Geotechnical instrumentation in practice purpose, performance and interpretation : proceedings of the conference Geotechnical instrumentation in civil engineering projects organized by the Institution of Civil Engineers and co-sponsored by the British Geotechnical Society, the British Tunnelling Society and the British National Committee on Large Dams and held in Nottingham on 3-5 April 1989. purpose, performance and interpretation : proceedings of the conference Geotechnical instrumentation in civil engineering projects organized by the Institution of Civil Engineers and co-sponsored by the British Geotechnical Society, the British Tunnelling Society and the British National Committee on Large Dams and held in Nottingham on 3-5 April 1989.