Underground Infrastructure

Low-carbon underground infrastructure, such as buried utilities (e.g., water, electricity, gas, telecommunications) and tunnels/caverns (e.g., for gas storage, waste disposal) is an important part of mitigation measures for climate change. The time-dependent behaviour of both shallow and deep infrastructure must be evaluated. For instance, underground cables, because of the insulation and surrounding environment, tend to retain the heat produced in the conductor and then dissipate it to the surrounding environment. For cables installed in deep bore tunnels, cable cooling is provided by forced air ventilation or water cooling. Therefore, to optimise the electrical performance of a cable, adequate heat dissipation is required to prevent overheating and subsequent reduction in its capacity for carrying current. Similarly, thermal, hydraulic, chemical and mechanical responses can be expected in repositories where the waste has been emplaced.

Quintessa has in-depth understanding of the natural (e.g., soil, rocks) and man-made materials (e.g., cement, metals) and how these evolve over time due to thermal, hydrological, mechanical and chemical interactions. Quintessa has extensive capability and experience in developing and applying conceptual and mathematical models for the key processes that contribute to the behaviour and performance of the underground infrastructure.

As a part of the DECOVALEX research project, Quintessa made significant progress in understanding the fundamental processes for tunnel-scale drying and wetting, in support of the geological disposal of radioactive waste. Quintessa staff members also have experience in developing a methodology for deriving health assessment of a subset of National Grid Electricity Transmission’s (NGET) buried circuits using coupled numerical models, which can be harnessed to allow safe cable rating adjustments of buried transmission circuits.