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Publications (316)
Acid mine drainage (AMD), wherein acidic water is generated from pyrite-containing waste rock, can be mitigated by encapsulating pyritic waste rock with cover materials to restrict the inflow of oxygen and water. However, acidic water inevitably forms during the construction of waste rock dumps before applying cover materials. Considering that the...
Traditional rectangular tunnel boring machines have low tunneling efficiency, poor soil mixing effects, which has hindered the construction of long-distance and large-section box jacking projects. To overcome these limitations, a new type of full-face excavation boring machine was developed based on a planetary transmission mechanism. This machine...
Underground coal gasification (UCG) is process of directly recovering energy as combustible gases such as hydrogen and carbon monoxide by combusting unmined coal resources in situ. During UCG process, the temperature in the gasification zone can exceed 1,300 °C, raising concerns about the potential melting of the steel pipe for oxidant injection. T...
In order to cope with climate change and achieve the goal of carbon neutrality, the use of carbonization technology to enhance the performance of cement-based materials and achieve the purpose of carbon sequestration has become a very promising research direction. This paper considers the use of CO2NBW as mixing water for cement-based materials, ai...
Accurate estimation of the mean fragment size is crucial for optimizing open-pit mining operations. This study presents an approach that combines clustering, hyperparameter optimization, and data augmentation to enhance prediction accuracy using the Xtreme Gradient Boosting (XGBoost) regression model. A dataset of 110 blasts was divided into 97 bla...
Underground Coal Gasification (UCG) is a promising process for recovering energy from potential underground coal resources as combustible gases such as hydrogen and carbon monoxide. The gasification process that occurs underground is an invisible phenomenon, and the temperature in the underground gasification reaction zone can be over 1,000 °C. The...
Underground reservoirs in coal mines, consisting of goafs (By goaf, we mean the space that remains underground after the extraction of valuable minerals), are commonly utilized for mine water storage and drainage, with their primary load-bearing structures being the “roof–coal pillar” systems. Consequently, this structure must endure the repeated i...
The objective of this study is to investigate the effect of longwall mining on the stability of the gate roadway in an underground coal mine. The PT Gerbang Daya Mandiri (GDM) underground coal mine in Indonesia, with weak rocks, was chosen as a representative study site. To achieve the research objective, the finite diffrence code software FLAC3D w...
Blasting is a cost-effective technique to break hard rock volumes by using explosives in the mining and civil engineering realms. Moreover, although blasting is a designed process and plays an indispensable role in these industries, it can also have multiple adverse environmental impacts. One such effect is flyrock, which poses risks to nearby mach...
This paper presents an alternative methodology for the study of flyrock hazards in mining, utilizing Artificial Intelligence (AI) through machine learning by classification. By using distance as a delineator to denote the consequences of a blast, the models generated two classes of blasts: safe and unsafe. In this study, statistical learning models...
Chemical grouting is a method to improve or accelerate the solidification process on a loose soil. The implementation of improper chemical grouting may lead to affect the safety level of groundwater; thus, the technical ability and safety should be analyzed comprehensively to prevent degenerative effect on environment. Volcanic soil is targeted on...
In this paper, a multi-point geostatistical (MPS) method based on variational function partition simulation is proposed to solve the key problem of MPS 3D modeling using 2D training images. The new method uses the FILTERSIM algorithm framework, and the variational function is used to construct simulation partitions and training image sequences, and...
Underground coal gasification (UCG) is the process of directly recovering energy as combustible gases such as hydrogen and carbon monoxide by combusting unmined coal resources in situ. The UCG process is an invisible phenomenon, in which fracturing activity at high temperature (>1000 °C) in coal seams expands the gasification zone and increases the...
The number of successful box-jacking drives completed in Japan has witnessed a rapid growth. However, the current predictions of jacking force depend on a combination of empiricism drawn from on-site experience and ad hoc theoretical relationships. The complexity involved in predicting the total jacking force is exacerbated by site geology, the usa...
Pipe-jacking is one of the trenchless methods being widely used for the construction and maintenance of urban
underground pipelines. As an eco-friendly construction method, it has the capacity for the installation of pipe�lines with diameters from 100 mm (4 in.) to 5000 mm (200 in.) covering the majority needs of municipal pipeline
construction a...
Accurate prediction of blast-induced ground vibration is crucial for mine safety. Peak Vector Sum (PVS) provides a comprehensive representation of vibration compared to Peak Particle Velocity (PPV), ensuring accurate risk evaluation. This paper presents a hybrid machine learning approach for PVS prediction in a Lignite mine. Explanatory variables (...
Although the rapid increase in successful rectangular pipe-jacking projects in Japan, current predictions for jacking force in the capital region heavily rely on on-site experience gained through works in shallow strata with soft soil. The ground conditions in Tsunashima Tunnel, mainly comprising mudstone and sediment-mixed layers with better stren...
This study investigates the transition from surface to underground mining at the Sepon Gold mine. The stability of surface slopes is assessed prior to commencing underground operations. Stope mining is adopted based on ore body characteristics and geological features. Finite element numerical analysis, employing the Generalized Hoek–Brown criterion...
This study investigates the transition from surface to underground mining at the Sepon Gold mine. The stability of surface slopes is assessed prior to commencing underground operations. Stope mining is adopted based on ore body characteristics and geological features. Finite element numerical analysis, employing the Generalized Hoek-Brown criterion...
Underground Coal Gasification (UCG) requires monitoring of the gasification area because the gasification process is invisible and the reaction temperature exceeds 1000 °C. Many fracturing events that occurred due to coal heating can be captured with Acoustic Emission (AE) monitoring technique during UCG. However, the temperature conditions to gene...
The accurate forecasting of metal prices is of great importance to industrial producers as the supply of metal raw materials is a very important part of industrial production. The futures market is subject to many factors, and metal prices are highly volatile. In the past, most of the relevant research has focused only on deterministic point foreca...
In Indonesia, the adoption of the underground coal mining method is discussed to extend coal production. However, the geological conditions in Indonesia are very weak. In particular, the mechanical properties of the immediate roof/floor in shallow depths are weaker than those of coal. Therefore, the control measures to maintain stability around the...
This paper described the use of fly ash for soil amelioration of acidic soils to promote plant growth. In mining sites, acid sulfate soils/rocks, which contain sulfide minerals (e.g. pyrite FeS 2 ), have appeared as a result of overburden excavation. The excessively acidic condition inhibits plant growth due to the dissolution of harmful elements,...
The increasing demand for tin-tungsten (W-Sn) due to its versatile applications in various industries and its attractive high market price has created a motivation for mining companies to extract deep-seated tin-tungsten deposits in Myanmar at a fast pace to meet the world demands. At Hermyingyi (W-Sn) Deposit Mine, the feasibility of exploiting or...
Conducting research on the stress regime in underground coal mines, particularly in the early stages of mine development, can result in a high benefit and economic return of safer and cost-effective long-term mining projects under various geological and geotechnical conditions. Optimizing the correlation between gate road direction and major horizo...
High economic benefits and a good infrastructure network have been pushing ongoing coal projects near the southern border of Mongolia for a long time. To continue the consistent run of the coal export and to make good returns, the transition from open-pit to underground has to be considered further due to the economic pit limit is reached with mini...
Carbonatites
are generally competent rock masses with Rock Mass Rating class II rating 60–74. In spite of their competency, they tend to be affected by weak features like Mn-Fe veins and/or in situ rock damage due to brecciation associated with carbonatite complexes. Rock slope failure in such hard rocks is complex since such structures within the...
More than 99% of coal mining in Indonesia is open-pit mining. Nowadays, the adoption of the underground coal mining method is discussed to extend coal production due to the increasing demand for coal. However, the geological conditions in Indonesia are very weak compared to the U.S., Europe, and Australia where the longwall mining method is often a...
Vipingo quarry in Kilifi county, Kenya, is one of the quarries supplying coral limestone for limestone manufacturing in the coastal region. Due to its close proximity to the Indian ocean, the semidiurnal ocean tides tend to have an influence on the stability of the quarry slopes adjacent to the shoreline. Finite element numerical analysis using the...
This paper attempts to predict the surface subsidence induced by multi-seam longwall mining in the PT Gerbang Daya Mandiri (GDM) underground coal mine in Indonesia. Several numerical models of multi-seam longwall mining under various depths were built in the finite difference code software “FLAC3D” which was used as a tool for numerical simulations...
Crown pillars provide regional and local support by isolating the ground surface from underground mine workings. Topography above the underground mine may be a relatively flat ground surface or an open-pit structure. Depending on what lies above and design of the underground mine, the crown pillar behaviour will differ. In transitioning setups (ope...
Numerical simulation is very useful for understanding the hydraulic fracture (HF) re-orientation mechanism from artificial weaknesses. In this paper, the UDEC T-W (Trigon–Weibull distribution) modeling method is adopted to simulate the hydraulic fracturing process in heterogeneous rocks. First, the reliability of this method is validated against pr...
The typical reinforcements and supports used in the main gate of underground coal mining (particularly in the weak to very weak rock strata), such as rock/cable bolts, steel sets, and grouting materials, often allow the mine to remain serviceable in the long run, but in complicated geotechnical and geological conditions, they are insufficient. Low...
In rectangular pipe-jacking, excessive friction force resulting from the pipe-soil interaction is the dominant factor hindering its further application in long-distance, larger-section, and deep-buried scenarios in urban underground construction. These complex scenes are the frontiers and key issues that need to be developed in this method. To this...
Developing longwall mining under weak geological conditions imposes a substantial challenge with regard to the higher risk of falling roofs. Maintaining the stability of the longwall face in this aforementioned condition is crucial for smooth operation. Investigating roof conditions in longwall requires detailed study of rock behavior in response t...
For rectangular pipe-jacking construction, the primary priorities of smooth construction include minimizing the ground response and designating the appropriate jacking force to achieve the best results in environmental protection and energy conservation. The geometric cross-section design of the jacking rectangular pipe and its engineering performa...
This paper studies the stability and ground behavior of the main roadway excavated in a soft rock mass at PT Gerbang Daya Mandiri (GDM) underground coal mine in Indonesia. The stability and ground behavior of the main roadway under various geological and excavation conditions was analyzed and discussed through numerical simulations and field measur...
This paper studies the stability and ground behavior of the main roadway excavated in a soft rock mass at PT Gerbang Daya Mandiri (GDM) underground coal mine in Indonesia. The stability and ground behavior of the main roadway under various geological and excavation conditions was analyzed and discussed through numerical simulations and field measur...
Characterization of the mechanical properties of cracked rock masses is essential for ensuring the long-term stability of the engineering environment. This paper is aimed at studying the relationship between the strength characteristics of specimen and the angle of precrack, as well as the interaction of cracks under uniaxial compression. To this e...
Jacking force is a controlling factor in design and construction of pipe jacking. To date, there is few researches focused on prediction of jacking force in frozen ground. Therefore, this paper investigates the main geotechnical issues, including the jacking force and pipe-soil interaction of pipe jacking in frozen ground. Firstly, a series of nume...
In this paper, the behaviour of the pipe roof method with different pipe roofs disposition schemes including the pipe roof gate system and L-shaped system is discussed in terms of ground settlement reduction in the condition of underground space construction adjacent to the existing structure by using numerical simulation method. Considering the co...
This paper focuses on the stability analysis and support design of the coal mine tunnel excavated in weak rock mass in an Indonesian underground coal mine through numerical simulations using the FLAC3D software. The PT Gerbang Daya Mandiri (GDM) coal mine situated in Indonesia was selected as a mine site in this study. According to the results of a...
The investigation of the influence of in situ stress in Open Pit Mine (OPM) projects has not been accorded a deserved attention despite being a fundamental concern in the design of underground excavations. Hence, its long-term potential adverse impacts on pit slope performance are overly undermined. Nevertheless, in mines located in tectonically ac...
Bulking characteristics of gangue are of great significance for the stability of goafs in mining overburden in the caving zones. In this paper, a particle discrete element method with clusters to represent gangue was adopted to explore the bulking coefficient time effect of the broken rock in the caving zone under three-dimensional triaxial compres...
Rehabilitation is an important stage in mining operations for environmental conservation. However, the shortage of topsoil makesit difficult to achieve rehabilitation in open-cast coal mines. Securing topsoil by mixing soil with fly ash (FA), which is treated asan industrial waste, is expected to solve this issue in coal mines. While mixing soil wi...
With the increase of the coal consumption, the gob scale has become significantly large, increasing the risk of subsidence. Using Brillouin optical time-domain reflectometer (BOTDR) technology, this paper studied the deformation and failure state of overburden above the gob. An overburden subsidence calculation model considering rock mechanical par...
Application of underground mining in Southeast Asia is one of the addressing challenges for the mining engineers. Since there isn't adequate guideline for underground coal mining, plenty of coal resources have still been buried under highwall that economic stripping ratio is reached. But, however, in order to meet demand of coal for energy producti...
This paper based on a study carried out by means empirical method and series of numerical analysis to discuss the stability and dimensioning of coal pillars/openings at varies with depths with highwall mining system for remaining coal around highwall after economic pit limit is reached by surface mining. The results of study show that ratio of pill...
Złoża metali rzadkich są bardzo ważne a ich istotność wzrasta w ostatnich latach. Zatem, dno morskie, które zawiera duże ilości tegotypu pierwiastków posiada potencjał do zaspokojenia potrzeb w tym zakresie. Jako jedną z efektywnych metod górniczych w tymaspekcie należy traktować ssanie. Osad denny z dna morskiego, który zawiera pierwiastki ziem rz...
Underground Coal Gasification (UCG) is a technique to recover the energy of coal by converting coal into gas. One or two wells are drilled from the surface to underground coal seam in order to inject oxidant which consists of oxygen and air for burning the coal seam in situ and recover syngas such as carbon monoxide, hydrogen, and methane in the su...
The pipe jacking method is relatively reasonable among trenchless construction methods.For the application of this method, the acid sulfate soils have negative impacts on filling materials (one of the cement materials) injected into the tail-void which are over-cutting areas formed to reduce the friction between the pipes and the surrounding soils....
The present research primarily focuses on the investigation of gate-entry stability of longwall trial panel under weak geological condition in Indonesia coal mine by means of numerical analysis. This work aims at identifying appropriate roof support at 100 m and 150 m of depth during gate development. Due to depth depending competency of dominant r...
Kyaukpahto gold deposit is located in the Kawlin Township, Sagaing Region, Myanmar. Gold deposit is classified as a shallow level epithermal deposit and gold mineralization is characterized by stockworks quartz vein and dissemination hosted by sandstones of Eocene Male Formation. Common ore minerals of mineralization include pyrite, arsenopyrite, a...