Unravelling the interplay of temperature fluctuation and water leakage in frost damage of shotcrete-lined rock tunnels under freeze-thaw cycles
Many Swedish traffic tunnels constructed in shallow hard rocks are subject to seasonal frost, where temperature fluctuation, water leakage, and associated freeze-thaw cycles during the winter season have led to ice growth accompanied with rock/shotcrete degradation and fallouts. To avoid unexpected traffic disruptions, ice and fallen shotcrete and rock within the tunnel need to be removed, incurring substantial maintenance efforts and costs.
Details
- Period: 2025-01-01 – 2028-12-31
- Budget: 4,346,000 SEK
- Funder: Befo
- Type of funding: Project Grant
Description
This project will advance our understanding of the interplay of freezing temperature fluctuation and water leakage in Swedish rock tunnels, to better predict the conditions under which ice growth-induced failures would occur. These results will help to optimise the tunnel design, reduce the subsequent maintenance efforts, and ultimately minimise the life cycle costs. To achieve this goal, in this project, we will develop a multiphysics simulation framework for modelling coupled thermo-hydro-mechanical processes in freeze-thawed composite materials. The model will be validated based on available laboratory experimental data of freeze-thaw tests and then applied to study the frost hazards at the tunnel scale. A classification system will be suggested in order to quantitatively assess the frost damage proneness based on geotechnical, hydrological, and thermal conditions. The outcomes will support the optimisation of tunnel construction and decrease maintenance costs.