Underground Quarries Research Articles

Subsidence hazards connected to quarrying activities in a karst area: the case of the Moncalvo sinkhole event (Piedmont, NW Italy)

Gypsum is an important raw material for constructions and other industrial sectors. In Piedmont (NW Italy), main gypsum bodies are located in the Monferrato area, where large open pits and underground quarries are present. The gypsum- bearing formation outcropping in this area shows typical geological, structural, and hydrogeological features, which affect the quarrying and the related interaction with natural phenomena, human activities, and land use. In particular, gypsum karst has considerable influence on mining operations, as well as mining operations can produce strong impact on gypsum karst. In Monferrato, a specific case of interaction between the quarrying activity and geological, hydrogeological, and territorial setting is represented by the event of water inrush that happened in the Moncalvo underground quarry in association with the development of a surface sinkhole phenomenon.

A ‘verlan’ scribe in Deir el-Bersha: some Demotic inscriptions on quarry ceilings

Three fourth century bc Demotic inscriptions on the ceiling of underground limestone quarries in Deir el-Bersha turn out to be written from left to right with reversed signs. The only parallel for these Demotic reversals is another inscription on a quarry ceiling not far from Ptolemaïs, where parts are also written in mirror script.

Sinkhole formation above underground limestone quarries: A case study in South Limburg (Belgium)

Historical records were used for the compilation of a database of sinkholes resulted from collapses of abandoned shallow underground limestone quarries (mines) in two villages in Belgian South Limburg. During the last 350 years the formation of such sinkholes caused at least 38 casualties, but more often it caused a change in topography and damage to public and private property. The objective of this study is to better understand the spatial and temporal patterns of quarry collapse-related sinkholes in the study area. Apart from sinkhole locations and ages, the compiled database provides information on the dimensions of the area affected and the damage caused by sinkhole formation, as well as the causal factors of sinkholes. One hundred seventy-three sinkholes have been reported since 1665, but most (80%) reported sinkholes postdate 1965. Sinkhole dimensions provided information on the type of collapse. Seven large sinkholes, displacing a total sediment volume of 480,000 m 3, resulted from large-scale roof breakdown after pillar failure. The smaller sinkholes were the result of fall of the overburden into galleries after local roof collapse or suffosion of a solution pipe. In total, these small sinkholes displaced 12,300 m 3 of sediment. At present almost all large underground quarries in the study area have been affected by sinkholes. These features were caused by natural and anthropogenic factors, and occur in zones with thin roofs, where pillars were affected by pillar robbing, or on locations with inappropriate sewerage systems above quarries. The formation of sinkholes was often reported in spring during years with high moisture contents in the overburden, caused by high groundwater recharge or above average precipitation. With increasing time since quarry abandonment, quarries become more susceptible to pillar creep and bending of the roof. Hence, if no appropriate mitigation measures are taken to reduce such deterioration processes, the number of sinkholes is expected to increase.

The rediscovery of an ancient exploitation site of Piperno, a valuable historical stone from the Phlegraean Fields (Italy)

Abstract This paper reports the research results over several years on Piperno, the most important ornamental architectural stone of Naples. Particular attention is paid to the rediscovery of the old exploitation sites of this rock and to the survey of the last underground quarry site, still accessible, at the base of the Camaldoli Hill (western Naples) at Pianura. The conservation state was assessed by means of specific surveys in view of possible futu re utilization. At present, the re-opening of abandoned quarries is not possible owing to unsafe site conditions. The cultural relevance of the Pianura quarry site could suggest its possible restoration as a museum of mining and a centre for teaching the working of ornamental stone within the Campania Region.

A three‐dimensional model of an underground excavation and comparison with in situ measurements

AbstractIn this paper we make the first attempt to construct a three‐dimensional (3D) distinct element model (DEM) of an underground room with a central pillar in Dionysos marble deposit. This model can be employed in the future by the quarrymen to improve the design of the underground quarry. In order to decrease the effort and time of the simulations, the approach followed here is first to upscale intact rock properties to the size of the pillar considering also secondary joints, and next to model explicitly the major joint sets that transect the marble by virtue of a 3D DEM. The estimation of the effective marble properties is based on the concept of ‘damage’ as it is defined in damage mechanics theory, the phenomenon of the size effect of strength of intact rocks and the Rock Mass Rating (RMR) classification. Furthermore, a pre‐processor has been written in C language for the efficient transfer of the large number of successive excavations around the central pillar to the 3D numerical model. Finally, the validity of this first series of numerical simulations, results and inherent assumptions are checked against in situ stress and deformation measurements inside the underground quarry. Copyright © 2006 John Wiley & Sons, Ltd.

Long-term persistence of the spatial organization of temperature fluctuation lifetime in turbulent air avalanches

It has been recently proposed that some natural phenomena, such as sunspot occurrence, can be represented by a modulated Markov jitter, which is a high-frequency Markov signal multiplied by a long-term component. The two parameters of this model can be estimated using a nonlinear method based on absolute derivatives. This analysis is applied here to a different physical system: the temperature time series measured during air avalanches in the vertical access pit of an underground quarry. The thermal fluctuations associated with these turbulent flows, driven by the external temperature forcing, actually appear as another practical realization of a modulated Markov jitter. One parameter of the model provides the lifetime of the temperature fluctuations, which can be estimated as a function of time and position. The obtained lifetime is of the order of 10 to 25 min , and is remarkably constant in time for each sensor, independently of the amplitude of the forcing. Furthermore, a significant and persistent spatial structure is observed, revealing a long-term intrinsic organization of the turbulent air flows in the pit. Such a stable spatial organization may reflect a general feature of turbulent phenomena.

Sizing room and pillar by numerical modeling for underground marble quarries in Turkey

Optimal parameters of room-and-pillar mining have been established by numerical modeling based on in-situ data on topography, geological structure and physico-mechanical properties for three marble quarries in Turkey. Vertical stresses in pillars are estimated and rock stability classification is developed.

Geophysical and Geomechanical Investigations Applied to the Rock Mass Characterisation for Distinct Element Modelling

The paper describes the experience gathered in an underground quarry of crystalline marble where the rock mass structure has been characterised by a joint approach using geomechanical mapping and geophysical investigations with a high resolution radar system. Standard geomechanical surveys have been coupled and integrated by radar acquisition performed on a selected pillar of the quarry to improve the rock mass description. The fracture pattern has been computed on the basis of the deterministic model on the rock faces of the pillar and taking into account both the statistical approach to describe the extent within the rock mass and the fracture pattern described by radar survey.

Non-adiabatic boundaries and thermal stratification in a confined volume

Heating experiments have been performed during 1.5–18 days in a confined room of volume about 300 m 3 in an underground quarry near Paris (France). During heating, a thermal stratification of the atmosphere is observed. After a time depending on the presence or not of ventilation, this stratification reaches a stationary state during which the temperature difference between the rock and the atmosphere is constant. During this stationary phase, both temperatures increase linearly with time. We propose here a new model of filling box with radiative heat exchanges and cooling by direct contact at the boundaries, which accounts for the observed vertical profiles of temperature in the atmosphere, and for the temperature variation with time. Such contributions of heat transfer at the boundaries are important in situations such as fire in confined cavities, presence of visitors in a painted cave, or in the study of building ventilation.

Thermal stratification induced by heating in a non-adiabatic context

Thermal stratification associated with thermal plumes in semi-confined and confined non-adiabatic environments has been investigated using heating experiments performed in the atmosphere of an underground quarry. A 100 W source is used during 24 h, followed by 6 days of recovery. Vertical and horizontal profiles of temperature are recorded in the atmosphere, supplemented by a vertical profile at the wall. During a heating, an equilibrium stratification is observed in the atmosphere, compatible with a filling box mechanism modified by heat exchanges with the boundaries. At the wall, an initial cooling is observed, indicating the importance of phase changes of water in the energy budget. Such experiments should improve our understanding of the effect of turbulent plumes in air, which is relevant for proper ventilation and heating of buildings, and more generally, engineering, cultural and environmental applications.

High-characterization of Vadose Zone Dynamics in Limestone Underground Quarries by Time Domain Reflectometry

The aim of this paper is to study the vadose zone dynamics during a hydrological cycle. The application of the Time Domain Reflectometry (TDR) method to determine the water content of porous rock has been widely investigated. More than 657 point measurements of rock water content observed during a hydrological cycle and distributed among three abandoned underground quarries in Gironde, France show a permanently undersaturated limestone. Two periods of maximum water content correspond to two occurring effective precipitations. The dephasing and amplitude attenuation of the hydraulic wave with the depth can be modelled and explained by the physical properties of the porous medium. Maps of the spatial distribution of water content show the heterogeneity of water flow in a vadose zone.

THE MILLSTONES OF PETROTA THRACE COUNTY, GREECE

The surrounding area of Petrota village - Rhodopi County, West Thrace - consists , mainly, of volcanic rocks (rhyolites, rhyodacites, tuffs, volcanic breccias and lahars). In the pyroclastic formations a quarry for millstones has been developed. Engraved or halfcarved handmills, larger millstones, tubs and cisterns can be seen and they are witnesses of the art and skill of the stone cutters. Larger millstones which needed animal or water power to be rotate were also carved. Some of them are abandoned on the floor of the quarry or lay lower near the river bank. On the quarry walls can be seen all the stages of carving and cuttering the millstones : a drawing circle - the first stage, close to it the beginning of the carving and nearby the fully carved but still uncuttered millstones. Amazing is also the underground quarrying and carving the millostones. Having in mind the size of the walls, the underground excavation and the bulk of dums we can roughly estimate the number of carved millstones which probably reaches several thousands of millstones of different sizes. The beginning of quarrying and carving of millstones of Petrota is not known but surely it could be traced back to the depth of the ages, not excluding the prehistoric period. The activity of the quarry ended a little before the II World War. A similar quarry in almost the same rock is located near the Petrota village of Evros County.

Radon-222 signatures of natural ventilation regimes in an underground quarry

Radon-222 activity concentration has been monitored since 1999 in an underground limestone quarry located in Vincennes, near Paris, France. It is homogeneous in summer, with an average value of 1700 Bq m −3, and varies from 730 to 1450 Bq m −3 in winter, indicating natural ventilation with a rate ranging from 0.5 to 2.4×10 −6 s −1 (0.04–0.22 day −1). This hypothesis is supported by measurements in the vertical access pit where, in winter, a turbulent air current produces a stable radon profile, smoothly decreasing from 700 Bq m −3 at 20 m depth to 300 Bq m −3 at surface. In summer, a thermal stratification is maintained in the pit, but the radon-222 concentration jumps repeatedly between 100 and 2000 Bq m −3. These jumps are due to atmospheric pressure pumping, which induces ventilation in the quarry at a rate of about 0.1×10 −6 s −1 (0.009 day −1). Radon-222 monitoring thus provides a dynamical characterisation of ventilation regimes, which is important for the assessment of the long-term evolution of underground systems.

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Abstract Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ 1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).

Geophysical investigation to optimize excavation of an underground marble quarry in Stazzema, Italy

A major consideration in planning underground excavation of marble is optimization of the rock extraction ratio—the ratio between the volume of the excavated void and the volume of the residual rock left in place as a supporting structure (pillars, long pillars, etc.).

Long-term thermal evolution and effect of low power heating in an underground quarry

Abstract Vertical profiles of temperature have been monitored in the atmosphere of an underground quarry since June 2001. A long-term temperature increase of the order of 0.1 °C per year is observed. Three heating experiments with 100-W sources, performed to study plume dynamics, can also be used to investigate the effect of visits on this increase. Ten days after the 24-h heatings, the initial state is not restored. Artificial contributions to the observed long-term temperature trend, triggered by internal heat release, thus cannot be ruled out. This experiment defines strict criteria for the underground monitoring of global warming or the preservation of painted caves. To cite this article: C. Crouzeix et al., C. R. Geoscience 335 (2003).

Dynamics of air avalanches in the access pit of an underground quarry.

Temperature measurements have been performed in the vertical access pit of an underground quarry. During autumn, air avalanches induce an initial thermal feedback and a stationary mixing state characterized by spatially coherent broad-band fluctuations with a standard deviation of about 0.2 degrees C, linearly increasing with the inside-minus-outside temperature difference. Phase changes of water are shown to contribute to the onset condition, the feedback, and the stationary mixing state. This experiment may give insight on turbulent thermal and compositional convection with nonadiabatic boundaries.

Analyse quantitative de l'hétérogénéité de la fracturation : application aux carrières souterraines

Abstract The quantitative analysis of fracturation heterogeneity from Geographic Information System (GIS) has become very important for the modelling of underground quarries stability, the reservoir properties deduced from fracturing and their consequences on the groundwater run-off. This paper aims to give a method of quantitative analysis of fracturing in three underground limestone quarries of Gironde. More than 1000 fractures were measured, mapped and numbered. The heterogeneity analysis and the fracturing connectivity are based on the spatial distribution of geometrical parameters of each fracture, such as: openness, length, direction, orientation, spatial distribution of different fracture classes and connexity. To cite this article: A. Cerepi, C. R. Geoscience 334 (2002) 163–170.

Le karst et les carrières souterraines du Barrois : un siècle et demi de relations Hommes/Milieu

The karst and the underground quarries of Barrois : 150 years of relationship Human/Nature. The exploitation of the " Pierre de Savonnières " in Barrois area (Lorraine/Champagne) was made during the last 150 years by underground quarries. The development of these quarries is estimated between 300 and 350 km today. During this exploitation the cutting of a paleokarst ("viailles") and an active karst (pits), disturb the exploitation obliging the quarrymen to fill or to avoid the karst. Karstic water added a supplementary constraint but gived a good contribution for the exploitation of the quarry. In the final, karst and waters are for the quarry a minor set of constraints and potentialities, which structure a spatial organization of this anthropological underground space. Quarry, karst, geology, fauna... constitute an unique underground patrimony in Lorraine which would deserve interest and adapted protection.

Pressure induced temperature variations in an underground quarry

Temperature measurements have been performed in the rock and atmosphere of an underground limestone quarry in Vincennes, France. In the atmosphere, temperature variations associated with variations of the atmospheric pressure are continuously observed, with an average coupling of 70 m°C/hPa at a period of 4 min, 35 m°C/hPa at 1 h, and 3 m°C/hPa at 1 day, and an increasing phase advance for increasing period. At the highest frequencies, the coupling is close to its adiabatic value of 80 m°C/hPa. The reduction of coupling with decreasing frequency is interpreted as diabatic thermal stabilisation of the atmosphere by heat flow and coupled feedback due to phase changes of water. During extreme events, such as the tempests that occurred in France in December 1999, additional effects were observed in the atmosphere and in the rock material as well. Pressure induced temperature variations may be important to study in underground monitoring experiments, and may be a useful tool for the characterisation of nuclear waste storage sites.