Local ground movements and effects on infrastructures

Usually local ground movements are monitored and studied in low- and middle-range mountain environments, where the interaction and the hazard to human settlements are more elevated. In high mountain range these movements are rarely investigated, because of (1) logistical difficulties, (2) scarce interaction with infrastructures and villages and (3) the low level of knowledge on the phenomena related with the cryosphere. Recent increase in global temperature and the ever more presence of human tourism and infrastructures in high mountains, has pointed out the importance of a more detailed study of these phenomena. The presence of permafrost in high alpine environments increases the difficulty in dealing with the analysis of local ground movements. In fact, the current approach on analyzing slope deformations and landslides has often been hydro-mechanical, i.e. the tensions and deformations have normally been related to water pressure and mechanical stress-strain relationship. If this approach may be well suited for low range mountain elevations, this might be insufficient in high elevations, where the thermal effect could play an important role on the stability (Harris). For this reason it is important to start the monitoring of these phenomena in high alpine sites, and include to the current monitoring techniques the measurements of temperature. This will ultimately allow correlating the deformations of the slope to temperature variations. Furthermore, the presence of permafrost and its degradation could be taken into consideration in the analysis, in order to evaluate the hazard of high mountain environments to future climate change. These movements have rarely been noticed and categorized in the past, due to the remoteness of the locations and the low interest. Nowadays more people are present at high elevations, thanks to winter and summer sports, and so various infrastructures (shelters, refuge, cable cars…) have been built. This has therefore increased the attention on this environment and also opened the path to a regular investigation and inventory of the occurrence of these phenomena. The frequency of occurrence is consequently hard to define because of the scarce database available. Permafrost, infrastructures and local ground movements are sometimes linked together. Sometimes permafrost has been found while building an infrastructure, e.g. discovering ice cores in the rock. At the same time, local ground movements have been noticed by recording damages in the infrastructures, probably related to permafrost degradation. It is thus important to analyze the effects of local ground movement on infrastructures in an environment characterized by permafrost, in order to infer common problems and find possible correlations between slope movement and permafrost degradation.