Rockfall Analysis

The Historic Center of Florence, a UNESCO World Heritage Site, includes many examples of architecture characterized by rough-hewn rusticated block facades—a very common masonry technique in the Florentine Renaissance—made in Pietraforte sandstone. The latter features numerous criticalities related to its intrinsic characteristics and to decay phenomena that are due to weathering and pollution. A multidisciplinary methodology has been developed starting from historic analysis and architectural survey to a complete optometric, mechanical, physical, mineralogical, and petrographic characterization of rough-hewn rusticated blocks, applied to the case study of the Palazzo Medici Riccardi facades. The studies performed in this work cover several research fields, from architecture to geology, going through material diagnostics, and aim at improving knowledge and designing new restoration solutions for Pietraforte building-material criticalities. The research proposes an operative protocol aimed at supporting restoration projects and monitoring plans, with the aim to protect historical, architectural, and artistic cultural heritage and to safeguard the people who visit the city of Florence every year.

The use of remotely piloted aircraft systems (RPASs) in geosciences is often aimed at the acquisition of an image sequence to produce digital models and orthopho-tographs of the topographic surface. The technology can be applied for rockfall hazard and risk assessment. To study rockfalls, an approach consists in the application of numerical models for the computation of rockfall trajectories. Data required for such simulations include digital terrain models, location of the instability source areas, and the mechanical properties of the terrain. In this article, we present an analysis of the earthquake-triggered rockfall that occurred along the SP18 in Villanova di Accumoli (Lazio, central Italy) during the seismic sequence that started on 24 August 2016. A survey with a multicopter was carried out to obtain a surface model of the terrain and identify and characterize the source areas and other instable blocks in areas not accessible in the field. The investigated area extends for 6500 m 2 and was covered by 161 photographs that were used to obtain an orthophoto with a ground resolution of 2.5 cm and a digital surface model with a ground resolution of 20 cm × 20 cm, which was processed and fused with GNSS real-time kine-matic data. To obtain a map of potential rockfall trajecto-ries, we run the numerical model STONE, using as origin of the boulders both source areas mapped in the field and pixels with a slope angle above a selected threshold. Results showed that only the part of the road SP18 already affected by the rockfall was exposed to further rockfall impacts. In particular, it was observed that 29.2 % (i.e. 12 123) of the 41 500 simulated trajectories may potentially reach or cross this tract of the road. Based on these data, limited protection measures were suggested. The combined use of RPAS data, fused with ground GPS points, an accurate geomorpholog-ical survey, and terrain static and dynamic parameters from the literature allows fast, low-cost, and replicable rockfall numerical modelling useful for emergency response and adoption of proper protection measures.

Rockfall creates a significant threat to road users and it is required to continuous monitoring the rock movements to identify the rockfall events. UAV photogrammetry along with structure-from-motion in combination with multi-view-stereo (SFM – MVS) technology-based 3D model is precise technology in the monitoring of rock surfaces. Time series UAV photogrammetry surveys are led to monitor the area at low cost.
Point cloud-based displacement measurement is one of method under the SFM-MVS technology based on 3D models for displacement analysis. In this method, SFM applied to estimate and calibrate the geo location, orientation and camera parameters. MVS applied to construct the dense point clouds for both master and slave imageries. Finally point clouds of both models compared in Cloud Compare platform by utilizing C2C and M3C2 plugins, which estimated the deviation of the dense points from the master and slave point clouds.
Rockfall site, located at 18th bends of Kandy – Mahiyanganya Rd, is selected as the study area. Experimentally, Master imageries captured with manually placed measured boxes and then, slave images were captured after three-dimensional adjustment of the boxes. Displacements were calculated for X, Y and Z directions. Results were visualized through displacement maps with scalar bar and numerical statistics, which indicated spatial adjustment taken place in the slave models with 90 % accuracy.
This procedure was applied for another set of master and slave models which covered the area without the manual placement of the objects. But the precession map and displacement statistics revealed no spatial variation at rock surface area. So, it can be concluded that there is no any displacement has occurred in the study area within the time span of the UAV photogrammetric survey.

Voice disorders often remain undiagnosed. Many self-perceived questionnaires exist for various medical conditions. Here, we used the Greek Voice Handicap Index (VHI) to address the aforementioned problem. Everyone can fill in the VHI questionnaire and rate their symptoms easily. The innovative feature of this research is the global cut-off score calculated for the VHI. Therefore, the VHI is now capable of helping clinicians establish a more customizable treatment plan with the cut-off point identifying patients without normal phonation. For the purpose of finding the global cut-off point, a group of 180 participants was recruited in Greece (90 non-dysphonic participants and 90 with different types of dysphonia). The voice disordered group had higher VHI scores than those of the control group. In contrast to previous studies, we provided and validated for the first time the cut-off points for all VHI domains and, finally, a global cut-off point through ROC and precision-recall analysis in a voice disordered population. In practice, a score higher than the well-estimated global score indicates (without intervention) a possible voice disorder. Nevertheless, if the score is near the threshold, then the patient should definitely follow preventive measures.