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
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
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
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
The aim of this study is to create alternative approaches to predict human response to ground vibration.Site measurements were conducted in an urban quarry.The multiple discriminant analysis technique was used to deve...The aim of this study is to create alternative approaches to predict human response to ground vibration.Site measurements were conducted in an urban quarry.The multiple discriminant analysis technique was used to develop classification models.The measured ground vibration values were grouped based on the limit values appearing in the literature.Two classification models were created to predict human response to ground vibration.In addition,classical predictor equations were developed to compare to the classification models.The best equations were chosen considering several error measures.All the models were tested on the independent data.The prediction accuracy of the discriminant analysis models is quite promising.Nearly eighty-nine percent of the test data were correctly classified.The classification models have a combined structure.The results of the models can be directly presented to the neighbors of the studied quarry.The models are not complex.They do not require additional software or information to practice and can be easily used by site engineers.展开更多
The main objective of this study is to determine the rates of vertically and horizontally oriented drilling processes in marble quarries and to observe the factors affecting the drilling rates in terms of physical and...The main objective of this study is to determine the rates of vertically and horizontally oriented drilling processes in marble quarries and to observe the factors affecting the drilling rates in terms of physical and mechanical properties of the rocks. In situ drilling tests were performed in different marble quarries with different marble types and drilling times and penetration rates for a series of successive depthincrements were trying to be determined under vertically and horizontally oriented conditions. In order to understand the relation between the parameters that are investigated within the scope of this research, uniaxial compressive strength, Brazilian tensile strength, impact strength, Bohme abrasion strength, P-wave velocity, porosity, unit volume weight, Schmidt hardness index and brittleness index values were correlated with the drilling rates. It was noticed that the porosity and unit volume weight could be taken as the key parameters among them for obtaining meaningful correlation with drilling performance. It was also observed that the physical and mechanical rock properties are more relevant in vertical drilling than horizontal drilling.展开更多
The improvement of the soil physical and chemical properties is the most important foundation for mine ecological restoration.The experiment is aimed at undisturbed area,restored area,and damaged area of abandoned Yon...The improvement of the soil physical and chemical properties is the most important foundation for mine ecological restoration.The experiment is aimed at undisturbed area,restored area,and damaged area of abandoned Yongledian Quarry in Beijing.Through determination and analysis of soil physical and chemical properties,it shows that there are significant differences in the composite effects of soil physical and chemical properties between restored area,and undisturbed area,damaged area,and engineering restoration effectively improves the composite effects of soil physical and chemical properties in the restored area.The single factor hypothesis test shows that soil pH value,organic matter,alkali-hydrolyzable nitrogen,and total nitrogen traits are the key targets to be restored in this mining area.展开更多
To meet the requirements of construction of concretes filled in the steel tube arches,a C60 grade micro-expansive self-compacting concrete （SCC） was prepared from manufactured sand （MS）.The utilization of MS with ...To meet the requirements of construction of concretes filled in the steel tube arches,a C60 grade micro-expansive self-compacting concrete （SCC） was prepared from manufactured sand （MS）.The utilization of MS with a high content of quarry limestone fines was dealed for SCC applications.The workability,compressive and splitting strength,modulus of elasticity,restrained expansion and chloride ion permeability as well as freeze-thaw resistance of three MS-SCC mixes with fines content of 3%,7% and 10% were tested and compared with those of the natural sand （NS）-SCC mix.The experimental results indicate that the performances of the C60 MS-SCC with fines content of 7% are excellent and compared favorably with those of C60 NS-SCC.展开更多
Extraction of Limestone is an economically important and widespread activity in Ghana and has existed since historical times. However, in spite of its remarkable contribution towards economic development, some adverse...Extraction of Limestone is an economically important and widespread activity in Ghana and has existed since historical times. However, in spite of its remarkable contribution towards economic development, some adverse impacts have been noticed, especially where extraction is carried out without proper planning and use of modern technology and scientific methods. We have carried out an assessment on the environmental effects of limestone quarrying on some communities in the Lower Manya Krobo District in the Eastern region of Ghana. Dust emission is one of the major effects of the practice of limestone extraction and as such, dust (PM10) sampling was conducted at the affected communities. Mean dry season results recorded in these communities stand at 125.0 μg/m3 or Bueryonye, 116.0 μg/m3 at Odugblase and 109.3 μg/m3 at Klo-Begoro. Oterkpolu community which served as the control recorded an average of 50.5 μg/m3. Average rainy season values recorded for the communities were 83.3 μg/m3 for Bueryonye, 113.1 μg/m3 at Odugblase and 74.4 μg/m3 at Klo-Begoro. The control community, Oterkpolu, had 43.3 μg/m3. These values are above the EPA, Ghana daily guideline level of 70 μg/m3 over a time-weighted average per 24 hours. Questionnaires administration and health records obtained from the health facilities in the communities revealed notable deteriorations in the health of the people as a result of the quarrying activities in the area. Notable among these is the prevalence of malaria though not related to dust emissions, it results from mosquitoes breeding in the stagnant pools of water found in pits created as a result of the mining activity. Other common health cases recorded were acute respiratory tract infection, ear and eye infections, cough and pneumonia.展开更多
The study aimed at assessing the distribution and composition of dust produced at Pomona Stone Quarry mine in Harare, Zimbabwe. The source contribution to ambient PM2.5 and PM10 dust levels were quantified and their s...The study aimed at assessing the distribution and composition of dust produced at Pomona Stone Quarry mine in Harare, Zimbabwe. The source contribution to ambient PM2.5 and PM10 dust levels were quantified and their spatial distribution from the quarry to the receptor (community). The study also analysed the pH of soils around the mine, SiO2 and Al2O3 levels in quarry dust. Data was collected through direct observations, personal communications, experiments, soil and dust sampling and analyses. Dust sampling was done in January, April and August, to assess the effect of meteorological conditions on dust concentrations in two phases. Phase 1 was conducted during plant shut down (baseline measurements) while phase 2 was carried out during full plant operations (normal operating conditions), to assess the effect of quarry operations on the surrounding areas. Within the quarry production processes, crushing stage was the most dust emitting stage. Phase 1 dust results showed that both respirable (PM2.5) and inhalable (PM10) dust at all stages were below the legal limit, thus below 35 mg/m3 (respirable) and 180 mg/m3 (inhalable). Highest dust levels (209.9 mg/m3 inhalable and 69.01 mg/m3 respirable) were recorded in August, followed by April (206.9 mg/m3 inhalable and 67.52 mg/m3 respirable) then January (206.82 mg/m3 inhalable and 65.27 mg/m3 respirable). At all stages, highest dust concentrations for both parameters were recorded near the plant and decreased with increasing distance from the plant ( ranging from 209.9 mg/m3 - 19.41 mg/m3 inhalable and 69.01 mg/m3 - 14.23 mg/m3 respirable). This was attributed to the effect of particle size. August recorded the biggest area for both parameters falling within the non-permissible category, followed by April then January. The findings also revealed that the quarry dust contained higher levels of SiO2 (0.752 mg/cm3) which were 7 times higher than the recommended 0.1 mg/cm3 (NSSA). Low Al2O3 levels of 0.102 mg/cm3 were recorded and this was considered as environmentally safe. Soils were slightly acidic-alkaline and the t-test results at 95% confidence interval showed no significant difference between the results from site A and B (p = 0.526). It was concluded that quarry dust from Pomona had no significant effects on soil pH but possible health impacts on the receiving community. The study recommended that dust suppression systems such as water sprays, vegetation, air nets and enclosed production process must be implemented to curb dust emissions.展开更多
The quarry and damaged mountain in peri-urban have an important influence to ecological environment. They have had a series of serious environmental -geological problems to the socio-economic development and urban mod...The quarry and damaged mountain in peri-urban have an important influence to ecological environment. They have had a series of serious environmental -geological problems to the socio-economic development and urban modernization process, such as increased environmental pollution and soil erosion,destruction of landscape aesthetic。展开更多
As such in any industrial raw material site characterization study, making a lithological evaluation for cement raw materials includes a description of physical characteristics as well as grain size and chemical compo...As such in any industrial raw material site characterization study, making a lithological evaluation for cement raw materials includes a description of physical characteristics as well as grain size and chemical composition. For providing the cement components in accordance with the specifications required, making the classification of the cement raw material pit is needed. To make this identification in a spatial system at a quarry stage, the supervised pattern recognition analysis has been performed. By using four discriminant analysis algorithms, lithological classifications at three levels, which are with limestone, marly-limestone (calcareous marl) and marl, have been made based on the main chemical components such as calcium oxide (CaO), alumina (Al2O3), silica (SiO2), and iron (Fe2O3). The results show that discriminant algorithms can be used as strong classifiers in cement quarry identification. It has also recorded that the conditional and mixed classifiers perform better than the conventional discriminant algorithms.展开更多
Excavating sands and gravel on land in combination with constructing reservoirs for storing fresh water is an ideal approach in atolls. Appropriate mining of gravel from the prograding gravel beach is acceptable. Digg...Excavating sands and gravel on land in combination with constructing reservoirs for storing fresh water is an ideal approach in atolls. Appropriate mining of gravel from the prograding gravel beach is acceptable. Digging reef rock close to the edge of the wide ocean reef flat without surface loose sediments on it or sand beach can be accepted. Excavating sand from some depths in lagoon is a scientific approach particularly important for urbanized atolls. However, selecting appropriate sites for mining sand other than at some depths in lagoon is suitable to rural islands without dense populations. These sites include up drift side of long groin on the reef flat, partly filled access channel-port, outlet of artificial channel and lagoon margin on the prograding coast.展开更多
The cause of Longyou Grotto has been analyzed by combining with historical materials.It has found through field survey that many grottos and rock caves have distributed on both banks of Qujiang River and its branches,...The cause of Longyou Grotto has been analyzed by combining with historical materials.It has found through field survey that many grottos and rock caves have distributed on both banks of Qujiang River and its branches,and Longyou red sandstone grotto is not confined to Fenghuang Mountain.Based on the visit and investigation of local ancient villages,it has found that local vernacular architectures are pervasively constructed by red sandstone which has been consumed a lot.After the analysis and demonstration,it considers that red sandstone grottos are exploited as construction materials for local area,and rivers have been taken as the transport channel,convenient and cost-saving.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.
基金Research Fund of the Istanbul Technical University under Grant No.MGA-2017-40581the Scientific and Technological Research Council of Turkey-TUBITAK-under Grant No.217M071。
文摘The aim of this study is to create alternative approaches to predict human response to ground vibration.Site measurements were conducted in an urban quarry.The multiple discriminant analysis technique was used to develop classification models.The measured ground vibration values were grouped based on the limit values appearing in the literature.Two classification models were created to predict human response to ground vibration.In addition,classical predictor equations were developed to compare to the classification models.The best equations were chosen considering several error measures.All the models were tested on the independent data.The prediction accuracy of the discriminant analysis models is quite promising.Nearly eighty-nine percent of the test data were correctly classified.The classification models have a combined structure.The results of the models can be directly presented to the neighbors of the studied quarry.The models are not complex.They do not require additional software or information to practice and can be easily used by site engineers.
文摘The main objective of this study is to determine the rates of vertically and horizontally oriented drilling processes in marble quarries and to observe the factors affecting the drilling rates in terms of physical and mechanical properties of the rocks. In situ drilling tests were performed in different marble quarries with different marble types and drilling times and penetration rates for a series of successive depthincrements were trying to be determined under vertically and horizontally oriented conditions. In order to understand the relation between the parameters that are investigated within the scope of this research, uniaxial compressive strength, Brazilian tensile strength, impact strength, Bohme abrasion strength, P-wave velocity, porosity, unit volume weight, Schmidt hardness index and brittleness index values were correlated with the drilling rates. It was noticed that the porosity and unit volume weight could be taken as the key parameters among them for obtaining meaningful correlation with drilling performance. It was also observed that the physical and mechanical rock properties are more relevant in vertical drilling than horizontal drilling.
文摘The improvement of the soil physical and chemical properties is the most important foundation for mine ecological restoration.The experiment is aimed at undisturbed area,restored area,and damaged area of abandoned Yongledian Quarry in Beijing.Through determination and analysis of soil physical and chemical properties,it shows that there are significant differences in the composite effects of soil physical and chemical properties between restored area,and undisturbed area,damaged area,and engineering restoration effectively improves the composite effects of soil physical and chemical properties in the restored area.The single factor hypothesis test shows that soil pH value,organic matter,alkali-hydrolyzable nitrogen,and total nitrogen traits are the key targets to be restored in this mining area.
基金Funded by the Science and Technology Item of Communication Construction for West China (No.2009318811082)
文摘To meet the requirements of construction of concretes filled in the steel tube arches,a C60 grade micro-expansive self-compacting concrete （SCC） was prepared from manufactured sand （MS）.The utilization of MS with a high content of quarry limestone fines was dealed for SCC applications.The workability,compressive and splitting strength,modulus of elasticity,restrained expansion and chloride ion permeability as well as freeze-thaw resistance of three MS-SCC mixes with fines content of 3%,7% and 10% were tested and compared with those of the natural sand （NS）-SCC mix.The experimental results indicate that the performances of the C60 MS-SCC with fines content of 7% are excellent and compared favorably with those of C60 NS-SCC.
文摘Extraction of Limestone is an economically important and widespread activity in Ghana and has existed since historical times. However, in spite of its remarkable contribution towards economic development, some adverse impacts have been noticed, especially where extraction is carried out without proper planning and use of modern technology and scientific methods. We have carried out an assessment on the environmental effects of limestone quarrying on some communities in the Lower Manya Krobo District in the Eastern region of Ghana. Dust emission is one of the major effects of the practice of limestone extraction and as such, dust (PM10) sampling was conducted at the affected communities. Mean dry season results recorded in these communities stand at 125.0 μg/m3 or Bueryonye, 116.0 μg/m3 at Odugblase and 109.3 μg/m3 at Klo-Begoro. Oterkpolu community which served as the control recorded an average of 50.5 μg/m3. Average rainy season values recorded for the communities were 83.3 μg/m3 for Bueryonye, 113.1 μg/m3 at Odugblase and 74.4 μg/m3 at Klo-Begoro. The control community, Oterkpolu, had 43.3 μg/m3. These values are above the EPA, Ghana daily guideline level of 70 μg/m3 over a time-weighted average per 24 hours. Questionnaires administration and health records obtained from the health facilities in the communities revealed notable deteriorations in the health of the people as a result of the quarrying activities in the area. Notable among these is the prevalence of malaria though not related to dust emissions, it results from mosquitoes breeding in the stagnant pools of water found in pits created as a result of the mining activity. Other common health cases recorded were acute respiratory tract infection, ear and eye infections, cough and pneumonia.
文摘The study aimed at assessing the distribution and composition of dust produced at Pomona Stone Quarry mine in Harare, Zimbabwe. The source contribution to ambient PM2.5 and PM10 dust levels were quantified and their spatial distribution from the quarry to the receptor (community). The study also analysed the pH of soils around the mine, SiO2 and Al2O3 levels in quarry dust. Data was collected through direct observations, personal communications, experiments, soil and dust sampling and analyses. Dust sampling was done in January, April and August, to assess the effect of meteorological conditions on dust concentrations in two phases. Phase 1 was conducted during plant shut down (baseline measurements) while phase 2 was carried out during full plant operations (normal operating conditions), to assess the effect of quarry operations on the surrounding areas. Within the quarry production processes, crushing stage was the most dust emitting stage. Phase 1 dust results showed that both respirable (PM2.5) and inhalable (PM10) dust at all stages were below the legal limit, thus below 35 mg/m3 (respirable) and 180 mg/m3 (inhalable). Highest dust levels (209.9 mg/m3 inhalable and 69.01 mg/m3 respirable) were recorded in August, followed by April (206.9 mg/m3 inhalable and 67.52 mg/m3 respirable) then January (206.82 mg/m3 inhalable and 65.27 mg/m3 respirable). At all stages, highest dust concentrations for both parameters were recorded near the plant and decreased with increasing distance from the plant ( ranging from 209.9 mg/m3 - 19.41 mg/m3 inhalable and 69.01 mg/m3 - 14.23 mg/m3 respirable). This was attributed to the effect of particle size. August recorded the biggest area for both parameters falling within the non-permissible category, followed by April then January. The findings also revealed that the quarry dust contained higher levels of SiO2 (0.752 mg/cm3) which were 7 times higher than the recommended 0.1 mg/cm3 (NSSA). Low Al2O3 levels of 0.102 mg/cm3 were recorded and this was considered as environmentally safe. Soils were slightly acidic-alkaline and the t-test results at 95% confidence interval showed no significant difference between the results from site A and B (p = 0.526). It was concluded that quarry dust from Pomona had no significant effects on soil pH but possible health impacts on the receiving community. The study recommended that dust suppression systems such as water sprays, vegetation, air nets and enclosed production process must be implemented to curb dust emissions.
文摘The quarry and damaged mountain in peri-urban have an important influence to ecological environment. They have had a series of serious environmental -geological problems to the socio-economic development and urban modernization process, such as increased environmental pollution and soil erosion,destruction of landscape aesthetic。
文摘As such in any industrial raw material site characterization study, making a lithological evaluation for cement raw materials includes a description of physical characteristics as well as grain size and chemical composition. For providing the cement components in accordance with the specifications required, making the classification of the cement raw material pit is needed. To make this identification in a spatial system at a quarry stage, the supervised pattern recognition analysis has been performed. By using four discriminant analysis algorithms, lithological classifications at three levels, which are with limestone, marly-limestone (calcareous marl) and marl, have been made based on the main chemical components such as calcium oxide (CaO), alumina (Al2O3), silica (SiO2), and iron (Fe2O3). The results show that discriminant algorithms can be used as strong classifiers in cement quarry identification. It has also recorded that the conditional and mixed classifiers perform better than the conventional discriminant algorithms.
文摘Excavating sands and gravel on land in combination with constructing reservoirs for storing fresh water is an ideal approach in atolls. Appropriate mining of gravel from the prograding gravel beach is acceptable. Digging reef rock close to the edge of the wide ocean reef flat without surface loose sediments on it or sand beach can be accepted. Excavating sand from some depths in lagoon is a scientific approach particularly important for urbanized atolls. However, selecting appropriate sites for mining sand other than at some depths in lagoon is suitable to rural islands without dense populations. These sites include up drift side of long groin on the reef flat, partly filled access channel-port, outlet of artificial channel and lagoon margin on the prograding coast.
文摘The cause of Longyou Grotto has been analyzed by combining with historical materials.It has found through field survey that many grottos and rock caves have distributed on both banks of Qujiang River and its branches,and Longyou red sandstone grotto is not confined to Fenghuang Mountain.Based on the visit and investigation of local ancient villages,it has found that local vernacular architectures are pervasively constructed by red sandstone which has been consumed a lot.After the analysis and demonstration,it considers that red sandstone grottos are exploited as construction materials for local area,and rivers have been taken as the transport channel,convenient and cost-saving.
