Advanced geological prediction in tunnels primarily focuses on the weak layer, identified by shear wave velocity. Traditional methods using longitudinal and transverse wave velocities have low accuracy due to ambiguities. Surface waves offer a more precise alternative, though "mode kissing" during dispersion can cause misinterpretations, increasing construction risks. We propose a novel model-substitution method to invert weak layer models and spatial measurement data from tunnels, improving prediction accuracy. Our approach, validated by comparing with advanced drilling results, effectively inverts velocity structures of weak layers, offering a new method for geological prediction using surface-wave and reflection-wave techniques.

The old Grohovo rock avalanche, near the City of Rijeka, Croatia, was activated in 1870 and reactivated in 1885 after prolonged heavy rain period. In its reactivation this rock avalanche of about 16 Mm3 buried 7 houses in its foot. The dimensions of the landslide are length of 490 m, width of 810 m and the slip surface depth of about 85 m. The landslide is situated at the Rječina River Valley slope built in siliciclastic flysch deposits in the bottom and limestone rocks at the top of the valley slopes. The slip surface passes through limestone rock mass at the top of the slope and through flysch rock mass in the lower part of the slope. The Grohovo rock avalanche, the most probably dormant landslide in the last 140 years, was never deeply investigated. In this manuscript, preliminary results of landslide mechanism based on remote sensing surveys are presented. Based on analysis of these data, the landslide model is estab-lished and its activity in the last 70 years was estimated.

The understanding of preparatory processes like thermo-mechanical deformations in charge of natural and man-made rock slope stability strongly condition the efficiency of triggering actions. i.e., rain- and snowfalls, dynamic vibrations, blasts which can operate as near-surface processes. In this sense, the qualitative understanding of preparatory and triggering factors is often limited to qualitative register, and limited is the knowledge about the role (single or in combination) of the environmental conditions that contribute to the occurrence of rock failures (mostly falls and sliding) in critical and subcritical regimes. To achieve the general objective to predict timing and location of ultimate failures in rock walls and quantitatively assess cause-to-effect empirical relationships, an experimental site integrating geotechnical and geophysical monitoring is active since 2016 in Central Italy in an abandoned quarry, namely the Acuto Field Lab managed by the “Sapienza” University of Rome. The Acuto Field Lab acquisition focuses on i) full monitoring of weather conditions and rock strain acquisition by strain gauges and joint meters; ii) 3D InfraRed Thermographic monitoring and contact thermal monitoring, iii) seismic noise measurement devoted to assessing permanent changes in physical and mechanical parameters, iv) Acoustic Emission (AE) and Microseismic (MS) event detection as precursors of incipient failures. The data collected to date supported, in an analytical stage, the numerical quantification of inelastic deformation occurrence in rock mass under periodic forces through stress-strain modelling. The main outcomes focused on the effect of temperature changes over the rock surface and across joints, highlighting the response of major rock fractures and microcracks to the experienced temperature fluctuations at different depths (i.e., thermally active layers). Geophysical monitoring registered the dynamic response of the exposed rock wall under daily and ordinary thermal cycles and a non-ordinary weather event, highlighting, as preliminary results, the occurrence of acoustic emissions as effect of cooling relaxation. Under intense weather events that caused fast freezing, low-frequency MS signals have been attributed to different driving mechanisms caused either by thermal dilation or contraction and by freezing-thawing mechanisms.

Detecting displacement trends is critical in engineering geotechnics to prevent structure collapse, especially in mining operations where monitoring ground movement is vital. Tailings Storage Facilities (TSF) store mining by-products, posing risks of dam collapse. Limited global data makes TSF management complex, accentuating the need for rigorous monitoring. Rio Tinto, collaborating with Atalaya Mining and CSIC, aims for a digital transition to enhance geodetic and geotechnical monitoring. Utilizing Hexagon GeoMonitoring Hub (GMH) platform, data from various sensors are integrated for comprehensive analysis. This strategy allows to detect a slow movement estimated on average at 1 mm/month; the correlation between the data made it possible to understand where the movement is located (with a different displacement trend from the top to the bottom portion), the direction of movement and the structural discontinuities of the dam. This study presents insights for future modeling and best practices in mining and civil engineering monitoring, benefitting structures like road slopes and water dams.

In November 2022, near the village of Castrocucco di Maratea (PZ), a severe rockfall, over 5000 m3 of dolomitic rocks, affected the national road n. 18 ”Tirrena Inferiore” at Km 241+600, whom surveillance and manutention are operated by ANAS spa (Gruppo Fs Italiane), the Italian leading Concessionaire of national road and motorway network. In the 25 Km section between Sapri and Castrocucco di Maratea, the road is a very tortuous, panoramic and tourist itinerary with a two-lanes single carriageway. The road is “carved” in intensely fractured and karst rock cliffs subjected to fast landslides. The route is the only national road serving a critical seaside tourist area and provides a direct connection between the coastlines of Campania, Basilicata and Calabria regions. The rockfall of November 2022 started as a major planar sliding developed on a low-angle fault and triggered by the intense rains of the preceding month. It destroyed part of the road with complete collapse of the retaining structures, fortunately with no fatalities nor injuries. As a consequence, the road had to be closed, and an alternative viability was instituted. However, the road needed to be reopened before the start of the approaching summer season. ANAS SpA, in cooperation with other national and local authorities, accomplished to rebuild the road body and to mitigate the hazard. On the 14th of July the road was temporarily reopened up to the 30th of September 2023, with traffic restrictions. To enhance traffic safety and ensure the functionality of the protection structures, ANAS activated the onsite surveillance and implemented a remote real-time monitoring activity of the slope movement integrated with automatic real time early warning systems. The monitoring points were defined following a structural analysis of the fracture system. The latter was performed by means of field surveys and remote analysis via Virtual Outcrop Models (VOM) developed after image acquisition via drones. This system consists of automated topographic measurements integrated with a meteorological station and remote-controlled security cameras. Furthermore, inclinometers and strain gauges are installed on the rock slopes. A Virtual Machine Service (VMS) receives the monitored data via a wireless system. The software identifies settlements and/or displacements that exceed the threshold limits and sends an e-mail alert. This article presents the monitoring system made to prevent or reduce risks in case of rock mass deformation and consequent rockfalls, showing how early warning could play a significant role for a safe road management.