ISRM 2023 - PUBLICATIONS

T18: Early Career Forum (Young Researchers)Andor NÉMETH, Ákos TÖRÖKBudapest University of Technology and Economics, Faculty of Civil Engineering, Department of Engineering Geology and Geotechnics, Budapest, HungaryMechanical behavior of granitic rocks under elevated temperatures: implications for underground radioactive waste disposal safety and tunnellingThe study focuses on heat-induced physical property changes ingranitic rocks, which are vital for the stability of underground spaces such as tunnels or radioactive waste disposal chambers. Monzogranite from Bátaapáti Radioactive waste repository was tested at different temperatures (22 °C, 250 °C, 375 °C, 500 °C, 625 °C, 750 °C) for P and S-ultrasound velocities, bulk density, Duroskop rebound, uniaxial compressive strength, and modulus of elasticity. Analysis revealed temperature-related physical deterioration via test results. Significant changes occurred above 500 °C, and physical deterioration of the monzogranite was drastic at 750 °C. This data could predict the heating temperature in granitic rocks under unknown conditions, aiding the design and global monitoring systems. | radioactive repository, granite, heat treatment, mechanical properties
T18: Early Career Forum (Young Researchers)Michael ALBER (1), Leandro ALEJANO (2), Tobias BACKERS (3)1: Alber GeoMechanics / Ruhr University Bochum, Germany; 2: University of Vigo, Spain; 3: Ruhr University Bochum, GermanyHow to form competent rock engineersThe profession of a rock engineer is not defined in any academic curriculum. We discuss the professional requirements for civil engineering or mining engineering applications and recommend the necessary classes to form a competent rock engineer. Emphasis is placed on the knowledge about the creation of the appropriate geological and geotechnical model through abstraction of results from site investigation and rock mechanical principles. Design analysis and constructability are further important parts in rock engineering education. The key challenge is, however, to recruit students into entering this rewarding professional career and to provide proper education to them. As most universities tend to hire basic scientists there is little conveyance of personal experience from rock engineering practitioners and little appreciation for rock engineering works. | Rock Engineering, Education, Professional requirements, Career satisfaction
T18: Early Career Forum (Young Researchers)Ardita MALAJ, Skender ALLKJA, Iljana KERO, Julian BELLIU, Besian XHAGOLLIALTEA & Geostudio 2000, AlbaniaSkavica Hydropower plant, one of the most important energetical projects to be constructed in AlbaniaSkavica area is in the north-eastern part of Albania. This article aims to characterize the soils and rocks met in the area under study following the national and international building codes and standards, focusing on the characterizations of rock formations. The main works for the geological and geotechnical study for Skavica HPP project, included the data received recently from A.L.T.E.A. & Geostudio 2000 company investigation. These works comprised a careful geological mapping; geological drillings; trial pits; sampling; field testing (SPT, Lugeon test, Le franc test, borehole optical readings, seismic measurements including refraction and reflection measurements; geophysical measurements, electrical measurements etc...); laboratory testing. This article will present and include all of the findings of our study; the interpretation of field and laboratory testing results and recommendations of the engineering measures to be taken to ensure dam stability and reservoir water conservation. | geological investigation, rock formation, rock characterization, field testing, laboratory testing, dam stability
T18: Early Career Forum (Young Researchers)Maria Teresa CARRIERO (1), Maria Rita MIGLIAZZA (1), Claudio SCAVIA (1), Leandro R. ALEJANO (2)1: Department of Structural, Building and Geotechnical Engineering, Politecnico di Torino, Italy; 2: Department of Natural Resources and Environmental Engineering, University of Vigo, SpainApplication of empirical rockfall classification methods to risk management in an Alpine valley roadMountain secondary roads often follows complex land forms with high sub-vertical rock-cuts in outcropping rock prone to rock-fall events. Geo-structural rock mass surveys and collection of discontinuity data provide the basis for rock mass characterization and enable slope stability analysis and rock-fall hazard assessment. With this aim, a multiscale approach joining the non-contact techniques to the traditional one has been carried out focusing the rock cuts of a mountain road in Elva Valley (Piamonte, Italy). Based on collected data and the field visits, two different rock fall risk assessment empirical approaches were applied, namely the Rockfall Hazard Rating System (RHRS) and the so called Rockfall Risk Assessment for Quarries (ROFRAQ), adapted to road traffic. The application of these approaches to different road sections is demonstrated in the paper. Presented results will be the base to make risk management decisions and a discussion on results is eventually provided. | Rockfall, Risk assessment, RHRS method, ROFRAQ method
T18: Early Career Forum (Young Researchers)Anastasios TSIKRIKIS (1), Vassilis MARINOS (2), Theodosios PAPALIANGAS (1)1: Department of Environmental Engineering, Hellenic International University, Thermi, Greece; 2: Department of Civil Engineering, National Technical University of Athens, GreeceA study on the correlation between Hoek–Brown mi constant and Brinell hardness of intact rocksConventional triaxial compression tests were conducted on dry cylindrical samples of three silicate and three carbonate rocks with porosities in the range 0.3%-24.0%, and confining pressures 0-70 MPa, in order to determine the constant mi of the Hoek-Brown criterion for intact rock. The same rock types were used to determine the Brinell hardness number (BHN) using a spherical indenter with 10 mm diameter and a vertical indentation force of 500 kgf. The values of BHN ranged from 8 to 150 and those of mi from 5 to 24. The experimental results show that the constant mi increases linearly with Brinell hardness and that both BHN and constant mi depend on mineralogy and porosity. The results may be proved useful in estimating the Hoek-Brown mi constant from Brinell hardness which can be determined using small and easily prepared rock samples and sufficiently compact and easy to operate indentation testers. | constant mi, Brinell hardness, triaxial tests, Hoek-Brown criterion, porosity
T18: Early Career Forum (Young Researchers)Gustavo André PANEIRO (1), Ignacio PÉREZ-REY (2), Xian ESTÉVEZ-VENTOSA (2), Leandro R. ALEJANO (2)1: DER/CERENA, Técnico Lisboa, ULisboa, Portugal; 2: CINTECX, Grupo de Xestión Segura e Sostible de Recursos Minerais, Universidade de Vigo, SpainExperimental assessment of high temperature-induced changes on frictional behavior of planar rock jointsIt is accepted that heat waves, whose occurrence have been increasing throughout the last decades in the Iberian Peninsula, associated with climate change, are one of the main hazards linked to the occurrence of wildfires and the increase of fire risk in the open-pit mining industry. To the best of our knowledge, studies that relate the effect of temperature (produced by a fire) on jointed rock masses are scarce. This paper considers the development of benchmark work for the determination of the basic friction angle on suitably prepared saw-cut planar granitic joints, some of them subjected to thermal ageing, and by means of an automatic tilt test apparatus for both reference (no thermal ageing) and thermally aged samples. The results show the influence of high temperatures on the frictional behavior of rock joints, particularly relevant for the stability assessment after a fire or wildfire occurrence near outcrops and excavations. | Rock mass, joint, thermal ageing, friction angle, tilt test
T18: Early Career Forum (Young Researchers)Renato PEREIRA, José MURALHA, Luís LAMASLNEC, PortugalStability analysis of a rock slope: Fully-probabilistic approachStability analysis of rock slopes is an exercise that poses a variety of challenges to a rock engineer. Field information is often lacking and subjective modelling of the rock mass is required. Expert judgment also influences the quantification of the targeted safety level, reflecting the confidence of the designer in his own assumptions and hypothesis. With the introduction of the EN1997 in Europe, structural reliability concepts were brought to the design of geotechnical structures, now also including rock masses after its current revision. Yet, fully-probabilistic methods are still considered valid alternatives to the partial safety method recommended there. Understanding how to address rock engineering problems from a probabilistic perspective becomes essential to move beyond the traditional practice. In this study, a simple problem relating to the stability of a rock slope is explored. Limit states for foreseeable failure mechanisms are defined and the system reliability problem is formulated and solved. | Rock slope, wedge stability, probabilistic approach, system reliability, failure mode analysis