of movement. The explanation was that the one of the host buildings, the hotel, was also moving, and engineers were concerned that data was incorrect.
The Topcon stations replaced the other instruments, using NRG monitoring software adapted for the project. The software ensures the stations can resect their positions every time they take a reading, so engineers can see instantly if the host building is stable.
The residential development, managed by Knightsbridge Project Management, will be finished in mid-2004.