Towards European Standards in Performance Monitoring of Geotechnical Structures

Eurocode EC 7 "Geotechnical Design", being the fundamental geotechnical code in Europe and, since 2004, mandatory in all countries of the European Union and EFTA, states that "when prediction of geotechnical behaviour is difficult, it can be appropriate to apply ...the observational method, in which the design is reviewed during construction". EC 7 is issued in two parts: Part 1 (EN 1997-1) "General rules", and Part 2 (EN 1997-2) "Ground investigation and testing". Whilst Part 2 provides guidance for the planning and interpretation of a wide range of geotechnical laboratory and field tests for parameter input into Part 1, it does not yet contain specific guidance for the performance monitoring of geotechnical structures typically carried out within the framework of the "Observational Method". In identifying this deficiency, the German FMGM Group has embarked on a standardisation project by means of the national DIN 4107 "Geotechnical Monitoring". Once DIN 4107 is finalised, it will be suggested for the introduction into the European standardisation procedure with a view to widening the scope of EN 1997-2. As currently drafted, DIN 4107 comprises the following four parts: Part 1: General rules; Part 2: Extensometer and convergence tape measurements; Part 3: Inclinometer and deflectometer measurements and Part 4: TPC (Total Pressure Cell) measurements. The principal outline and content of the current draft versions are presented in some detail, with particular reference to Part 1. The observations are made against the background of the US debate on geotechnical and geo-instrumentation standards of the years 1997–98.