## 4 Results
### OBA Analysis  
Weather conditions and induced strains were monitored by continuous data recording, detecting daily and seasonal changes due to temperature, rainfall and wind that can cause rock mass deformations. The air temperature, considered as the main possible continuous _preparatory factor_ (_sensu_ [PERSON] et al. [12]), showed daily and seasonal cyclic oscillations (Figure 6a) typical of the latitude and climatic zone in which the test-site is located. During the Summer season, the air temperature can exceed 30 \({}^{\circ}\)C, while in Winter, it may drop below 0 \({}^{\circ}\)C. The daily thermal excursion follows a similar trend to that of the average air temperature, showing the highest values (up to 16 \({}^{\circ}\)C) in the Spring and Summer seasons. The lower values (down to 2 \({}^{\circ}\)C) are concentrated in the Autumn and Winter, in conjunction with the decrease of the air temperature average values. The air temperature directly influences the rock temperature (Figure 6a), as its trend follows that of the air temperature very well. This occurs on both a daily and seasonal trend, revealing that the temperature is the main external forcing that continuously acts on the rock mass deformation (Figure 6a-blue line). Similarly to the trend of the air temperature, during the summertime, the rock temperature (Figure 6a) can exceed 40 \({}^{\circ}\)C thanks to the influence of direct solar radiation, while in wintertime, it may drop to \(-\)5 \({}^{\circ}\)C. The daily thermal excursion follows a more different trend relative to that of the average rock temperature. In fact, the highest values (up to 19 \({}^{\circ}\)C) were recorded in the Spring and Autumn seasons, and the lower values (down to 2 \({}^{\circ}\)C) were concentrated in the Summer and Winter seasons (Figure 6a-red line). The low Winter temperatures may give rise to freezing effects in the rock block, which are considered a _trigger factor_ for micro-fracture propagation. The rock temperature, as well as the resulting deformation, is influenced not only by the air temperature but also primarily by the direct action of solar radiation, as shown by [PERSON] et al. [44]. In fact, the rock temperature value is greater than the air temperature value, also presenting the peak of the thermal maximum of each daily cycle generally anticipated with respect to that of the air temperature because of their different thermal conductivities. The role played by rainfall can be considered a _preparatory factor_ in the case of regular occurrence or as a _trigger factor_ in the case of intense and concentrated episodes. The rainfall regime (Figure 6b) also shows a seasonal trend, with frequent and intense rain concentrated in the Autumn and Spring months, during which the possibility of rock strain is highly. During the monitoring period, a total of 2034 mm of rain was cumulated, with a maximum daily precipitation of 82 mm/day that occurred in September 2017 (Figure 6b). Unlike the temperature that acts continuously and cyclically on the rock mass strain, the rainfall shows an aperiodic (or non-cyclical) behaviour. In addition, windstorms can be occasionally considered as a _trigger factor_ for joint opening. Only events with the wind direction in an azimuth range between N 10\({}^{\circ}\) and N 190\({}^{\circ}\), which is the same aspect of the rock wall, can be taken into account. During the monitoring period, six strong windstorms occurred, characterised by wind speeds higher than the average value (15 m/s for each winter storm). In the considered case, a very small scatter in rock mass deformation trend occurred immediately after storm phenomena in the period during which rainfall was absent and the thermal input was constant, but, in principle, the wind does not seem to be a forcing able to make appreciable deformations in the natural system (Figure 6c).