Underground Quarries Research Articles

Strategies to challenge the simulation of confined fires

The numerical simulation of fires concerns an increasingly wide range of applications, among which archaeology. The Chauvet-Pont d’Arc Cave (France) presents thermal marks on some of its walls. These marks result from prehistorical fires and archaeologists would like to know their characteristics (fire location, mass of fuel, number of fires, etc) to make assumptions about their functions. Being impossible to carry out fires in the cave, combustion simulation is a suitable tool to discuss this question. However, simulating a fire in a confined geometry is still challenging and some inherent difficulties must be overcome. In that respect, we reproduced four experimental fires in a cave-like geometry. Four tepee-like hearths, composed of different initial wood masses (16, 32, 60 and 90 kg), were burnt in an underground quarry. Twenty-seven thermocouples measured the temperature in the cold and hot gas layers, as well as in the ceiling jet area. The measurements in the ceiling jet resulting from the 90 kg fire are successfully compared to the corrected Delichatsios correlations. In addition, the measured mass loss rate is compared to a tailored modeling for tepee hearths. We alsopropose three strategies to simulate the combustion process of the 90 kg hearth: (i) with a significant refinement in the ceiling jet area (approximately 1,500,000 cells) and the law of the wall, (ii) without refinement but with Newton’s law of cooling and (iii) without refinement but with simplifying assumptions and adjustments. While the first and third approaches provide meaningful results, the second case is found to be inconvenient for compartment fires. Based on experimental data, this study aims to give some keys to perform simulations of compartment fires (in tunnels, buildings, car parks, etc) and numerically approximate the combustion of wood.

Stability analysis of Cavern No. 5 with the largest span in Heidong large ancient underground quarry

The Heidong Cavern Group of China includes 21 large-scale caverns that have remained stable for 1400 years. Cavern No. 5 of the Heidong Cavern Group is characterized by an unsupported span of up to 92 m, which is considered to be the largest span in a single underground artificial rock cavern. Cavern No. 5 may have gone through a period during which it was the only cavern and a period during which it had adjacent caverns; recent investigations have proved that Cavern No. 5 is suffering from considerably serious partial damage. The factors affecting the stability of Cavern No. 5, including waste rock accumulations, rock mass structures, surrounding rock quality, and cavern structures, were analyzed to prevent further damage and analyze the influence of the existence of adjacent caverns on the stability of Cavern No. 5. The numerical analysis software MIDAS GTS (Geotechnical and tunnel analysis system) was used to simulate and compare the stability of Cavern No. 5 under the single-cavern and adjacent-cavern cases. Research proves that when this cavern is independently considered and the remaining caverns are excluded, the arched roof structure is considerably favorable to ensure the cavern’s stability and the horizontal compressive stress of the roof becomes approximately equivalent to the vertical tensile stress. The horizontal forces generated by the cavern’s inclined roof contribute to the cavern’s stability. The horizontal compressive stress area of the roof and the effect of the arched structure decrease when adjacent caverns are present, causing the roof to become prone to tensile failure. These results provide a reference for modern underground engineering construction and a theoretical basis for long-term protection of the large and ancient Heidong Caverns.

Crack coalescence and strain accommodation in gypsum rock

Gypsum is a soft rock with low strength and high propensity to plastic deformation. Its mechanical properties are relevant in a wide range of technical application (e.g. tunnel excavation, stability assessment of underground quarries, oil and gas accumulation). The micro-mechanisms involved in the deformation of gypsum rock have for long time interested the scientific world and are still not completely understood. The peculiar crystallographic structure of this bi-hydrate salt, with water molecules layered in the salt structure, favours the development of plastic structures in the rock. The present work proposes an experimental investigation of strain accommodation mechanisms in gypsum rock, reporting data referred to uniaxial and triaxial stress conditions. The rock strain was studied with a multiscale approach, with the comparison of results from DIC and microstructural analyses.

Regional socio-economic aspects in the field of coal mining

Over time, the discovery of the deposit, the exploitation and processing of coal has led to the development and prosperity of many areas called “coal regions”. In the last decades we have witnessed the closing process of many exploitation capacities (underground mines or open pit quarries) with complex socio-economic and even cultural impact in the coal region and on the continent. Debates for or against “coal” with related arguments, policies, strategies and measures at global, regional, national and local level integrate holistically from the “resource” issue to large dynamic systems (energy, climate, urbanism). The relationship between the coal industry and the socio-economic aspects is multifaceted and not yet fully explored. Our paper proposes a statistically documented research on regional development using representative socio-economic indicators. The paper is aiming to present the current socio-economic state in Jiu Valley micro-region, as a result of the structural transformations / changes in the coal industry of Romania’s largest hard coal-fired coal basin.

Making Space for the Dead: Catacombs, Cemeteries, and the Reimagining of Paris, 1780–1830 by Erin-Marie Legacey

Reviewed by: Making Space for the Dead: Catacombs, Cemeteries, and the Reimagining of Paris, 1780–1830 by Erin-Marie Legacey Alice J. Strange Legacey, Erin-Marie. Making Space for the Dead: Catacombs, Cemeteries, and the Reimagining of Paris, 1780–1830. Cornell UP, 2019. ISBN 978-1-5017-1559-4. Pp. 210. This work examines the crisis in the burial practices of Paris prior to the French Revolution and the chaos that followed as a new burial culture was created. For centuries the remains of the dead of Paris had been deposited into anonymous mass graves in one of the thirty-two churchyards in the city. The oldest and largest gravesite was the Cemetery of the Holy Innocents in central Paris, in use for more than five hundred years. By the late eighteenth century, it was overflowing with decomposing human remains and was a peril to neighboring residents. Although the space was surrounded by a wall, it emitted noxious airs and underground vapors that invaded surrounding buildings and made their way into living spaces. In 1780, a royal proclamation ordered the closure of this and other cemeteries and the relocation of remains to an underground quarry on the urban periphery, which eventually became the Paris Catacombs. The Old Regime failed to address the burial problem before its own demise in 1789, and cemetery reform was left to successive regimes. Legacey argues that the French Revolution was central to transforming attitudes about the proper treatment of the dead. Revolutionaries called for an end to religious burial practices and a new system based on the ideals of equality and fraternity. They were unable to realize these goals, and during the Terror, the remains of thousands of secretly executed victims were placed in open mass graves, complicating the problem. Instability continued into the Napoleonic Empire. It was gradually accepted that individual burial sites were preferable to communal graves. Architects and urban planners offered innovative reforms. One proposal, for example, argued that the dead should be judged for their civic contributions and assigned a place in a new cemetery according to their worthiness. Finally, in 1804, burial standards were codified by Napoleon in a decree that set forth twenty-six articles governing the design for burial spaces. Cemeteries were to be located on the periphery of cities rather than within urban areas, preferably on an elevated terrain east of the city. Père-Lachaise cemetery was opened in 1804 in accordance with the guidelines. Cemeteries were no longer unpleasant and unhealthy places to be avoided, but aesthetic and attractive sites. The new design aimed to accommodate individual gravesites with monuments, although some communal graves continued to exist. The living were encouraged to contemplate the achievements of the heroic dead. Ideally, the new cemetery would unite Parisians of all classes and instill a sense of shared history. The Paris Catacombs, opened to the public in 1809, were an indispensable component of the new culture. Bones from many cemeteries were arranged artistically to draw visitors, combining a macabre appeal with a reminder of the leveling effect of death. In this thoroughly researched study, Legacey presents compelling archival material to trace the revolution in Parisian cemetery culture and the corresponding transformation of attitudes toward the dead. Her work [End Page 240] makes a significant contribution to the social history of Paris in the early nineteenth century. Alice J. Strange Southeast Missouri State University, emerita Copyright © 2020 American Association of Teachers of French

Dependence of macro mechanical behaviour of gypsum on micro-scale grain-size distribution

The exploitation of gypsum by both open pit and underground quarries requires a close evaluation of the mechanical features and variability. However, gypsum rock testing often neglects the natural heterogeneity. The result is an inaccurate mechanical characterisation that averages the strength values of different materials leading to an underestimation or overestimation of the stability conditions, without offering a real representation of the mechanical behaviour of the rock. Grain-size, grain-sorting, mineral composition and porosity significantly influence gypsum mechanical behaviour. The individuation of textural and compositional features that primarily influence the variation in mechanical parameters may offer an interpretation key of the phenomenon. In this study, the relation between the features at the microscale and macro-mechanical behaviour of gypsum rock was analysed with a multiscale approach. Relationships between uniaxial compression strength (UCS), grain-size distribution and porosity were analysed and discussed. Microscopic observations on thin sections were performed, developing an image analysis procedure for correlating textural and structural parameters with UCS.

Development of a Fluid–Structure Coupling Validated with a Confined Fire: Application to Painted Caves

In 1994, three speleologists discovered the Chauvet–Pont d’Arc Cave, which contains singular thermal marks on walls deep in the cavity. These alterations arose from intense fires, and understanding their characteristics would help archaeologists suggest hypotheses about the function of such activities. In this context, three confined fires were conducted in a former underground quarry to reproduce thermo-alterations similar to those in the Chauvet–Pont d’Arc Cave and extract experimental data. Each fire involved approximately 135 kg of wood, which was continuously supplied by firemen for safety reasons (> 500°C) and burnt in the shape of a tepee 80 cm in diameter for 50 min. This paper presents the validation of a numerical model on this experimentation. The modelling requires coupling between the combustion and wall impact simulations. Thus, a link between the combustion code FireFOAM and the thermo-mechanical code Cast3m was created with Python scripts. The results from the simulation agree with the measurements and the observations. More specifically, the analysis is based on the temperatures, gas and particle concentrations, gas velocities, soot deposition, colour changes at the walls and areas likely to spall. These data were collected from thirty-seven measuring points covering the whole quarry. This validated tool will provide information about the features of the fires that occurred within the Chauvet–Pont d’Arc Cave.

Geomorphology of the Anthropocene in Mediterranean urban areas

Urban-geomorphology studies in historical cities provide a significant contribution towards the broad definition of the Anthropocene, perhaps even including its consideration as a new unit of geological time. Specific methodological approaches to recognize and map landforms in urban environments, where human-induced geomorphic processes have often overcome the natural ones, are proposed. This paper reports the results from, and comparison of, studies conducted in coastal historical cities facing the core of the Mediterranean Sea – that is, Genoa, Rome, Naples, Palermo (Italy) and Patras (Greece). Their settlements were facilitated by similar climatic and geographical contexts, with high grounds functional for defence, as well as by the availability of rocks useful as construction materials, which were excavated both in opencast and underground quarries. Over centuries, urbanization has also required the levelling of relief, which was performed by the excavation of heights, filling of depressions and by slope terracing. Consequently, highly modified hydrographic networks, whose streams were dammed, diverted, modified in a culvert or simply buried, characterize the selected cities. Their urban growth, which has been driven by maritime commercial activities, has determined anthropogenic coastal progradation through port and defence or waterfront works. Aggradation of artificial ground has also occurred as a consequence of repeated destruction because of both human and natural events, and subsequent reconstruction even over ruins, buried depressions and shallow cavities. As a result, the selected cities represent anthropogenic landscapes that have been predominately shaped by several human-driven processes, sometimes over centuries. Each landform represents the current result, often from multiple activities with opposing geomorphic effects. Beyond academic progress, we believe that detecting and mapping these landforms and processes should be compulsory, even in risk-assessment urban planning, because of the increase of both hazards and vulnerability as a result of climate-change-induced extreme events and extensive urbanization, respectively.

GPR surveys for the prevention of karst risk in underground gypsum quarries

The investigation and prediction of geological anomalies in underground quarries is fundamental to ensure safety, efficiency and economic convenience of the exploitation. For these aims, non-destructive geophysical surveys may be an effective alternative approach to classical destructive prospecting techniques (i.e. horizontal drilling), with great advantages particularly in complex geological frameworks and in areas subjected to specific geo-hazards. Ground Penetrating Radar (GPR), for its high resolution, is a suitable technique for underground excavations, particularly for the identification of water bodies, fissures and fractured rocks. The present study is focused on the application of GPR for the prediction of karst structures in underground gypsum quarries. Karst phenomenon is a main risk factor for gypsum orebodies, where large cavities may be intersected by the excavation. The possible filling with clay or pressurized water of these cavities exponentially increases the dangerousness of the phenomenon, due to swelling problems and violent water inrushes. The aim of the present study is to propose, through modelling and field surveys, a description of GPR outputs for principal elements of karst hazard in gypsum bodies, with particular attention to the discrimination of fillings (air, water or clay).

A practical tool for the stability estimation of underground quarries in North France

Purpose The presence of underground quarries in North France in close proximity to urbanized areas, imposes serious problems in terms of security of both people and constructions at one hand, and induces a strong constraint against planning and urban development on the other hand. The purpose of this paper is to provide a practical tool for the preliminary estimation of the stability of underground quarries. Design/methodology/approach In this paper, a numerical stability study of quarries, excavated in chalk of North France with or without joints, by the method of rooms and pillars, is presented. This integrates the data provided from site: mechanical properties of the chalk and geometric characteristics of the quarries (width of the pillar W, height of the pillar H and span between pillars L), as well as the orientation of the joints (α). Numerical parametric analysis is conducted using FLAC 3D. Factors of safety are computed from the numerical models. Then, a second-order regression technique is applied on these numerically obtained factors, to correlate new formulae. Findings As a result, user-friendly formulae for the calculation of factors of safety Fs (ex) are extrapolated. Besides, abacuses to determine the minimum permissible effective width of safe pillars are proposed. Originality/value By this, it becomes possible, knowing only few parameters about geometry and properties, to give a fast estimation of the stability state of any quarry in the region.

Transfer and degradation of the common pesticide atrazine through the unsaturated zone of the Chalk aquifer (Northern France)

Groundwater in the Chalk aquifer is an important water resource whose quality has degraded due to fertilizer and pesticide use. Atrazine, classified as a priority substance, has been one of the most applied pesticides and also one of the most frequently detected pesticides in groundwater. The present study investigated the transfer and degradation of atrazine in the unsaturated zone of the Chalk aquifer in Northern France. The study was conducted in an underground quarry (Saint-Martin-le-Noeud), which provides a direct access to the water table and intercepts the unsaturated zone at different depths. The lake and the ceiling percolation of 16 sites throughout the quarry were followed. For 16 sites, the percolating flow rate and lake level were measured and the lake water was sampled for nitrate, atrazine and deethylatrazine (DEA, main degradation product of atrazine) analysis over 2.5 years. High spatial variations in hydrodynamics (percolating flow rate and lake level) and in lake water quality (atrazine between 55±11 and 202±40 ng L−1 and DEA between 269±53 and 1727±345 ng L−1) indicate that the properties of the unsaturated zone influence the transfer and the degradation of atrazine. A counterclockwise hysteresis characterizes the relationship between the lake level and atrazine concentration. Temporal variation shows that the atrazine is transferred through the matrix and fractures with a delay caused by the sorption process that differs in atrazine and DEA. The layer of clay-with-flints is shown to favor the degradation of atrazine near the surface. Preferential pathways may be created below clay-with-flints, through which the transfer of atrazine is quicker.

Chance-Constrained Scheduling of Underground Pumped Hydro Energy Storage in Presence of Model Uncertainties

Abandoned underground quarries or mines may be rehabilitated as natural reservoirs for underground pumped hydro energy storage (UPHES). In addition to the inherent modeling inaccuracies of the traditional PHES that arise from, e.g., approximating the nonlinear pump/turbine head-dependent performance curves, the optimal operation of these underground plants is also affected by endogenous model uncertainties. The latter typically arise from a limited knowledge of the physical characteristics of the system such as the geometry and hydraulic properties of the underground cavity. In this paper, chance-constrained programming is leveraged to immunize the day-ahead scheduling of an UPHES owner against both these model uncertainties and the modeling approximations. The proposed method is tested on a fictitious UPHES system using an existing underground quarry as lower reservoir. Results demonstrate that the methodology allows finding a compromise between conservativeness and economic performance, while being computationally efficient. This model may thus be integrated in the daily scheduling routine of UPHES owners, or may help regulators and system operators to better estimate the available flexibility of such resources.

Shallow chalk quarry stability using an original shear strength reduction approach

Unexploited underground quarries may represent a potential hazard for the surrounding urban environment. In this context, this work presents a stability study of quarries in North France. A shear non-uniform non-homogeneous degradation approach is proposed for the stability study. The presence of joints in the chalk continuum is considered by using an anisotropic plasticity model accounting for the accumulation of permanent strains along these joints. Stability analysis using proposed degradation approach is performed and compared with the conventional shear strength reduction approach. The comparison shows that the proposed degradation approach might be an alternative to conventional shear strength reduction approach.

Aggregate supply in Hong Kong: past, present and looking to the future

Hong Kong is one of the most densely developed and populated places on the planet, with a population density of just under 7000 people per km 2 and over 300 buildings with heights greater than 150 m, more than 90% of which used concrete as their main structural material. The nature and scale of this development means that aggregates from local hard rock quarries have formed an essential construction material for the development of the territory. However, the small area of Hong Kong (1104 km 2 ), its lack of readily developable land and increasing public concern on the impact of quarrying have led to the rehabilitation and closure of most local quarry sites over the last 20 years. The decline in local aggregate supply caused by this has resulted in an increasing reliance on aggregate imported from elsewhere, with associated implications in terms of supply, cost and quality control. Quarry closure has also reduced Hong Kong's readiness to process and reuse good-quality rock generated by construction projects. To combat these issues, a detailed review of the short- and long-term aggregate supply strategies for Hong Kong was conducted, including a territory-wide search for potential new quarry sites together with assessments of the feasibility of integrating other aggregate sources in the supply chain such as underground quarrying and the use of recycled aggregate.

Multitemporal Terrestrial Laser Scanning for Marble Extraction Assessment in an Underground Quarry of the Apuan Alps (Italy).

This article focuses on the use of Terrestrial Laser Scanning (TLS) for change detection analysis of multitemporal point clouds datasets. Two topographic surveys were carried out during the years 2016 and 2017 in an underground marble quarry of the Apuan Alps (Italy) combining TLS with Global Navigation Satellite System (GNSS) and Total Station (TS) studies. Multitemporal 3D point clouds were processed and compared with the aim of identifying areas subjected to significant material extraction. Point clouds representing changed areas were converted into triangular meshes in order to compute the volume of extracted material over one year of quarrying activities. General purpose of this work is to show a valid method to examine the morphological changes due to raw material extraction with the focus of highlighting benefits, accuracies and drawbacks. The purpose of the executed survey was that of supporting the planning of quarrying activities in respect of regional rules, safety and commercial reasons.

Underground quarries in the area of Agiades, Samos Island, Greece: Notes on historical topography and chronology

This paper shows the need for cataloguing and comparing tool marks left on the quarries’ front in order for the chronological sequence of the different phases of limestone exposed in underground quarries at Agiades, Chora Samos, to be assessed. Up to now, an archaic and a roman phase of exploitation is inferred by surface pottery, tools, tool marks, the monuments themselves, and parallels from underground quarries on the island of Crete. The proximity of the quarries to a temenos of Apollo and the Nymphs is comparable to other cases from the Greek world. In an attempt to understand the social status of the quarrymen and their level of literacy, data from the graffiti observed in Eupalinos’ tunnel were correlated with the lack of patronym and ethnonym observed in quarries in the Aegean, and related to the characterization of the Samians as «πολυγράμματοι». A control of Hera’s sanctuary over the quarries at Agiades is implied by the frequent appearance of the letters HP on slabs used in Eupalinos’ tunnel.

Water, nitrate and atrazine transfer through the unsaturated zone of the Chalk aquifer in northern France

The water quality of the Chalk aquifer is degrading due to fertilizers and pesticides use which are classified as toxic to public health. The study aims to provide a better understanding of the transfer processes in the unsaturated zone of the Chalk aquifer using different environmental tracers (nitrate, atrazine and tritium). The study was conducted in an underground quarry in northern France (St. Martin le Noeud). The quarry provides direct access to the lower part of the unsaturated zone of the Chalk at a depth of 18–30 m. Fifteen sites throughout the quarry display percolation directly from the unsaturated zone. Since percolation intensity is heterogeneous at one site, a comparison was made between the variation of geochemical properties of ten samples from one site and the spatial variation of samples from 15 sites throughout the quarry. Using the Siegel-Tukey and Wilcoxon tests, we found that the variation between the sites is higher than the variation within one site. Therefore, one percolation sample can be used to represent one site. The transfer time of nitrate and atrazine is estimated based on its use in the cultivated fields. Pore water with no contamination indicates water infiltrated before the use of contaminants at the surface, and pore water with a high concentration of contaminants indicates water infiltrated during the use of contaminants at the surface. The transfer time of water molecules is estimated using the time series of tritium. Transfer velocities were computed for each environmental tracer (nitrate, atrazine and tritium) by dividing the estimated transfer time by the depth of each site. Two transfer velocity ranges are determined: (1) <0.32 ± 0.02 m/year and (2) between 0.72 ± 0.14 and 2.15 ± 0.43 m/year, showing most water transfer through the matrix but also a mixture of water with different velocities.

3D modelling of the ancient underground quarries of the famous Parian marble in the Aegean Sea, Greece and assessment of their stability using LiDAR scanning

Laser scanning has proven useful in the stability assessment of underground openings. High accuracy points are used to generate 3D surface models to evaluate their stability by assessing rockmass structural features. A series of scans obtained from underground ancient quarries in Paros Island were processed. The structural analysis of the openings was complemented by field observations and measurements, serving as input parameters for numerical software used to evaluate the potential failure mechanisms and overall stability. Blocks with a higher risk of detaching are encountered mostly at tunnel portals where support is required to secure unstable blocks to preserve this geotope.

Research on the relationship between Wenling traditional dwellings-slabstone cottages and Changyudongtian quarries, China

ABSTRACTIn this article, a type of traditional dwelling referred to as Wenling slabstone cottages, which are found in Aoli Village, Wenling City, Zhejiang Province, China is discussed. Stones are used as the main building materials of these dwellings, while they have seven characteristics that distinguish them from other traditional stone cottages. It was also determined in this article that the location of the Wenling slabstone cottages with distinct characteristics in Aoli Village was adjacent to the large ancient underground quarries of Changyudongtian. Moreover, it was confirmed that the latter provided important high-quality stone materials at low prices for the construction of the Wenling slabstone cottages. It was also pointed out in this article that with the rapid development of modern construction, the unreported Wenling slabstone cottages are gradually disappearing. Therefore, it is very important to carry out the exploration, research, and protection of these cottages in a timely manner.

Natural and anthropogenic cavities and sinkholes in Rome metropolitan area: from geological and speleological research to land management

Since XVIII century, Rome and its metropolitan area represented a natural laboratory for the development of geological studies in urbanized areas. The peculiar geological framework of the Eternal City and of the surrounding municipalities depends on the tectono-sedimentary evolution of the Tyrrhenian margin of Central Apennines, strongly affected by volcanism during Quaternary. Moreover, three millenniums of human activity induced permanent bioturbation of the natural environment in the Roman area, thus creating a unique scenario attracting the interest of naturalists, geologists and archaeologists in the last three centuries. Systematic studies of the town territory and of its underground have been progressively carried out over time, both for technical and scientific purposes, aimed to describe Rome's geological setting and thus to provide a useful tool for sustainable landuse planning and management and for urban development.Starting from early works on karst caves performed by geologists, speleology increasingly developed in Rome, since the institution of the first organized group in 1904. Along this path, an overlapping between geological research and speleological exploration often occurred especially after WW2, being the members of the group mostly recruited among University students. It was the age of geological renaissance in Italy; youth was encouraged to Earth sciences studies because of possible career opportunities in hydrocarbon research field.At the same time local administrations, firstly the Province of Rome, started to consider mapping of underground cavities network essential for land management and planning. In these terms, attention for anthropogenic cavities and for previous archaeological and historical studies on Rome catacombs and underground quarries renewed, being the issue of sudden collapses in urban and suburban areas detected as a serious hazard. For these reasons, local institutions supported and promoted systematic studies on the underground of Rome and of its province.In such a context, Ugo Ventriglia was surely the pioneer of this approach to urban geology in Rome's natural laboratory. On the other hand, Renato Funiciello, working on the same topic with differentmethods, paid as well attention to underground voids in the studies about Rome he coordinated through years. Consequently, Ugo and Renato, in their geological race for the Seven Hills during the last three decades of the XX century, metaphorically crossed each other also in the underground of Rome. The scientific competition led both scientists, following different approaches and independent paths, to improve the geological knowledge of the Eternal City, leaving a precious legacy to present and future generations and guiding subsequent studies. Nowadays land planning and management of Rome metropolitan area lay thus on this solid foundation.