Assessment of the influence of natural thermal cycles on dolomitic limestone rock columns: A 10-year monitoring study

Rock instabilities hazards can lead to major risks. Even if different external factors such as precipitation, seismic activity or freezing, are known to trigger rockfalls, it is more and more assumed that thermal cycling has a role in rock mass deformation, displacement and, moreover cracking initiation or propagation. Here we present 10 years monitoring of a 50-meter-high dolomitic cliff, located above an important highway in the south of France to support this thinking. Local rock surface temperature and joint apertures were recorded on eleven sensors. Their evolution is studied separately and together to characterise the influence of temperature variation on joint apertures. During small time periods, a reversible and proportional behaviour is observed, that can be attributed to thermoelasticity, but over the whole period, a significant drift in displacements is measured, meaning that at least a viscoplastic or fatigue behaviour should be considered. •Local temperature and joint apertures were recorded on 11 sensors in a 10-year monitoring of a 50m-high dolomitic cliff.•Variations of temperature, daily temperature amplitude and joint apertures are analysed over 10 years.•Seasonality of displacement is quantified.•Correlations between temp and disp show in short term thermoelasticity and in long term (fatigue or viscoplasticity).•Study of incremental variation of temp and displ show that temperature path plays a role in the resulting displacement.•Thus, a cumulative effect should also be considered to model the thermomechanical behaviour of the rock mass.