bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mitigation measures for the protection of coastal railways in the Flysch of Western Liguria
Authors: Foria F , Giordano R , Avancini G , Miceli G 
Published: September 2021

Abstract
In the countries bordered by the sea, it’s common to have an infrastructure in proximity or on the coastlines. The strategic value of transportation systems along the sea is still fundamental for commercial, emergency and touristic purposes. The sea level and the action of the sea waves are relevant issues for the safety and protection of the infrastructure. The Genova-Ventimiglia railway runs along the coast of the Liguria region of Italy. The meteoric events and the sea storms between November 2019 and June 2020 caused different issues along a stretch of the line. The paper presents the study, the planning and the design of the mitigation measures. An investigation campaign involved both the existing structures and the geological context. The structures on the sea are investigated with GPRs analyses and specific tests performed by rock-climbers during the night disruptions of the line. The geotechnical-geomechanical tests revealed a scenario with the western Liguria Flysch in different facies. ETS Srl has also implemented and deployed a marine Unmanned Surface Vehicle (USV) for the bathymetric survey. The processed data are integrated with the topographic survey to obtain a 3D reconstruction of both the above-sea and undersea surface. The aforementioned data are used for the study, the characterization of the materials and the design of the solution to reinforce the existing structures and mitigate the erosion effect near the line.
Analysis of heaving phenomenon in mountain tunnel and consideration to shallow shaped invert as countermeasures
Authors: Nakano K , Kuremochi N , Matsuda M , Kunimura S , Isago N 
Published: September 2021

Abstract
Heaving in some mountain tunnels after completion occurs in roadbeds that were built without an inverted arch structure because the ground was relatively stable during construction. The stress-release by excavation, along with subsequent swelling by groundwater, cause the roadbed to lose strength, allowing upheaval of the road surface. In this study, we analysed geological degradation characteristics and the state of past tunnels in cases where inverts were installed. We also analysed measurement data for axial forces of inverts. The necessary performance was discussed through the result obtained by numerical analysis to compare support effectiveness of the invert shape and consider a shallow structure.
Seismic activity of hard coal longwall mining in protective shaft pillar near closed room and pillar panel
Authors: Konicek P. , Kajzar V. , Schreiber J. 
Published: September 2021

Abstract
Monitoring of seismic activity during mining in the Upper Silesian Coal Basin is a part of rockburst prevention system. System is composed from two parts - seismological (SL) and seismoacoustic (SA) monitoring. Evaluation of data from both systems allows describing stress deformation process during mining and evaluation of rockburst mitigation techniques effectiveness. Described longwall was mining in a protective pillar after two trial room and pillar (R&P) testing panels were completed.
Evaluation of seismic activity was carried out by special software tool which allows simulating daily advance of mining and registered seismic activity. Different mining stages were identified for evaluation of seismic activity (e.g. weekly and daily summary graph of seismic activity, Benioff graph, event rate graph, energy vs time graph etc.). Evaluation of seismic activity provides many interesting results, mainly in the area of longwall panel termination when one pillar of the R&P trial was impacted by the longwall. This work presents seismic activity analysis, detailed site conditions and implemented active rockburst measures and its effectiveness. Analysis of seismic activity allows to formulate conclusions for longwall mining operations and evaluation of seismic activity in unfavourable geomechanical conditions within the area of protective shaft pillar border.
The role of joint spacing on the stability analysis of wedge failures
Authors: Pérez-Rey I , Moreno J , Muñiz-Menéndez M 
Published: September 2021

Abstract
Kinematic analyses of wedge failures in rock slopes are usually carried out based on stereographic techniques. Nevertheless, this methodology presents several limitations that could lead to poorly accurate conclusions. In line with this idea, the main objective of this work is to evaluate the effect of joint spacing in the estimation of the factor of safety of rock slopes affected by potential wedge failures. For this purpose, a 3D numerical distinct-element code (3DEC) was selected to carry out a good number of simulations in which the factor of safety a slope, affected by different discontinuity sets, was studied by using the Shear Strength Reduction (SSR) method. Different values of joint spacing, cohesion and friction angles were considered, combined with two angles of the slope face under study. The joint spacing has been found to relevantly affect the values of the factor of safety, which showed variations of up to 40% in comparison with those obtained from limit-equilibrium methods for rock slopes with similar structural features. This work provides an insight into a more realistic interpretation of rock slope analyses against wedge failures, and particularly to more accurate estimations of the factor of safety.
A Hybrid FEM/DEM Approach to Estimating Rock Block Breakage due to Gravity Free-Fall
Authors: Veltin K , Elmo D , Rogers S 
Published: September 2021

Abstract
An understanding of the fragmentation of rock blocks from gravity free-fall has applications to rock fall analysis as well as block cave mining. In the case of a rock fall, blocks splitting mechanics can reduce the overall block energy and therefore reduce the travel distance of the blocks. Conversely, splitting may result in a larger number of smaller fragments that may still pose a risk despite their reduced dimensions. In the case of block caving, splitting of blocks it is believed to aid the flow of the ore column, to reduce the potential of hang-ups, and to allow for easier extraction and processing of the ore. Traditional methods for block fragmentation analysis use empirical relationships and rule-based approaches that heavily rely on the block geometry, rather than block-to-block interactions. In this paper we present a study of fragmentation processes using a hybrid finite-element/discrete-element method (FEM/DEM). The approach is capable to account for the numerical instability generally associated with the simulation of high velocity surface interactions and subsequent fracturing. To date the analysis has focused on the simulation of free-falling blocks onto a fixed surface. The initial and final block breakage has been compared against parameters including the roughness and curvature of the impacted surface, and the rock block orientation in space during free fall. We believe the results could provide useful insight into designing catchments for rock fall, as well as an increased understanding of the complexities of secondary fragmentation estimates and the range of fragmentation that could be expected in block caving.
Investigation into the influence of macro-scale geometry on the stability of underground excavations in layered rock masses
Authors: Ingham J , Vazaios I , Paraskevopoulou C 
Published: September 2021

Abstract
Underground excavations for the development of infrastructure, mining operations, waste management etc. require support measures to ensure stability both during their construction and operational phases, which highly depends on the rock mass strength and deformability. Discontinuities within the rock mass are intrinsic features which determine said strength and deformability and affect the excavation stability. Several defining parameters demonstrate that rock mass variability has significant control in the material response during an excavation, especially in sedimentary rocks. In this paper, the Thornhill Sandstone is examined by applying numerical analysis and its mechanical response is investigated under several scenarios with varying excavation geometries, stress conditions while incorporating the influence of discontinuities explicitly within the numerical model. A two-dimensional parametric analysis is performed by applying the Finite Element Method (FEM) and integrating Discrete Fracture Networks (DFNs). More specifically, four different excavation geometries and three different in situ stress regimes are investigated. Drawing on the results, this paper provides insights for tunnel design optimisation when layered rock masses are encountered during an excavation in various underground stress environments with different opening geometries.
A Discrete Element Framework for the modelling of rock-filled gabions
Authors: Marigo Nicola , Gabrieli Fabio , Pol Antonio , Bisson Alberto , Brezzi Lorenzo 
Published: September 2021

Abstract
Gabions are steel mesh cages filled with stones. Recently, they have had a great diffusion for numerous applications such as erosion control and soil retention along cuts and natural slopes. The study of their mechanical behaviour under different loading conditions is a fundamental prerequisite for an improved understanding of their overall performance and in a design perspective. In this respect, the Discrete Element Method (DEM) appears a robust and effective technique. The DEM is particularly suited for modelling granular materials, and recently it has efficiently been applied for modelling deformable structures such as welded meshes. This work presents a discrete framework for the modelling of rock-filled gabions. The gabion module is modelled as an assembly of deformable cylindrical elements, while the filling material is represented using rigid aggregates of spherical particles. The tensile behaviour of the gabion elements is set in order to fit the mechanical response of the steel bars adopted in practice. The model is applied to analyse a uniaxial compression test on a single gabion.
Investigation of hydro-mechanical processes in fluid-saturated fractured rock based on numerical model generation
Authors: Pollmann N , Gallas J , Brandenburg M Ch , Witte L , Backers T 
Published: September 2021

AbstractTo realistically simulate fluid flow in fractured rock mass, a scheme to represent the discrete fracture networks (DFN) in the numerical model is of utmost importance. In this paper we discuss a workflow to implement a field-measurement based DFN into an FEM code (COMSOL Multiphysics) by means of a MATLAB routine. This workflow is involved in the ZoKrateS project which aims at showing the feasibility to enhanced fractured carbonate Rock Mass by proppant placement for geothermal application.The model generation is based on analytical geometry including the equations for dip, azimuth and spacing of lines. The spacing between the discontinuities and the characteristic fracture length and aperture as well as orientation serve as input parameters for the model. It is possible to generate periodic models to be able to include periodic boundary conditions in simulations. In 2D the fractures are modeled as poroelastic ellipses in a poroelastic square-matrix. We investigate hydro-mechanically triggered fluid transport in stationary fractures that are mechanically and hydraulically active.An extension to 3D fracture networks requires an algorithm based on analytical geometry including the equations for azimuth, dip and spacing of planes. To decrease the numerical costs of the 3D simulation a diffuse interface approach is strived for, including a modified model generation.With the numerical model generator (NUMOG) a workflow is developed which allows numerical investigations of (thermo-) hydro-mechanically triggered fluid transport in a geothermal reservoir.
Numerical modelling of a large tunnel lining in a creeping rock mass based on 20 years monitoring data
Authors: Plassart R , Martin F , Saïtta A , Lopard G 
Published: September 2021

Abstract
The French project of deep geological storage for nuclear waste (Cigéo) gives rise to a lot of innovative issues for underground space technologies. For example, the nuclear activity of the waste generates temperature effects on the lining, needing to mitigate the number of waste containers in the gallery section. For the Intermediate-Level waste (ILW), thanks to lower temperature effects, the number of containers in the cross section can safely be increased. Therefore, a largest diameter gallery (10 meters) could be more cost effective. The challenge is to design the lining of such a gallery for 100 years in a context of high displacements, due to 500 meters overburden and the creeping behaviour of the rock mass (COx argillite). To improve our understanding of long term behaviour of large galleries, this paper details the experience of the road tunnel of Chamoise (France), including an advanced processing of the available data (rock and lining displacements, linings yielding) recorded since the tunnel excavation, more than 20 years ago. Besides, a numerical modelling of the tunnel has been carried out, using two constitutive laws accounting for a viscoplastic mechanism: L&K (EDF) and H&B-Lemaitre (ANDRA). The simulations results have then been compared with the processed records on 20 years. Finally, the calculations have been carried on until 100 years, improving the demonstration of feasibility of a large gallery in claystone for the challenging Cigéo project.
The Carrara Marble: geology, geomechanics and quarrying
Authors: Coli M , Criscuolo A 
Published: September 2021

Abstract
The industrial exploitation of the Carrara Marble dates back to I century B.C. with the Romans. After a black out in the Early Mediaeval age due to barbarian invasions, since XIII century the Carrara Marble has becoming more and more used for ornamental purposes and appreciated and requested worldwide. Geologically the Carrara Marble derives from a Tertiary polyphasic tectono-metamorphic deformation of an Early Jurassic epicontinental carbonate platform. That got rise to the diverse merceological types of the Carrara Marble, this and two neo-tectonic sub-vertical fracture systems, NNE-SSW and NW-SE trending respectively and grouped into bands irregularly spaced, control the geo-mining setting of the Carrara Marble. For centuries the Carrara Marble has been excavated only following the feeling the quarrymen had with the rock-mass, but the new cultivation technologies with diamond-wire cutting machines and saw-cutting chains, with big frontal-loaders and excavators, have greatly increased the production and require for a robust design based on reliable geomechanical data. Underground quarrying is increasing because technical and environmental concerns and asks for robust design and in situ stress determinations.
Influence of rock’s structure at grain-scale on rockburst proneness
Authors: Klammer A , Gottsbacher L , Biermann J , Zobl F , Marschallinger R , Hofmann P , Marcher T , Schubert W 
Published: September 2021

Abstract
As projects advance to deeper areas, rockbursts occur more frequently. This failure mode is particularly problematic, as the rock mass fails abruptly, releasing high amounts of energy, endangering the life of workers and damaging equipment. The hazard mode is highly influenced by the grain-level structure of the rock. The authors demonstrate this by comparing the grain-level structure of different rocks to their failure mechanism. For this an extensive laboratory program was performed, including uniaxial compression tests (incl. post-failure tests to evaluate the failure energy), acoustic emission testing (to monitor the cracking activity) and Object Based Image Analysis (OBIA) to analyze rock’s structure at grain scale using thin sections taken before and after the compression test. The results allow a better understanding of the underlying mechanism and emphasize the usefulness of petrographic information within rockburst risk analysis.
Empirical relationship for drilling rate in hard rock underground mines
Authors: Adoko A C , Moesi D , Sharipov A S 
Published: September 2021

Abstract
A reliable estimate of the drilling rate is essential in a successful drill and blast planning and mine production. Owing to this importance, numerous empirical equations of the drilling rate using the rock mass properties and the machine parameters have been proposed. However, these existing equations cannot be used in all site conditions. Hence, this paper aims to develop an empirical model for drilling rate estimation in hard rock mining. The data used for this study were collected from an underground mine located in Selibi-Phikwe, Botswana and included in-situ drilling rate, drilling machine specification and rock mass properties. Nonlinear regression model was used to derive the drill rate model. The result indicates high correlation between the estimated and the actual drill rates. In addition, it was found that the uniaxial compressive strength of the rock, the angle between the rock mass discontinuity planes and the drilling direction are the parameters impacting the drill rate the most. Also, the presence of quartz in the rock indicated good predictability of the drill rates.
Use of a miniaturized data-logger for determining the state of stress induced in abandoned pillars
Authors: Saltarin S , Iabichino G 
Published: September 2021

Abstract
The measurement of the natural and/or induced stress state in rock masses excavations is generally carried out thanks to techniques able of providing results both in the two-dimensional (2D) and in the three-dimensional (3D) environment, coded in the “Suggested Method” of the ISRM. The stress relief method is one of the most consolidated measurement methods, based on the differences in strain intensity evaluated in selected directions before and after making a continuous notch around the sensors involved in the measurement. With a special miniaturized data-logger applied to the sensors used for the evaluation of the rock stress in a 2D (doorstopper) or 3D (HI cell, CSIRO) environment, the execution of the measurement on site can be considerably simplified, and the complete strain-time diagram acquired due to over-coring can be obtained. The paper presents an example of measurement of the state of stress induced in some abandoned pillars in an underground quarry.
Monitoring deformations related to geological risks with InSaR data – the MOMPA project
Authors: Gasc-Barbier Muriel , Barra Anna , Buxó Pere , Trapero Laura , Crosetto Michele , Colell Xavier , Fabregat Ivan , Echeverria Anna , Marturia Jordi 
Published: September 2021

Abstract
Co-financed by the Interreg V Program in Spain-France-Andorra (POCTEFA) the European project MOMPA (MOnitoring of ground Movements and Action Protocol) study the landslide hazard in the Eastern Pyrenees. It groups together scientific partners from CTTC (Telecommunications Centre of Catalonia), ICGC (Cartographical and Geological Institute of Catalunya) IEA (Andorran Research Institute), and Cerema (Centre for studies and expertise on risks, the environment, mobility, and development). This cross-border project provides the expertise of four partners, which are specialized in remote sensing and techniques of risk analysis and management. More specifically, the goal of this project is to improve risk management by evolving from a “reactive” approach to a “proactive” one that is rarely used today because of its financial cost. To identify movements, the technique of interferometric SAR (InSAR) based on satellite images is used. This technique is sensitive to very small ground deformations and allows early detection of movements.
Constructive analysis of the role that engineering geological and rock mechanics methods could play in a complex emergency. Lessons Learned from the Totalán Case
Authors: Zango-Pascual M , Osorno Guerrero O 
Published: September 2021

Abstract
The emergency services receive a notice on 13/01/2019 that a 2-year-old boy has fallen into a borehole in Totalán, (Málaga, Spain). After almost 13 days of unusual and overwhelming engineering and solidarity efforts his body is recovered. This was an extraordinary and unusual emergency case, due to: the superhuman effort made by the more than 300 people involved in the rescue operation; the follow-up made by the media, and all the engineering work carried out in record time. For this purpose, it was decided to build a parallel shaft and a 71-meter-deep transversal tunnel, to access the supposed hole, where he is expected to be alive. The cost was approximately 700,000 €. The contribution of geology might have been small, according to sources in the authorities and the media, due to time constraints. But was it really like that? it could have been much more useful, in terms of reducing time frames or even to making different decisions to facilitate the rescue, if other geophysical and engineering geological research methods had been taken into account in the early days. This retrospective analysis is approached with the utmost respect for the efforts made and always with the greatest possible scientific rigour.
Remote monitoring of natural slopes: Combining use of Terrestrial Laser Scanning and innovative rockfall alert system
Authors: Berlinghieri M , Pandolfi O 
Published: September 2021

AbstractThe article describes the first results of a research project aimed to digitalize the monitoring activities of natural rock masses. The project started with a geotechnical remote analysis on the high-definition 3D point cloud detected by a terrestrial laser scanner (TLS), and with the identification of principal discontinuities elements through 3D manual and automatic analysis of the fractures. The results of these survey campaigns have allowed identifying geometrical information of the blocks at risk, to perform a detachment risk assessment and an evaluation of the potential falling trajectories through the lumped mass methodology. The geotechnical monitoring of the rocky mass has seen the combined use of two techniques: the use of a terrestrial laser scanner (TLS) combined with Imaging Matching algorithms; and the implementation of an innovative smart warning system for detachment phenomenon realized by Maccaferri s.p.a., applied to rockfall barriers and drapery mesh, able to provide real-time status notifications and warning alerts. According to the first data analyses, both the proposed techniques can provide excellent monitoring of the rocky slopes, with low costs. The methodological approach proposed perfectly integrates with smart management of excavation sites and the infrastructure and can guarantee an extremely high level of health and safety.
Kriging-based optimization design of deep tunnel in the rheological Burger rock
Authors: Do D P , Tran N T , Hoxha D , Vu M N , Armand G 
Published: September 2021

Abstract
The principal purpose of this work consists in optimizing the support system of a deep tunnel accounting for the uncertainty of the time-dependent behaviour of the surrounding rock, which is described by the rheological Burger law. The stochastic approach is chosen for this aim. On one hand the Quantile Monte Carlo (QMC) simulation is used to determine the optimal design variables (i.e., the thickness of two liners). On the other hand, the well-known Kriging metamodeling technique is undertaken to approximate the limit state function in the augmented reliability space (i.e., the tensor product between the random variable space and the design variable space). The adopted optimization process allows to derive the optimal tunnel support that verifies two failure modes, namely the support capacity criterion and the maximum tunnel convergence.