In France, abrupt collapse raises more problems of risk management than progressive subsidence. Thus, these two types of phenomenon need to be distinguished. Bases on Tincelin & Sinou (1962) principle, we have attempted to develop an easy-to-use methodology through the retro-analysis of the subsidence of part of the Vins-sur-Caramy mine in 1959. Works is based on a geotechnical analysis of a core drilling and mechanical laboratory tests. Method consist on the examination of two criteria a stability criterion (geometric criterion) and an overburden massiveness criterion (geological criterion). The geological criterion, more complex to understand, was examined using the deformation modulus (Em) of the overburden. This method provides an initial response to the case of the Vins sur Caramy mine. Further research will involve comparing this and other cases.

The present paper summarises the activities related to 3D rockfall hazard assessment in the zone of the heritage dam Matka near Skopje. The concrete arch dam is 29 meters high and it was constructed in the mid 30^ties of the 20^th century. It is the first ever built dam in Macedonia, is survived the infamous Skopje earthquake of 1963, and still working today at full capacity, after almost 90 years of operation. The wider zone around the dam and its lake are situated in the steep gorge of river Treska, characterized by pronounced rockfall hazard in general terms. The entire area is also known as a natural rarities site and attracts many tourists and rock climbers. In order to assess the rockfall hazard for the dam and its appurtenant structure (spillway) a 3D rockfall simulation was performed. In the first stage, the main challenge was to prepare a high-quality 3D model of the terrain and the dam. Several contemporary and innovative surveying techniques were combined in order to achieve this, explained briefly in the paper. Based on findings from engineering-geological mapping, old geological datasets, stereographic analysis, and defining seismic forces, local slope stability analyses were performed. Kinematic analyses confirmed the possibility for detachment of rockfalls, which is observed in reality, and not only in the exact zone of the dam profile. Next were defined the properties of the rockfall seeder zones. The shape, size, and weight of the possible rockfall blocks endangering the dam and the spillway structure were modeled. Due to uncertainties, both point and line types of seeders were applied. The software RocFall3D of the company Rocscience was used to perform the simulations. After running of the program, the paths of possible rockfalls were obtained and then analyzed. Results show that for the given position of the familiar rockfall zones, there is no direct hazard for the dam. The opposite was concluded for the spillway structure. Therefore, for this zone were performed additional analyses of the expected kinetic energy and the other dynamic components of the possible rockfalls. Possible protection types for the spillway were then discussed. The application of protection measures is obvious and subject to further design, however, many limitations can be expected due to the natural protected status of the entire area.

The doublet disastrous earthquakes occurred on February 6, 2023 in the south-east part of Türkiye. The first earthquake is named as The Pazarcık earthquake and occurred at 4:17 on February 6, 2023 and the second earthquake is named as Ekinözü (Elbistan) earthquake and occurred at 13:24 on the same day after about 9 hours. The first earthquake ruptured the segments of East Anadolu Fault (EAF) and Dead-Sea Fault. The Pazarcık earthquake was initiated at Narlı fault belonging the Deas Sea Fault System and involved the Pazarcık segment and Amanos segment belonging to East Anadolu Fault System, subsequently. The estimated total rupture length was about 250-270 km. The Ekinözü earthquake involved E-W trending Çardak fault with a total rupture length of 120-130 km. The magnitude of the Pazarcık earthquake has been estimated by different institutes and it ranged between 7.7 and 8.0 while the magnitude of the Ekinözü earthquake estimated by different institutes and they range between 7.6 and 7.7 (Aydan and Ulusay, 2023).

Several roadways and railway and underpass tunnels were damaged by the Pazarcık earthquake. In addition many rockfalls occurred at the portals of railway and roadway tunnels. The damage by faulting was quite severe at the railway tunnel near Ozan village and the offset was more than 200 cm. Another faulting induced damage occurred at an railway underpass tunnel at Kozdere and the relative slip was more than 30cm. The damage to concrete lining of the new Erkenek tunnels occurred at several places. Despite linings were reinforced, severe spalling and collapse were observed. DLI of the Erkenek tunnels ay be designated as 5 while it may be designated as 7 for the Ozan tunnel. These tunnels were excavated in weak rocks such as phyllite, serpantinized ophiolite and some slope mass movements were observed during excavation. The damage in the new Erkenek tunnels may be related to mass movements caused by heavy ground shaking. The old Erkenek tunnel was excavated in hard limestone and the damage was light although the tunnel was unsupported.

The Shaimdrone Project developed by Geoconsult, with the collaboration of the Polytechnical University of Madrid (UPM, Civil Engineering & Telecommunications Engineering), and financed by the Center for Technological Development and Innovation (CDTI), proposes a methodology for semi-automatic analysis, evaluation and management of massive geometrical data (3D point-cloud models, or 3DPC models) collected from rock slopes using drones. These technological advances increase the working safety of the technician who performs inspections on slopes at the roadside and reduces the impact on the road user due to temporary occupations. Both benefits optimize the duration of field work and increase the capacity and objectivity of risk analyses of the road slopes using and therefore of a better risk assessment.

From the R-SHRS (Rock and Soil Hazard Rating System) risk indexes for rock slopes (Geoconsult 2019, 2021) and the parameters that conform them, advances associated to Shaimdron allow the semi-automatic gathering of data, to compute geometrical parameters from the analysis of the 3DPC models, which are integrated in the R-SHRS_infra category. Similarly, the measurable aspects of the rock and soil masses that form the slopes are grouped in the category R-SHRS_geo, while the parameters that require historical records and frequency phenomena –hence being not measurable from point clouds– are groupted into R-SHRS_freq.

For the Shaimdrone Project, a methodology is developed to obtain data through drone flights, in which their flight operating parameters –distances, heights and flight speeds– are optimized for adequate data collection. Algorithms are also developed to obtain cross sections of the 3DPC models, and to identify lithoclases and joints. The identification of joints defining the rock mass structure of the study area has been carried out with advanced image processing techniques that reduce the noise associated to the irregularity of rock masses. The advanced data processing allows the user to compute aspects such as spacing, persistence, fracture rates (RQD), roughness, block volume, etc. Results obtained from the analysis of the 3DPC models, as well as from other complementary analyses, are integrated into a “risk reports application” that develops risk measures for a given road section, to be also stored in databases and integrated into GIS/BIM environments, for an adequate management of the information and to facilitate subsequent mitigation and investment plans to be conducted by the infrastructure manager.

The area of Ollon, Switzerland is regularly subject to different ground instability phenom-enas like landslides due to the nature of its lithology. It is mostly composed of weathered gypsum and anhydrite. This study aims to investigate and characterize the causes of the landslide in Ollon in 2021 by analyzing topographic, historical, geological, and hydrologi-cal data. The last landslide occurred recently on the 1st December 2023.Our analysis ob-serves that the landslide was triggered by geological superficial soil alteration that goes along with a series of rainfalls. The investigation showed that the geological characteristics of the area, including the fast alteration process and steep slopes contributes to a high sus-ceptibility and frequency of landslides in this area.

Rockburst can be referred to the damage that occurs in rock excavations as a result of a seismic event that generates sufficient energy to cause violent failure of the rock mass. Rockburst events are known for their unpredictable and violent nature, representing a significant threat to workers’ safety, mining productivity, and operational costs. Therefore, a quantitative assessment of rockburst damage is significant for geotechnical risk management in seismically active underground mines. Over the past few decades, numerous studies have been conducted on predicting rockburst damage potential. Despite the scientific achievements and technological advances in ground control, rockburst damage still threating underground mine operations because of the elusive character of the rockburst phenomenon. This paper introduces a dimensionless index to quantify the rockburst damage hazard. Well-documented rockburst damage data compiled from an underground mine located in Canada and Australia were used to establish the index. The input data parameters include the capacity of the ground support system, stress conditions, presence of geological structure, excavation span, and peak particle velocity. The overall results showed that the predicted hazard level using the proposed index had good correlations with the actual rockburst damage scale. In addition, it was found that the most important parameters were the stress and support conditions. It was concluded that the results of this research could be used as a prediction tool to help engineers to adequately assess rockburst damage in seismically active mines.