Numerical Simulation in the Field of Geotechnics and Underground Engineering—Examples of Research and Development Projects

The introduction of numerical simulation in underground engineering proved to be a major advancement compared to traditional analytical calculations. However, building an appropriate model of rock or soil is very difficult because some geomaterials show very complex material behaviour. In addition, reliable input parameters of the ground are rarely available because a geological exploration can only give punctual insights of the project area. Hence, results of simulations in geotechnics are never as accurate as in many other disciplines. The combination of exploration, well developed characterisation methods, material models and the right choice of software can however provide good results. The validity of a simulation result always needs to be checked carefully with the help of profound engineering judgement. This paper presents recent research and development projects in the field of numerical simulations in geotechnics carried out at the Chair of Subsurface Engineering and some of its partners.     

3-Dimensional Numerical Calculations Considering Geotechnical Measurement Data

This paper discusses the numerical analysis of a specific part of the deep seated Gotthard Base Tunnel. A section of the western tube situated in the Clavaniev Zone was simulated with the finite element programme ABAQUS. Geological and geotechnical documentation from the design stage and the construction stage as well as daily and monthly reports of the construction site were provided by AlpTransit Gotthard Ltd. This documentation has been used to perform 3-dimensional analyses with implementation of support elements in a realistic construction sequence. For the simulations different constitutive laws were used. The aim of this research project was to investigate whether measurements of radial deformations and the core extrusion in front of the face can be matched with the results of 3-dimensional FE simulations based on information available during the design and the construction stage.