Inżynieria Mineralna <p><strong><span class="aCOpRe">Inżynieria Mineralna – <em>Journal of the Polish Mineral Engineering Society</em></span></strong></p> <p>Inżynieria Mineralna to oficjalne czasopismo Polskiego Towarzystwa Przeróbki Kopalin.</p> <p>Polityka wydawnicza Inżynierii Mineralnej wynika z realizacji podstawowego celu istnienia czasopisma naukowego – nauka to publikowanie.</p> <p>Inżynieria Mineralna zakłada przede wszystkim wsparcie dla autorów oraz młodych naukowców (stąd bardzo liberalne reguły publikowania w IM) oraz na upowszechnianiu nauki w najszerszy możliwy sposób.</p> <p>Inżynieria Mineralna tworzyła swą politykę wydawnicza w opraciu o model 3. sektorowy, wynikający ze statutu wydawcy: mamy ambicję łączyć samorząd, politykę, NGOsy, przemysł oraz naukę, w poszukiwaniu najefektowniejszych rozwiązań w zakresie inżynierii mineralnej i nauk pokrewnych.&nbsp;</p> <p>Co istotne, wydawca Inżynierii Mineralnej działa non-profit, w dodatku często wspiera organizację konferencji naukowych.</p> pl-PL (Barbara Tora) (Julia Okręglicka) śro, 22 gru 2021 00:00:00 +0100 OJS 60 Cretaceous Granitic Magmatism in South-Central Vietnam: Constraints from Zircon U–Pb Geochronology <p>South-central Vietnam abundantly presents magmatic rocks with larger volumes of<br>Cretaceous granitic rocks. In this study, zircon U–Pb geochronology of granite samples from the Deoca,<br>Ankroet, and Dinhquan complexes in south-central Vietnam are utilized to investigate Cretaceous<br>granitic magmatism. According to U–Pb analysis results, zircon ages of granitic rocks display the Deoca<br>at ~113–92 Ma, the Ankroet at ~103–98 Ma, and the Dinhquan at ~97–113 Ma. The range of ages is<br>narrow from 113 to 92 Ma, with most common ages date at ~100 Ma. Published data and our results<br>display that Cretaceous granitic magmatism was active between ~87–118 Ma and most active at ~100<br>Ma in south-central Vietnam. Additionally, the Deoca and Dinhquan complexes show inherited ages in<br>Triassic followed by Proterozoic and Carboniferous to Ordovician. The obtained ages indicate that Itype<br>granitic rocks could be derived from melting of basement rocks. Our study suggests that I-type<br>granitic rocks in south-central Vietnam were significantly intruded around 100 Ma.</p> Huu Hiep NGUYEN,Nhu Sang PHAM, Van Long HOANG, Carter ANDREW,Vinh Hau BUI ,Hoang Bac BUI ,Thanh Trung TRINH,Lam Anh NGUYEN Copyright (c) 2021 Huu Hiep NGUYEN,Nhu Sang PHAM, Van Long HOANG, Carter ANDREW,Vinh Hau BUI ,Hoang Bac BUI ,Thanh Trung TRINH,Lam Anh NGUYEN pon, 13 gru 2021 00:00:00 +0100 Automatic Monitoring System Designed for Controlling the Stability of Underground Excavation <p>Ensuring the stability of mining excavations is a crucial aspect of underground mining. For this<br>purpose, appropriate shapes, dimensions, and support of workings are designed for the given mining and<br>geological conditions. However, for the proper assessment of the adequacy of the used technical solutions,<br>and the calibration of the models used in the support design, it is necessary to monitor the behavior of the<br>excavation. It should apply to the rock mass and the support. The paper presents the automatic system<br>designed for underground workings monitoring, and the example of its use in the heading. Electronic<br>devices that measure the rock mass movements in the roof, the load on the standing support, and on bolts,<br>the stress in the rock mass, are connected to the datalogger and can collect data for a long of time without<br>any maintenance, also in hard-to-reach places. This feature enables the system to be widely used, in<br>particular, in excavations in the vicinity of exploitation, goafs, or in the area of a liquidated exploitation<br>field.</p> Piotr MAŁKOWSKI,Zbigniew NIEDBALSKI,Łukasz BEDNAREK Copyright (c) 2021 Piotr MAŁKOWSKI,Zbigniew NIEDBALSKI,Łukasz BEDNAREK pon, 13 gru 2021 00:00:00 +0100 Applying Electrical Impedance Tomography Techniques for Detection of Decay Inside Trees <p>Trees play a critical role in creating green spaces in public areas such as streets, parks, schools,<br>offices. Over time, the trees often get pests and diseases, and then rotten trees can break. To care for and<br>conserve the trees, it is necessary to determine the condition inside the trunk, especially the possibility of<br>having a hollow or not. Wood decay, modifications of moisture and ion content, density due to biotic and<br>abiotic stress agents of water extremity, salinity, and infection strongly change (di-) electrical properties<br>of wood. Hence, we propose to use electrical impedance tomography to detect the change in electrical<br>properties inside the trees that can link to wood decay. In electrical impedance tomography, an array of<br>electrodes is attached around the tree trunk, and small alternating currents are injected via these electrodes,<br>so the resulting voltages are measured. Processing the data, we can construct the spatial distribution of<br>impedance (or resistivity) of the object. In this work, we will present the preliminary results of our group<br>research. We will show theoretical forward modeling results, followed by laboratory experiments and real<br>data application. The results illustrate that electrical impedance tomography can be useful to define several<br>decay scenarios inside the trees.</p> Duy Thong KIEU,Hong Duong VU,Thi Thu Hang NGUYEN, Thu Thuy NGUYEN Copyright (c) 2021 Duy Thong KIEU,Hong Duong VU,Thi Thu Hang NGUYEN, Thu Thuy NGUYEN pon, 13 gru 2021 00:00:00 +0100 Mining-induced Land Subsidence Detected by Sentinel-1 SAR Images: An Example from the Historical Tadeusz Kościuszko Salt Mine at Wapno, Greater Poland Voivodeship, Poland <p>There are many mines in Poland that have been in operation for over 100 years, with the<br>Tadeusz Kościuszko mine being a large salt mine in Wapno, northern Poland. The mine was closed in<br>1977 due to the greatest catastrophe in the history of Polish mining, but in the first days of 2021, a very<br>large hole has been created in this area due to land subsidence. This article uses InSAR technology with<br>Sentinel-1 images to determine settlement and ongoing deformation in this mine. The study results are<br>useful for policymakers, managers, and authorities because land subsidence has caused serious and<br>dangerous effects on people living in the area. The results processed by the Persistent Scatterer InSAR<br>(PSInSAR) method with the Sentinel Application Platform and the Stanford Method for Persistent<br>Scatterers software packages show that deformation in the Wapno village area has been detected in both<br>residential and non-residential areas, with maximum subsidence of up to −19 mm/yr. The subsidence in<br>the mine reaches −12 mm/yr, and that at surrounding area range from 0 to −18.8 mm/yr.</p> Thi Thu Huong KIM,Hong Ha TRAN,Khac Luyen BUI, Tomasz LIPECKI Copyright (c) 2021 Thi Thu Huong KIM,Hong Ha TRAN,Khac Luyen BUI, Tomasz LIPECKI pon, 13 gru 2021 00:00:00 +0100 Riverbank Filtration – A Potential Water Source Exploitation for the Red River Delta Region <p>Riverbank filtration technology has been widely applied worldwide because of its high-capacity<br>collection and good water quality throughout natural purification processes. Infiltration water can be<br>extracted from Holocene (qh) layer or the Pleistocene deep layer (qp), replenished with water from the<br>river through hydrogeological windows. Hydrodynamic and isotopic signatures were employed to<br>determine water seepage capacity. The results show that infiltrated water is found in the sand layers along<br>the rivers. However, the seepage rate shows a heterogeneously spatial variation ranging from 30 m3/d in<br>the Dinh Dao river to 33,600 m3/d. Km along the shoreline in the Red River (RRD). Also, the exploitation<br>capacity of seepage water differs widely in order of large (&gt; 3,000 m3/d), medium (1,000-3,000 m3/d),<br>small (500-1,000 m3/d), and very small capacity (200-500 m3/d). This study indicated that RRD could<br>apply riverbank filtration techniques to overcome freshwater scarcity in the delta due to increasing surface<br>pollution and discharge reduction.</p> Trung Hieu NGUYEN ,Thu Ha DOAN ,Van Duy HOANG ,Thanh Tung TONG Copyright (c) 2021 Trung Hieu NGUYEN ,Thu Ha DOAN ,Van Duy HOANG ,Thanh Tung TONG pon, 13 gru 2021 00:00:00 +0100 The Influence of the Sample Preparation on the Result of Coal Propensity to Spontaneous Combustion in the High-temperature Adiabatic Method <p>The liability of coal to spontaneous combustion is the principal cause of mine fires. Spontaneous<br>combustion is one of the main threats in Polish and Vietnamese coal mines. The article presents an analysis<br>of the spontaneous combustion of coal in mines of both countries. It is related to the natural prone of coal<br>to spontaneous heating and consequently to its self-ignition. Despite the relevant recognition of the<br>methods of preventing this threat, in mines, spontaneous combustion occurs during the exploitation of<br>coal seams with low and very high self-ignition tendency. Apart from the technical factors related to the<br>design of coal seam mining, the properties of coal have a significant impact on the occurrence of<br>spontaneous combustion. Their correct recognition is essential to the precautions against spontaneous<br>combustion for minimalizing the risk of a mine fire. Therefore, it is necessary to study the factors<br>influencing the propensity of coal to spontaneous heating. A review of the methods used to determine the<br>propensity of coal to spontaneous combustion is presented in the article. Based on the high-temperature<br>method of determining the propensity of coals to spontaneous combustion, the influence of selected<br>factors related to samples' preparation for testing on the determination result was investigated. The<br>influence of the fractional decomposition and the moisture content in the prepared samples on the<br>determination result was demonstrated. The presented research results may improve research procedures<br>for determining the propensity of coal to spontaneous combustion.</p> Dariusz OBRACAJ ,Marek KORZEC ,Tien Tung VU Copyright (c) 2021 Dariusz OBRACAJ ,Marek KORZEC ,Tien Tung VU pon, 13 gru 2021 00:00:00 +0100 Artificial Neural Network Optimized by Modified Particle Swarm Optimization for Predicting Peak Particle Velocity Induced by Blasting Operations in Open Pit Mines <p>Blasting is an indispensable part of the open pit mining operations. It plays a vital role in<br>preparing the rock mass for subsequent operations, such as loading/unloading, transporting, crushing, and<br>dumping. However, adverse effects, especially blast-induced ground vibrations, are considered one of the<br>most dangerous problems. In this study, artificial intelligence was supposed to predict the intensity of<br>blast-induced ground vibration, which is represented by the peak particle velocity (PPV). Accordingly, an<br>artificial neural network was designed to predict PPV at the Coc Sau open pit coal mine with 137 blasting<br>events were collected. Aiming to optimize the ANN model, the modified version of the particle swarm<br>optimization (MPSO) algorithm was applied to optimize the ANN model for predicting PPV, called the<br>MPSO-ANN model. For the comparison purposes, two forms of empirical equations, namely United<br>States Bureau of Mining (USBM) and U Langefors - Kihlstrom, were also developed to predict PPV and<br>compared with the proposed MPSO-ANN model. The results showed that the proposed MPSO-ANN<br>model provided a better performance with a mean absolute error (MAE) of 1.217, root-mean-squared error<br>(RMSE) of 1.456, and coefficient of determination (R2) of 0.956. Meanwhile, the empirical models only<br>provided poorer performances with an MAE of 1.830 and 2.012, RMSE of 2.268 and 2.464, and R2 of<br>0.874 and 0.852 for the USBM and U Langefors – Kihlstrom empirical models, respectively.</p> Xuan-Nam BUI ,Hoang NGUYEN ,Truc Anh NGUYEN Copyright (c) 2021 Xuan-Nam BUI ,Hoang NGUYEN ,Truc Anh NGUYEN pon, 13 gru 2021 00:00:00 +0100 Integration of Delphi Technique and Analytical Hierarchy Process Method in Assessment the Groundwater Potential Influence Criteria: A Case Study of the Ba River Basin <p>Water is a boon for all living beings over the world and groundwater is considered one of the<br>indispensable natural sources of potable water. It is necessary to assess and predict the groundwater<br>potential to provide insights for decision-makers for proper planning and management of groundwater.<br>The occurrence of groundwater depends on hydrological, ecological, climate, geological, and<br>physiographical criteria. The purpose of the present study is to choose and attribute scores to all various<br>factors that affected groundwater prospects in the Ba river basin. Firstly, the Delphi method was applied<br>in the expert-based survey to choose six parameters that are considered as influencing factors, namely,<br>lineament density, rainfall, slope, land cover, drainage density, and geology. Then, the weights for the<br>various factors were generated using the Analytic Hierarchy Process (AHP) approach which allows the<br>pairwise comparison of criteria influencing the potential areas. The consistency analyses show that the<br>findings were consistent with a previous study. The consistency and sensitivity analyses showed that the<br>obtained results were coherent, providing the weight vector of the achievable criteria that affect the<br>groundwater prospect in the study area. The study reveals that lineament density and slope are criteria<br>affecting the most prominent groundwater occurrence with 35.1% and 20.1%, respectively. However, the<br>influence of other factors (rainfall, land cover, drainage density, and geology) is not visible. These criteria<br>are assigned to the small weights and do not have a significant influence on the groundwater potential.<br>The study results provide baseline</p> Tuyet Minh DANG ,Le Tung Duong NGUYEN Copyright (c) 2021 Tuyet Minh DANG ,Le Tung Duong NGUYEN wto, 14 gru 2021 00:00:00 +0100 Rule-based Classification of Airborne Laser Scanner Data for Automatic Extraction of 3D Objects in the Urban Area <p>LiDAR technology has been widely adopted as a proper method for land cover classification.<br>Recently with the development of technology, LiDAR systems can now capture high-resolution<br>multispectral bands images with high-density LiDAR point cloud simultaneously. Therefore, it opens new<br>opportunities for more precise automatic land-use classification methods by utilizing LiDAR data. This<br>article introduces a combining technique of point cloud classification algorithms. The algorithms include<br>ground detection, building detection, and close point classification - the classification is based on point<br>clouds’ attributes. The main attributes are heigh, intensity, and NDVI index calculated from 4 bands of<br>colors extracted from multispectral images for each point. Data of the Leica City Mapper LiDAR system<br>in an area of 80 ha in Quang Xuong town, Thanh Hoa province, Vietnam was used to deploy the<br>classification. The data is classified into eight different types of land use consist of asphalt road, other<br>ground, low vegetation, medium vegetation, high vegetation, building, water, and other objects. The<br>classification workflow was implemented in the TerraSolid suite, with the result of the automation process<br>came out with 97% overall accuracy of classification points. The</p> Ngoc Quy BUI ,Dinh Hien LE ,Anh Quan DUONG ,Quoc Long NGUYEN Copyright (c) 2021 Ngoc Quy BUI ,Dinh Hien LE ,Anh Quan DUONG ,Quoc Long NGUYEN wto, 14 gru 2021 00:00:00 +0100 Development of Integrated Reporting in Poland <p>Organizational reporting is the most important tool of communication between an enterprise<br>and its stakeholders. However, it is not a static tool but continues to develop and adapt to ongoing<br>economic and social changes. Formerly covering only financial information; currently, it is supplemented<br>by a wide range of non-financial information relating to all aspects of the business. The evolution of<br>reporting is particularly fostered by the rapid development of the concepts of corporate social<br>responsibility and sustainable development, as well as the progressing changes in the information needs<br>of stakeholders. Enterprises are increasingly publishing voluntary reports concerning the social,<br>environmental, and employment aspects of their business in addition to reports required by law. This<br>results in the multiplication of reports and duplication of content, which has a negative impact on the<br>reports' usefulness. The solution to this problem may be integrated reporting, which integrates and<br>interconnects financial and non-financial disclosures. A milestone for the development of integrated<br>reporting was the elaboration of integrated reporting guidelines by the International Integrated Reporting<br>Council (IIRC) in December 2013. The aim of the paper is to present the development of integrated<br>reporting in Poland in 2014-2020 on the example of public companies listed on the Warsaw Stock<br>Exchange. The quality of reports was assessed from the point of view of compliance with IIRC guidelines,<br>as well as their usefulness for stakeholders. Content analysis of corporate publications and comparative<br>analysis was used for this purpose.</p> Bartosz Rymkiewicz Copyright (c) 2021 Bartosz Rymkiewicz wto, 14 gru 2021 00:00:00 +0100 Identifying Correlation of Coal Seams in the Tien Hai Area, Northern Vietnam by Using Multivariate Statistic Methods <p>In northern Vietnam, the Tien Hai area is considered a high potential area of coal deposits. Two<br>hundred fifty-six geochemical coal samples of 13 cores in the Tien Hai area investigate coal seams and<br>coal deposits to identify the correlation of coal seams. According to the statistical method and cluster<br>analysis of geochemical samples, the results indicate that the Mg, V, As, Ca, Zn, Cr, Co, K, Na, Sr, Fe,<br>Ge, Re, U, Mo, Th, and Ga elements are good indicator elements of the major and trace elements in coal.<br>Most of them comply with the normal or lognormal distribution rules. Besides, the Yb, Sc, Ho, Er, Tm,<br>Lu, Y, Tb, Pr, Dy, and Sm elements are also good indicator elements for rare earth elements in the region.<br>Therefore, the selected elements are used to identify the correlation of the coal seams in the Tien Hai area.<br>Based on the similarity degree between studied objects, the results of grouping boreholes in coal seams<br>show that the correlation of coal seam TV2-11 is suitable and acceptable, the coal seams TV3-6a, TV3-<br>6b, and TV3-6c can be grouped into the coal seam TV3-6. These results present that the models can help<br>study geochemical coal samples and identify the correlation of the coal seams in the Tien Hai area.<br>Additionally, the statistical analysis shows a remarkable degree to determine the correlation of the coal<br>seams. Geochemical coal data can help to evaluate the indicator elements of the major, trace elements,<br>and rare earth elements in coal seams and coal rashing of adjoining and pillar rocks in the Tien Hai area,<br>northern Vietnam.</p> The Hung KHUONG ,Phuong NGUYEN ,Thi Cuc NGUYEN ,Nhu Sang PHAM ,Danh Tuyen NGUYEN Copyright (c) 2021 The Hung KHUONG ,Phuong NGUYEN ,Thi Cuc NGUYEN ,Nhu Sang PHAM ,Danh Tuyen NGUYEN wto, 14 gru 2021 00:00:00 +0100 Influence of Harmonics on the Working Efficiency of a 6/1.2 kV Transformer in a Pit Mine <p>Explosion-proof transformers 6/1.2 kV is important electrical equipment responsible for<br>supplying electricity in underground mine electrical networks. A failure of this transformer will cause an<br>interruption in the power supply and loss of safety in underground mining. Usually, explosion-proof<br>transformers in underground mine electrical networks are designed and manufactured to work with ideal<br>parameters such as sinusoidal currents, and the network structure is symmetrical. However, today in<br>underground mine electric networks, many power electronics are connected to the network, such as<br>inverters and soft starters. As a result, a current flowing through the transformer is non-sinusoidal,<br>overloading the transformer even by working with the design specifications. This paper studies the<br>influence of harmonics on the working efficiency of a 6/1.2 kV transformer in a pit mine. Research results<br>suggest reasonable solutions for transformer operation to ensure longevity and not cause damage to the<br>transformer.</p> Xuan Cuong NGO ,Nhu Y DO Copyright (c) 2021 Xuan Cuong NGO ,Nhu Y DO wto, 14 gru 2021 00:00:00 +0100 Stabilization of Deep Roadways in Weak Rocks Using the System of Two-level Rock Bolts <p>Large rock mass deformation around deep roadways in the weak rocks was a significant<br>problem in mining activities in Vietnam and other countries. The excavation of roadways leads to high<br>releasing stress, which exceeds the peak strength of spalling surrounding rock and causes it to enter the<br>post-failure stage. Tensile failures then initiate and develop around the roadways, which causes the<br>fragmentation, dilation, and separation of surrounding rock. The capacity of the primary support system<br>is low, which results in a severe contraction in the whole section of roadways, which requires finding<br>solutions to prevent the deformation of rock mass around roadways and technical solutions from<br>stabilizing for deep roadways. To stability analysis of roadways can be applied analytical, experimental,<br>semi-experimental, and numerical methods. This paper introduces the prevention mechanism of large<br>deformation of rock mass around roadways using 2-level rock bolts. The research results show that using<br>the system of two-level rock bolts can reduce the values of tensile stress on the boundary of roadways<br>range from 10 to 15% compared with only one. The importance of the total displacement of rock mass on<br>the boundary of roadways will be reduced from 3.47 to 13.85% using six long cable bolts.</p> Tuan Minh TRAN ,Ngoc Thai DO ,Trung Thanh DANG ,Duyen Phong NGUYEN ,Trong Hung VO Copyright (c) 2021 Tuan Minh TRAN ,Ngoc Thai DO ,Trung Thanh DANG ,Duyen Phong NGUYEN ,Trong Hung VO wto, 14 gru 2021 00:00:00 +0100 Stress Distribution Around Mechanized Longwall Face at Deep Mining in Quang Ninh Underground Coal Mine <p>Quang Ninh underground coal mines are currently in the phase of finishing up the mineral<br>reserves located near the surface. Also, in this phase, a number of coal mines have opened and prepared<br>new mine sites for the extraction of the reserves at greater depth. Several mines have mined at -350 m<br>depth and are driving opening excavations at -500 m depth below sea level. The mining at greater depth<br>faces many difficulties, such as a significant increase in support and excavation pressures. The longwall<br>face pressure is mostly manifested in great magnitude that causes support overloaded and jumped and<br>face spall/roof fall. This paper, based on the geological condition of the Seam 11 Ha Lam coal mine,<br>uses the numerical program UDEC for studying the impact of mining depth on stress distribution around<br>the longwall face. The results show that the deeper the mining is, the greater the plastic deformation<br>zone is. The peak front abutment stress moves closer to the coal wall, mainly concentrating on the<br>immediate roof and top coal. The top coal is greatly broken, and its bearing capacity is decreased. Some<br>solutions to the stability of roof strata are proposed, and a proper working resistance of support is<br>determined. Additionally, the paper suggests that the starting depth for deep mining in Quang Ninh<br>underground coal mines should be -350 m below sea level.</p> Manh Tung BUI ,Tien Dung LE ,Trong Hung VO Copyright (c) 2021 Manh Tung BUI ,Tien Dung LE ,Trong Hung VO wto, 14 gru 2021 00:00:00 +0100 Geometrical Tests of Powered Roof Support Positioning in a Longwall Complex <p>A powered roof support protects people and equipment in the longwall from potential danger<br>posed by the surrounding rock mass. The study to determine the position of the powered roof support<br>was conducted in an active longwall. The research team made measurements of the geometric height of<br>the powered roof support structure located in the longwall complex. The main objective of this study<br>was to determine the position of the powered roof support in actual underground conditions. The<br>analysis of the results provided data on whether the assumed height of the longwall was maintained<br>during operation of the complex.</p> Dawid SZURGACZ ,Sergey ZHIRONKIN ,Konrad TRZOP ,Stefan VÖTH ,Leszek SOBIK ,Michal CEHLÁR Copyright (c) 2021 Dawid SZURGACZ ,Sergey ZHIRONKIN ,Konrad TRZOP ,Stefan VÖTH ,Leszek SOBIK ,Michal CEHLÁR czw, 16 gru 2021 00:00:00 +0100 General Geometric Model of GNSS Position Time Series for Crustal Deformation Studies – A Case Study of CORS Stations in Vietnam <p>In processing of position time series of crustal deformation monitoring stations by continuous<br>GNSS station, it is very important to determine the motion model to accurately determine the displacement<br>velocity and other movements in the time series. This paper proposes (1) the general geometric model for<br>analyzing GNSS position time series, including common phenomena such as linear trend, seasonal term,<br>jumps, and post-seismic deformation; and (2) the approach for directly estimating time decay of<br>postseismic deformations from GNSS position time series, which normally is determined based on seismic<br>models or the physical process seismicity, etc. This model and approach are tested by synthetic position<br>time series, of which the calculation results show that the estimated parameters are equal to the given<br>parameters. In addition they were also used to process the real data which is GNSS position time series of<br>4 CORS stations in Vietnam, then the estimated velocity of these stations: DANA (n, e, u = -9.5, 31.5, 1.5<br>mm/year), HCMC (n, e, u = -9.5, 26.2, 1.9 mm/year), NADI (n, e, u = -10.6, 31.5, -13.4 mm/year), and<br>NAVI (n, e, u = -13.9, 32.8, -1.1 mm/year) is similar to previous studies.</p> Dinh Trong TRAN ,Quoc Long NGUYEN ,Dinh Huy NGUYEN Copyright (c) 2021 Dinh Trong TRAN ,Quoc Long NGUYEN ,Dinh Huy NGUYEN czw, 16 gru 2021 00:00:00 +0100 Phase Diagrams of the Excitonic Insulator State: Analyzing the Excitonic Susceptibility <p>In this paper, the formation of the excitonic insulator state in the rare-earth chalcogenides has<br>been investigated through the extended Falicov-Kimball model. Adapting the unrestricted Hartree-Fock<br>approximation, we have derived a set of explicitly self-consistent equations determining expectation<br>values and the excitonic susceptibility in the system. Analyzing the excitonic susceptibility, we have<br>established phase diagrams of the excitonic insulator state depending on the model parameters. The phase<br>structures confirmed the excitonic insulator state is found at low temperature and between two critical<br>values of the Coulomb interaction. The effect of the external pressure on the formation of the excitonic<br>insulator state is also shown.</p> Thi Hong Hai DO ,Thi Hau NGUYEN Copyright (c) 2021 Thi Hong Hai DO ,Thi Hau NGUYEN czw, 16 gru 2021 00:00:00 +0100 Geotechnical Properties of Soft Marine Soil at Chan May Port, Vietnam <p>Soft marine soil deposit is distributed under the sea with many special properties. This type of<br>soil is rarely researched in Vietnam because of the difficult geotechnical investigation under the sea level.<br>In this paper, the experimental laboratories were performed to investigate the geotechnical properties of<br>soft marine soil at Chan May port, Vietnam. The field investigation results indicate that the thickness of<br>soft soil varies from a few meters to more than ten meters. Soft soil has a high value of water content,<br>void ratio, and compressibility and a low value of shear strength. The compression index has a good<br>relationship with water content, liquid limit, and dry unit weight. The unit weight, shear strength, and preconsolidation<br>pressure increase with the increase of depth. These results show that the soil in the study<br>area is unfavorable for construction activities.</p> Thi Nu NGUYEN ,Thanh Duong NGUYEN ,Truong Son BUI Copyright (c) 2021 Thi Nu NGUYEN ,Thanh Duong NGUYEN ,Truong Son BUI czw, 16 gru 2021 00:00:00 +0100 Applying the Lessons Learned from the Economics Nobel Prize 2020 to Land Use Right Auction in Vietnam <p>This paper mainly relies on qualitative research methodology and secondary data. The paper<br>examines the existing legal framework for land use right auction in Vietnam and its practical<br>implementation, focusing on acquiring agricultural land for non-agricultural purposes. It shows the<br>limitations of sharing information and the disadvantages in distributing and balancing the benefits among<br>different stakeholders who participated in the land use right auction. Also, this paper analyses and<br>propounds the key lessons learned from the 2020 Economics Nobel Prize in creating the information<br>sharing and benefit-sharing mechanism among participants. The paper applies these lessons learned from<br>the 2020 Economics Nobel Prize to create a foundation for policy change the legal regulations of land use<br>right auction in Vietnam in order to bring benefits to households, investors, and the State.</p> Ngoc Huong Quynh PHAM ,Thi Ngoc Mai NGUYEN Copyright (c) 2021 Ngoc Huong Quynh PHAM ,Thi Ngoc Mai NGUYEN czw, 16 gru 2021 00:00:00 +0100 An Overview of Rare Earth Ores Beneficiation in Vietnam <p>Rare earth metals are used in electricity, electronics, nuclear, optics, space, metallurgy,<br>superconducting and super magnetic materials, glass and ceramics, and agriculture. Some rare earth<br>elements are added to fertilizers for crops and some trials for animal feed. Rare earth elements, except<br>for radioactive promethium, are relatively abundant in the earth's crust. Vietnam has a tremendous rare<br>earth potential, distributed mainly in the Northwest, including Nam Xe, Dong Pao, Muong Hum, and<br>Yen Bai. There are many research projects on rare earth ores of different types globally, but the focus is<br>mainly on the essential minerals, including monazite, xenotime, and bastnaesite. This report summarizes<br>research data on rare earth ore intending to produce a general assessment of rare earth ore and its<br>beneficiation technology in Vietnam.</p> Thi Kim Dung NHU ,Van Luan PHAM ,Thi Chinh VU ,Van Duoc TRAN Copyright (c) 2021 Thi Kim Dung NHU ,Van Luan PHAM ,Thi Chinh VU ,Van Duoc TRAN czw, 16 gru 2021 00:00:00 +0100 Technological and Economic Analysis of the Application of Surface Miner on the Example of a Limestone Deposit in Poland <p>Mining a deposit utilizing surface miner is very popular in many countries. Presently, a surface<br>miner has also experimented with extracting different deposits: bauxite, hematite, sandstone, shale etc.<br>Surface miners can completely eliminate drilling and blasting operation and primary crushing unit, thus<br>reducing their associated environmental hazards. Apart from this, the sized excavated material increases<br>transport or conveying efficiency and saves the energy requirement in processing. So far, these machines<br>have not been used in Poland. To evaluate this technology, tests were carried out on one of the limestone<br>deposit in Poland. During these tests, basic parameters of efficiency, output quantity and mining costs<br>were defined. The conducted tests have shown that this technology cannot be used in all geological and<br>mining conditions. Therefore, the article presents the advantages and disadvantages of using surface<br>miner, taking into account the Polish geological and mining conditions.</p> Maciej ZAJĄCZKOWSKI Copyright (c) 2021 Maciej ZAJĄCZKOWSKI czw, 16 gru 2021 00:00:00 +0100 Determination of Land Fund for the Development of Static Road Traffic Demand in Hanoi (Vietnam) <p>Determining a reasonable proportion of land fund for urban static traffic will meet the current<br>needs and future development of urban areas, contributing to improving the operational quality of urban<br>transport systems and improve the quality of life of people in urban areas [1]. Hanoi, the capital of Viet<br>Nam, is facing difficulties in meeting the land fund for static traffic development. In 2020, the city's land<br>fund meets only 38.73% of the demand for traffic system development in general, static traffic in particular<br>[2]. By using a regression model on the relationship between GDP per capita and demand for means of<br>transport in Hanoi, the article forcats the demand for urban static traffic development in Hanoi city,<br>demand demand for land fund for its static traffic development to 2025 and 2030. From the forecast results,<br>the article proposes some solutions on meeting the land fund demand for static traffic development in<br>order to achieve efficiency of the government's policis on static traffic development in Hanoi.</p> Anh PHAN ,Thi Hong Lan VO ,Huy Duong PHAN Copyright (c) 2021 Anh PHAN ,Thi Hong Lan VO ,Huy Duong PHAN czw, 16 gru 2021 00:00:00 +0100 Assessment of Change in Urban Green Spaces Using Sentinel 2 MSI Data and GIS Techniques: A Case Study in Thanh Hoa City, Vietnam <p>This paper presents the results of an assessment of change in urban green spaces in Thanh Hoa<br>city (Vietnam). Sentinel 2 MSI data in 2015 and 2021 are used to calculate 3 parameters: percentage of<br>green, weight of green types, and weight of proximity to green. These parameters are used to calculate the<br>Weighted Urban Green Space Index (WUGSI). The final result shows the distribution of green space in<br>the study area consisted of very high-quality green, high-quality green, moderate quality green, and low<br>quality green. The obtained results show that the quality of urban green space in Thanh Hoa city has<br>changed significantly in the period 2015-2021, in which the area with category “low quality green space”<br>increased from 7.17% up to 9.48%; areas with category “very high-quality green space” reduced from<br>65.02% to 47.39%.</p> Viet Nghia NGUYEN ,Le Hung TRINH ,Thi Thu Nga NGUYEN ,Thi Le LE Copyright (c) 2021 Viet Nghia NGUYEN ,Le Hung TRINH ,Thi Thu Nga NGUYEN ,Thi Le LE czw, 16 gru 2021 00:00:00 +0100 Mineralogical and Geochemical Characteristics of Lead-zinc Ore Deposits, and Potential Accompanying Components in the Cho Don - Cho Dien Area, Bac Kan Province, Vietnam <p>The Pb-Zn mineralization in the Cho Don - Cho Dien ore districts often occurs in 2 types: (1)<br>oxidized ore near to the surface and (2) sulfide ore at deeper section. Based on microscopic observations,<br>sulfide ores can be divided into sphalerite-galena-pyrite and/or galena-sphalerite mineralization types. To<br>examine the geochemical features of the Pb-Zn ores, SEM-EDX and ICP-MS analytical methods were<br>performed in this study. Previous δ34S data of Pb-Zn concentrates, and sulfide minerals from various<br>deposits suggest that the Pb-Zn ore-forming fluids might be related to the felsic-granitic magmatic<br>activities rather than a genesis of stratiform type. Geochemical data show that the major, minor, and trace<br>element compositions of lead-zinc ores have wide ranges of variation even in each deposit. The sulfide<br>ores are generally higher in economic components than those in the oxidized ores. The positive<br>correlations between Pb-Ag can be found in the entire dataset, whereas excellent Zn-Cd correlation can<br>only be observed from Cho Don ore samples. Apart from the principal components (Pb and Zn), the ores<br>also contain other accompanying elements that supply high-technological manufacturing industries. Of<br>which As, Cu, Ag, Sb, and Cd could be potential by-products and can be extracted during smelting Pb/Zn<br>concentrate processes, and need more detailed studies for every deposit.</p> Tien Dung NGUYEN ,Khac Du NGUYEN ,Ngoc Thom NGUYEN Copyright (c) 2021 Tien Dung NGUYEN ,Khac Du NGUYEN ,Ngoc Thom NGUYEN czw, 16 gru 2021 00:00:00 +0100 State Governance of Coal Mining Industry towards Sustainable Development in Vietnam <p>Coal is one of the most precious mineral resource, mining and mineral processing contributes<br>to the economic development. In Vietnam, coal mining industry is economically profitable. However, this<br>industry shows several disadvantages such as low productivity, wasting resources, negative environmental<br>impact. Therefore, the State of Vietnam need to improve the coal mining governance to raise revenues,<br>avoid wasting resources and meet the requirements of sustainable development. The paper aims to<br>evaluate State governance of coal mining industry in Vietnam, and shows the advantages and<br>disadvantages of this governance. Therefore, this paper proposes the strategies and solutions to improve<br>coal mining governance in Vietnam towards sustainable development. The structure of the paper includes:<br>(i) Literature review of the importance and requirements of state governance of coal mining industry<br>towards sustainable development; (ii) State governance of coal mining industry in Vietnam; (iii) Proposals<br>to improve State governance of coal mining industry towards sustainable development in Vietnam.</p> Thi Khanh Ly CHU ,Ngoc Huong Quynh PHAM ,Tu Phuong PHAM ,Quynh Nga NGUYEN Copyright (c) 2021 Thi Khanh Ly CHU ,Ngoc Huong Quynh PHAM ,Tu Phuong PHAM ,Quynh Nga NGUYEN czw, 16 gru 2021 00:00:00 +0100 Life Cycle Inventory (LCI) Stochastic Approach Used for Rare Earth Elements (REEs), Considering Uncertainty <p>The purpose of the paper is to present the results of the stochastic modelling with uncertainty<br>performed with the use of Monte Carlo (MC) simulation with 10,000 cycles and a confidence interval of<br>95 %, as recommended. Analysed REEs were fitted by lognormal distributions by using the Crystal Ball®<br>(CB) spreadsheet-based software after defining the geometric mean value (μg) and the standard deviation<br>(σg), automatically calculated (matches) the lower, as well as, upper boundaries of lognormal distribution.<br>The number of replications of a simulation affects the quality of the results. The principal output report<br>provided by CB and presented in this study consists of the graphical representation in the form of the<br>frequency chart, percentiles summary, and statistics summary. Additional CB options provide a sensitivity<br>analysis with tornado diagrams. The data that was used for MC simulation of the LCI model includes<br>available and published data concerning associated with the REEs. This paper discusses the results and<br>show that the adopted approach is applicable for any REEs used in the LCI studies under uncertainty. The<br>results obtained from this study can be used as the first step in performing a full LCA analysis and help<br>practitioners as well as decision-makers in the environmental engineering and management.</p> Dariusz SALA ,Bogusław BIEDA Copyright (c) 2021 Dariusz SALA ,Bogusław BIEDA czw, 16 gru 2021 12:48:54 +0100 Estimation of Suspended Sediment Concentration in Downstream of the Ba River Basin using Remote Sensing Images <p>Assessing the tendency of suspended sediment concentration (SSC) in the river watersheds<br>enables a better understanding of the hydromorphological properties of its basins and the associated<br>processes. In addition, analyzing this trend is essential to address several important issues such as erosion,<br>water pollution, human health risks, etc. Therefore, it is critical to determine a proper method to quantify<br>spatio-temporal variability in SSC. In recent years, remote sensing and GIS technologies are being widely<br>applied to support scientists, researchers, and environmental resource investigators to quickly and<br>synchronously capture information on a large scale. The combination of remote sensing and GIS data will<br>become the reliable and timely updated data source for the managers, researchers on many fields. There<br>are several tools, software, algorithms being used in extracting information from satellites and support for<br>the analysis, image interpretation, data collection. The information from satellite images related to water<br>resources includes vegetational cover, flooding events on a large scale, rain forecast, population<br>distribution, forest fire, landslide movements, sedimentation, etc., and especially information on water<br>quality, sediment concentration. This paper presents the initial result from LANDSAT satellite image<br>interpretation to investigate the amount of sediment carried downstream of the Ba river basin.</p> Ba Dung NGUYEN ,Tuyet Minh DANG Copyright (c) 2021 Ba Dung NGUYEN ,Tuyet Minh DANG czw, 16 gru 2021 13:10:51 +0100 A Numerical Method for the Design of the U-Shaped Segmental Tunnel Lining under the Impact of Earthquakes: A Case Study of a Tunnel in the Hanoi Metro System <p>Circular tunnels are usually encountered when excavation tunnel. However, the U-shaped<br>tunnel lining is used a lot in practice because of it’s advantages. However, there are not many studies in<br>the world to calculate and design for underground structures with U-shaped tunnel lining, especially in<br>the case of tunnels being affected by earthquakes. This paper proposes a new numerical-HRM method<br>approach for the analysis of U-shaped segmental tunnel lining under the impact of earthquakes. Hanoi is<br>the capital of Vietnam, this is a big city with more than 8 million people. Hanoi is located between two<br>major fault systems, the Red River fault system and the Son La-Dien Bien-Lai Chau fault system.<br>Therefore, the Hanoi area is assessed as likely to be affected by earthquakes of magnitude Mw = 6.1 up to<br>6.5 Richter. The Hanoi metro system is constructed by TBM and the U-shaped segmental tunnel lining is<br>also one of the types of tunnel lining considered for use in the construction of metro tunnels in Hanoi. The<br>improved HRM method has been used to investigate the effect of joints in the tunnel lining from the Hanoi<br>system metro under the impact of earthquakes is conducted considering from the results of the tunnel<br>lining behavior in terms of bending moment (M), normal forces (N) and tunnel lining displacements (δn)<br>in both cases: the U-shaped continuous tunnel lining and the U-shaped segmental tunnel lining.</p> Chi Thanh NGUYEN ,Ngoc Anh DO ,Van Vi PHAM ,Alexandr GOSPODARIKOV Copyright (c) 2021 Chi Thanh NGUYEN ,Ngoc Anh DO ,Van Vi PHAM ,Alexandr GOSPODARIKOV czw, 16 gru 2021 13:14:10 +0100 Development of Support Plan and Operation Scheme for Semimechanized Longwall Face of Coal Seam 10T, Nam Khe Tam Mine – 86 Company, Dong Bac Corporation <p>Support plans and operation schemes of mine faces are critical technical documents in<br>underground coal mining management. The development and selection of a reasonable support plan and<br>operation scheme of the face are complicated because they involve many factors. In specific mining<br>conditions, developing and selecting an appropriate support plan and operation scheme will improve the<br>working efficiency of equipment, increase labor productivity, and ensure workers' safety. This article<br>researched a mining technology for the thin seams, focusing on coal seam 10T in Nam Khe Tam coal<br>mine, 86 Coal Company. From the analysis of geo-mining conditions, the article developed and selected<br>a reasonable support plan and operation scheme for the face in coal seam 10T. After being used in the<br>field, the support plan and operation scheme have brought the face efficiency and safety.</p> Trung Tien VU ,Tien Dung LE ,Tien Dung LE ,Thai Tien Dung VU Copyright (c) 2021 Trung Tien VU ,Tien Dung LE ,Tien Dung LE ,Thai Tien Dung VU czw, 16 gru 2021 13:32:22 +0100 Research the Integration of Geodetic and Geotechnical Methods in Monitoring the Horizontal Displacement of Diaphragm Walls <p>This article investigates the integration of geodetic and geotechnical methods for monitoring<br>the horizontal displacement of diaphragm walls. The results show that when the horizontal displacement<br>is measured by the geotechnical method using an inclinometer sensor, the center point at the bottom of<br>the guide pipe is usually chosen to be the origin to calculate displacements of the upper points. However,<br>it is challenging to survey the bottom point for checking its stability directly. If this bottom point moves,<br>the observation results will be incorrect. Thus, the guide pipe must be installed in the stable rock layer.<br>But in the soft ground, this rock layer locates more deeply than the diaphragm walls, so the guide pipe<br>cannot be laid out at the required location. Geodetic methods can directly observe the displacement of the<br>center point on the top of the guide pipe with absolute displacement values at high accuracy. Because the<br>displacements of observation points are determined at stable benchmarks, these values are considered the<br>pipe's displacement. Thus, an integrated solution allows the center point on the top of the pipe to be the<br>origin to calculate the displacements of different points located inside the diaphragm wall. Then, the<br>calculated values are calibrated back to the inclinometer observed values to achieve highly reliable<br>displacement, which reflects the moving of diaphragm walls. An experiment integrating the geodetic and<br>geotechnical methods is conducted with an observation point at a depth of 20 meters at a construction site<br>in Ho Chi Minh city. The deviations of the top point that are observed by the two methods are -4.37<br>millimeters and -3.69 millimeters on the X-axis and the Y-axis, respectively. The corrected observed<br>results prove that the integrated solution has a good efficiency in monitoring the horizontal displacement<br>of diaphragm walls. The bottom point observed by an inclinometer is unconfident enough to choose to be<br>a reference point.</p> Quoc Khanh PHAM ,Ngoc Dong TRAN ,Thi Kim Thanh NGUYEN ,Van Chung PHAM Copyright (c) 2021 Quoc Khanh PHAM ,Ngoc Dong TRAN ,Thi Kim Thanh NGUYEN ,Van Chung PHAM czw, 16 gru 2021 00:00:00 +0100 Influence of Single-Phase Voltage Loss and Load Carrying Mode on Mine Drainage Pump Motor in Vietnam <p>Mine drainage pump is the most important load in mining which requires high reliability<br>when operating. Currently, the power supply of a mine drainage pump is connected to the same power<br>line with many nonlinear loads, and is equipped with power electronic converters, which makes the<br>power supply nonsinusoidal. During the working process of a mine drainage pump, the load-carrying<br>factor often changes, and many types of failures occur, among which single-phase voltage loss is the<br>most common problem. In the case of a nonsinusoidal power supply, if a single-phase voltage loss<br>occurs in different load modes, it will greatly affect the working mode of the mine drainage pump<br>leading to influences on the working efficiency, the life of the pump, and sometimes it is necessary to<br>recalculate the protection parameters. This paper studies the influence of single-phase voltage loss and<br>load carrying mode on the working mode of mine drainage pump motor in case the of nonsinusoidal<br>power supply. Research results show that, in the case of nonsinusoidal power supplied with single-phase<br>voltage loss, copper losses in the rotor and stator circuits increase with increases in voltage total<br>harmonic distortion (THD) and load-carrying factor, 5th order reverse harmonic increases copper loss in<br>asynchronous motor the most, and higher harmonic components have less effect on copper loss in the<br>motor. At the same time, the speed ripple decreases with the increase of the motor load factor and<br>decreases in the presence of the 5th order negative sequence harmonic, and increases significantly in the<br>presence of the 7th order positive sequence harmonic. 5th order negative sequence harmonic increases,<br>the torque ripple increases, while the 7th order positive sequence harmonic reduces the torque ripple in<br>the case of single-phase voltage loss. The results of the paper will help improve the operational<br>efficiency of the mine drainage pump in Vietnam's mines.</p> Nhu Y DO ,Xuan Cuong NGO Copyright (c) 2021 Nhu Y DO ,Xuan Cuong NGO czw, 16 gru 2021 14:20:11 +0100 Method of Air Temperature Forecast in Mechanized Longwall Workings in the Conditions of Vietnamese Mines <p>In the most recent years, the Vietnam National Coal - Mineral Industries Holding Corporation<br>Limited (VINACOMIN) has been dynamically developing mechanization technologies in underground<br>coal mines. The climatic conditions of Vietnam, as well as increasing the depth of the coal seams and the<br>production capacity, contribute to an air temperature increasing in mining excavations. The article<br>presents statistical equations enabling air temperature forecasting at the outlet of mechanized longwall<br>workings. The results of numerical calculations, obtained from the solutions of the adopted mathematical<br>descriptions, were compared with the measurement results and the statistical significance of the obtained<br>deviations was determined. The performed analysis allowed to assess the practical usefulness of the<br>adopted model for the air temperature forecasting in the workings of mechanized underground mines in<br>Vietnam. The presented method can be used as a tool for mining services in the fight against the climate<br>threat in underground excavations.</p> Tien Quan TRUONG ,Rafał ŁUCZAK,Piotr ŻYCZKOWSKI,Marek BOROWSKI Copyright (c) 2021 Tien Quan TRUONG ,Rafał ŁUCZAK,Piotr ŻYCZKOWSKI,Marek BOROWSKI czw, 16 gru 2021 14:23:15 +0100 VISION ZERO – Tools for Safety, Health, and Well-being Management and the Application in the Vietnamese Coal Mining Industry <p>The Vietnamese mining industry is one of the most dangerous industries in the country. Mining<br>companies understand safety and health for sustainable development at the mining sector and the national<br>level. Thus, they have been applying many measures to improve their safety and health management<br>achievements. Besides technology measures, organizational and personal measures are priorities. At the<br>international level, VISION ZERO is a global movement based on the belief that all accidents, diseases,<br>and harm at work are preventable. VISION ZERO develops its Seven Golden Rules to guide leaders,<br>managers, and workers to create a safe and healthy working environment for the well-being of employees.<br>The paper focuses on VISION ZERO, its theoretical aspects, and the application process in the Vietnamese<br>coal mining companies.</p> Nga NGUYEN ,Ulrich MEESMANN ,Ngoc-Linh TRUONG ,Vu-Hoa TRINH Copyright (c) 2021 Nga NGUYEN ,Ulrich MEESMANN ,Ngoc-Linh TRUONG ,Vu-Hoa TRINH czw, 16 gru 2021 14:33:42 +0100 Current Status of Coal Mining and Some Highlights in the 2030 Development Plan of Coal Industry in Vietnam <p>Coal mining is one of the key mining industries in Vietnam. Coal is also an important fuel for<br>many other industries. Currently, coal mining is mainly concentrated in Quang Ninh coal basin, the<br>proportion of open-pit coal mining and underground mining is quite similar. However, according to<br>Decision 403/QD-Ttg on approving the adjustment of the Vietnam coal industry development plan up to<br>2020, considering the prospects by 2030, the mining output will be from 51 to 54 million tons by year<br>2025 and from 55 to 57 million tons by 2030. In which, the proportion of underground coal mining will<br>increase gradually compared with that of open-cast mining, specifically, by 2030, the proportion of the<br>later compared to that of the former will be only 11%. According to this plan, open-pit coal mines have<br>been shifting to underground mining technology, due to the increasingly deep conditions of coal seams.<br>The following article will analyze the current status of coal mining in Vietnam and some highlights of the<br>coal industry development plan to 2030, in order to provide a general picture of Vietnam’s coal industry<br>in the future.</p> Quynh Nga NGUYEN ,Van Hau NGUYEN ,Tu Phuong PHAM ,Thi Khanh Ly CHU Copyright (c) 2021 Quynh Nga NGUYEN ,Van Hau NGUYEN ,Tu Phuong PHAM ,Thi Khanh Ly CHU czw, 16 gru 2021 14:46:51 +0100 Cause and Solution to Roadway Deformation in Vietnam Underground Coal Mines <p>The deformation and support method of roadways have always been important issues in safe<br>mining and production. Vinacomin's statistics show that, by 2021, there will be 64.19 km of roadways<br>that need to be repaired (accounting for 25% of the total new roadways). Thus, the problem of maintaining<br>roadway stability is facing difficulties in underground coal mines in Vietnam. To find out the causes of<br>roadway failures, a case study at roadways of the Khe Cham I and Khe Cham III coal mines, Vietnam, is<br>presented in this paper. Based on the results of a detailed field survey, the deformation characteristics of<br>roadways and the failure mode of support structures were investigated. The results show that the roadway<br>deformation is severe and the main support cannot control surrounding rock mass. Also, the destruction<br>of support structure is frequent on reused roadways, affecting production efficiency and work safety.<br>Therefore, to reduce deformation and increase roadway stability, a new support method called “multistage<br>anchor of rock bolt + cable bolt” has been developed and a new longwall mining system with critical<br>coal pillar width has been proposed. The new findings of the research can provide references for scientific<br>studies, and apply them in Vietnam's underground coal mine practices.</p> Quang Phuc LE Copyright (c) 2021 Quang Phuc LE czw, 16 gru 2021 14:57:58 +0100 Research and Development of Real-time High-precision GNSS Receivers: A Feasible Application for Surveying and Mapping in Vietnam <p>In recent years, the Global Navigation Satellite System (GNSS) has been widely applied in<br>surveying and mapping. Currently, in Vietnam, dual-frequency GNSS receivers are quite extensively<br>applied with the real-time kinematic (RTK) measurement technique using a continuously operating<br>reference station network. However, high-accuracy GNSS receivers are often expensive, sometimes not<br>meeting the needs of users for specific applications. This research develops two types of low-cost highprecision<br>GNSS receivers for RTK positioning for different purposes. First, the millimeter precision<br>GNSS receiver used in real-time displacement monitoring is based on Trimble's BD970 mainboard<br>technology and some other modules. These components are interconnected according to a standard<br>design scheme and assembled in an enclosure to form a GNSS receiver. In addition, a GNSS data<br>transmission in the National Marine Electronics Association standard format by Networked Transport of<br>Radio Technical Commission for Maritime Services via Internet Protocol (NTRIP) has been<br>designed and developed. The GNSS receiver after development is loaded with program code written in<br>the C# programming language, using the Arduino programming tool. Second, the GNSS receivers have<br>the centimeter accuracy for RTK positioning used in surveying and mapping based on U-blox's<br>mainboard technology and some other modules. These modules are also connected together according to<br>a standard design scheme and assembled in an enclosure to form a complete GNSS receiver. The<br>evaluation results show that the designed and developed GNSS receivers completely meet the<br>requirements of surveying and mapping in coal mines in Vietnam, such as real-time monitoring of<br>landslides, surveying and topographical mapping and other surveying works to serve the mining process.</p> Cong Khai PHAM ,Gia Trong NGUYEN ,Van Hai NGUYEN,Trong Xuan TRAN Copyright (c) 2021 Cong Khai PHAM ,Gia Trong NGUYEN ,Van Hai NGUYEN,Trong Xuan TRAN czw, 16 gru 2021 15:01:39 +0100 Promoting Information and Communication Technology in Online Service Delivery in Vietnam <p>Applying Information and Communication Technology (ICT) to public service delivery<br>contributes to transparency, accountability, and cost-saving to improve administrative efficiency. This<br>application has become an inevitable trend for administrative reform worldwide. This paper examines the<br>policy of promoting ICT in public service delivery and its implementation in Vietnam. Recently, the<br>Vietnamese government has created a thoroughly legal foundation to develop information infrastructure<br>for public service delivery. However, online public service delivery results are still lower than expected,<br>and the online service index in Vietnam has just reached the average level of the world. Therefore, to<br>encourage citizens to use online public services, the government should improve the personal<br>identification data system and promote propagating and popularize online public services. The<br>government also should protect personal data and administrative system security to ensure organizational<br>system safety and efficiency.</p> Thi Ngoc Mai NGUYEN ,Ngoc Huong Quynh PHAM Copyright (c) 2021 Thi Ngoc Mai NGUYEN ,Ngoc Huong Quynh PHAM czw, 16 gru 2021 15:06:18 +0100 Strengthening Inspection and Audit of Occupational Safety and Health in Coal Mining Enterprises in Vietnam <p>Coal mining is one of the heavy, hazardous industries. Therefore, workers in this industry<br>always face high risks of occupational accidents and diseases. According to the annual report of the<br>Ministry of Labor, Invalids and Social Affairs (MoLISA), the situation of occupational accidents and<br>illnesses in the mining sector in recent years has increased both in terms of number and severity, and this<br>includes fatal occupational accidents in the coal mining industry. Currently, the authorities have been<br>implementing inspection of occupational safety and health (OSH) to prevent and limit the situation. In the<br>scope of this article, the author focuses on clarifying the position and the role of OSH inspecting while<br>presenting and analyzing the results of the inspection of OSH legislation compliance within the coal<br>mining industry nationwide. From there, proposing several solutions to strengthen inspection of OSH,<br>prevent and limit occupational accidents and diseases in the coming time, contributing to improving the<br>efficiency of state management of OSH in the coal mining industry in Vietnam today.</p> Kim Tu NGO Copyright (c) 2021 Kim Tu NGO czw, 16 gru 2021 15:15:47 +0100 Some Effects on the Temperature of the Mine Air at the Heading Face <p>Currently, with the increase in mining output leading to deeper mining levels, the volume of<br>heading face serving production has also increased. The thermal environment tends to worsen when<br>digging deep due to the geothermal's effect, which increases the air temperature at the heading face.<br>According to QCVN01/2011-BCT, the temperature at the heading face is not allowed to exceed 300C. To<br>ensure this, in Vietnam today, mainly forced ventilation method uses local fans to provide a clean amount<br>of air to ensure a favorable environment for workers. With the forced ventilation method, the duct position<br>is usually arranged on the side, and the distance from the duct mouth to the heading face is determined to<br>ensure that l &lt; 6√s. In this study, a numerical simulation method by Ansys CFX software is applied to<br>study the influence of several factors such as duct position, air temperature of duct, and roughness<br>characteristics of roadway on the temperature of the mine air at the heading face. The models are set up<br>with six duct positions and four air temperature of duct parameters. Model 1 (y =1.1 m) is better than<br>models 2 to 6 in terms of temperature distribution and the lowest temperature values. Four models have<br>different wind temperatures, and we can see the significant influence of the inlet air temperature of the<br>duct on the thermal environment of the heading face. The results show that with the model T = 297.15K,<br>the temperature value on the roadway length is guaranteed as specified &lt; 303K. The result is a reference<br>for determining the duct position and cool for the high-temperature heading face.</p> Van Quang NGUYEN ,Van Thinh NGUYEN ,Cao Khai NGUYEN ,Van Chung PHAM Copyright (c) 2021 Van Quang NGUYEN ,Van Thinh NGUYEN ,Cao Khai NGUYEN ,Van Chung PHAM czw, 16 gru 2021 15:19:01 +0100 Circular Economy Model and the Implementation in Vietnamese Coal Mining Industry <p>The circular economy is the economic model that has been applied for a long time in the<br>world. This model is applied at all three levels: micro (enterprise-level), intermediate (industry level,<br>industrial zone level), and macro-level (local level, regional level, or national level). Vietnamese Coal<br>Mining Industry has been having important contributions to the socio-economic development of<br>Vietnam. However, this industry also causes lots of issues about environmental pollution. In the context<br>of resource depletion, environmental pollution and the cost of exploiting and processing increases with<br>the deep exploiting process; the tastes of utilizing resources, minimizing environmental pollution, and<br>creating more value-added for this industry are inevitable requirements. Because of the tasks, applying<br>the circular economy model into this industry (both intermediate and micro-level) is the urgent solution<br>for the sustainable development of the Vietnamese Coal Mining Industry. The paper uses a combination<br>of research methods such as theoretical research, case study research, statistical data analysis, etc., to<br>propose the circular economy model for the Vietnamese Coal Mining Industry and some solutions to<br>deploy this model into the industry's operations towards sustainable development.</p> Dinh Chieu LE ,Thi Bich DONG Copyright (c) 2021 Dinh Chieu LE ,Thi Bich DONG czw, 16 gru 2021 15:21:17 +0100 Monitoring Vegetation Cover Changes by Sentinel-1 Radar Images Using Random Forest Classification Method <p>Vietnam is an Asian country with hot and humid tropical climate throughout the year. Forests<br>account for more than 40% of the total land area and have a very rich and diverse vegetation.<br>Monitoring the changes in the vegetation cover is obviously important yet challenging, considering such<br>large varying areas and climatic conditions. A traditional remote sensing technique to monitor the<br>vegetation cover involves the use of optical satellite images. However, in presence of the cloud cover,<br>the analyses done using optical satellite image are not reliable. In such a scenario, radar images are a<br>useful alternative due to the ability of radar pulses in penetrating through the clouds, regardless of day or<br>night. In this study, we have used multi temporal C band satellite images to monitor vegetation cover<br>changes for an area in Dau Tieng and Ben Cat districts of Binh Duong province, Mekong Delta,<br>Vietnam. With a collection of 46 images between March 2015 and February 2017, the changes of five<br>land cover types including vegetation loss and replanting in 2017 were analyzed by selecting two cases,<br>using 9 images in the dry season of 3 years 2015, 2016 and 2017 and using all of 46 images to conduct<br>Random Forest classifier with 100, 200, 300 and 500 trees respectively. The result in which the model<br>with nine images and 300 trees gave the best accuracy with an overall accuracy of 98.4% and a Kappa<br>of 0.97. The results demonstrated that using VH polarization, Sentinel-1 gives quite a good accuracy for<br>vegetation cover change. Therefore, Sentinel-1 can also be used to generate reliable land cover maps<br>suitable for different applications.</p> Van Anh TRAN ,Thi Le LE ,Nhu Hung NGUYEN ,Thanh Nghi LE ,Hong Hanh TRAN Copyright (c) 2021 Van Anh TRAN ,Thi Le LE ,Nhu Hung NGUYEN ,Thanh Nghi LE ,Hong Hanh TRAN czw, 16 gru 2021 00:00:00 +0100 Doing Business in Vietnam from the Perspectives of Polish Entrepreneurs – the Role of Local Partners <p>The purpose of this paper is to investigate the challenges of expanding into an emerging market<br>for multinational enterprises (MNEs) and the strategies they adopted to overcome these adversities. While<br>interest in the expansion of MNEs into the Vietnamese market is increasing, there is a lack of research on<br>this process from the Polish businesses' perspectives, which may differ from existing literature. The<br>analysis of information obtained by a semi-structured interview method shows that the psychic/cultural<br>distance is the most critical challenge the Polish enterprises must face when entering the Vietnamese<br>market. The study also shows that the key success factor for the expansion of the Polish enterprises into<br>this market is a local partner, i.e., acquiring an appropriate Vietnamese partner, good cooperation with<br>him/her, and building mutual trust. As a result, among the available forms of internationalization, the<br>Polish enterprises most often choose export and various forms of cooperation with local partners as the<br>main ways to enter this market.</p> Cao Son NGUYEN Copyright (c) 2021 Cao Son NGUYEN czw, 16 gru 2021 16:03:21 +0100 Genotype TNF-α(-308) and Silicosis on Factory Workers in Vietnam in 2020 <p>The studFigy aims to determine the TNF-α single-nucleotide polymorphism TNF-α (-308) and<br>assess the association of TNF-a(-308) SNP with the risk of silicosis among workers directly exposed to<br>silica dust in Vietnam. A study was undertaken among 78 cases with silicosis and 103 controls without<br>silicosis in Vietnam. Blood samples were collected for genomic DNA extraction from each subject. The<br>phenotyping of TNF-α(-308) was performed using polymerase chain reaction‐based restriction fragment<br>length polymorphism (PCR‐RFLP) and dye termination sequencing. Results: The average exposure time<br>of the case group was slightly higher than that of the control group (12.46 ± 6.732 years vs. 12.09 ± 7.854<br>years). The majority of genotypes in both silicosis and non-silicosis was GG. When analyzing the<br>concentration of TNF-α in the study participants' blood, it is shown that the average concentration of TNF-<br>α in the case group was higher than that in the control group. The genotype AG in the case group was<br>1.368 times higher than that in the control group. The percentage of all A alleles in the case group with<br>silicosis was 1.342 times higher than the control group without the disease, similar to previous studies.<br>Conclusion: The majority of genotypes in both groups was GG. The average concentration of TNF-α in<br>blood, genotype AG, and the percentage of all A alleles in the case group was higher than that in the<br>control group.</p> Viet NGUYEN ,Thi Thu Huyen NGUYEN ,Xuan Dat DAO ,Xuan Quy VU ,Thi Quan PHAM ,Thi Kim Chung LE ,Huy Thinh TRAN ,Thi Huong LE ,Ngoc Anh NGUYEN ,Viet Nhung NGUYEN ,Ngoc Hong NGUYEN ,Mai Anh LUONG ,Thi Thanh Xuan LE Copyright (c) 2021 Viet NGUYEN ,Thi Thu Huyen NGUYEN ,Xuan Dat DAO ,Xuan Quy VU ,Thi Quan PHAM ,Thi Kim Chung LE ,Huy Thinh TRAN ,Thi Huong LE ,Ngoc Anh NGUYEN ,Viet Nhung NGUYEN ,Ngoc Hong NGUYEN ,Mai Anh LUONG ,Thi Thanh Xuan LE pią, 17 gru 2021 00:00:00 +0100 Assessing Impacts of Mining Activities on Land Use/Land Cover Change Using Remote Sensing and GIS Techniques: A Case Study in Campha City, Vietnam <p>Coal is one of the most mining commodities to date, especially to supply both national and<br>international energy needs. Coal mining activities that are not well managed will have an impact on the<br>occurrence of environmental damage. The present study was undertaken to analyze the process of humaninduced<br>landscape transformation in the coal mines affected areas of Cam Pha, northeast Vietnam by<br>interpreting temporal remote sensing data and using Geographic Information System. This experiment<br>revealed that most of the study area was dominated by forest in all the time sequence period. The forest<br>cover has decreased about 21.3%, meanwhile having nine fold increase in mining area from 1990 to 2020.<br>The forest area lost during the study period was 7983.45 ha due to land cover conversion into mining area.<br>The mining activities were also detrimental to the bare land and water body cover. The results of this study<br>are expected to be used to support government efforts and mining managers in post-mining coal activities.</p> Thi Thu Ha LE Copyright (c) 2021 Thi Thu Ha LE pon, 20 gru 2021 15:38:38 +0100 Research and Solution Proposals to Optimize Distribution Power Grids in Smart Grid Condition <p>Smart Grid is a concept for transforming the electric power grid by using advanced automatic<br>control and communications techniques and other forms of information technology. It integrates<br>innovative tools and technologies from: generation, transmission and distribution. This also includes<br>consumer appliances and equipment. This concept integrates energy infrastructure, processes, devices,<br>information and markets into a coordinated and collaborative process. All allowing energy to be generated,<br>distributed and consumed flexibly and efficiently. However, the Smart Grid with the integration of<br>distributed generation itself also creates a several disadvantages. There can be problems with: stability<br>and reliability, relay protection, isolation and operational isolation in which the problem is to create a<br>burden on the distribution grid when transmitting electrical energy sources. Optimizing power flow and<br>bringing high operating efficiency on Smart Grid conditions is an urgent issue. This paper focuses on<br>researching and proposing solutions for optimal calculation of power flow on Smart Grid. The paper has<br>researched, and analyzed calculation solutions to optimize power flow and proposed to use the Lagrange<br>multiplier method. The study performed calculations for a typical Smart Grid model with three distributed<br>generations. Calculation results have shown that the role of the method is to fully perform the optimal<br>calculation of the power flow on the grid. This is in order to reduce power loss and energy loss as well as<br>increasing operational efficiency while improving power quality in Smart Grid conditions.</p> Trung Son PHAM ,Dinh Tien NGUYEN ,Quang Thuan NGUYEN ,Quang Khoa DANG Copyright (c) 2021 Trung Son PHAM ,Dinh Tien NGUYEN ,Quang Thuan NGUYEN ,Quang Khoa DANG pon, 20 gru 2021 15:43:57 +0100 Strategy in Dispatching Trucks and Shovels with Different Capacity to Increase the Operating Efficiency in Cao Son Surface Coal Mine, Vietnam <p>In surface mining operations, the operating costs of truck-shovel system constitutes 50-60% of<br>the total. Only a little save in the operation costs in this system will bring large profit for the mines. Due<br>to many investment periods, the capacity of both trucks and shovels in Cao Son surface coal mine is<br>different. This leads to the low efficiency and the difficulty in dispatching strategy for the mine. This<br>paper presents the current situation and selection of advanced dispatching strategy for increasing the<br>efficiency trucks and shovels at this surface coal mine. The results show the detailed match factor reflects<br>the state of each team of loader and trucks and should be use as the indicator for dispatching decision for<br>the heterogeneous truck and shovel fleet at Cao Son surface coal mine.</p> Van Hoa PHAM ,Trung Chuyen TRAN ,Hong Anh LE ,Thi Thu Hoa LE ,Van Viet PHAM Copyright (c) 2021 Van Hoa PHAM ,Trung Chuyen TRAN ,Hong Anh LE ,Thi Thu Hoa LE ,Van Viet PHAM pon, 20 gru 2021 15:47:21 +0100 The capability of terrestrial laser scanning for monitoring the displacement of high-rise buildings <p>Recently, terrestrial laser scanner (TLS) has been increasingly used to monitor of<br>displacement of high-rise buildings. The main advantages of this technique are time-saving, higher<br>point density, and higher accuracy in comparison with GPS and conventional methods. While TLS is<br>ordinary worldwide, there has been no study of the capability of TLS in monitoring the displacement of<br>high-rise buildings yet in Vietnam. The paper's goal is to build a procedure for displacement monitoring<br>of high-rise buildings and assess the accuracy of TLS in this application. In the experiments, a scanned<br>board with a 60 cm x 60 cm mounted on a moveable monument system is scanned by Faro Focus3D<br>X130. A monitoring procedure using TLS is proposed, including three main stages: site investigation,<br>data acquisition and processing, and displacement determination by the Cloud-to-Cloud method (C2C).<br>As a result, the displacement of the scanned object between epochs is computed. In order to evaluate the<br>accuracy, the estimated displacement using TLS is compared with the real displacement. The accuracy<br>depends on scanning geometry, surface property, and point density conditions. Our results show that the<br>accuracy of the estimated displacement is within ± 2 mm for buildings lower than 50 m of height. Thus,<br>TLS completely meets the accuracy requirements of monitoring displacement in the Vietnam Standards<br>of Engineering Surveying. With such outstanding performance, our workflow of using TLS could be<br>applied to monitor the displacement of high-rise buildings in the reality of geodetic production in<br>Vietnam.</p> Trung Dung PHAM ,Quoc Khanh PHAM ,Xuan Cuong CAO ,Viet Hung NGUYEN ,Sy Cuong NGO Copyright (c) 2021 Trung Dung PHAM ,Quoc Khanh PHAM ,Xuan Cuong CAO ,Viet Hung NGUYEN ,Sy Cuong NGO pon, 20 gru 2021 15:50:43 +0100 Protection of Female Workers' rights in Employment and Incomes in Vietnam <p>As an important task of the country's socio-economic development, protecting the rights of<br>female workers in employment and income is concerned and implemented by international organizations<br>and all countries in the world. The COVID-19 pandemic has been affecting the global economy and hurt<br>the incomes and employment of many female workers. In Vietnam nowadays, there is an increase in the<br>unemployment rate of female workers, gender inequality in employment and income, and the ability to<br>secure their jobs and income. The article analyzes the current regulations and their implementation in the<br>employment and income of Vietnamese female workers in the context of the COVID-19 pandemic. The<br>article also proposes some recommendations on legal provisions related to training backup jobs, arranging<br>and employing female employees, providing income support for female employees during leave due to<br>the COVID-19 epidemic; and policies related to female workers and their employers. These<br>recommendations will improve Vietnam's labor law on female workers’ rights in employment and income<br>and enhance the efficiency of human resource use and socio-economic development.</p> Thi Hong Loan NGUYEN ,Thu Trang PHAM ,Thi Ngoc Anh NGUYEN ,Thi Thu Thuy BUI ,Hong Thai NGUYEN Copyright (c) 2021 Thi Hong Loan NGUYEN ,Thu Trang PHAM ,Thi Ngoc Anh NGUYEN ,Thi Thu Thuy BUI ,Hong Thai NGUYEN pon, 20 gru 2021 15:53:55 +0100 Research, Calculation and Proposal of Ventilation Solution for Duong Huy Coal Mine when Mining Down to -250 m Depth <p>At present, according to the extraction plan in the year 2020 of Duong Huy Coal Company -<br>Vinacomin, the mining is divided into three main zones: Central Zone extracts 06 faces; South Zone<br>extracts 2 faces and Northeast Zone extracts 2 faces. The designated total production of all zones is<br>1,880,000 tons/year. To ensure the production of each mining zone, exhaust fan stations are installed at<br>ventilation roadway adits with a total of 05 main fan stations. However, in the near future, to ensure and<br>maintain production activities, the mine is being planned and operated using 03 main fan stations. The<br>calculation results for the reasonable working mode of fan stations are as follows: for fan station FBCDZ-<br>8-№32B at level +47 m, airflow is 167.69 m3/s and air pressure is 243.74 mm H2O; for fan station 2K56-<br>№30 level +40 m, airflow is 123.37 m3/s and air pressure is 324.79 mm H2O; for fan station FBCDZ-8-<br>№32B at level +44 m, airflow is 167.69 m3/s and air pressure is 354.99 mm H2O.</p> Van Chi DAO ,Tien Dung LE ,Thai Tien Dung VU ,Hong Cuong NGUYEN Copyright (c) 2021 Van Chi DAO ,Tien Dung LE ,Thai Tien Dung VU ,Hong Cuong NGUYEN pon, 20 gru 2021 15:56:58 +0100 The Impact of Coal Exploitation on Tidal Flat Changes, an Investigation Using Remote Sensing Data in Vietnam <p>Tidal flat plays a crucial role in socio-economic development and ecological environment.<br>Tidal flats in Ha Long-Cam Pha in Vietnam are impacted by human activities, especially coal mining<br>activities. Using remote sensing data is able to detect, extract, and monitor the changes of tidal flats and<br>exploited coal mine area with multi-temporal, in various scales, and for a large coverage. This study<br>aims to investigate the impact of coal mining activities on the changes of tidal flats using remote sensing<br>in Cam Pha, Ha Long, one of the biggest coal basins in Vietnam. Digital Elevation Models (DEMs) of<br>tidal flats constructed by Landsat satellite images acquired in years 1989, 2001, and 2014 are compared<br>to determine the volume changes. Besides, coal mining activities including coal production, waste rock<br>dump area, and the expansion of open coal mine during the period 1989-2014 are investigated using<br>correspondent Landsat images and the reports from the coal mine companies in the study area. Sediment<br>samples in tidal flats are analyzed to determine the origin of the sediments. As the results, organic matter<br>in the tidal flats is dominant with the concentration of 459 g/kg to 607 g/kg, which is evidence for the<br>impact of coal exploitation on the coastal environment. In addition, the relationship between coal mine<br>activities and tidal flat variation is well observed in this study.</p> Thi Lan PHAM ,Si Son TONG,Thi Thu Ha LE ,Thi Le LE ,Huu Duc HOANG Copyright (c) 2021 Thi Lan PHAM ,Si Son TONG,Thi Thu Ha LE ,Thi Le LE ,Huu Duc HOANG pon, 20 gru 2021 16:01:05 +0100 A Solution to Ensure Ventilation when Expanding the Area of Cam Thanh Underground Coal Mine, Ha Long Coal Company, Vietnam <p>In the process of underground mining, the mining system changes for various reasons. One of<br>the main reasons is changes in the mining production plans, especially the scales and outputs. Nowadays,<br>coal mines in Vietnam have been expanding in width and depth, and so have the mines’ ventilation<br>systems. Consequently, there will be changes in the alteration of the structure of the design ventilation<br>system, which reduces the effectiveness of the ventilation and does not meet the main objective of mine<br>ventilation, directly affect the safety of the working environment in the mine. Therefore, it is necessary to<br>research the improvement of the ventilation system with the development and specific conditions of<br>underground coal mines in Vietnam, improving the efficiency of the ventilation work and assuring the<br>safety of the mine environment. Cam Thanh coal mine, Ha Long coal company, Vietnam, is the case study<br>for this research. The article considers the plan of increases the mining output by more than 1.5 times,<br>propose solutions to improve the ventilation system accordingly, helping the company proactively<br>implement the production plan, ensure the working environment's safety, and reduce the costs of mine<br>ventilation.</p> Cao Khai NGUYEN ,Van Thinh NGUYEN ,Phi Hung NGUYEN ,Van Quang NGUYEN Copyright (c) 2021 Cao Khai NGUYEN ,Van Thinh NGUYEN ,Phi Hung NGUYEN ,Van Quang NGUYEN pon, 20 gru 2021 16:05:20 +0100 Prediction of Ground Subsidence During Underground Construction of Metro Line 2, Section 1, Ben Thanh - Tham Luong <p>Urban metro line No. 2 from An Suong station to Thu Thiem is one of the six metro lines that<br>is planned to be built in Ho Chi Minh City (HCMC). The metro line goes through the area in which the<br>stratigraphy consists of many units, distributed from 20-80 m. The hydrogeology mainly has 2 aquifers,<br>namely Holocene, and Pleistocene which affecting the deep excavation. During construction, there will<br>be some problems that will affect the work on the surface such as settlement, cracking, and damage. By<br>finite element method on Plaxis software, the article forecasts the surface settlement during this metro<br>line No.2. The results show that the ground settlement is relatively large in areas with soft ground<br>structures. The settlement results depend on the geological structure characteristics, hydrogeological<br>characteristics, and the shape and size of the tunnels.</p> Nhat Luan VO ,Thi Nu NGUYEN ,Minh Toan DO Copyright (c) 2021 Nhat Luan VO ,Thi Nu NGUYEN ,Minh Toan DO pon, 20 gru 2021 16:07:55 +0100 Career Orientation of Students in the Faculty of Mining at Hanoi University of Mining and Geology <p>Career orientation has become significant in Vietnamese education recently. To students of the<br>Mining Faculty of Hanoi University of Mining and Geology, this issue is more important as society<br>changes its acceptance of mining. The research uses investigation, interview, and observation methods for<br>205 students to see their career orientation. The performance is on the following criteria: 1) Career choice<br>based on individual interests, abilities, personalities, career values; 2) Understanding of the profession in<br>aspects of quality and capacity, workplace, future working environment, the development trend, etc.; 3)<br>The suitability of the profession with individual interests, abilities, personality, and values of the<br>profession during the study; 4) Study plans to meet industry requirements; 5) Self-development plans in<br>the future career. Research results show that the majority of students have the right and appropriate career.<br>These students have clear and positive motivations and goals in the learning process. Only a few students<br>have not determined the proper position in the profession due to their emotions, which are not stable and<br>oriented.</p> Thi Hoa TRUONG ,Thuy Quynh NGUYEN ,Thi Thanh Tra NGUYEN ,Tat Thang NGUYEN Copyright (c) 2021 Thi Hoa TRUONG ,Thuy Quynh NGUYEN ,Thi Thanh Tra NGUYEN ,Tat Thang NGUYEN pon, 20 gru 2021 16:11:37 +0100 Exploring the Relation between Seismic Coefficient and Rock Properties Through Field Measurements and Empirical Model for Evaluating the Effect of Blast-Induced Ground Vibration in Open- Pit Mines: A Case Study at the Thuong Tan III Quarry (Vietnam) <p>Blasting is one of the most effective methods for fragmenting rock in quarries. Nevertheless, its<br>adverse effects are significant, especially blast-induced ground vibration. Field measurement and<br>empirical equations are simple methods to determine and estimate the intensity of blast-induced ground<br>vibration. However, we cannot evaluate the effects of blast-induced ground vibration on the surrounding<br>environment based on these outcomes. Therefore, this study explores the relation between seismic<br>coefficient and rock properties through field measurements and an empirical model for evaluating the<br>effect of blast-induced ground vibration in open-pit mines. Accordingly, the seismic coefficient (K) is<br>considered the main objective in this study. Firstly, it was determined based on the rock properties.<br>Subsequently, an empirical model for estimating blast-induced ground vibration was developed based on<br>field measurements. This empirical equation was then expanded to determine K to check whether it<br>matches the determined K by the rock properties. Finally, it was used as the threshold to determine the<br>maximum explosive charged per delay to ensure the safety of the surrounding environment from blastinduced<br>ground vibration. For this aim, the Thuong Tan III quarry (in Binh Duong province, Vietnam)<br>was selected as a case study. Fifth-teen blasting events with a total of 75 blast-induced ground vibration<br>values were recorded and collected. An empirical equation for estimating blast-induced ground vibration<br>was then developed based on the collected dataset, and K was determined in the range of 539 to 713 for<br>the Thuong Tan III quarry. Based on the measured blast-induced ground vibrations, developed empirical<br>model, and K values, the Phase 2 software was applied to simulate the effects of blast-induced ground<br>vibration on the stability of slopes as one of the impacts on the surrounding environment. From the<br>simulation results, we can determine the maximum explosive charged per delay for each type of rock to<br>ensure the stability of the slope.</p> Quang Hieu TRAN Copyright (c) 2021 Quang Hieu TRAN pon, 20 gru 2021 16:15:04 +0100 Improvement of State Institution on Mineral Resources Management and Exploitation in Vietnam <p>Vietnam's mining industry has a long history with mines distributed throughout the country. It<br>has contributed significantly to national economic growth. However, it also causes negative impacts on<br>the environment, thereby affecting sustainable development and mineral resource management.<br>Therefore, mineral resource management is one of the most critical tasks of state management. The factors<br>that directly affect this issue are the institutional system and state management tools by the law. State<br>institutions are an essential tool to regulate behaviors and establish social orders and disciplines in all<br>fields, including mineral resources management. This article presents the current law on managing and<br>exploiting mineral resources to provide orientations and solutions to improve the state institution on these<br>activities in Vietnam. Based on clarifying the theory of state institutions and analyzing the current legal<br>document systems in Viet Nam, the paper emphasizes the role of appraisal in improving the quality of<br>legal documents and perfecting state institutions.</p> Ngoc Huyen PHAM ,Thi Hoai Nga NGUYEN ,Quoc Long NGUYEN ,Quoc Cuong NGUYEN ,Ngoc Bich NGUYEN Copyright (c) 2021 Ngoc Huyen PHAM ,Thi Hoai Nga NGUYEN ,Quoc Long NGUYEN ,Quoc Cuong NGUYEN ,Ngoc Bich NGUYEN pon, 20 gru 2021 16:18:01 +0100 Applying Artificial Pillar to Replace the Coal Pillar Protecting Roadway to Increase Production Efficiency and Sustainable Development in the Vietnamese Coal Industry <p>Vietnam's domestic coal production is growing fast and is expected to reach 68.9 million tons<br>in 2030, nearly 1.5 times higher than today. Open-pit mines will gradually reduce production and close,<br>and underground mining coal output will increase progressively year by year and take a leading role.<br>Besides the investment in new mines to achieve these goals, it is necessary to maximize the coal reserve<br>exploited annually of existing underground mine projects, which its coal reserve in pillars protecting<br>roadways currently accounts for 12−15%. The further exploitation of this coal reserve will decrease the<br>costs of preparation of underground mines and granting mining rights and depreciation of infrastructure<br>assets. Moreover, it will help reduce the loss of non-renewable resources and contributing to the<br>sustainable development of Vietnam’s coal industry.</p> Van Cuong DINH ,Anh Tuan NGUYEN ,Van Thanh TRAN ,Thi Hoai Nga NGUYEN ,Duc Hai DUONG Copyright (c) 2021 Van Cuong DINH ,Anh Tuan NGUYEN ,Van Thanh TRAN ,Thi Hoai Nga NGUYEN ,Duc Hai DUONG pon, 20 gru 2021 16:21:19 +0100 Using the Potential of The Employees' Expertise and Awareness of Occupational Hazards in The Mining Industry <p>The paper highlights the results of a study that examined the employees' expertise and<br>awareness of occupational hazards in their work environment. The research involved a survey conducted<br>in the form of a short questionnaire among employees responsible for loading and hauling of excavated<br>material in an opencast mine. Among 23 major hazards that were thus identified, there were global hazards<br>(affecting the entire mining process) as well as local, task-specific hazards. Depending on the number of<br>responses, 10 local and 3 global hazards were identified in the analyzed area, involving noise, stress and<br>dust. Active participation of the crew in the risk identification process helped in the assessment of their<br>criticality levels, according to employees carrying out various task, highlighting the benefits of such<br>approach for effective work safety management in a mining company. The conducted research<br>demonstrated yet another goal to be achieved - i.e. the comparison of criticality levels of hazards as<br>identified by employees and those reported in occupational risk assessment reports in the mine.</p> Dagmara Nowak-Senderowska,Michał Patyk Copyright (c) 2021 Dagmara Nowak-Senderowska,Michał Patyk pon, 20 gru 2021 16:25:22 +0100