GCG was asked by the Client to provide advice on the ground conditions and selection of geotechnical design parameters so that a new design could be implemented, and comprehensive monitoring installed. Full-time site supervision was provided by GCG which enabled rapid interpretation of the monitoring results and development and validation of a new design. Site support by GCG was also continued to cover the rebuilding of damaged sections and construction of new sections to the new designs.
GCG was also closely involved in evaluating the seismic design and construction and retrofit of the tunnels and following two Turkish earthquakes of magnitudes 7.4 and 7.2. This experience is described in a separate job sheet. Aspects of earthquake design included the collection of dynamic and small strain soil parameters, the mapping and assessment of faults and their activity, and the design of tunnels incorporating dynamic loads with special construction details to limit potential damage and permit displacement along an active fault crossed by the tunnels.
Publications:
Menkiti, C. O, Miles, R. and Mair, R. J. (2001) “Tunnelling in Complex Ground Conditions in Bolu Turkey”, Proceedings of the Underground Construction 2001 Symposium, London, 18th – 20th September 2001.
Invited lecture, Institution of the Engineers of Ireland: Tunnelling in Complex Ground Conditions in Bolu, Turkey – 7th October 2002
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