Monitoring of West Bay towers l Qatar

Tunnelling under skyscrapers

The Doha Metro is a planned rapid transit system in Qatar’s capital city, scheduled to become operational by the end of 2019. In mid May 2013, the Impregilo – SK E&C – Galfar Al Misnad Joint Venture (ISG) was awarded the construction of the Red Line North (RLN) segment, running from Musheireb to Al Khor North.

This line goes through West Bay area, the business district with its iconic skyline Sixense was awarded the instrumentation and monitoring services on RLN in 2014. Within the monitoring contract, special attention was focused on sensitive buildings.

Comprehensive monitoring

Located directly next to the future West Bay Station, Barzan Tower requested special instrumentation. Whilst the 2 tunnel boring machines (TBM) were passing under the basement parking of the 15,000 m2 tower in early 2015, ISG requested to get precise measurements of the movements of the tower and its foundations. Sixense installed 3 theodolites to monitor the building facades and the roof of the parking, as well as tiltmeters in the elevator shaft for data verification.

A monitoring system comprising of tiltmeters on the elevator shafts, geophones and accelerometers as well as liquid levelling cells has been deployed on five other major buildings located on the alignment of the TBMs: Mariott City Centre Hotel, Gate Mall, Ministry of Interior, Qatar Insurance Company and Qatar Islamic Bank.

On the latter structure, a Cyclops was monitoring the movements of the architecturally distinctive lower part of the tower while tiltmeters monitored the basement.

Real-time follow up with Geoscope was provided, with continuous adjustment to the TBMs progress and parameters.
The data obtained provided the assurance necessary to allow the safe passage of the TBMs and maintain all the buildings integrity.