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2023 | Buch

Advances in Geospatial Technology in Mining and Earth Sciences

Selected Papers of the 2nd International Conference on Geo-spatial Technologies and Earth Resources 2022


Über dieses Buch

This book composes the proceedings of the international conference on Geo-Spatial Technologies and Earth Resources (GTER 2022) which was co-organized by Hanoi University of Mining and Geology and the International Society for Mine Surveying (ISM) held at Hanoi city on October 13–14, 2022.
GTER 2022 is technically co-sponsored by Vietnam Mining Science and Technology Association (VMST), Vietnam Association of Geodesy, Cartography and Remote Sensing (VGCR), Vietnam National Coal-Mineral Industries Holding Corporation Limited (VINACOMIN), and the Dong Bac Corporation (NECO).
GTER 2022 aims to bring together experts, researchers, engineers, and policymakers to discuss and exchange their knowledge and experiences in recent geospatial technologies, advances in mining and earth sciences.


Application of Unmanned Aerial Vehicles for Surveying and Mapping in Mines: A Review

The use of unmanned aerial vehicles (UAVs) is increasing in the mining industry because of the obvious economic and environmental benefits as well as reducing the risk to mineworkers. This paper presents a review of recent developments in relation to the applications of UAVs in surveying and mapping of surface, underground, and abandoned mines. Additionally, after detecting the barriers associated with the deployment of UAV technology in mine surveying, the counter methods to overcome these challenges will be discussed. Finally, the prospects for the development of UAVs are also considered. The results indicate that UAVs can be used for constructing surfaces, creating three-dimensional (3D) models, evaluating their accuracy, and conducting topographic surveying of surface mines. Additionally, this system is a useful tool for mapping underground and abandoned mines. This paper provides a technical reference for expanding the knowledge and recognition of UAV applications in surveying and mapping in mine areas.

Long Quoc Nguyen, Minh Tuyet Dang, Luyen K. Bui, Quy Bui Ngoc, Truong Xuan Tran
Mining-Induced Land Subsidence Detected by Persistent Scatterer InSAR: Case Study in Pniówek Coal Mine, Silesian Voivodeship, Poland

In Europe, coal energy has recently been limited due to environmental pollution. However, other sources still do not provide enough energy for European countries. Additionally, the limitation in coal exploitation has resulted in reducing labor market in mining workers. Therefore, despite having to pay a fine every day, coal mines are still operated in Poland. Pniówek is a fifty-year coal mine in the south of Poland with over 1000 m depth. It is one of the largest coal reserves in Poland, with a total operative resource 101.9 million tons. This mine provides about 12,200 tons of coal every day. This paper uses 44 images Sentinel-1A satellite data from June 19th 2018 to December 23rd 2019 with InSAR technology to determine subsidence and ongoing deformation on and around this mine. The study results are useful for policymakers, managers, and authorities with a better management system. This is because land subsidence is happening and destroying infrastructure, and threatening people live in the area. The results, which are processed by the Persistent Scatterer InSAR (PSInSAR) method with the Sentinel Application Platform (SNAP) and the Stanford Method for Persistent Scatterers software packages (StaMPS), show that the subsidence has occurred in most of the areas. The maximum line-of-sight (LOS) displacement of up to −40 mm/yr is found in the residential area near the mine in Pawłowice village, while the LOS displacement within the Pniówek mine reaches −36.7 mm/yr.

Thi Thu Huong Kim, Hong Ha Tran, Tuan Anh Phan, Tomasz Lipecki
Slope Stability Evaluation of Fenghuangshan Landfill Under Rainfall Condition: A Case Study

The landfill is usually instable by rainfall. This paper uses GeoStudio software to analyze the stability of the landfill. Four methods, including Morgenstern-Price method, Bishop method, Janbu method, and Spencer method, were used to calculate and evaluate the stability of the slope. The results show that with the duration of rainstorm, the pore water pressure increases gradually, and the slip resistance moment decreases linearly. The factor of safety is highest when the anti-slip pile is set in the middle of the slope with a maximum safety factor of 2.12. As the length of the anti-slip pile increases, the circular damage surface of the sliding bed in front of the pile gradually moves downward. When the pile length is 30 m, the sliding surface runs through the whole sliding area from the top to the foot of the slope; at this point, the sliding resistance on the slope of the central anti-slip pile reached 2921.58 kN. The shear strength of the soil is fully utilized, and the economic efficiency is optimized. Compared to the slip resistance moment under storm conditions, the minimum slip resistance moment is increased by 11,506.23 kN⋅m.

Yuru Chen, Jun Kuang, Renmin Zhu, Jianlin Cao, Jun Zhou, Qiang Tang
Forecasting PM10 Concentration from Blasting Operations in Open-Pit Mines Using Unmanned Aerial Vehicles and Adaptive Neuro-Fuzzy Inference System

In this paper, a state-of-the-art technology for modeling and controlling dust concentration from blasting operations in open-pit mines was introduced. Accordingly, a variety of smart sensors were mounted on an unmanned aerial vehicle to measure dust concentration (i.e., PM10) from blasting operations at the Thuong Tan IV quarry (Binh Duong). The meteorological conditions were also considered related to the air quality in open-pit mines. The dataset was then used to develop an artificial intelligence model for forecasting PM10 concentration in the spatial of the quarry, namely adaptive neuro-fuzzy inference system (ANFIS). The results indicated that PM10 induced by blasting operations in the quarry exceeds the allowable limit many times, and the ANFIS model can forecast PM10 concentration in the quarry with a high acceptable accuracy (~90%). It can be used to evaluate and control the air quality in the entire quarry. The paper also provided the evidence to develop better machine learning/artificial intelligence models for forecasting PM10 concentration induced by blasting operations, as well as other parameters in the air quality controlling in open-pit mines.

Xuan-Nam Bui, Chang Woo Lee, Hoang Nguyen
Assessing the Effect of Open-Pit Mining Activities and Urbanization on Fine Particulate Matter Concentration by Using Remote Sensing Imagery: A Case Study in Binh Duong Province, Vietnam

Fine particulate matter (PM2.5) leads to respiratory and cardiovascular diseases. Nowadays, PM2.5 monitoring on a large scale is a significant concern. The study aims to estimate the PM2.5 concentrations and assess the effect of open-pit mining and urbanization on PM2.5 concentrations by using satellite observations and ground-based stations over Binh Duong province, Vietnam. Aerosol Optical Depth (AOD) from Moderate Resolution Imaging Spectroradiometer (MODIS) and hourly data of PM2.5 concentrations, temperature, and relative humidity at ground-based stations in 2020 (May–December) are matched to establish the relationship between AOD and PM2.5. Linear regression and multiple linear regression methods show a good correlation with R = 0.806 and R = 0.817, respectively. The study applies both regression models to estimate the spatial distribution of monthly PM2.5 concentrations over Binh Duong province and validate with ground-based stations data (R = 0.878; RMSE = 6.62 µg/m3). The results show that the annual PM2.5 concentrations are high in the southern districts where it is densely populated and tend to decrease in the northern districts of which the highest are found in Di An (18.76 µg/m3) and Thuan An (18.76 µg/m3), the lowest is in Phu Giao (14.20 µg/m3). The study demonstrates that the development of urban built-up density and population density increases the contribution of fine particles. At the same time, open-pit mine areas are the main contribution of coarse particles.

Thanh Dong Khuc, Long Quoc Nguyen, Dinh Trong Tran, Van Anh Tran, Quynh Nga Nguyen, Xuan Quang Truong, Hien Quang Pham
Effect of Loading Frequency on the Liquefaction Resistance of Poorly Graded Sand

Cyclic simple shear tests were carried out to study the effect of frequency (f) on the poorly graded sand’s liquefaction resistance. The samples are prepared in the medium state (Dr = 60%) by the deposition method, and a wide range of f (f = 0.03, 0.05, 0.1, 0.2, and 0.5 Hz) is considered. The results show that the liquefaction resistance is uninfluenced by low f (0.03 and 0.05 Hz). When the f is higher than the optimum frequency (fopt = 0.1 Hz), the liquefaction resistance increases with increasing f.

Sung- Sik Park, Dong- Kiem -Lam Tran, Tan-No Nguyen, Seung-Wook Woo, Hee -Young Sung
An Automatic Method for Clay Minerals Extraction from Landsat 8 OLI Data. A Case Study in Chi Linh City, Hai Duong Province

Landsat satellite data have been effectively used for mineral resources extraction. This paper presents an automatic method for clay minerals extraction from Landsat 8 OLI image based on band rationing and principal component analysis methods. Firstly, the Landsat 8 data is used to calculate the NIR/RED (band5/band4) and SWIR1/SWIR2 (band6/band7) band rationing images. To highlight the distribution of clay minerals, these band rationing images are further used to multiply the digital number values of NIR and SWIR2 bands, then obtaining (band5/4) × band5 and (band6/7) × band7 images. Finally, the principal component analysis (PCA) method is used to calculate the principal components, then select the 2nd principal component (PC2) to detect clay minerals by the automatic thresholding method. The results in this research can be used to provide input information for mineral exploration.

Trinh Le Hung, Nguyen Sach Thanh, Vuong Trong Kha
Evaluation of the Precision of SARAL/AltiKa and Sentinel-3A Satellite Altimetry Data Over the Vietnam Sea and Its Surroundings

Satellite altimetry has proven to be a useful tool to measure sea surface height, which is of diverse applications in oceanography, geodesy, among others. However, the precision of satellite altimetry data is different between missions and areas. This article evaluates the precision of observed data received by two satellite altimeters of SARAL/AltiKa and Sentinel-3A in the Exact Repeat Mission mode over the Vietnam Sea and its surroundings. The precision of the data is assessed based on height differences at intersection points between ascending and descending tracks. First, the positions of each intersection point between the ascending and descending tracks are interpolated from measure points with the second-order polynomial model. Then, the standard deviation of the height difference is estimated from all intersection points for each of 34 repeat cycles (SARAL/AltiKa) and 28 repeat cycles (Sentinel-3A) over the study area. The results show that the standard deviations of the SARAL/AltiKa data are between ± 4.5 cm and ± 7.5 cm, with an average of ± 5.9 cm, while those of Sentinel-3A range from ± 4.4 cm to ± 7.7 cm, with an average of ± 5.9 cm. Of both datasets, the height differences are greater at points located close to the coastlines and islands.

Do Van Mong, Nguyen Van Sang, Khuong Van Long, Luyen K. Bui
Detection of GNSS-TEC Noise Related to the Tonga Volcanic Eruption Using Optimization Machine Learning Techniques and Integrated Data

Total Electron Content (TEC) is the integral of the electron density along the path between receivers and satellites. TEC measured from Global Navigation Satellite Systems (GNSS) data is valuable to monitor space weather and correct ionospheric models. TEC noise detection is also an essential channel to forecast space weather and research the relationship between the atmosphere and natural phenomena like geomagnetic storms, earthquakes, volcanos, and tsunamis. In this study, we apply optimization machine learning techniques and integrated GNSS and solar activity data to determine GNSS-TEC noise at the International GNSS Service (IGS) stations in the Tonga volcanic region. We investigate 38 indices related to the geomagnetic field and solar wind plasma to select the essential parameters for forecast models. The findings show the best-suited parameters to predict vertical TEC time series: plasma temperature (or Plasma speed), proton density, Lyman alpha, R sunspot, Ap index (or Kp, Dst), and F10.7 index. Applying the Ensemble algorithm to build the TEC forecast models at the investigated IGS stations gets the accuracy from 1.01 to 3.17 TECU. The study also shows that machine learning combined with integrated data can provide a robust approach to detecting TEC noise caused by seismic activities.

Nhung Le, Benjamin Männel, Luyen K. Bui, Mihaela Jarema, Thai Chinh Nguyen, Harald Schuh
Stability of Road Embankments on Weak Soils

The stability of road embankments depends on three main factors. The first one is the maintenance of drainage facilities. Loss of embankment stability occurs with damaged gutters and ditches. The second main factor is the quality of implementation of bulk earthworks. The use of unsuitable materials and their insufficient sealing is the reason why in the case of an accident, a large part of the bulk body is replaced. The third main factor is the quality of the ground on which the embankment is laid. In the case of weak and sensitive soils, even the best quality embankments lose stability. Overcoming the emergency situation in this case requires not only increased recovery costs, but also more in-depth research, taking into account the current situation in the maintenance of road infrastructure. This paper is devoted to the specifics of these studies to ensure permanent and trouble-free operation of road embankments. An analysis of the issue of embankments on weak soils is made and recommendations for the practice are provided.

Rafail Rafailov
Indirect Georeferencing in Terrestrial Laser Scanning: One-Step and Two-Step Approaches

The georeferencing procedure is to transform geospatial data from a local coordinate system to a global coordinate system, notably geodetic coordinate system on a geocentric datum. In this paper, both the one-step and two-step approaches of indirect georeferencing of 3D point cloud from terrestrial laser scanning are investigated. The georeferencing procedure is applied to a real dataset acquired by a Faro Focus3M X130 laser scanner and the control points and targets are measured by total station TS06 plus. Five scenarios are used for the comparison between the one-step and two-step approaches in terms of both accuracies of the 3D model and time consumption. Besides, the influence of the target’s configuration on the 3D model is evaluated by changing either the number or the position of the targets. The results suggest that the 3D model’s accuracies when using both the one-step and two-step approaches of indirect georeferencing are comparable. Additionally, the target’s configuration greatly affects the 3D model with the one-step approach of indirect georeferencing. From the rigorous analyses of the benefit and drawbacks of both approaches evaluated on the real dataset, the paper significantly contributes to the indirect georeferencing procedure when transforming the 3D point cloud acquired from terrestrial laser scanning into the geodetic coordinate system.

Dung Trung Pham, Long Quoc Nguyen, Tinh Duc Le, Ha Thanh Tran
Technological Solutions for Fly Ash and Red Mud Upcycling Approach the Vietnam’s Government Target of Net-Zero Carbon by 2050

At the Conference of the Parties (COP26) in 2021, over 190 world leaders came together to address climate change. In the remarks at COP26, Vietnam’s Government had committed to the net-zero carbon emissions target by 2050. This can be considered as a critical goal for Vietnam Government to respond to climate change. To achieve the Vietnamese Government’s goal of net-zero emissions by 2050, the Vietnamese Government needs to focus on low-carbon sustainable development technologies. Carbon Capture Utilization and Storage (CCUS) technology solutions can be an appropriate option based on the experience of developed countries. Before COP26, CCUS technologies were not interested in Vietnam because of the expensive investment cost, and no emission targets had been set. However, after COP26, the Vietnam Government has begun to pay attention to advanced technologies which reduce greenhouse gas emission. Accordingly, the Decree 06/2022/ND-CP regulating the mitigation of greenhouse gas emissions and the protection of the ozone layer was issued on January 7, 2022. Advanced technologies that contribute to the reduction of greenhouse gas emissions are encouraged to apply to meet the demand for net-zero carbon by 2050. This study aims to evaluate the possibilities of applying CCUS technology to recycle fly ash and red mud as raw material for low CO2 emission cement production. Thus, CCUS technical solutions in recycling waste of fly ash from the thermal power plants and red mud from bauxite processing plants are proposed. These technical solutions can provide significant support in achieving the overall goal of the Vietnam Government to reduce greenhouse gas emissions to the net-zero by 2050.

Van-Duc Nguyen, Chang-Woo Lee, Xuan-Nam Bui, Pham Van Chung, Quang-Tuan Lai, Hoang Nguyen, Tran Thi Huong Hue, Van-Trieu Do, Ji-Whan Ahn
Pile–Soil Interaction Mechanism and Optimization Measures Based on Finite Element Method

With the wide application of foundation pit engineering, the design scheme of supporting structure needs to be adjusted accordingly. The optimization of retaining structure and deformation control of foundation pit are focused on as the important problems during the construction. The finite element model of a foundation pit in Suzhou was established; the simulated results are in good agreement with the measured ones. The maximum foundation heave of foundation pit is 3.63 cm, the maximum surface settlement is 3.12 cm, and the maximum displacement of pile is 2.18 cm. The sensitivity of the parameters of the retaining pile was discussed. The maximum displacement of the pile increases significantly with the decrease of the pile diameter. Pile spacing increases from 3 to 6 m, and the maximum bending moment of pile increases by 458.971 kN·m. The insertion ratio and elastic modulus have little effect on pile position movement. The surface subsidence changes little under the influence of various parameters.

Qi Xu, Remin Zhu, Jianlin Cao, Xuedong Li, Yi Zhang, Qiang Tang
Determination of Illegal Signs of Coal Mining Expansion in Thai Nguyen Province, Vietnam from a Combination of Radar and Optical Imagery

Vietnam has diverse and rich natural resources with over 5000 mines and 60 different types of minerals. Mineral activities in Vietnam are licensed by the Government and must ensure to protect the environment and daily activities. However, due to the high profits generated from mining, there have been many illegal mining activities taking place all over Vietnam. One of the causes leading to this situation is the insufficiency in monitoring and managing resources and minerals. Additionally, many mines are located in the forest which is difficult to detect. Therefore, in this study, we adopt Sentinel-1 radar satellite image and Sentinel-2 multi-temporal satellite image to determine illegal coal mining activities at the Minh Tien coal mine, Thai Nguyen province, Vietnam. The research method includes applying Google Earth Engine (GEE) for processing the Sentinel-1 images in both ascending and descending directions and Sentinel-2 optical images to calculate the Normalized Difference Vegetation Index (NDVI) series to control the different trends from 2016 to 2021. NDVI is then employed to mask the areas with vegetation that witness no abrupt changes in the land cover. This NDVI also acts as the basis for collecting samples for Random Forest classification of the Sentinel-2 images. The results from Sentinel-1 and Sentinel-2 combined with MASK from NDVI have determined the expansion area of the Minh Tien coal mine. The results are compared with those published on the website of Thai Nguyen Portal and have a significant similarity.

Tran Van Anh, Tran Hong Hanh, Nguyen Quynh Nga, Le Thanh Nghi, Truong Xuan Quang, Khuc Thanh Dong, Tran Trung Anh
Evaluation of Coal Reserve Reliability in the Nui Beo Mine, Quang Ninh Province Based on the Statistical and Stable Random Function Methods

The Nui Beo is a famous coal mine in the Hon Gai coal zone, Quang Ninh province, where contains many coal resources in Vietnam. In this study, synthesizing and processing data of the mining geological parameters by using the stable random function and statistical methods are used to evaluate the coal reserve reliability in the Nui Beo mine. The results show that the coal reserve reliability depends on geological conditions, especially in the distances between exploration works and parameters of calculating coal reserves (i.e., thickness, density, and declination angle on coal seams). Most exploration efforts in the Nui Beo mine satisfy the suitable pattern exploration grid for reserve level 122, according to the stable random function used to calculate the affected range. Statistical models based on a confidence probability of 0.95 are used to evaluate coal reserve dependability in the research region, resulting in ± 10.12 ÷  ± 16.46% of coal reserve errors. Estimating coal resources during the exploratory process is sufficient for the exploitation design. The findings also give an overview of the parts of coal resource dependability that have been impacted and a foundation for assessing the coal resource error in the Nui Beo mine. These can be used on other coal resources with general comparable geological and mining conditions.

Khuong The Hung, Vu Thai Linh, Pham Thanh Tinh, Nguyen Khac Duc
Chromite Ore Modeling Based on Detailed Gravity Method in Pursat, Cambodia

Researching mineral deposits is an essential task for Cambodia when its resources are gradually being exhausted. Among them, Chromite ore mine is one of the top priorities. This recent study presents an analysis process based on 25 highly detailed gravimetric profiles for solving the 2.5D/3D inverse gravity problems to image chromite ore structure at the Pursat area based on the Bouguer gravity anomaly map. As a result, a relatively realistic model of chromite ore distribution in the northeast region of Phnum Kri Mountain has been built. This area has extensive reserves of chromite ore and a fungal structure with a 200–300 m depth to the upper boundary of the core layer from the outcrop on the ground surface.

Trong Cao Dinh, Hung Pham Nam, Thanh Duong Van, Luc Nguyen Manh, Bach Mai Xuan, Trieu Cao Dinh, Hung Luu Viet
Relationship Between Shear Wave Velocity and Soil Depth and Evaluation of Soil Liquefaction in Quaternary Sedimentary Layer

Earthquake can cause severe damage to major projects of Quaternary sedimentary layer, and the vibration liquefaction by shear wave velocity has been widely used due to clear physical significance, high prediction reliability, and good economy. Taking Suzhou as a typical Quaternary sedimentary area, the shear wave velocity data of 40 borehole profiles are fitted and analyzed. The results show that there is an obvious correlation between the shear wave velocity and the buried depth of shallow soil layer. By testing the distribution of buried depth points, the distribution does not meet the normal distribution. The shear wave velocity of different soils varies greatly due to different depth or weathering degree, and the interval difference is between 60 and 190 m/s. Based on liquefaction discrimination methods, the liquefaction of soil layer is distinguished. The results show that the liquefaction probability of Quaternary sedimentary layer is limited. This paper can provide basic data for evaluating seismic impact based on Quaternary sedimentary layer.

Yu Zhou, Xuedong Li, Yi Zhang, Yibin Li, Xiaoyong Zhang, Qiang Tang
Characterization of the Natural Dolomite from Thanh Liem Area, Vietnam, and Its Applications

Natural dolomite is a common mineral in Thanh Liem area, Vietnam. Currently, many dolomite mines in the area have been searched, explored and put into operation, meeting raw materials for different fields of use. However, the literature evaluating the quality characteristics of limestone is limited. This paper aims to assess the quality of the natural dolomite in the study area by combining previous data and some new analytical results such as X-ray fluorescence (XRF), X-ray diffraction (XRD), the scanning electron microscope with energy-dispersive X-ray spectroscopy (SEM–EDS), inductively coupled plasma mass spectrometry (ICP-MS) and differential thermal analysis-thermogravimetry (DTA-TG). The results show that the regional dolomite has good quality and can be used in many different fields. Dolomite (CaMg(CO3)2) was the predominant mineral in the samples, followed by calcite (CaCO3) and other trace minerals (quartz,..). The main element oxide contents of CaO and MgO are 32.5–42.1%, and 12.7–19.6%, respectively. The content of other oxides such as Al2O3, T.Fe, SiO2, MnO and K2O is not significant. The mechanical and physical properties of the stone completely meet the fields of civil construction. In addition, to improve the quality of raw materials used for each field, some mineral processing charts of dolomite and their main applications are also presented in the paper. It will be useful information for planning, exploiting and using this dolomite effectively.

Nguyen Thi Thanh Thao, Le Thi Duyen, Phenglilern Sensousit
A Mine Production Tracking Platform and Its Initial Application in the Digital Transformation for a Vietnamese Coal Exploitation Company

Promoting the application of information technology in production management is essential to improve the efficiency. Mine production data usually come in multiple categories such as rough and detailed planning, execution, assessment, examination, inspection and accreditation. These data need to be frequently exchanged between related people and groups. In current Vietnamese coal companies, this is generally achieved by using a common shared folder on a local network, which is highly vulnerable to multiple risks, e.g., data loss or defect, lack of access permission control, file simultaneous access problem, difficulties in synthesizing data for reports… and overall, will result in efficiency decline in production administration. In this study, a data management platform for the mine production data tracking which aims to solve the above problems by using a centralized server is introduced. The solution is then deployed in a coal exploitation company in Vietnam. With support from Viettech Company Ltd, an initial evaluation of the system shows a 10% human errors reduction.

Dinh-Van Nguyen, Trung-Kien Dao, Viet-Tung Nguyen, Cong-Dinh Dinh, Trung-Kien Nguyen, Nguyen Quynh Nga, Chu Thi Khanh Ly
Shear Strength of Poorly Graded Granular Material in Multi-Stage Direct Shear Test

Shear strength of soils plays an important role in geotechnical stability design. A growing number of studies have been carried out on the assessment of the shear strength of granular material using direct shear tests. However, for the same soil sample, different testing procedures may create different shear strengths causing difficulties in selecting the suitable design parameters. In this study, single-stage and multi-stage reversal direct shear tests on granular material were investigated under the drained condition as the dried sample state. Tested samples were glass beads. The drained shear strength of granular material was investigated under various normal stresses of 50, 100, and 150 kPa and three shearing rates of 0.01, 0.1, and 1.0 mm/min corresponding to slow, intermediate, and rapid speeds. The study results indicated that the shear stress of samples obtained from the different testing approaches tended to increase as the reversals increased in both the single-stage method and the multi-stage method. The strength envelopes revealed a good agreement between the fourth reversal in the single-stage test and the multi-stage direct shear test. In addition, the friction angle of glass beads was independent of shear rates under drained conditions.

Sung-Sik Park, Tan-No Nguyen, Dong-Kiem-Lam Tran, Keum-Bee Hwang, Hee-Young Sung
High-Resolution Seismic Reflection Survey of Young Sediment at Can Gio Coast, Ho Chi Minh City, Vietnam

Young river sediment layers and seabed can be investigated by application of high-resolution seismic method supplied with a sub-bottom profiler. Contrast between different acoustic impedance leads to reflection of seismic waveform propagation that can image the interest geological targets. Soai Rap River is one of the two most important water gates in Ho Chi Minh city, Vietnam to the outside world. Studying its seabed and young sedimentology plays a vital in developing transportation and sea-ward economic Vietnamese policy. We have collected, processed, and interpreted ten of 2D high-resolution seismic profiles and two prior drill holes in the survey area, Can Gio district, Ho Chi Minh city. Its 3D seabed and 3D Holocene shallow sediment representations are interpolated different 2D boundaries which can be achieved by analysis of conventionally processed seismic data and seismic textural attributes (i.e., energy and entropy). Four resulted layers consists of water and young Holocene sediments and one trough channel in the middle of the river can be interpreted.

Thuan Van Nguyen, Cuong Van Anh Le, Man Ba Duong
Analysis of Geological Structures by 2D Magnetotelluric Inversion in Bang Hot Spring Area, Quang Binh Province

The magnetotelluric method can reveal geology structures information through conductivity distribution from a few hundred meters to kilometers depending on electromagnetic data frequency measurement. Although the raw magnetotelluric data does not clearly illustrate faults or geothermal reservoirs, they can be more visible in the conductivity models after inversion. However, the 2D inverted conductivity image is often distorted by geoelectrical strike as fault zones. Hence, in this work, we have integrated geology strike analysis to 2D magnetotelluric inversion to have better data quality interpretation in the Bang hot spring area, Quang Binh Province, Vietnam. The inverted conductivity model from the 2D integrated magnetotelluric inversion can show the fault system and possible hot source zone of Bang area. Great compatibility between the magnetotelluric inversion result with other geophysical data such as seismic and prior geology information can inspire its application in geothermal research.

Cuong Van Anh Le, Duy Thong Kieu, Ngoc Dat Pham, Hop Phong Lai
Physicochemical Characteristics of the Middle Triassic Limestone in Ha Nam Province, Vietnam and the Ability of Adsorption of Heavy Metal Ions from Aqueous Environments

Calcium carbonate rocks of middle Triassic age formations account for a large amount, up to 25% of Vietnam’s limestone potential. Ha Nam is one of the areas with large reserves of middle Triassic limestone of the Dong Giao Formation, up to billions of m3. Dozens of limestone quarries have been licensed to exploit the area for different applications such as cement, lime, light powder, and common building materials. The research on limestone as a raw material in the treatment of contaminated water is still limited. In this study, the middle Triassic limestone sample (Dong Giao formation) from Ha Nam area is used to determine physicochemical characteristics and then to investigate the ability to remove Pb2+ ions from an aqueous solution. The analysis results show that the limestone in the study area is of good quality. The mineral composition is mainly calcite and the CaO content is up to 92–100%. Other properties of limestone such as physical and radioactive properties indicate that the limestone here can be used safely for different fields. For environmental treatment, different conditions such as contact time, solution pH, adsorbent weight and initial concentration of Pb2+ were tested. The results show that experimental conditions of pH0 = 6.2 and a temperature of 30 °C, with 0.1 g of limestone material and an initial concentration of Pb2+ of 50 mg/L, the Pb2+ adsorption can reach equilibrium after about 40 min and efficiency reached 98.88%. The adsorption process follows the Langmuir adsorption isotherm model with the maximum monolayer adsorption capacity of 76.22 mg/g and follows the pseudo-second-order kinetic equation. The result indicate that unmodified the Triassic limestone powder has a significant potential for the removal of heavy ions from an aqueous solution.

Bui Hoang Bac, Le Thi Duyen, Nguyen Thi Thanh Thao, Nguyen Huu Tho
Local Mechanical Behaviors of Steel Box Girder During Skew Incremental Launching

In the process of incremental launching construction, deviation error will pose a threat to the bridge safety. Two adverse conditions were selected for numerical analysis to investigate the steel box girder local stress during skew incremental launching and the effects of deviation error in the process. The maximum stress of the two working conditions is similar to that of the web when the skewed and cantilevered conditions are 275.2 MPa and 195.0 MPa, respectively. The top plates stress is 211.7 MPa under skewed condition and 73.2 MPa under cantilevered condition. There is a great difference between the two conditions. Attention should be paid to the change of top plates stress in the actual launching process. Among the three launching deviations, the longitudinal deviation presents the least influence on the girder. The vertical deviation depicts the greatest influence, which will lead to a significant increase in the local stress of the steel box girder. When the vertical displacement reaches 10 cm, the web stress reaches almost four times of the normal condition. Thus, for actual incremental launching, the synchronization of vertical launching shall be ensured as far as possible to reduce the risk during incremental launching.

Jiabao Du, Wen Niu, Yu Shi, Yongzhe Wu, Yuan Chen, Qiang Tang
GIS Applications in Land Adaptability Mapping for Perennial Industrial Crops in Nghe An Province, Vietnam

Perennial industrial crops such as coffee, rubber, pepper, etc., are a group of key crops with high economic value, contributing an important role in promoting the socio-economic development of localities. Geographic information systems (GIS) and the analytical hierarchy process (AHP) are used to develop land adaptation maps for the perennial industrial crops based on land assessment methodology of Food and Agriculture Organization of the United Nations (FAO). This research is conducted in Nghe An province because it has the largest area of agricultural land in Vietnam and has the potential to develop perennial industrial crops. Ten impact factors including soil type, elements of soil mechanic, soil layer thickness, elevation, slope, distance to river, annual average rainfall, annual average air temperature, annual mean maximum temperature, and annual mean minimum temperature are selected for natural adaptation assessment of the perennial industrial crops. The results derived from weighted identification using AHP method in GIS indicate that the impact factors related to soil such as soil type, elements of soil mechanic, and soil layer thickness have the highest impact on perennial industrial crops adaptation. Validation of the adaptation map is verified with the current land use map of Nghe An province using the receiver operating characteristic (ROC) curve that comparing the actual land use and adaptation zones. Results from this research can assist managers, planners, as well as local communities in making rational decisions for the most effective land use.

Hanh Thi Tong, Kien-Trinh Thi Bui, Cuong Manh Nguyen, Yit Chanthol
Land-Use and Land-Cover Change Detection and Classification to Analyze Dynamics of Dragon Fruit Farming in Sand Dunes Area of Binh Thuan Province of Vietnam

Mapping of land use and land covers (LULCs) and their temporal changes are important subjects in remote sensing field. This study applies change detection and classification (CDC) in mapping and analyzing changes of dragon fruits area in sand dunes area of Binh Thuan province using MODIS NDVI time-series data from 2000 to 2020. Unlike the single-phase classification which assumes unchanged LULC in analyzed periods, the CDC divided time series into segments defined by change points for segment classification. The per-pixel change detection using Pelt method identified 18 wide-scaled change points in study area. Afterward, two-phased multi-class classification was conducted to delineate dragon fruit area using the Random Forest algorithm with statistical features of four time-series segments representing four periods 2000–2005, 2005–2010, 2010–2015, and 2015–2020. A robust paradigm combining validation of classification results with area estimation was applied to analyze changing of dragon fruit areas. The result suggests a steady increase of dragon fruit areas in sand dune areas of Binh Thuan province from 2000 to 2020 especially in two districts Ham Thuan Bac and Ham Thuan Nam and recent conversions to dragon fruits in Bac Binh, Tuy Phong, and La Gi districts.

Luan Hong Pham, Trong Dieu Hien Le, Lien T. H. Pham, Ho Nguyen, Hong Quan Nguyen
Random Forest Analysis of Land Use and Land Cover Change Using Sentinel-2 Data in Van Yen, Yen Bai Province, Vietnam

Land use land cover (LULC) change has become a crucial topic that needs to be addressed when the studying global and local sustainable development. In this research, time-series of Sentinel-2 images from 2019 to 2020 are used to derive LULC change in Mu Cang Chai (MCC) and Van Yen (VY) districts, Yen Bai province, Vietnam. We identified seven main land cover types and collected reference data from visual interpretation using Google Earth. The random forest (RF) classification algorithm is applied to construct the classified LULC map in these regions of Yen Bai province. The classification accuracy of the method is evaluated using producer’s accuracy, user’s accuracy, overall accuracy, and Kappa coefficient. We obtain a high overall accuracy (90.7%) with a corresponding Kappa coefficient of 0.85 for the classification in 2019. In the case of 2020, overall classification accuracy reaches about 91.1% and 0.87 of the Kappa coefficient. Then, the LULC change area in the period 2019–2020 of the study area is evaluated and discussed by using the transition matrix of LULC.

Xuan Quang Truong, Nguyen Hien Duong Dang, Thi Hang Do, Nhat Duong Tran, Thi Thu Nga Do, Van Anh Tran, Vasil Yordanov, Maria Antonia Brovelli, Thanh Dong Khuc
Engineering Geological Problems of Foundation Pit Construction in Quaternary Strata: Taking Suzhou Area as an Example

The Quaternary strata in Suzhou, China, are typical because of its abundant water system and intricate geological conditions. The characteristics of Quaternary sediments in Suzhou area were analyzed and integrated through borehole sampling, field investigation, and data collection. The results show that the thickness of Quaternary sediments in Suzhou area is approximately 200 m. Each aquifer group is divided into water-bearing stratum and water-resisting stratum with a thickness of approximately 15 m and 30 m, respectively. The soil layers are mostly silty clay with approximately 30% water content, which has a loose structure and poor engineering properties. Meanwhile, there are multiple fault zones, mainly East-North and East–West trending, accompanied by North–North-East trending tectonic traces. This common geological situation in coastal and lakeside areas often leads to several problems in foundation pit construction: failure of supporting structure and instability of foundation pit slope, seepage deformation, land subsidence and ground subsidence, and heave and inrush at the bottom of the pit. In this paper, considering the excavation depth, excavation mode, soil properties, and surrounding loads and other key influencing factors, the corresponding prevention and control measures are put forward for practical engineering. Meanwhile, a variety of protective drainage measures are used to enclose and lower the water for its foundation pit project, which effectively reduces the construction risk of the foundation pit project.

Xinyu Luo, Peng Yin, Yongsheng Zheng, Xuedong Li, Yi Zhang, Qiang Tang
Roof Condition Characteristics Affecting the Stability of Coal Pillars and Retained Roadway

The stability of the retained roadway next to the coal pillar in the longwall mining system is mainly affected by displacement and rock pressure of the roof rock layers of the coal seam. With the objective of forecasting negative impacts in underground coal mining, this article analyzes the roof structure of the coal seam to illustrate the mechanism that causes instability of roadway retained in different roof conditions. A computer program is then used to simulate and assess the instability of the coal pillars and roadways in various roof variations according to the geological and technical conditions of the Khe Cham mine #11 seam. The results show that lowering and rotation of the console of main roof seriously affect the stability of the protective coal pillars. Vertical stresses distribution on the coal pillar increases significantly when the thickness of the immediate roof rock is very thin and insufficient to fill the goaf. Therefore, corresponding to different roof conditions, there is an effective solution for coal pillar design and roadway support to ensure production safety. This article can be used as a reference to designate technical recommendations in similar geological conditions.

Quang Phuc Le, Van Chi Dao
On the Flow Assurance for Un-Insulated Subsea Pipeline Systems: Application on the Multiphase Pipeline from Pearl Field to FPSO Ruby II Offshore Vietnam

The Pearl field is an offshore oil field in Vietnam, located approximately 160 km from Vung Tau. This field signifies high-paraffin crude with wax appearance temperature of approximately 50 °C. With the ambient temperature recorded from 27 °C at the surface to 22 °C at the seabed, the transportation using un-insulated pipeline has to face great challenges such as: the hold-up of liquid, slugging, erosion and corrosion, and the deposition of wax etc.,. Therefore, it is obligatory to investigate the system’s performance periodically to predict undesirable mentioned phenomena to assure continuous flow though this pipeline may afford safety and stability to the conveyance of crude oil. The article contributes itself to the build of a dynamic model to characterize this pipeline system at actual working conditions. Flow assurance study is carried out in 3 cases corresponding to 3 different flow rates of the incoming mixture. We then compare these calculations with experimental data to assure its accuracy and reliability. Results of simulation enable us to observe a rapid drop of temperature inside the pipeline after 2 h of shutdown and a risk of slugging if gas appears in the flow and the wax layer of about 0.1 mm after 30 operational days. This layer is quite acceptable; however, regular maintenance and pigging are required during the transport.

Van Thinh Nguyen, Thi Hai Yen Nguyen, Sylvain S. Guillou, Thuy Huong Duong, Thi Thanh Thuy Truong, Thi Thao Nguyen
Detection of Underground Anomalies by Evaluation of Ground Penetrating Radar Attribute Combination

Detection of underground utilities can be done by application of the ground penetrating radar (GPR) method. Diffraction or reflection phenomena of high-frequency electromagnetic waves provide tools and physics principles for imaging their locations, sizes, and even shapes. In urban zones, GPR machines equipped with shielded antennas are often used in common offset recording settings which provide high quality data after filtering most of artificial noises from the air. Although the data is still contaminated by different noises, the underground works are often recognized through appearances of different hyperbolae. In our paper, we apply different processing techniques for researching underground anomalies to map 3D metal gas pipes in Ba Ria–Vung Tau province, Vietnam. We have collected many 2D GPR profiles in 2019 and conducted a new technique of their 3D representation. In the new 3D representation, different GPR attributes as processed data and its maximum energy difference attribute are applied for defining the two metal gas pipes and revealing their other nearby anomalies as optical fiber cables.

Duy Hoang Dang, Cuong Van Anh Le, Thuan Van Nguyen
Dynamic Failure Process of Soil Particles at the End of Shield Tunnel Based on Discrete Element

The soil at the end of the shield tunnel has large local deformation and strong nonlinearity; thus, the finite element method based on continuum mechanics cannot simulate the failure process of the soil at the end well. In order to analyze the dynamic failure process of soil particles at the end, a discrete element model of shield tunnel was established; the displacement, stress and settlement of soil particles were tracked, and the failure mechanism was analyzed. The results show that the end soil finally forms a circular arc shear zone with a slip radius of 0.87 m. The contact stress of the soil at the entrance shows a decreasing trend with time. Nonlinear settlement occurs on top of soil, and the final settlement reached 38.20 mm. The soil failure at the end of the shield tunnel presents a gradual development of slip failure characteristics. The soil slip failure surface at the end of the shallow-buried shield tunnel is a combined slip mode.

Zheyuan Feng, Bin Liu, Sijun Zhang, Fei Kang, Haipeng Hui, Qiang Tang
Early Triassic Tectonic Evolution of the Northeastern Kontum Massif: New Constraints from the S-type Granite in Ba To Area, Quang Ngai Province, Central Vietnam

The granitoids exposed in Ba To area, northeastern portion of the Kontum Massif, central Vietnam were previously assigned as part of the Hai Van complex. Field investigation and petrographic study reveal that the magmatic rocks in Ba To area comprise dominantly medium- to coarse-grained, per-aluminous two-mica granite of S-type origin. These rocks are strongly overprinted by several phases of tectonic activities including the emplacement of felsic and mafic dikes and veins, formation of weak ductile foliation, brittle fracturing, and widespread alteration under the influence of several post-magmatic thermotectonic processes. Results of U–Pb dating of zircons collected from granite in Ba To area show a crystallization age of 245.8 ± 1.5 Ma for the magmatic rock. The petrographic study and absolute age dating results conducted by this work are comparable to other recent works on similar granitoid occurred in the northern margin of the Kontum Massif. This indicates that the widespread Ca 245 Ma Hai Van-type S-type granitoid along the north and northeastern portions of the Kontum Massif were derived from a collisional orogenic event, which extended from Late Paleozoic onward during the assembly of Sibumasu Block to Indochina Block to form the Proto-Southeast Asia, which is correspondent to the Indosinian Orogeny. Several post-intrusive thermotectonic events due to the tectonic activities along the newly formed Proto-Indochina Block had resulted in subsequent deformation, injection of late magmas and alterations of the Hai Van—Type magmatic rocks.

Ha Thanh Tran, Bui Vinh Hau, Ngo Xuan Thanh, Nguyen Huu Hiep, Ngo Thi Kim Chi
Proposal of Study on InSAR-Based Land Subsidence Analysis as Basis for Subsequent Hydro-mechanical Modeling: A Case Study of Hanoi, Vietnam

In recent years, land subsidence has been intensively studied by many research projects due to its severe impacts on the human and environment. Radar remote sensing for mapping ground movement has been successfully applied in several areas for the quantification of land subsidence. In this paper, previous Interferometric Synthetic Aperture Radar (InSAR) studies for Hanoi, Vietnam, are reviewed. Specifically, SAR data at the X, C, and L bands have been applied successfully using mainly the small baseline subset (SBAS) and Persistent Scatterer InSAR (PSInSAR) methods for extracting deformation movement in the urban setting of Hanoi from 1995 to the present. Whereby, line-of-sight land deformation obtained from these studies was converted into the vertical direction with the assumption that horizontal movement in the urban setting of Hanoi is insignificant. However, the analysis of the relationship between InSAR deformation and triggering factors was not fully conducted. Therefore, a workflow in the part of the discussion in this paper is introduced that shows how subsidence data can be interpreted with the help of coupled hydro-mechanical simulations conducted with numerical multi-physics software. We present the data basis and model setup for the planned modeling study with the open-source software platform OpenGeoSys.

Hong Ha Tran, Luyen K. Bui, Hung Q. Ha, Thi Thu Huong Kim, Christoph Butscher
Advances in Geospatial Technology in Mining and Earth Sciences
herausgegeben von
Long Quoc Nguyen
Luyen Khac Bui
Xuan-Nam Bui
Ha Thanh Tran
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