Quarrying of ornamental stone has adverse effects that are both visual and environmental. This paper aims to develop a methodology for minimising the costs associated with reducing the visual impact of ornamental ston...Quarrying of ornamental stone has adverse effects that are both visual and environmental. This paper aims to develop a methodology for minimising the costs associated with reducing the visual impact of ornamental stone quarrying. This study uses digital topographical maps of the study zone and a GPS and GIS application to calculate the extent of the area affected by quarrying activities for each altitude designated in the work plan and to calculate the extent of the potential visual impact. The results obtained applying the proposed methodology for the selected area suggested that the potential visual impact is minimal for an altitude of 520 metres, this being the optimal point for the observer. When altitude increases, the potential visual impact increases and the optimal point for the observer diminishes until the highest impact altitude (740 m) is readied. The optimal point that the exploitation should reach is that at which the values of the diagram generated by the (%) area of potential visual impact and area of exploitation (%) intersect. The methodology allows the optimal altitude to be determined for mining exploitations and helps assess the viability of a given exploitation from an environmental point of view.展开更多
The unquenchable demand for rock materials has attracted many companies within the building and construction sector to invest in stone quarrying. However, this has brought about environmental impacts with health threa...The unquenchable demand for rock materials has attracted many companies within the building and construction sector to invest in stone quarrying. However, this has brought about environmental impacts with health threats to people. There is a paucity of information about the magnitude of pollution on air and water and how it varies with quarry sites. This study, therefore, investigated the physical impacts of quarrying on air and water and explored the in-situ mitigations to undesirable effects due to stone quarrying. Four active quarry sites were identified. Field measurements of dust (particulate matter) were conducted within the four quarry sites and in the nearby community. Water samples were collected from quarry pits and nearby shallow wells for laboratory analysis of water quality. Statistical Analysis of Variance (ANOVA) was used to test for differences in pollution across the four studied sites. Results revealed that, amidst the use of wet crushing and water sprinkling on bare surfaces, dust emission was higher than the recommended permissible standards levels with a significant variation across the quarry sites with ANOVA (P-value = 0.003) for PM 2.5 and (P-value = 0.04366) for PM 10. Water pollution was mainly contributed by the non-permissive levels of nitrates, chromium, and pH. Polluted air and water are associated with sparking off health threats to the users in the community. In conclusion, quarry companies should strengthen the already existing mitigation of dust suppression. The study recommends additional measures such as treating quarry pit water before discharging to the open environment to enhance environmental protection against the accumulating undesirable quarry impacts.展开更多
Long-term stability of large-span caverns is a challenging issue for design and construction of underground rock engineering.The Heidong cavern group consisting of 21 caverns was constructed about 1400 years ago for q...Long-term stability of large-span caverns is a challenging issue for design and construction of underground rock engineering.The Heidong cavern group consisting of 21 caverns was constructed about 1400 years ago for quarrying in massive Cretaceous tuff.The cavern No.5 of the Heidong cavern group is characterized by an unsupported span up to 92 m,with the overburden thickness of only 3-25 m.To analyze its long-term stability,a detailed investigation was conducted to obtain its geometry and rock mass characteristics,and to monitor surrounding rock displacements.Based on field survey and laboratory tests,numerical simulations were performed using the finite difference code FLAC;.The analysis results revealed that for the long-term stability of the cavern No.5,some major factors should be carefully considered,such as cavern excavation method in hard massive rocks,site investigation using trial pits,tools like short iron chisel and hammer for manual excavation,geometric dome roof,and waste rocks within abutment or on the floor.The highlights of the technologies obtained from this large-scale ancient underground project can provide reference for other similar project excavations in practice.展开更多
The El Pintado 1 Silurian section in Seville Province,Spain,described by Loydell et al.(2015),has been ratified by the IUGS as the replacement GSSP for the base of the Telychian Stage,to replace the Cefn Cerig quarry ...The El Pintado 1 Silurian section in Seville Province,Spain,described by Loydell et al.(2015),has been ratified by the IUGS as the replacement GSSP for the base of the Telychian Stage,to replace the Cefn Cerig quarry section in the Llandovery area of Wales,which was found to be within a sedimentary mélange and therefore not a continuous section.No section other than El Pintado 1 has been found to be continuously fossiliferous across the Aeronian/Telychian boundary.展开更多
This paper presents the relics of rock joints caulked with lead strips, unearthed by the authors in 2007 and 2008. The relics were in ancient quarry caverns in Shepan Island, Zhejiang Province, eastern China. The quar...This paper presents the relics of rock joints caulked with lead strips, unearthed by the authors in 2007 and 2008. The relics were in ancient quarry caverns in Shepan Island, Zhejiang Province, eastern China. The quarry activities were mainly carried out for production of regular tuff stone plates about 800 years ago. Each of the lead strips was sealed into a rock joint by punching manually and carefully. At present, the lead strips still contact tightly with the rock joints and new mineral cerussite is found to have formed at the contact surfaces between the lead strip and its caulked rock joint. The use of lead strips caulking rock joints in quarry caverns is found for prevention of water from seeping out of the country rocks into quarry cavern bases, where all of the in-situ intact tuff rock was manually and near-horizontally split into thin rock sheets one by one for production of regular tuff plates. Furthermore, it is found that the tensile splitting of tuff sheets at the cavern base required the intact rocks at the cavern base had to be dry. Through this horizontal base splitting for tuff sheets from the top to the bottom, a dome-shape interior space was formed for each rock cavern with the near horizontal imprints of thin sheet layers permanently on the sidewalls.展开更多
The competition between coral and algae in marine reefs is pervasive through geologic time;that competition determines the structure and composition of reef communities, which we see in the fossil record. However, the...The competition between coral and algae in marine reefs is pervasive through geologic time;that competition determines the structure and composition of reef communities, which we see in the fossil record. However, the relationships between coral and calcareous algae in reefs are poorly understood. To study this relationship, several hand samples and thin sections were examined from nine different foralgal reef localities around the world. Foralgal reefs typically extend from about 20 m depth or shallower on the seaward side of the reef. The first section is Salt Mountain, Alabama, which preserves a Paleocene reef. It contains a high percentage of red coralline algae with benthic foraminifera. The second section is IDOP-U1376, IIA Limestone, it is Middle Eocene, in the form of an isolated reef sandwiched between two igneous beds. The third section is the Utoe’ Limestone, New Caledonia, it is Middle Eocene in age and is composed mainly of grain-boundstone units with some igneous interlayered. The fourth section is the Darnah Formation in the West-Darnah roadcut section, Northeast Libya, it is Middle Eocene in age, it is composed of highly fossiliferous limestone (corals, red coralline algae, echinoids, mollusks, foraminifers, and bryozoans). The fifth section, the Al Bayda Formation (Algal Limestone Member) in Northeast Libya, is in the Drayanah—Al Abyar roadcut, Northeast Libya, it has several species of algae but also includes a high percentage of buildups of coral species. The sixth section is the Oligo-Miocene Al Faidiyah Formation (Al Fatayah Cement Quarry) limestone unit in Northeast Libya. The seventh section is (Core-core 20) late-early to middle Miocene Limestone Unit-Cicuco Field, NW Colombia. The eighth section is the Benghazi Formation at Benghazi Cement Quarry, in Northeast Libya, it is fossiliferous limestone, consisting of coral, algae, mollusks, and echinoids. The ninth and tenth sections are Quaternary reefs in the Bahamas and the Florida Keys, respectively. These reefs contain a high percentage of coral, red coralline algae, echinoids, mollusks, foraminifers, and ostracods. Based on the data and static analysis results on the thin sections and hand specimens, this study determines the occurrence and outcomes of coral-algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary). The Early Paleogene (Paleocene to Eocene) has the highest percentage of algae in two forms (crustose and frondose), which is a good indicator of a warm climate. In the Middle Eocene to Late Eocene, coral replaced algae in different localities in sections of that age. This change is an indicator of climatic cooling, especially in the western Lutetian Darnah section. In the Oligocene time, high-branching corals became abundant and escaped competition with the algae due to Icehouse conditions, as shown in the Al Bayda Formation. In the Miocene, coral species started to decline because of the return to Greenhouse conditions. Coral can lose its competitive edge when chemical and physical defense systems reduce growth and production due to warming. On the other hand, crustose-form algae attract the larvae of the coral. Algae induce them to get a more highly competitive frondose form, which is useful for corals as they decrease growth and production. Algae can quickly colonize the dead reef by using the firm substrate to rebuild themselves. This research may prove valuable when predicting the response of modern coral reef systems to future climatic warming conditions and provides a model for what future reefs may look like.展开更多
The exploitation of groundwater by drilling in the Mitendi South-East district constitutes a solution to the water shortage in this peripheral part of the Mont-Ngafula township in Kinshasa, the capital of the DR Congo...The exploitation of groundwater by drilling in the Mitendi South-East district constitutes a solution to the water shortage in this peripheral part of the Mont-Ngafula township in Kinshasa, the capital of the DR Congo. Individuals exploit groundwater in boreholes to serve the population without taking into account certain necessary aspects such as the origin of the groundwater table and the quality which constitute the major problems of this work such as: What is the quantity of water from the recharge of our aquifer? What is the state of the Mitendi South-East aquifer water in relation to some physico-chemical parameters? The cardinal objective of this work is to provide chemical data and trace elements in each analyzed borehole and determine the type of recharge of the underground aquifer. The specific objectives are as follows: analyze the potability of groundwater on a physico-chemical level and their chemical facies, take the geographical coordinates of water samples from the aquifer in each targeted borehole in order to develop the sampling map of the area under study;also check each parameter analyzed in relation to WHO standards. We carried out a general investigation of the study area by carrying out observations, sampling and in-situ measurements of each borehole, as well as the good conservation of the samples taken in a cooler. The various measurements that we took in-situ: pH, electrical conductivity, turbidity, salinity, temperature, and TDS were carried out by using a multi-parameter probe in the laboratory of appropriate methods such as titled-sorting, spectrophotometry, atomic absorption spectrometry, ArcGise and Excel software. With regard to the results from laboratory analysis (physical and chemical analysis), the parameters showed that the standards recommended by the WHO were not respected. We affirm that the water consumed in the Mitendi South-East district in Mont-Ngafula town ship is not drinkable. Since, it can cause several water-borne diseases. It would be better to treat that water before being drunk. .展开更多
The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type...The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type of activity in an urban environment. The approach method consisted of carrying out surveys combined with field observations and interviews with the various stakeholders as well as the local population. The results obtained made it possible to identify both positive and negative impacts. The positive impacts are above all the advantages derived from these aggregate quarries, in particular, the creation of direct and permanent jobs and the increase in community income. The price of piling up a truck costs around 28,000 CFA ($56 CAN) and that of loading is around 10,000 F CFA ($20 CAN). This has the effect of removing young people (20 - 39 years old) from the circuit of migration outside the region and even the country. The possibility of using the extraction sites by the local population was identified, in terms of profits relating to fish farming, off-season crops, animal drinking and reclaimed plots. The study also noted negative externalities, such as the temptation of young boys to become involved in extractive activities for immediate gains at the expense of school attendance. Added to this is the upheaval in the topography of the urban landscape, pollution and nuisances (noise, visual and olfactory), while the disappearance or clogging of quarry ponds is the cause of frequent flooding in the neighborhoods. In short, corrective measures (e.g. the revegetation of sites) certainly make it possible to minimize the harmful impacts on the urban environment. But, to improve the performance and organizational capacity of the quarrying industry in Niger, even stronger regulation, training and awareness of stakeholders prove to be the necessary measures.展开更多
Long-term stability of large span caverns is earnest but poorly understood in preservation of cultural relics.The life span of huge caverns is difficult to extrapolate from short period of monitoring or laboratory tes...Long-term stability of large span caverns is earnest but poorly understood in preservation of cultural relics.The life span of huge caverns is difficult to extrapolate from short period of monitoring or laboratory testing.A huge ancient quarry with 21 caverns whose original status is well kept over 1400 years was found in Tiantai County of South China.One of the caverns has an 81 m span which is far beyond the 50 m expectation on current knowledge.The tension at the core of long stability is the excavation speed versus deliberation.Here we show a unique technique of Digging Holes for Quarrying Vertical Flagstone(DQF)invented by ancestors to ensure the safety,which is much smarter compared to blasting and casting technique that commonly used after the Industrial Revolution.展开更多
Workers carrying out actions involving potential hazards,like mining and quarrying,can be subject to health issues derived from those activities.The case of asbestosis has generated an alarm in the society.Natural sto...Workers carrying out actions involving potential hazards,like mining and quarrying,can be subject to health issues derived from those activities.The case of asbestosis has generated an alarm in the society.Natural stones are very different from each other and generalisation can cause,first an unwanted alarm,and secondly a big economic crisis in the sector of the natural stone,as it has happened before with other health issues related to exploitation and use of natural stone in architecture.This paper highlights the need for an appropriate mineralogical characterization of rocks of economic interest,such as serpentinites,to protect mining workers of health issues derived from fibrous minerals content.We have studied the possible presence of fibrous minerals in samples of serpentinites from an abandoned quarry in Galicia(North Western Spain)to consider the viability of its re-opening based on the Spanish health and safety regulations applicable to jobs at risk of exposure to asbestos.From our study,it can be concluded that there is a scarce amount of fibrous phases,pending on further studies to differentiate such fibrous minerals,and therefore the reopening of the serpentinite quarry should not be a health problem for the workers.展开更多
Through the study on landscape reconstruction of abandoned quarry pits in mountainous area of Jiangzhe District, it was pointed out that it was of not only practical significance but also ecological significance of su...Through the study on landscape reconstruction of abandoned quarry pits in mountainous area of Jiangzhe District, it was pointed out that it was of not only practical significance but also ecological significance of sustainable development to some extent, to scientifically and rationally rebuild and exploit abandoned quarry pits and to create new landscape, so that their landscape value and environmental benefit would entirely improve and that culture would be inherited and developed by making use of overt cultural fragments.展开更多
The Valmalenco area(central Alps,northern Italy)is well-known for the widespread mining and quarrying activities.Serpentinites are extracted and processed as valuable dimension stone in open-cast quarries,and a big un...The Valmalenco area(central Alps,northern Italy)is well-known for the widespread mining and quarrying activities.Serpentinites are extracted and processed as valuable dimension stone in open-cast quarries,and a big underground mine provides talc as industrial mineral.The presence of long-fiber chrysotile veins,especially in the eastern part of the valley,gave rise in the past to widespread mining activity,particularly between the end of the XIX century and 1975,leaving huge amounts of mining waste and tailings.In recent times,part of the tailings have been stabilized and reclaimed,covered with soil and planted.Extensive sampling of mine tailings,soils and alluvial sediments was performed,to detect asbestos contamination(XRPD,SEMEDS,TEM).Airborne asbestos was measured by environmental monitoring on polycarbonate filters(SEM and TEM),at the abandoned mines and at the closest centers.Huge amounts of chrysotile are still present in mine tailings(up to 20 wt.%),whereas soils and sediments were mostly below the 1000 ppm threshold;chrysotile is widespread almost in every part of the valley.Small amounts(<400 ppm)of asbestiform tremolite were detected.Airborne asbestos was below the PEL of 2ff/l for living environments,with some peaks at mine dumps and close to active serpentine quarries.This preliminary study provides useful tips and effective technical measures for risk reduction in the extractive context.展开更多
Lede Stone is an important dimension stone with major relevance for Belgian and Dutch cultural heritage.It is sourced from the Eocene(Lutetian)Lede Formation,mainly in the region to the southeast of Ghent in Belgium.T...Lede Stone is an important dimension stone with major relevance for Belgian and Dutch cultural heritage.It is sourced from the Eocene(Lutetian)Lede Formation,mainly in the region to the southeast of Ghent in Belgium.The oldest known use dates back to Roman times.With the rise of Gothic architecture during the middle ages,the use of Lede Stone increased substantially.Quarries arose at different locations at different times.Today only one active quarry remains,after a period of nonproduction during the 20^(th) century.Current production is mainly used for restoration purposes.A major concern is the use of alien stones as a substitute for Lede Stone in cultural heritage restoration.In the light of the establishment of the“Heritage Stone Task Group”,this paper deals with requirements of its“Terms of Reference”and illustrates the stone’s nature,technical properties,utilization and associated issues.It should contribute to the cultural appreciation and preservation of this stone.展开更多
Information mainly collected decades ago,during and following its quarrying years,is here reviewed for the Jacobsville Sandstone,a well-known red bed sandstone of Neoproterozoic age from Upper Michigan,USA.This format...Information mainly collected decades ago,during and following its quarrying years,is here reviewed for the Jacobsville Sandstone,a well-known red bed sandstone of Neoproterozoic age from Upper Michigan,USA.This formation is here proposed as a suitable“Global Heritage Stone Resource”.The Jacobsville is an excellent example of a heritage stone as it was used extensively all over Eastern North America from 1880 to 1920 in hundreds of prominent buildings in major cities and many small towns,including the famous Waldorf Astoria Hotel in New York City.It was extensively mined from several quarry sites near Jacobsville,Michigan in Michigan’s Keweenaw Peninsula.The location is part of a significant geoheritage location,where native copper has also been mined for thousands of years.展开更多
Alpedrete granite is a monzogranite quarried in the Sierra de Guadarrana(Spanish Central System)foothills in and around Alpedrete,in the province of Madrid,Spain.Used as a building material since the Neolithic,it is o...Alpedrete granite is a monzogranite quarried in the Sierra de Guadarrana(Spanish Central System)foothills in and around Alpedrete,in the province of Madrid,Spain.Used as a building material since the Neolithic,it is one of the most representative of heritage granites of Madrid.Alpedrete and the surrounding region are characterised by a quarrying culture that has been maintained for centuries.The area is strewn with historic quarries,along with the one presently in operation.Traditional stone cutters who produce hand-finished granite ashlars are still to be found,while others use more modern techniques to achieve new types of products.展开更多
A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries...A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China： terrace for crushed materials （terrace）, spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, ferns, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.展开更多
The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing...The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing rock fracture. An empirical model based on hole spacing was developed to determine the pressure of NEEM in the rock fracture process. Primarily, the empirical model was developed by the mathematical method, utilizing dimensional analysis. Then, the Phase2 code, which is based on the finite element method, was utilized to predict crack growth in rocks. The results of numerical analysis show slight deviations from the empirical model. Hence, the polynomial re- gression analysis was used to modify the model. Finally, the modified model shows a good agreement with the results gained from numerical modeling.展开更多
The performance of industrial waste incineration bottom ash in controlled low-strength material （CLSM） was investigated in this paper, as the quarry dust was added. CLSM mixtures were made from the industrial waste ...The performance of industrial waste incineration bottom ash in controlled low-strength material （CLSM） was investigated in this paper, as the quarry dust was added. CLSM mixtures were made from the industrial waste incineration bottom ash, quarry dust, and cement. Tests for fresh density, bleeding, compressive strength, shear strength, hydraulic conductivity, and excavatability were carried out. The com- pressive strength ranges from 60 kPa to 6790 kPa, the friction angle varies from 5°to 19°, and the cohesion is from 4 to 604 kPa. Most of the mixtures are found to be non-excavatable. It is indicated that the quarry dust addition increases the compressive strength and shear parame- ters, decreases bleeding, and increases the removability modulus.展开更多
The management of overburden is an important task in open pit exploitations. Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important f...The management of overburden is an important task in open pit exploitations. Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important factors affecting the disposal phase. Economic and environmental requirements must be followed in order to achieve the best reclamation results, keeping into account site constraints such as slope stability, hauling and dumping issues, and interactions with groundwater. This paper deals with the above mentioned issues, illustrating a rational approach applied on the case of a large limestone quarry where the thickness of the overburden is relevant and the spoil material has to be dumped in a flooded pit. The proposed multidisciplinary approach led to the selection of most suitable methods for excavation, transportation and disposal. The selection was based on a detailed laboratory and site characterisation that defined favorable and adverse factors to be considered during the preliminary study of a large quarrying project.展开更多
Geophysical surveys are frequently applied in mining prospection to detect the presence and volume of ore bodies of different nature.Particularly,in gypsum ore bodies exploitation,electrical resistivity measurements a...Geophysical surveys are frequently applied in mining prospection to detect the presence and volume of ore bodies of different nature.Particularly,in gypsum ore bodies exploitation,electrical resistivity measurements are usually the most used methodology.However,it has been observed that different electrical resistivity values can be obtained depending on geometrical features and composition of gypsum.Indeed,electrical resistivity of gypsum rocks depends on several parameters,such as gypsum purity,nature of secondary minerals,porosity,saturation and interstitial fluid properties.Saturation and hydrogeological setting,in particular,were recognized as the most influencing parameters.Hydrogeological conditions of gypsum rock masses are also very relevant for exploitability,safety conditions and economic feasibility and should be accurately known during the prospection and planning phases of the quarries.In this work,a relationship between electrical resistivity and saturation degree of gypsum is proposed.The possibility to estimate gypsum porosity with the use of this relationship is also investigated.The reliability of laboratory measurements is finally verified in comparison with field and modelled resistivity data.The reported results underline the potentiality of the proposed approach to obtain a reliable characterization of the studied ore body.展开更多
文摘Quarrying of ornamental stone has adverse effects that are both visual and environmental. This paper aims to develop a methodology for minimising the costs associated with reducing the visual impact of ornamental stone quarrying. This study uses digital topographical maps of the study zone and a GPS and GIS application to calculate the extent of the area affected by quarrying activities for each altitude designated in the work plan and to calculate the extent of the potential visual impact. The results obtained applying the proposed methodology for the selected area suggested that the potential visual impact is minimal for an altitude of 520 metres, this being the optimal point for the observer. When altitude increases, the potential visual impact increases and the optimal point for the observer diminishes until the highest impact altitude (740 m) is readied. The optimal point that the exploitation should reach is that at which the values of the diagram generated by the (%) area of potential visual impact and area of exploitation (%) intersect. The methodology allows the optimal altitude to be determined for mining exploitations and helps assess the viability of a given exploitation from an environmental point of view.
文摘The unquenchable demand for rock materials has attracted many companies within the building and construction sector to invest in stone quarrying. However, this has brought about environmental impacts with health threats to people. There is a paucity of information about the magnitude of pollution on air and water and how it varies with quarry sites. This study, therefore, investigated the physical impacts of quarrying on air and water and explored the in-situ mitigations to undesirable effects due to stone quarrying. Four active quarry sites were identified. Field measurements of dust (particulate matter) were conducted within the four quarry sites and in the nearby community. Water samples were collected from quarry pits and nearby shallow wells for laboratory analysis of water quality. Statistical Analysis of Variance (ANOVA) was used to test for differences in pollution across the four studied sites. Results revealed that, amidst the use of wet crushing and water sprinkling on bare surfaces, dust emission was higher than the recommended permissible standards levels with a significant variation across the quarry sites with ANOVA (P-value = 0.003) for PM 2.5 and (P-value = 0.04366) for PM 10. Water pollution was mainly contributed by the non-permissive levels of nitrates, chromium, and pH. Polluted air and water are associated with sparking off health threats to the users in the community. In conclusion, quarry companies should strengthen the already existing mitigation of dust suppression. The study recommends additional measures such as treating quarry pit water before discharging to the open environment to enhance environmental protection against the accumulating undesirable quarry impacts.
基金financial support by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology(Grant No.SKLGP2011K007)the Key Research Program of the Chinese Academy of Sciences(KZZD-EW05-02)the National Natural Science Foundation of China (Nos.41372324,40972198 and 41172269)
文摘Long-term stability of large-span caverns is a challenging issue for design and construction of underground rock engineering.The Heidong cavern group consisting of 21 caverns was constructed about 1400 years ago for quarrying in massive Cretaceous tuff.The cavern No.5 of the Heidong cavern group is characterized by an unsupported span up to 92 m,with the overburden thickness of only 3-25 m.To analyze its long-term stability,a detailed investigation was conducted to obtain its geometry and rock mass characteristics,and to monitor surrounding rock displacements.Based on field survey and laboratory tests,numerical simulations were performed using the finite difference code FLAC;.The analysis results revealed that for the long-term stability of the cavern No.5,some major factors should be carefully considered,such as cavern excavation method in hard massive rocks,site investigation using trial pits,tools like short iron chisel and hammer for manual excavation,geometric dome roof,and waste rocks within abutment or on the floor.The highlights of the technologies obtained from this large-scale ancient underground project can provide reference for other similar project excavations in practice.
基金funded by project PDI2021-125585NB-I00 of the Spanish Ministry of Science,Innovation and Universities‒Agencia Estatal de Investigacion.JF thanks the Grant Agency of the Czech Republic for support of his study(GA23-06198S).
文摘The El Pintado 1 Silurian section in Seville Province,Spain,described by Loydell et al.(2015),has been ratified by the IUGS as the replacement GSSP for the base of the Telychian Stage,to replace the Cefn Cerig quarry section in the Llandovery area of Wales,which was found to be within a sedimentary mélange and therefore not a continuous section.No section other than El Pintado 1 has been found to be continuously fossiliferous across the Aeronian/Telychian boundary.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40902088, 40672190)the China Postdoctoral Science Foundation(Grant No. 20110490580)
文摘This paper presents the relics of rock joints caulked with lead strips, unearthed by the authors in 2007 and 2008. The relics were in ancient quarry caverns in Shepan Island, Zhejiang Province, eastern China. The quarry activities were mainly carried out for production of regular tuff stone plates about 800 years ago. Each of the lead strips was sealed into a rock joint by punching manually and carefully. At present, the lead strips still contact tightly with the rock joints and new mineral cerussite is found to have formed at the contact surfaces between the lead strip and its caulked rock joint. The use of lead strips caulking rock joints in quarry caverns is found for prevention of water from seeping out of the country rocks into quarry cavern bases, where all of the in-situ intact tuff rock was manually and near-horizontally split into thin rock sheets one by one for production of regular tuff plates. Furthermore, it is found that the tensile splitting of tuff sheets at the cavern base required the intact rocks at the cavern base had to be dry. Through this horizontal base splitting for tuff sheets from the top to the bottom, a dome-shape interior space was formed for each rock cavern with the near horizontal imprints of thin sheet layers permanently on the sidewalls.
文摘The competition between coral and algae in marine reefs is pervasive through geologic time;that competition determines the structure and composition of reef communities, which we see in the fossil record. However, the relationships between coral and calcareous algae in reefs are poorly understood. To study this relationship, several hand samples and thin sections were examined from nine different foralgal reef localities around the world. Foralgal reefs typically extend from about 20 m depth or shallower on the seaward side of the reef. The first section is Salt Mountain, Alabama, which preserves a Paleocene reef. It contains a high percentage of red coralline algae with benthic foraminifera. The second section is IDOP-U1376, IIA Limestone, it is Middle Eocene, in the form of an isolated reef sandwiched between two igneous beds. The third section is the Utoe’ Limestone, New Caledonia, it is Middle Eocene in age and is composed mainly of grain-boundstone units with some igneous interlayered. The fourth section is the Darnah Formation in the West-Darnah roadcut section, Northeast Libya, it is Middle Eocene in age, it is composed of highly fossiliferous limestone (corals, red coralline algae, echinoids, mollusks, foraminifers, and bryozoans). The fifth section, the Al Bayda Formation (Algal Limestone Member) in Northeast Libya, is in the Drayanah—Al Abyar roadcut, Northeast Libya, it has several species of algae but also includes a high percentage of buildups of coral species. The sixth section is the Oligo-Miocene Al Faidiyah Formation (Al Fatayah Cement Quarry) limestone unit in Northeast Libya. The seventh section is (Core-core 20) late-early to middle Miocene Limestone Unit-Cicuco Field, NW Colombia. The eighth section is the Benghazi Formation at Benghazi Cement Quarry, in Northeast Libya, it is fossiliferous limestone, consisting of coral, algae, mollusks, and echinoids. The ninth and tenth sections are Quaternary reefs in the Bahamas and the Florida Keys, respectively. These reefs contain a high percentage of coral, red coralline algae, echinoids, mollusks, foraminifers, and ostracods. Based on the data and static analysis results on the thin sections and hand specimens, this study determines the occurrence and outcomes of coral-algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary). The Early Paleogene (Paleocene to Eocene) has the highest percentage of algae in two forms (crustose and frondose), which is a good indicator of a warm climate. In the Middle Eocene to Late Eocene, coral replaced algae in different localities in sections of that age. This change is an indicator of climatic cooling, especially in the western Lutetian Darnah section. In the Oligocene time, high-branching corals became abundant and escaped competition with the algae due to Icehouse conditions, as shown in the Al Bayda Formation. In the Miocene, coral species started to decline because of the return to Greenhouse conditions. Coral can lose its competitive edge when chemical and physical defense systems reduce growth and production due to warming. On the other hand, crustose-form algae attract the larvae of the coral. Algae induce them to get a more highly competitive frondose form, which is useful for corals as they decrease growth and production. Algae can quickly colonize the dead reef by using the firm substrate to rebuild themselves. This research may prove valuable when predicting the response of modern coral reef systems to future climatic warming conditions and provides a model for what future reefs may look like.
文摘The exploitation of groundwater by drilling in the Mitendi South-East district constitutes a solution to the water shortage in this peripheral part of the Mont-Ngafula township in Kinshasa, the capital of the DR Congo. Individuals exploit groundwater in boreholes to serve the population without taking into account certain necessary aspects such as the origin of the groundwater table and the quality which constitute the major problems of this work such as: What is the quantity of water from the recharge of our aquifer? What is the state of the Mitendi South-East aquifer water in relation to some physico-chemical parameters? The cardinal objective of this work is to provide chemical data and trace elements in each analyzed borehole and determine the type of recharge of the underground aquifer. The specific objectives are as follows: analyze the potability of groundwater on a physico-chemical level and their chemical facies, take the geographical coordinates of water samples from the aquifer in each targeted borehole in order to develop the sampling map of the area under study;also check each parameter analyzed in relation to WHO standards. We carried out a general investigation of the study area by carrying out observations, sampling and in-situ measurements of each borehole, as well as the good conservation of the samples taken in a cooler. The various measurements that we took in-situ: pH, electrical conductivity, turbidity, salinity, temperature, and TDS were carried out by using a multi-parameter probe in the laboratory of appropriate methods such as titled-sorting, spectrophotometry, atomic absorption spectrometry, ArcGise and Excel software. With regard to the results from laboratory analysis (physical and chemical analysis), the parameters showed that the standards recommended by the WHO were not respected. We affirm that the water consumed in the Mitendi South-East district in Mont-Ngafula town ship is not drinkable. Since, it can cause several water-borne diseases. It would be better to treat that water before being drunk. .
文摘The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type of activity in an urban environment. The approach method consisted of carrying out surveys combined with field observations and interviews with the various stakeholders as well as the local population. The results obtained made it possible to identify both positive and negative impacts. The positive impacts are above all the advantages derived from these aggregate quarries, in particular, the creation of direct and permanent jobs and the increase in community income. The price of piling up a truck costs around 28,000 CFA ($56 CAN) and that of loading is around 10,000 F CFA ($20 CAN). This has the effect of removing young people (20 - 39 years old) from the circuit of migration outside the region and even the country. The possibility of using the extraction sites by the local population was identified, in terms of profits relating to fish farming, off-season crops, animal drinking and reclaimed plots. The study also noted negative externalities, such as the temptation of young boys to become involved in extractive activities for immediate gains at the expense of school attendance. Added to this is the upheaval in the topography of the urban landscape, pollution and nuisances (noise, visual and olfactory), while the disappearance or clogging of quarry ponds is the cause of frequent flooding in the neighborhoods. In short, corrective measures (e.g. the revegetation of sites) certainly make it possible to minimize the harmful impacts on the urban environment. But, to improve the performance and organizational capacity of the quarrying industry in Niger, even stronger regulation, training and awareness of stakeholders prove to be the necessary measures.
基金support by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(SKLGP2011K007)Chengdu University of Technology,the Key Research Program of the Chinese Academy of Sciences(KZZD-EW-05-02)+2 种基金by the National Natural Science Foundation of China(NSFC)(Nos.40972198,41172269)support is also from the Chinese Special Funds for Major State Basic Research Project under Grant No.2010CB732001Help provided by Master Chang Shen,Long Fu of Heidong CiEn Temple,and Mr.He Wantong during field investigations is thankfully acknowledged.
文摘Long-term stability of large span caverns is earnest but poorly understood in preservation of cultural relics.The life span of huge caverns is difficult to extrapolate from short period of monitoring or laboratory testing.A huge ancient quarry with 21 caverns whose original status is well kept over 1400 years was found in Tiantai County of South China.One of the caverns has an 81 m span which is far beyond the 50 m expectation on current knowledge.The tension at the core of long stability is the excavation speed versus deliberation.Here we show a unique technique of Digging Holes for Quarrying Vertical Flagstone(DQF)invented by ancestors to ensure the safety,which is much smarter compared to blasting and casting technique that commonly used after the Industrial Revolution.
基金The University of Salamanca is acknowledged for the funding support to the Research Group CHARROCK.
文摘Workers carrying out actions involving potential hazards,like mining and quarrying,can be subject to health issues derived from those activities.The case of asbestosis has generated an alarm in the society.Natural stones are very different from each other and generalisation can cause,first an unwanted alarm,and secondly a big economic crisis in the sector of the natural stone,as it has happened before with other health issues related to exploitation and use of natural stone in architecture.This paper highlights the need for an appropriate mineralogical characterization of rocks of economic interest,such as serpentinites,to protect mining workers of health issues derived from fibrous minerals content.We have studied the possible presence of fibrous minerals in samples of serpentinites from an abandoned quarry in Galicia(North Western Spain)to consider the viability of its re-opening based on the Spanish health and safety regulations applicable to jobs at risk of exposure to asbestos.From our study,it can be concluded that there is a scarce amount of fibrous phases,pending on further studies to differentiate such fibrous minerals,and therefore the reopening of the serpentinite quarry should not be a health problem for the workers.
文摘Through the study on landscape reconstruction of abandoned quarry pits in mountainous area of Jiangzhe District, it was pointed out that it was of not only practical significance but also ecological significance of sustainable development to some extent, to scientifically and rationally rebuild and exploit abandoned quarry pits and to create new landscape, so that their landscape value and environmental benefit would entirely improve and that culture would be inherited and developed by making use of overt cultural fragments.
文摘The Valmalenco area(central Alps,northern Italy)is well-known for the widespread mining and quarrying activities.Serpentinites are extracted and processed as valuable dimension stone in open-cast quarries,and a big underground mine provides talc as industrial mineral.The presence of long-fiber chrysotile veins,especially in the eastern part of the valley,gave rise in the past to widespread mining activity,particularly between the end of the XIX century and 1975,leaving huge amounts of mining waste and tailings.In recent times,part of the tailings have been stabilized and reclaimed,covered with soil and planted.Extensive sampling of mine tailings,soils and alluvial sediments was performed,to detect asbestos contamination(XRPD,SEMEDS,TEM).Airborne asbestos was measured by environmental monitoring on polycarbonate filters(SEM and TEM),at the abandoned mines and at the closest centers.Huge amounts of chrysotile are still present in mine tailings(up to 20 wt.%),whereas soils and sediments were mostly below the 1000 ppm threshold;chrysotile is widespread almost in every part of the valley.Small amounts(<400 ppm)of asbestiform tremolite were detected.Airborne asbestos was below the PEL of 2ff/l for living environments,with some peaks at mine dumps and close to active serpentine quarries.This preliminary study provides useful tips and effective technical measures for risk reduction in the extractive context.
文摘Lede Stone is an important dimension stone with major relevance for Belgian and Dutch cultural heritage.It is sourced from the Eocene(Lutetian)Lede Formation,mainly in the region to the southeast of Ghent in Belgium.The oldest known use dates back to Roman times.With the rise of Gothic architecture during the middle ages,the use of Lede Stone increased substantially.Quarries arose at different locations at different times.Today only one active quarry remains,after a period of nonproduction during the 20^(th) century.Current production is mainly used for restoration purposes.A major concern is the use of alien stones as a substitute for Lede Stone in cultural heritage restoration.In the light of the establishment of the“Heritage Stone Task Group”,this paper deals with requirements of its“Terms of Reference”and illustrates the stone’s nature,technical properties,utilization and associated issues.It should contribute to the cultural appreciation and preservation of this stone.
文摘Information mainly collected decades ago,during and following its quarrying years,is here reviewed for the Jacobsville Sandstone,a well-known red bed sandstone of Neoproterozoic age from Upper Michigan,USA.This formation is here proposed as a suitable“Global Heritage Stone Resource”.The Jacobsville is an excellent example of a heritage stone as it was used extensively all over Eastern North America from 1880 to 1920 in hundreds of prominent buildings in major cities and many small towns,including the famous Waldorf Astoria Hotel in New York City.It was extensively mined from several quarry sites near Jacobsville,Michigan in Michigan’s Keweenaw Peninsula.The location is part of a significant geoheritage location,where native copper has also been mined for thousands of years.
基金funded by the Community of Madrid under the GEOMATERIALS 2 project(S 2013/MIT-2914)。
文摘Alpedrete granite is a monzogranite quarried in the Sierra de Guadarrana(Spanish Central System)foothills in and around Alpedrete,in the province of Madrid,Spain.Used as a building material since the Neolithic,it is one of the most representative of heritage granites of Madrid.Alpedrete and the surrounding region are characterised by a quarrying culture that has been maintained for centuries.The area is strewn with historic quarries,along with the one presently in operation.Traditional stone cutters who produce hand-finished granite ashlars are still to be found,while others use more modern techniques to achieve new types of products.
文摘A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China： terrace for crushed materials （terrace）, spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, ferns, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.
文摘The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing rock fracture. An empirical model based on hole spacing was developed to determine the pressure of NEEM in the rock fracture process. Primarily, the empirical model was developed by the mathematical method, utilizing dimensional analysis. Then, the Phase2 code, which is based on the finite element method, was utilized to predict crack growth in rocks. The results of numerical analysis show slight deviations from the empirical model. Hence, the polynomial re- gression analysis was used to modify the model. Finally, the modified model shows a good agreement with the results gained from numerical modeling.
基金the Ministry of Science, Technology and Innovation (MOSTI), Government of Malaysia and University of Malaya for providing the funds to support this research work
文摘The performance of industrial waste incineration bottom ash in controlled low-strength material （CLSM） was investigated in this paper, as the quarry dust was added. CLSM mixtures were made from the industrial waste incineration bottom ash, quarry dust, and cement. Tests for fresh density, bleeding, compressive strength, shear strength, hydraulic conductivity, and excavatability were carried out. The com- pressive strength ranges from 60 kPa to 6790 kPa, the friction angle varies from 5°to 19°, and the cohesion is from 4 to 604 kPa. Most of the mixtures are found to be non-excavatable. It is indicated that the quarry dust addition increases the compressive strength and shear parame- ters, decreases bleeding, and increases the removability modulus.
文摘The management of overburden is an important task in open pit exploitations. Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important factors affecting the disposal phase. Economic and environmental requirements must be followed in order to achieve the best reclamation results, keeping into account site constraints such as slope stability, hauling and dumping issues, and interactions with groundwater. This paper deals with the above mentioned issues, illustrating a rational approach applied on the case of a large limestone quarry where the thickness of the overburden is relevant and the spoil material has to be dumped in a flooded pit. The proposed multidisciplinary approach led to the selection of most suitable methods for excavation, transportation and disposal. The selection was based on a detailed laboratory and site characterisation that defined favorable and adverse factors to be considered during the preliminary study of a large quarrying project.
文摘Geophysical surveys are frequently applied in mining prospection to detect the presence and volume of ore bodies of different nature.Particularly,in gypsum ore bodies exploitation,electrical resistivity measurements are usually the most used methodology.However,it has been observed that different electrical resistivity values can be obtained depending on geometrical features and composition of gypsum.Indeed,electrical resistivity of gypsum rocks depends on several parameters,such as gypsum purity,nature of secondary minerals,porosity,saturation and interstitial fluid properties.Saturation and hydrogeological setting,in particular,were recognized as the most influencing parameters.Hydrogeological conditions of gypsum rock masses are also very relevant for exploitability,safety conditions and economic feasibility and should be accurately known during the prospection and planning phases of the quarries.In this work,a relationship between electrical resistivity and saturation degree of gypsum is proposed.The possibility to estimate gypsum porosity with the use of this relationship is also investigated.The reliability of laboratory measurements is finally verified in comparison with field and modelled resistivity data.The reported results underline the potentiality of the proposed approach to obtain a reliable characterization of the studied ore body.
