ABSTRACT

Our aim is the inclusion of representative geological conditions into a 3D numerical simulation code (i.e. finite element, boundary element etc.) accompanied with uncertainty estimates of: (a) the necessary input geotechnical parameters of the distinct geological formations and (b) their boundaries in 3D space. This is because geological, exploratory (core drilling, in situ testing, geophysical etc.) and laboratory test data have to be transformed into digital information that is required by the numerical model. We also consider the continuous upgrade of the soil or rock mass model during underground construction based on feedback from excavation machines for a continuous reduction of the residual risk. The new ideas that will be presented in this Chapter touch the above subjects and refer first to recent developments on a hierarchical, relational and web-driven database based on a calibration procedure to formally evaluate the parameters of a triaxial hyperbolic Mohr-Coulomb yield criterion for rocks. Secondly, a special uspcaling theory for rock mass parameters at the full-scale numerical or “ground model” is presented that is based on the rock testing data extracted from the database, the Scale or Size Effect exhibited by rocks, the theory of Damage Mechanics and rock joint data and the theory of Geostatistics for the interpolation and uncertainty evaluation of geomaterial parameters. Finally, a method of back-analysis of TBM logged excavation data for geomaterial characterization is illustrated.