In 2021, a new tunnel of about 100 m length will be excavated as an important infrastructure element for a project on earthquake research (FEAR) funded by the European Research Council (ERC) and the Werner Siemens Foundation. The basic idea of the research project PRECODE - PROGRESSIVE EXCAVATION DAMAGE ZONE EVOLUTION DURING AND POST MINE-BY TUNNELLING is to use a section of this new adit for a mine-by experiment with state-of-the-art monitoring tools aimed at a detailed understanding of:
- damage initiation during tunnelling,
- the progressive, time-dependent evolution of the excavation damage zone over many years and its couplings to hydraulic properties and long-term environmental variations, and
- the effects of tunnelling on the reactivation and permeability of fault zones in the immediate vicinity of the tunnel.
The main objectives of PRECODE are:
- Improve our understanding of short-term rock mass behaviour during tunnelling with state-of-the-art monitoring systems that were not available in previous experiments in crystalline rock (e.g. fibre-optic strain sensors, highly sensitive microseismic sensors, LiDAR scanning, etc.).
- Improve our understanding of the influence of natural variations in environmental parameters (moisture, seismicity, etc.) on progressive, time-dependent microcrack development within the excavation damage zone.
- Determination of changes in excavation damage zone permeability over time (up to 2 years).
- Analysis of the impact of tunnel construction on potential reactivation of fault zones and the associated changes in their hydraulic properties
- Creation of a hydro-seismo-mechanically coupled reference data set for numerical simulations, which will be made available to modelling groups.
Project Leader Institution
Chair of Engineering Geology, RWTH Aachen University
ETH; BGE Technology GmbH; Civil Engineering department at the Lassonde School of Engineering, York University; Department of Civil and Resource Engineering, Dalhousie University