Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).02
V. T. Dang, G. Nguyen
As we know, vascular plants (Tracheophyta) in general and crop plants require a defined amount of trace elements to ensure normal growth and development. In many developed countries, some natural materials have been used as an addition for growing ornamental plants, vegetables, and hydroculture plants. In Vietnam, natural minerals to support plant growth is still very limited. Meanwhile, the source of raw materials in the territory of Vietnam is quite popular, so the research and experiments using Vietnamese volcanic ash and felsic volcanic rocks as improving materials for plant growing is important and very necessary work. Analytical methods such as Ronghen Fluorescence (XRF), Mass Spectrometry (ICP-MS), Scanning electron microscopy (SEM) and calcination at 6500C, 7500C, and 9000C have been used to determine the composition of felsic tuff samples belonging to the Don Duong Formation (PY19) and mafic ash samples of the Dai Nga Formation (KR2/2). In addition, control sample matching method was also used in the research process to evaluate the growth plants. The experiment materials (raw samples and calcined samples at 9000C) were mixed with the soil for planting (in different proportions); two types of plants, named Caviar Cockatio (Chicken Crest Vegetables) and Amaranth Asiatica (Purple Amaranth), were selected for experimenting. In general, both Caviar Cockatio and Amaranth Asiatica developed quicker when grew on a ground of soil mixed with the experiment material. The plant’s growth rate depends on the type of material (unbaked, calcined), support material content, plant type and stage of growth. Primary research results show that volcanic materials in Vietnam can support the growth of plants.
{"title":"Preliminary research results on the use of volcanic ash and felsic volcanic rock in Vietnam as materials to support crop growth","authors":"V. T. Dang, G. Nguyen","doi":"10.46326/jmes.2022.63(6).02","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).02","url":null,"abstract":"As we know, vascular plants (Tracheophyta) in general and crop plants require a defined amount of trace elements to ensure normal growth and development. In many developed countries, some natural materials have been used as an addition for growing ornamental plants, vegetables, and hydroculture plants. In Vietnam, natural minerals to support plant growth is still very limited. Meanwhile, the source of raw materials in the territory of Vietnam is quite popular, so the research and experiments using Vietnamese volcanic ash and felsic volcanic rocks as improving materials for plant growing is important and very necessary work. Analytical methods such as Ronghen Fluorescence (XRF), Mass Spectrometry (ICP-MS), Scanning electron microscopy (SEM) and calcination at 6500C, 7500C, and 9000C have been used to determine the composition of felsic tuff samples belonging to the Don Duong Formation (PY19) and mafic ash samples of the Dai Nga Formation (KR2/2). In addition, control sample matching method was also used in the research process to evaluate the growth plants. The experiment materials (raw samples and calcined samples at 9000C) were mixed with the soil for planting (in different proportions); two types of plants, named Caviar Cockatio (Chicken Crest Vegetables) and Amaranth Asiatica (Purple Amaranth), were selected for experimenting. In general, both Caviar Cockatio and Amaranth Asiatica developed quicker when grew on a ground of soil mixed with the experiment material. The plant’s growth rate depends on the type of material (unbaked, calcined), support material content, plant type and stage of growth. Primary research results show that volcanic materials in Vietnam can support the growth of plants.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124316047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).05
Dat Pham, K. N. Pham, Phong Hop Lai, Ninh Thi
Geophysical methods are effective tools for geotechnical analysis. In particular, the two-dimensional electrical resistivity method is widely applied in the determination of broken, cracked, and karst cave structures in many countries around the world. The information given by this method plays an important role in preventing and mitigating the risk of geological hazards caused by geological structures. Geotechnical analysis is also an important step in civil construction. However, the interpretation of two-dimensional problems with individual sections still has certain limitations, such as the delineation of the spatial distribution of interesting objects in the entire survey area. We propose a new data processing procedure for the two-dimensional electrical resistivity methods based on rearranging the data as the input of three-dimensional inversion. If the distribution of survey lines is dense enough, we can use two-dimensional data to solve the three-dimensional inverse problems. This inversion will give us a diagram of resistivity distribution in three-dimensional space, which is intuitive and high detail in identifying interesting objects. In this study, the authors have solved the three-dimensional inverse problems from the two-dimensional electrical resistivity survey carried out in the Hoa Lac area, west of Hanoi city. The result shows that the resistivity distribution in three-dimensional space not only increases the intuition but also the accuracy in reflecting the spatial distribution of hidden underground objects. This also defines the localization and determination of fracture zones in the study area as more reliable than explained in each section according to the results of solving two-dimensional inverse problems. The effectiveness of this new method has been proven when compared with drilling results in the studied area.
{"title":"3D inversion of 2D electrical resistivity data for geotechnical analysis","authors":"Dat Pham, K. N. Pham, Phong Hop Lai, Ninh Thi","doi":"10.46326/jmes.2022.63(6).05","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).05","url":null,"abstract":"Geophysical methods are effective tools for geotechnical analysis. In particular, the two-dimensional electrical resistivity method is widely applied in the determination of broken, cracked, and karst cave structures in many countries around the world. The information given by this method plays an important role in preventing and mitigating the risk of geological hazards caused by geological structures. Geotechnical analysis is also an important step in civil construction. However, the interpretation of two-dimensional problems with individual sections still has certain limitations, such as the delineation of the spatial distribution of interesting objects in the entire survey area. We propose a new data processing procedure for the two-dimensional electrical resistivity methods based on rearranging the data as the input of three-dimensional inversion. If the distribution of survey lines is dense enough, we can use two-dimensional data to solve the three-dimensional inverse problems. This inversion will give us a diagram of resistivity distribution in three-dimensional space, which is intuitive and high detail in identifying interesting objects. In this study, the authors have solved the three-dimensional inverse problems from the two-dimensional electrical resistivity survey carried out in the Hoa Lac area, west of Hanoi city. The result shows that the resistivity distribution in three-dimensional space not only increases the intuition but also the accuracy in reflecting the spatial distribution of hidden underground objects. This also defines the localization and determination of fracture zones in the study area as more reliable than explained in each section according to the results of solving two-dimensional inverse problems. The effectiveness of this new method has been proven when compared with drilling results in the studied area.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116000271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).04
A. H. Nguyen, Vinh The Nguyen, Thang Manh Pham
The production of heavy oil at Dong Do field located in CuuLong basin is a success in the application of advanced technologies. Dong Do field is a marginal project in Vietnam, so its development requires to overcome several challenges, such as high water-cut from early stage, highly unconsolidated sandstone reservoir, flow assurance problems of sour and viscous crude oil, high power artificial lift system, and complex crude treatment at topsides, among others. Over the past decades, production technology application in heavy oil production has been widely deployed in the industry. Apart from the thermal method, the combination of gaslift and ESP technology makes the remarkable advances by enlarging the draw-down created over the conventional pumping lift in heavy oil projects. In fact, heavy oil production with a high flow rate has appeared water-coning in near wellbore region that made the water breakthrough early and water-cut increased rapidly. The pilot test of injecting diesel into heavy oil wells has been applied to producers with the positive results while significantly reduced water-cut comparing before wells shutin. This paper provides a thorough analysis of the new technologies that are applied to Dong Do field, highlighting its key difficulties and how they were resolved through a successful pilot and testing of the cutting-edge advanced solutions, improving the project reliability and thus motivating the consortium to move on to the new field. Also, the updated new heavy oil field schedule is described, highlighting the challenges to be faced during the next projects of marginal development.
{"title":"Technology solutions and challenges for marginal development of heavy oil fields in CuuLong basin, offshore Vietnam","authors":"A. H. Nguyen, Vinh The Nguyen, Thang Manh Pham","doi":"10.46326/jmes.2022.63(6).04","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).04","url":null,"abstract":"The production of heavy oil at Dong Do field located in CuuLong basin is a success in the application of advanced technologies. Dong Do field is a marginal project in Vietnam, so its development requires to overcome several challenges, such as high water-cut from early stage, highly unconsolidated sandstone reservoir, flow assurance problems of sour and viscous crude oil, high power artificial lift system, and complex crude treatment at topsides, among others. Over the past decades, production technology application in heavy oil production has been widely deployed in the industry. Apart from the thermal method, the combination of gaslift and ESP technology makes the remarkable advances by enlarging the draw-down created over the conventional pumping lift in heavy oil projects. In fact, heavy oil production with a high flow rate has appeared water-coning in near wellbore region that made the water breakthrough early and water-cut increased rapidly. The pilot test of injecting diesel into heavy oil wells has been applied to producers with the positive results while significantly reduced water-cut comparing before wells shutin. This paper provides a thorough analysis of the new technologies that are applied to Dong Do field, highlighting its key difficulties and how they were resolved through a successful pilot and testing of the cutting-edge advanced solutions, improving the project reliability and thus motivating the consortium to move on to the new field. Also, the updated new heavy oil field schedule is described, highlighting the challenges to be faced during the next projects of marginal development.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127394135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).09
D. T. Le, Hai Hong Mai
Assessment of top coal fall potential is of great importance for sustainable longwall caving mining. However, available assessment tools/indices for the fall are applicable to roof rock only, and their use for top coal (whose geological structures may be different) can be inappropriate. This paper presents a new index for top coal fall in longwall mining where the fall is controlled by the cantilever effect. The index is developed from an integrated numerical and statistical analysis using the database from Ha Lam coal mine in Vietnam. The numerical analysis reveals that the strength and stiffness of in-seam discrete fractures and coal’s elastic modulus are inversely proportional to top coal fall. Meanwhile, the density of discrete fractures and seam depth are found to be directly proportional to the fall. A procedure for the development of assessment equation for top coal is established using single and multiple regressions and model transformation technique. A new assessment index for longwall top coal fall named Fall Index (FI) is proposed, taking coal elastic modulus, fracture density, fracture friction angle, fracture stiffness and seam depth as input parameters. The study also reveals that statistically seam depth has the most significant effect while fracture density and fracture strength show the least significant effect on top coal fall. At the same time, coal’s elastic modulus and fracture stiffness play similar roles in the fall. The results from this paper assist engineers in better assessing top coal fall potential and subsequently better controlling longwall stability for various geological conditions in mine design.
{"title":"Longwall top coal fall index from an integrated numerical and statistical analysis","authors":"D. T. Le, Hai Hong Mai","doi":"10.46326/jmes.2022.63(6).09","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).09","url":null,"abstract":"Assessment of top coal fall potential is of great importance for sustainable longwall caving mining. However, available assessment tools/indices for the fall are applicable to roof rock only, and their use for top coal (whose geological structures may be different) can be inappropriate. This paper presents a new index for top coal fall in longwall mining where the fall is controlled by the cantilever effect. The index is developed from an integrated numerical and statistical analysis using the database from Ha Lam coal mine in Vietnam. The numerical analysis reveals that the strength and stiffness of in-seam discrete fractures and coal’s elastic modulus are inversely proportional to top coal fall. Meanwhile, the density of discrete fractures and seam depth are found to be directly proportional to the fall. A procedure for the development of assessment equation for top coal is established using single and multiple regressions and model transformation technique. A new assessment index for longwall top coal fall named Fall Index (FI) is proposed, taking coal elastic modulus, fracture density, fracture friction angle, fracture stiffness and seam depth as input parameters. The study also reveals that statistically seam depth has the most significant effect while fracture density and fracture strength show the least significant effect on top coal fall. At the same time, coal’s elastic modulus and fracture stiffness play similar roles in the fall. The results from this paper assist engineers in better assessing top coal fall potential and subsequently better controlling longwall stability for various geological conditions in mine design.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127890914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).06
Thanh Huu Le, S. Ngo, T. Tran, H. T. Nguyen
The solution plasma process (SPP) is a revolutionary approach for production of nanomaterials employing plasma discharge in liquid. The SPP can quickly deionize metal into the neutral state in the absence of a reducing agent. Selenium nanoparticles are created in solution plasma in this investigation. The approach is capable of producing selenium nanoparticles with uniform size in water and great stability without the use of a stabilizer. UV-Visible Spectrophotometry (UV-vis), X-Ray Diffraction (XRD), Dynamic Light Scattering Particle Size Analyzer (DLS), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) techniques are used to analyze the produced selenium nanoparticles. In an ethanol/water mixture, the better solvent compares to distilled water, the SeNPs forms uniform flower-like nanostructures with diameters ranging from 50÷70 nm. Also, the effects of other parameters such as voltage, electrode spacing and reaction time on the production of nano selenium are investigated. The findings show that solution plasma can help form selenium nano particle in a very short time which is about 60 minutes. In addition, the electrodes must be separated by a minimum distance which is 0.5 mm . The ideal voltage to achieve a highly efficient process is 2 kV The higher voltage cause the reaction solution boil leading to the loss of reactants while the lower value cannot ignite the reaction. The reaction efficiency reaches 100% when applied those conditions. Also, those parameters help to shorten the reaction time which is an advantage of the synthesis method. As a result, the solution plasma method of synthesising nanoselenium makes it extremely promising for use in biomedical applications.
{"title":"Study on factors affecting the synthesis of selenium nanoparticles by solution plasma method","authors":"Thanh Huu Le, S. Ngo, T. Tran, H. T. Nguyen","doi":"10.46326/jmes.2022.63(6).06","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).06","url":null,"abstract":"The solution plasma process (SPP) is a revolutionary approach for production of nanomaterials employing plasma discharge in liquid. The SPP can quickly deionize metal into the neutral state in the absence of a reducing agent. Selenium nanoparticles are created in solution plasma in this investigation. The approach is capable of producing selenium nanoparticles with uniform size in water and great stability without the use of a stabilizer. UV-Visible Spectrophotometry (UV-vis), X-Ray Diffraction (XRD), Dynamic Light Scattering Particle Size Analyzer (DLS), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) techniques are used to analyze the produced selenium nanoparticles. In an ethanol/water mixture, the better solvent compares to distilled water, the SeNPs forms uniform flower-like nanostructures with diameters ranging from 50÷70 nm. Also, the effects of other parameters such as voltage, electrode spacing and reaction time on the production of nano selenium are investigated. The findings show that solution plasma can help form selenium nano particle in a very short time which is about 60 minutes. In addition, the electrodes must be separated by a minimum distance which is 0.5 mm . The ideal voltage to achieve a highly efficient process is 2 kV The higher voltage cause the reaction solution boil leading to the loss of reactants while the lower value cannot ignite the reaction. The reaction efficiency reaches 100% when applied those conditions. Also, those parameters help to shorten the reaction time which is an advantage of the synthesis method. As a result, the solution plasma method of synthesising nanoselenium makes it extremely promising for use in biomedical applications.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126460202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).10
Hang Minh Le, A. Tran
Natural disasters and human activities are now causing an increase in land subsidence, or surface displacement. The effects of land subsidence cause landslides and construction cracking. PSInSAR (Persistent Scatter Interferometry) was identified to estimate surface displacement from a time series of Synthetic Aperture Radar (SAR) images. This technique is a subset of the DInSAR (Differential Interferometric Synthetic Aperture Radar) method. In this article, the authors determined and analyzed land subsidence in Thai Nguyen Province, Vietnam, using time series Sentinel-1A data with VV polarization from July 2019 to December 2020 and the PSInSAR method. There are numerous mineral exploitation mines in Thai Nguyen Province. It is one of the causes of an unusual amount of land subsidence in the region. According to the results determined by the InSAR technique, the velocity of displacement along the line of sight (LOS) of the study area ranges from -23.2 mm per year to +21.0 mm per year. The analysis of time-series SAR images reveals anomalous land subsidence at persistent scatter (PS) points. By analyzing the time-series displacement at PS points using the StaMPS Visualizer tool, the land subsidence during the image acquisition period and surface displacement trends over time were determined. According to this, coal mining regions have the highest land subsidence values ranging from -40 mm to -60 mm. The city and mine regions of Thai Nguyen, where operations have stopped, are largely stable. In addition, the time-series analysis at PS points will allow us to identify unusual displacement points, enabling the implementation of early warning plans.
自然灾害和人类活动正在造成地面沉降或地表位移的增加。地面沉降的影响导致山体滑坡和建筑开裂。采用PSInSAR(持续散射干涉测量法)从合成孔径雷达(SAR)图像的时间序列中估计地表位移。该技术是差分干涉合成孔径雷达(DInSAR)方法的一个子集。本文利用2019年7月至2020年12月的Sentinel-1A VV极化时间序列数据和PSInSAR方法，对越南太原省的地面沉降进行了确定和分析。太原省有许多矿产开采矿山。这是该地区地面沉降异常严重的原因之一。根据InSAR技术确定的结果，研究区域沿视线(LOS)的位移速度为-23.2 mm /年至+21.0 mm /年。对时间序列SAR图像的分析揭示了持续散射点(PS)的地表沉降异常。通过使用StaMPS Visualizer工具分析PS点的时间序列位移，确定了图像采集期间的地面沉降和地表位移随时间的变化趋势。由此可见，采煤区地表沉降值最高，为-40 ~ -60 mm。泰阮的城市和矿区已经停止了开采，基本稳定。此外，PS点的时间序列分析将使我们能够识别异常位移点，从而实施早期预警计划。
{"title":"Analyzing of land subsidence by Sentinel-1 time-series images using PSInSAR method: A case study of Thai Nguyen, Vietnam","authors":"Hang Minh Le, A. Tran","doi":"10.46326/jmes.2022.63(6).10","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).10","url":null,"abstract":"Natural disasters and human activities are now causing an increase in land subsidence, or surface displacement. The effects of land subsidence cause landslides and construction cracking. PSInSAR (Persistent Scatter Interferometry) was identified to estimate surface displacement from a time series of Synthetic Aperture Radar (SAR) images. This technique is a subset of the DInSAR (Differential Interferometric Synthetic Aperture Radar) method. In this article, the authors determined and analyzed land subsidence in Thai Nguyen Province, Vietnam, using time series Sentinel-1A data with VV polarization from July 2019 to December 2020 and the PSInSAR method. There are numerous mineral exploitation mines in Thai Nguyen Province. It is one of the causes of an unusual amount of land subsidence in the region. According to the results determined by the InSAR technique, the velocity of displacement along the line of sight (LOS) of the study area ranges from -23.2 mm per year to +21.0 mm per year. The analysis of time-series SAR images reveals anomalous land subsidence at persistent scatter (PS) points. By analyzing the time-series displacement at PS points using the StaMPS Visualizer tool, the land subsidence during the image acquisition period and surface displacement trends over time were determined. According to this, coal mining regions have the highest land subsidence values ranging from -40 mm to -60 mm. The city and mine regions of Thai Nguyen, where operations have stopped, are largely stable. In addition, the time-series analysis at PS points will allow us to identify unusual displacement points, enabling the implementation of early warning plans.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121714701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).07
D. Bui, M. V. Nguyen, N. T. Pham, T. Bui, Trong Dang Nguyen, P. Osiński, Benedic Tatiana
Reconstruction and building extensions have become popular trends, even being recognized as one of the most appropriate options for homes, especially in high population density areas or crowded cities. Due to the changes in the size of buildings (by applying additional loads), the existing foundations themselves are incapable of resisting extra stresses. Therefore, it is imperative to increase the bearing capacity as well as the overall stability of existing foundations. The paper aims to present a numerical case study on the use of micropile elements for enhancing the performance of the boundary footing of a renovated building in terms of bearing capacity and stability. Moreover, the effect of cohesionless soil types on the bearing capacity of boundary foundations was presented. Numerically calculated results show that the stability of the boundary footing, presented in terms of the safety factor, was increased as strengthened by micropiles. The bearing capacity ratio (BCR) of the boundary footing was significantly improved when the relative distance (S) between the micropile and the boundary footing decreased, and the length of micropiles (L) increased; however, the BCR rose as the micropile’s angle (() with respect to the vertical increase. In other words, the performance of the foundation underneath the boundary footing was significantly affected by some micropile parameters, including length, inclination, and the distance between the micropile and the boundary footing. These crucial factors must be carefully examined during the design of the micropiles’ configuration for strengthening the boundary footing. Lastly, the load-carrying capacity improvement of the loose sand using micropiles was found to be more significant than that of denser ones.
{"title":"Enhancing the performance of boundary footing of a renovated building using micropiles: Numerical and Site Visual Assessment","authors":"D. Bui, M. V. Nguyen, N. T. Pham, T. Bui, Trong Dang Nguyen, P. Osiński, Benedic Tatiana","doi":"10.46326/jmes.2022.63(6).07","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).07","url":null,"abstract":"Reconstruction and building extensions have become popular trends, even being recognized as one of the most appropriate options for homes, especially in high population density areas or crowded cities. Due to the changes in the size of buildings (by applying additional loads), the existing foundations themselves are incapable of resisting extra stresses. Therefore, it is imperative to increase the bearing capacity as well as the overall stability of existing foundations. The paper aims to present a numerical case study on the use of micropile elements for enhancing the performance of the boundary footing of a renovated building in terms of bearing capacity and stability. Moreover, the effect of cohesionless soil types on the bearing capacity of boundary foundations was presented. Numerically calculated results show that the stability of the boundary footing, presented in terms of the safety factor, was increased as strengthened by micropiles. The bearing capacity ratio (BCR) of the boundary footing was significantly improved when the relative distance (S) between the micropile and the boundary footing decreased, and the length of micropiles (L) increased; however, the BCR rose as the micropile’s angle (() with respect to the vertical increase. In other words, the performance of the foundation underneath the boundary footing was significantly affected by some micropile parameters, including length, inclination, and the distance between the micropile and the boundary footing. These crucial factors must be carefully examined during the design of the micropiles’ configuration for strengthening the boundary footing. Lastly, the load-carrying capacity improvement of the loose sand using micropiles was found to be more significant than that of denser ones.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"353 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115916981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).08
Tien Trung Vu, Son Anh Do, D. T. Le, H. D. Pham, Kien Trung Tran
When exploiting the working face located under the surface works need to be protected, it may lead to potential risks that cause unsafety and effect for the stability of those works. The degree of influence on the surface works depends on many factors, including the exploitation technology factor. It is always necessary to study and evaluate the impact of mining on the surface works to propose appropriate technical solutions and mining technology to ensure the safety during mining process. Through the field study at Mong Duong Coal Mine, finding a reasonable mining solution for the longwall in Seam L7 at East Side is important to ensure the stability of the G9 surface works. These works include a coal storage, and some construction works of level 4 houses, equipment and machinery for coal transportation and their total weight is estimated about 200,000 tons. Research methods used include numerical modeling method combined with comparative data analysis method. The authors have determined the heights of the collapse zone and fracture zone corresponding to the face advance of the longwall and the degree of influence on the surface works. These are considered as a basis for choosing a reasonable mining solution for the condition of the longwall to ensure the stability of the surface works. The above methods are applied to the condition of the longwall in Seam L7 at East Side of Mong Duong Coal Mine and find a reasonable exploitation for the longwall in Seam L7 with a cutting height of 2.2 m and recovering 100% of top coal (corresponding to 0.8 m). When the longwall is exploited in the strike direction to 140 m, the G9 surface works remain unaffected. When the longwall is exploited in the strike direction of 160 m onward, those works will be affected. The paper’s results are used as a basis for Mong Duong Coal Mine to choose a mining solution and to timely adjust the mining solution of the longwall in Seam L7, ensuring efficiency and stability for G9 surface works.
{"title":"Reasonable exploitation solution for longwall in Seam L7 at East Side to ensure the stability of G9 surface works of Mong Duong Coal Mine","authors":"Tien Trung Vu, Son Anh Do, D. T. Le, H. D. Pham, Kien Trung Tran","doi":"10.46326/jmes.2022.63(6).08","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).08","url":null,"abstract":"When exploiting the working face located under the surface works need to be protected, it may lead to potential risks that cause unsafety and effect for the stability of those works. The degree of influence on the surface works depends on many factors, including the exploitation technology factor. It is always necessary to study and evaluate the impact of mining on the surface works to propose appropriate technical solutions and mining technology to ensure the safety during mining process. Through the field study at Mong Duong Coal Mine, finding a reasonable mining solution for the longwall in Seam L7 at East Side is important to ensure the stability of the G9 surface works. These works include a coal storage, and some construction works of level 4 houses, equipment and machinery for coal transportation and their total weight is estimated about 200,000 tons. Research methods used include numerical modeling method combined with comparative data analysis method. The authors have determined the heights of the collapse zone and fracture zone corresponding to the face advance of the longwall and the degree of influence on the surface works. These are considered as a basis for choosing a reasonable mining solution for the condition of the longwall to ensure the stability of the surface works. The above methods are applied to the condition of the longwall in Seam L7 at East Side of Mong Duong Coal Mine and find a reasonable exploitation for the longwall in Seam L7 with a cutting height of 2.2 m and recovering 100% of top coal (corresponding to 0.8 m). When the longwall is exploited in the strike direction to 140 m, the G9 surface works remain unaffected. When the longwall is exploited in the strike direction of 160 m onward, those works will be affected. The paper’s results are used as a basis for Mong Duong Coal Mine to choose a mining solution and to timely adjust the mining solution of the longwall in Seam L7, ensuring efficiency and stability for G9 surface works.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123215273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).01
Khang Quang Luong, Hung The Khuong, Dung Tien Vo, Tuyen Danh Nguyen
Typically, granitic intrusions that document the lengthy and intricate history of the magmatic-hydrothermal system are linked to tungsten deposits. Uncertainty persists about the genetic relationship between tungsten mineralization and magmatic-hydrothermal development. The primary tungsten deposit in the Dai Tu region, known as the Nui Phao deposit, has been the subject of a petrographical and microscopic examination. Tungsten mineralization in the Dai Tu area often occurs in association with the formation of skarn and greisen bodies, and it has drawn much attention from geoscientists. Based on microscopic observations, tungsten ores can be divided into three mineralization stages, namely skarnisation, greisenization, and hydrothermal stage. To examine the geochemical features of the tungsten ores, the SEM-EDS and Microscope analytical methods were performed in this study. Research results indicate that the Nui Phao tungsten deposit was formed due to different tectonic and magmatism episodes. Accordingly, the Nui Phao tungsten deposit is relatively complicated with the multi-sources of ore components. Most of the tungsten ore was accumulated in association with the metasomatism between the Ordovician-Silurian carbonate-terrigenous sedimentary rocks of the Phu Ngu formation and the Cretaceous two-mica granite of the Pia Oac complex. The research results indicate that tungsten resources obtained at levels 122 and 333 are about 227.6 thousand tons. Moreover, the hydrothermal alteration and metasomatism in the study area are influenced by at least three metasomatic episodes, including skarnisation, greisenisation, and the late hydrothermal alteration of medium to a low temperature that is genetically related to fluorite-polymetallic mineralization.
{"title":"Mineralogical and geological characteristics of the Nui Phao tungsten deposit and its resource in the Dai Tu area, northeastern Vietnam","authors":"Khang Quang Luong, Hung The Khuong, Dung Tien Vo, Tuyen Danh Nguyen","doi":"10.46326/jmes.2022.63(6).01","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).01","url":null,"abstract":"Typically, granitic intrusions that document the lengthy and intricate history of the magmatic-hydrothermal system are linked to tungsten deposits. Uncertainty persists about the genetic relationship between tungsten mineralization and magmatic-hydrothermal development. The primary tungsten deposit in the Dai Tu region, known as the Nui Phao deposit, has been the subject of a petrographical and microscopic examination. Tungsten mineralization in the Dai Tu area often occurs in association with the formation of skarn and greisen bodies, and it has drawn much attention from geoscientists. Based on microscopic observations, tungsten ores can be divided into three mineralization stages, namely skarnisation, greisenization, and hydrothermal stage. To examine the geochemical features of the tungsten ores, the SEM-EDS and Microscope analytical methods were performed in this study. Research results indicate that the Nui Phao tungsten deposit was formed due to different tectonic and magmatism episodes. Accordingly, the Nui Phao tungsten deposit is relatively complicated with the multi-sources of ore components. Most of the tungsten ore was accumulated in association with the metasomatism between the Ordovician-Silurian carbonate-terrigenous sedimentary rocks of the Phu Ngu formation and the Cretaceous two-mica granite of the Pia Oac complex. The research results indicate that tungsten resources obtained at levels 122 and 333 are about 227.6 thousand tons. Moreover, the hydrothermal alteration and metasomatism in the study area are influenced by at least three metasomatic episodes, including skarnisation, greisenisation, and the late hydrothermal alteration of medium to a low temperature that is genetically related to fluorite-polymetallic mineralization.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128687190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.46326/jmes.2022.63(6).03
Toan Huu To, Thanh Van Nguyen, Long Khac Nguyen, H. Dinh
In the past, the application of magnetic susceptibility of diamagnetic and paramagnetic minerals to the study of rock magnetism was believed to be limited, due to both of their susceptibility signals being small compared to those of minerals in other magnetic. However, recent works have proved the usefulness of diamagnetic and paramagnetic susceptibility for reservoir studies. This paper summarizes results from previous studies showing the application of magnetic susceptibility measurements for characterizing different reservoir properties. Studies on the magnetic susceptibility of crude oils from different oil field regions around the world have shown good correlations of the susceptibility values with crude oil densities as well as other physical and chemical properties. In other studies, the measurements of magnetic susceptibility at the low and high fields have also been applied on rock core samples collected from different types of oil and gas reservoirs such as clastic shoreface, carbonate, shale and oil sand reservoirs. The magnetic susceptibility measurements for core samples without damaging the core by using the probe magnetic technique is probably used as a rapid, reasonable screening method for the initial estimation of core samples. The susceptibility of rock samples does not only show good correspondence with other reservoir characterizing methods, such as downhole gamma ray, spontaneous potential logs and core permeability, but it also shows some advantages over the traditional ones. The results suggested that the measurements of magnetic susceptibility could be used as an independent and improved method for distinguishing crude oil from different types of reservoirs, identifying main lithologies and predicting the permeable zone of a reservoir as well as estimating clay mineral contents.
{"title":"A review of the applications of magnetic susceptibility measurements for improved reservoir characterization","authors":"Toan Huu To, Thanh Van Nguyen, Long Khac Nguyen, H. Dinh","doi":"10.46326/jmes.2022.63(6).03","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(6).03","url":null,"abstract":"In the past, the application of magnetic susceptibility of diamagnetic and paramagnetic minerals to the study of rock magnetism was believed to be limited, due to both of their susceptibility signals being small compared to those of minerals in other magnetic. However, recent works have proved the usefulness of diamagnetic and paramagnetic susceptibility for reservoir studies. This paper summarizes results from previous studies showing the application of magnetic susceptibility measurements for characterizing different reservoir properties. Studies on the magnetic susceptibility of crude oils from different oil field regions around the world have shown good correlations of the susceptibility values with crude oil densities as well as other physical and chemical properties. In other studies, the measurements of magnetic susceptibility at the low and high fields have also been applied on rock core samples collected from different types of oil and gas reservoirs such as clastic shoreface, carbonate, shale and oil sand reservoirs. The magnetic susceptibility measurements for core samples without damaging the core by using the probe magnetic technique is probably used as a rapid, reasonable screening method for the initial estimation of core samples. The susceptibility of rock samples does not only show good correspondence with other reservoir characterizing methods, such as downhole gamma ray, spontaneous potential logs and core permeability, but it also shows some advantages over the traditional ones. The results suggested that the measurements of magnetic susceptibility could be used as an independent and improved method for distinguishing crude oil from different types of reservoirs, identifying main lithologies and predicting the permeable zone of a reservoir as well as estimating clay mineral contents.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128495278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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