Thermal conductivity of compacted Opalinus Clay at different degrees of saturation

Tunnelling in bedded shale rocks induces damage around the excavation. Consequently, rock mass excavation damaged zone (EDZ) shows different thermo-hydro-mechanical (THM) properties from intact rock. In turn, material close to tunnel wall is affected by seasonal fluctuations temperature and relative humidity (RH) variations associated with ventilation, impacting total suction saturation state of EDZ. The monitoring data at new Swiss BelchenA2 highway excavated Opalinus Clay (OPA) captured these stressacting on lining this RH fluctuation. Within context, assessing field EDZ requires determining thermal conductivity degrees saturation. However, obtaining good-quality cores OPA not straightforward, partially desaturating them using controlled techniques time-consuming. instead testing OPA, statically compacted samples powder have been considered study conductivity. addition, two natural (with bedding orientations) retrieved Belchen tested cross-check experimental procedure results, which indicated a consistent increase degree