Original Research Paper
Exploration
Babak Sohrabian; Abdullah Erhan Tercan
Abstract
Mineral Resources have commonly been estimated through the kriging method that assigns weights to the samples based on variogram distance to the estimation point without considering their values. More robust estimators such as spatial copulas are promising tools because they consider both distance ...
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Mineral Resources have commonly been estimated through the kriging method that assigns weights to the samples based on variogram distance to the estimation point without considering their values. More robust estimators such as spatial copulas are promising tools because they consider both distance and sample values in determining weights. The purpose of this study is to demonstrate the effectiveness of the Gaussian copulas (GC) by estimating the copper grade values in the Sungun porphyry copper deposit located in Iran. Performance of the method was compared to ordinary kriging (OK) and indicator kriging (IK) by running the Jackknife test of cross-validation. The metrics used in measuring performance of the methods are global accuracy and precision of the distribution of the estimates, error statistics, and variability for globally accurate and precise estimates. The case study shows advantages of GC over OK and IK by producing globally accurate and precise estimates with acceptable error statistics and variability.
Original Research Paper
Rock Mechanics
Jagdish Lohar; Neha Shrivastava
Abstract
India is a leading producer and exporter of dimensional marble. The processing of marble into dimensional and finished forms involves sawing, grinding, and polishing, generating significant quantities of Marble Processing Waste (MPW). Efforts for bulk recycling of MPW from the rapidly expanding marble ...
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India is a leading producer and exporter of dimensional marble. The processing of marble into dimensional and finished forms involves sawing, grinding, and polishing, generating significant quantities of Marble Processing Waste (MPW). Efforts for bulk recycling of MPW from the rapidly expanding marble industry are essential due to significant environmental impacts, hindered by limited inclusion rates and complex processing requirements in current practices. Concurrently, the increased demand for geotechnical fill materials and the depletion of natural soils necessitates sustainable alternatives. Using MPW in geotechnical fills offers a viable solution, yet it lacks comprehensive characterization. The aim of this study is to evaluate MPW as a sustainable alternative to conventional geotechnical fill materials. In this study, a comprehensive analysis of MPW's physical, geotechnical, and electrochemical properties, along with its mineralogical, elemental, and chemical composition, was conducted. The findings show that MPW, being non-plastic and non-swelling with a grain size distribution and hydraulic conductivity similar to silty sands, can be used directly from disposal sites without further processing. Notably, MPW achieves a maximum dry density of 1.84 g/cm³ and exhibits internal friction angles of 36.5°, ensuring stability. Electrochemical analysis indicates low leachability risks, with pH levels of 8.1 and electrical resistivity of 6,200 ohm-cm. Scanning Electron Microscopy images reveal that MPW particles are irregular, with considerable angularity and surface roughness. These results position MPW as a viable and environmentally friendly alternative to conventional fill materials, with the potential to significantly reduce the exploitation of natural resources and advance sustainable waste management practices.
Original Research Paper
Exploitation
Assefa Hailesilasie Wolearegay; Yowhas Birhanu Amare; Asmelash Abay Hagos; Kassa Amare Mesfin; Hagos Abraha; Bereket Gebresilassie; Nageswara Rao Cheepurupalli; Yewuhalashet Fissha
Abstract
The Dichinama area in northern Ethiopia is a potential source of dimension stone, but the quality of the marble has been a major challenge for mining operations. This research aims to evaluate the quality of dimension stone by conducting a comprehensive study involving geological mapping, geotechnical ...
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The Dichinama area in northern Ethiopia is a potential source of dimension stone, but the quality of the marble has been a major challenge for mining operations. This research aims to evaluate the quality of dimension stone by conducting a comprehensive study involving geological mapping, geotechnical testing, and geochemical analysis. The study collected nine rock samples from three active mining sites in the Dichinama area, analyzing properties such as density, water absorption, compressive strength, flexural strength, and abrasion resistance. Additionally, ten samples were collected for geochemical analysis, focusing on parameters like calcite, CaO values, LOI, SiO2 content, and other oxide concentrations. The geotechnical tests revealed that the properties of the marble in the Dichinama area were mainly calcite, with compressive strength values ranging from 29.6 to 74.5 MPa, flexural strength from 7 to 52.5 MPa, abrasion resistance from 8.3 to 17.2, density from 2257 to 2562 kg/m3, and water absorption from 0.12 to 0.93. However, most of these parameters fell below the minimum ASTM standards for marble dimension stone. The results suggest that these inferior characteristics negatively affect the recovery and quality of the dimension stone.
Original Research Paper
Rock Mechanics
Ajay Sharma; Neha Shrivastava
Abstract
The present study aims to assess the utility of construction and demolition (C&D) waste, specifically recycled concrete aggregates (RCA) and recycled brick aggregates (RBA), as fill materials in highway embankments. The assessment of slope stability is crucial in determining the suitability of any ...
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The present study aims to assess the utility of construction and demolition (C&D) waste, specifically recycled concrete aggregates (RCA) and recycled brick aggregates (RBA), as fill materials in highway embankments. The assessment of slope stability is crucial in determining the suitability of any material for embankment fill. GeoStudio software is employed in this study for slope stability assessment of 12 models with LS, RCA, RBA, and their blends as embankment fill materials. The embankment configuration is designed to represent a six-lane highway (carriageway width = 13 m, adhering to IRC: 36 standards), featuring varying slope elevations (3 m, 6 m, and 9 m) and diverse horizontal to vertical slope ratios (H:V = 2:1, 1:1, 1:2, and 1:3). The Morgenstern-Price method is employed to analyze slope stability and determine factor of safety (FOS) values. The study highlights the impact of slope heights, slope ratios, and fill materials (RCA, RBA, LS, and their blends) on FOS values in embankment models. Incorporating RCA or RBA in LS significantly boosts embankment FOS, exceeding stability expectations beyond 45˚ slope angles, potentially reducing costs and required area in construction projects. The incorporation of RCA/RBA into LS increases the FOS values to a range of 1.38 to 5.91, indicating very stable slopes for highway embankments. Based on the findings, replacing LS with RCA or RBA in embankment fill can enhance environmental sustainability and economic efficiency. However, these slope stability results apply specifically to C&D waste with similar composition, grain size, geotechnical properties, and embankment conditions.
Original Research Paper
Exploitation
Yehia Z. Darwish; Abdelrahem Khalefa Embaby; Samir Selim; Darwish El Kholy; Hani Sharafeldin; Hussin Farag
Abstract
The younger granites of Gabal Gattar area, Northern Eastern Desert of Egypt, host hydrothermal uranium mineralization at the northern segment of Gattar batholith and along its contacts with the oldest Hammamat sediments. The host rocks display many features of hydrothermal overprint results in changing ...
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The younger granites of Gabal Gattar area, Northern Eastern Desert of Egypt, host hydrothermal uranium mineralization at the northern segment of Gattar batholith and along its contacts with the oldest Hammamat sediments. The host rocks display many features of hydrothermal overprint results in changing their basic engineering characteristics as a function of variations of the degree of alteration. Progression from less altered to altered and mineralized rocks as the result of the alteration processes was assessed by the chemical index of alteration (CIA). The CIA numerical values were calculated by the molecular proportion of Al to the cations Ca, Na, and K. The studied rocks were divided into five grades according to degree of alteration and strength properties including: fresh (AG-I), slightly altered (AG-II), moderately altered (AG-III), highly altered (AG-IV) and very highly altered (AG-V). The strength properties of the studied rock units correlated well with the alteration grades assigned to them. That is, as the grade increased from AG-I to AG-V, abrasion resistance and crushability index increased, whereas compressive strength, slake durability and impact strength decreased.
Original Research Paper
Exploitation
Sri Chandrahas; Bhanwar Singh Choudhary; MS Venkataramayya; Yewuhalashet Fissha; Blessing Olamide Taiwo
Abstract
To conducting efficient blasting operations, one needs to analyze the bench geology, structural and dimensional parameters to obtain the required optimum fragmentation with minimum amount of ground vibration. Joints presence causes difficulty during drilling and subsequent rock breakage mechanism. An ...
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To conducting efficient blasting operations, one needs to analyze the bench geology, structural and dimensional parameters to obtain the required optimum fragmentation with minimum amount of ground vibration. Joints presence causes difficulty during drilling and subsequent rock breakage mechanism. An idea on joints density will give an idea on deciding with column charging in-terms of decking-stemming and firing patterns. The goal of the research is to develop a hybrid algorithm model to predict joints width and joint angle. In order to achieve the task, advanced softwares, machine learning models and a field data tests were used in this study.
Original Research Paper
Rock Mechanics
Manendra Singh; Moqin Mushtaq Zargar; Vivek Kumar Sharma; Ritu Raj Nath
Abstract
Non-structural slope stabilization techniques are gaining popularity for cost-affordability and environmental sustainability and are intended primarily to enhance the soil shear strength parameters. The present study evaluates the performance of three biopolymers: Guar Gum, Gellan Gum, and Xanthan Gum ...
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Non-structural slope stabilization techniques are gaining popularity for cost-affordability and environmental sustainability and are intended primarily to enhance the soil shear strength parameters. The present study evaluates the performance of three biopolymers: Guar Gum, Gellan Gum, and Xanthan Gum as slope stabilizers for a quintessential soil slope of a local district in the foothills of the Lesser Himalayas. The study measures the shear strength of biopolymer-treated soil at varying concentrations and moisture contents, and concludes that the soil shear strength is highly influenced by the concentration of biopolymer and the moisture content. The results demonstrate significant increase (48% and 7%) of the cohesion and friction angle of a particular biopolymer-treated sample for a specific moisture content. However, the addition of biopolymers to the soil also leads to a decrease in the permeability of the original sample. The study, in the next phase, numerically computes the Factor of Safety of the test-bed slope before and after the application of biopolymers, and observes that the addition of biopolymers in soil significantly increases (34%) the factor of safety at an optimum combination concentration and moisture content for all three biopolymers. This signifies their utility as non-structural slope stabilizers. By highlighting the improved shear strength of the biopolymer-treated soils, the study complements the current initiatives for non-structural slope stabilization and sustainable soil enhancement and adds to the new yet expanding body of information regarding long-term, non-structural slope stabilizing techniques.
Original Research Paper
Rock Mechanics
Kapoor Chand; Ved Kumar; Priyanshu Raj; Nikita Sharma; Amit Kumar Mankar; Radhakanta Koner
Abstract
Failure of tailings dams is a major issue in the mining industry as it critically impacts the environment and life. A major cause of the failure of tailings dams is the unplanned depositing of tailings and the increase in saturation due to rainfall events. This study using numerical modelling and artificial ...
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Failure of tailings dams is a major issue in the mining industry as it critically impacts the environment and life. A major cause of the failure of tailings dams is the unplanned depositing of tailings and the increase in saturation due to rainfall events. This study using numerical modelling and artificial intelligence techniques (like MLR, SVR, DT, RF, and XGB) aims to predict the slope stability of tailings dams to avoid failure. The stability of tailings dams is analysed using the finite difference method (FDM), which computes the factor of safety (FoS) using the shear strength reduction (SSR) technique. This investigation mainly focuses on the geotechnical and geometric parameters of the tailings dam, such as density, cohesion, friction angle, saturation, embankment height, slope angle and haul road width. Results of numerical modelling have been used for developing ML models and predicting slope stability. The efficiency of ML models was analysed based on the R2 and root mean square error (RMSE), mean squared errors (MSE), and mean absolute error (MAE). The XGB algorithm proved to be the most effective as it gave the highest accuracy and lowest RMSE value compared to other ML models. AI tool was developed based on the ML model results for dam slope stability prediction. The developed AI tool will help understand the role of saturation and geometry parameters in embankment stability at the initial level of investigation.
Original Research Paper
Exploration
Eid R. Abo-Ezz; El Sayed I Selim; Hatem Aboelkhair; Haytham Sehsah
Abstract
The bimodal hypsometry of the Arabian-Nubian Shield in the Neoproterozoic triggered the formation of post-amalgamation marine bains in the low-stand terranes of the Arabian shield (AS). The carbonate successions in the extraordinary marine basins in the AS are intruded by granite plutons of different ...
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The bimodal hypsometry of the Arabian-Nubian Shield in the Neoproterozoic triggered the formation of post-amalgamation marine bains in the low-stand terranes of the Arabian shield (AS). The carbonate successions in the extraordinary marine basins in the AS are intruded by granite plutons of different causative types, with major shear zones pathways. Therefore, the conditions for the formation of skarn deposits are mature at the contact of the carbonate succession with the causative granite plutons. Multidisciplinary approaches including ASTER data, Magnetic data, and geochemical data have been applied to the Murdama basin to locate the promising areas for skarn deposits. The Murdama basin has contrasting magnetic anomalies of different intensity at the contact between the Murdama limestone and the post-Murdama causative batholiths; significant magnetic anomalies exist at the contact with the Idah causative magmas. Lineaments related to the Najd fault system (NFS) exist eastward, where calc-silicate alteration-related minerals were evolved, with no clues for penetrative effect for such alteration activity along pathways related to the fracture system or at contact with the Abanat suite. Different spectral mapping techniques, including Spectral Information Divergence (SID), Spectral Angle Mapper (SAM), and Constrained Energy Minimization (CEM) confirm that the Idah suite is the predominant causative magma in the study area with highly evolved calc-silicate alteration-related minerals, such as wollastonite, garnet, and pyroxene. Meanwhile, The Idah suite has been identified as the main causative magma for other reduced skarn localities that have been recorded from the Murdama basin, i.e. the Qitan and An Nimriyah South. Alteration related mineral zones of kaolinite, chlorite, muscovite, and hematite are evolved alongside with calc-silicate minerals at the contact bewteen Idah suite, and the Murdama carbonate member. The geochemical data suggests reducing effect for the Idah suite at the contact between the Murdama carbonate succession and Idah plutons. These preliminary results of this study need detailed field investigations and geochemical explorations for the proposed skarn deposits in the Neoproterozoic molasse basins of the AS.
Original Research Paper
Exploitation
Sahil Kumar; Abhishek Sharma; Kanwarpreet Singh
Abstract
This study investigates the application of the Rapid Mass Movement Simulation (RAMMS) tool in assessing and mitigating various types of landslides. The research encompasses comprehensive field visits to diverse landslide-prone areas, capturing detailed photographic evidence to document pre- and post-landslide ...
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This study investigates the application of the Rapid Mass Movement Simulation (RAMMS) tool in assessing and mitigating various types of landslides. The research encompasses comprehensive field visits to diverse landslide-prone areas, capturing detailed photographic evidence to document pre- and post-landslide conditions. Utilizing the field data, RAMMS simulations were conducted to model the dynamics of different landslide scenarios, including rockfalls, debris flows, and avalanches. The simulations provided insights into the potential impact zones, flow velocities, and deposition patterns of landslides under varying environmental conditions. The results highlight the efficacy of RAMMS in predicting landslide behavior and guiding mitigation strategies. By comparing the simulation outputs with field observations, we validated the accuracy of RAMMS models, demonstrating their utility in real-world applications. Furthermore, the study identifies key factors influencing landslide susceptibility and proposes targeted mitigation measures to enhance community flexibility. This research underscores the importance of integrating advanced simulation tools like RAMMS with empirical field data to develop strong landslide risk management frameworks.
Original Research Paper
Exploration
Devraj Dhakal; Kanwarpreet Singh
Abstract
Landslides pose significant risks to human life, infrastructure, and the environment, particularly in geologically unstable regions like the Himalayas. This study aims to develop and validate landslide susceptibility maps using Frequency Ratio (FR) and Information Value (IV) models within a GIS framework. ...
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Landslides pose significant risks to human life, infrastructure, and the environment, particularly in geologically unstable regions like the Himalayas. This study aims to develop and validate landslide susceptibility maps using Frequency Ratio (FR) and Information Value (IV) models within a GIS framework. Employing high-resolution geospatial data, including geomorphological, topographical, and hydrological factors derived from high-resolution digital elevation models (DEMs) and other geospatial datasets. The susceptibility maps were classified into five categories: Low, Moderate, High, Very High, and Extremely High. The models were trained and validated using a landslide inventory of 1313 landslide events, with a 70:30 split for training and testing datasets. The predictive performance of the models was evaluated using the Area Under the Curve (AUC) of the Receiver Operating Characteristic (ROC) curve, yielding AUC values of 84.1 for the FR model and 83.9 for the IV model. The Landslide Density Index (LDI) further confirmed the models' reliability, indicating higher landslide densities in the predicted high-susceptibility zones. The study demonstrates that both FR and IV models are effective tools for landslide susceptibility mapping and its validation. The findings highlight the FR model's superior predictive accuracy in this specific area. Future research should leverage advanced machine learning techniques, such as XGBoost, Random Forest (RF), Naive Bayes (NB), and K-Nearest Neighbors (KNN), to enhance the reliability and precision of landslide susceptibility models.
Original Research Paper
Environment
Lateef Bankole Adamolekun; Taiwo Blessing Olamide; Muyideen Alade Saliu; Esma Kahraman; Victor Afolabi Jebutu; Yewuhalashet Fissha; Adams Abiodun Akinlabi
Abstract
Examining the applicability of laterite clay for landfill and other engineering applications is critical due to the daily challenges that practitioners face as a result of material property variation. The suitability of seven selected laterite deposits in southwestern Nigeria as usable liner material ...
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Examining the applicability of laterite clay for landfill and other engineering applications is critical due to the daily challenges that practitioners face as a result of material property variation. The suitability of seven selected laterite deposits in southwestern Nigeria as usable liner material in solid waste landfill construction was investigated in this study, taking geotechnical properties and chemical composition into account. Purposive samples were collected and tested in accordance with ASTM standard procedures for analyzing geotechnical properties. X-ray diffraction analysis was used to determine the soil's clay mineral composition. The clay mineral composition of the soil was determined using X-ray diffraction analysis. The geotechnical analysis revealed the following ranges for the samples: gravel particle size percentage (3.7% to 34.0%), fines particle size percentage (17.4% to 71.7%), liquid limit (28.1% to 65.8%), plasticity index (3.95 to 45.53), activity (0.44 to 0.81), coefficient of permeability (6.75 x10-10 m/s to 5.80 x 10-6 m/s), specific gravity (2.639 to 2.768), and maximum dry density (1462 kg/m3 to 2065 kg/m3). X-ray diffraction test revealed that the clay minerals content in the seven location clay deposit varies depending on location. The study revealed that the clay mineralogical composition affects the suitability of the soil as a landfill liner material. Four among the seven clay deposits considered in this study were found suitable as a liner for solid waste landfills as compared with landfill material standard specifications.
Original Research Paper
Rock Mechanics
Vahab Sarfarazi; Lei Zhou; Hadi Haeri; Parastou Salehipour; Ali Elahi; Ali Moayer; Mohammad Fatehi Marji
Abstract
The mechanical behavior of rock-rock bolt interface considering the effects of indents’ shape and their number was numerically simulated based on discrete element method using the two-dimensional particle flow code. The conventional and standard uniaxial compressive and Brazilian tensile strengths ...
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The mechanical behavior of rock-rock bolt interface considering the effects of indents’ shape and their number was numerically simulated based on discrete element method using the two-dimensional particle flow code. The conventional and standard uniaxial compressive and Brazilian tensile strengths tests were used to calibrate the modelled samples with 100 cm 100 cm in dimension. The numerical models were prepared such that different indent shape and number were inserted in the cable bolts arrangements during the rock reinforcement process. The effects of confining pressure 3.7 MPa and different shear failure loads were modeled for the punch shear test of the concrete specimens. The results of this study showed that the dominant failure mode of the rock-cable bolt interface was of tensile mode and the shape and number of cable indents significantly affected the strength and mechanical behavior of the modelled samples. It has also been showed that the indent dimensions and number affected the shear strength of the interfaces.
Original Research Paper
Rock Mechanics
Masoud Yazdani; Mohammad Fatehi Marji; Mehdi Najafi; Manouchehr Sanei
Abstract
Around 70% of the world's hydrocarbon fields are situated in reservoirs containing low-strength rocks, such as sandstone. During the production of hydrocarbons from sandstone reservoirs, sand-sized particles may become dislodged from the formation and enter the hydrocarbon fluid flow. Sand production ...
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Around 70% of the world's hydrocarbon fields are situated in reservoirs containing low-strength rocks, such as sandstone. During the production of hydrocarbons from sandstone reservoirs, sand-sized particles may become dislodged from the formation and enter the hydrocarbon fluid flow. Sand production is a significant issue in the oil industry due to its potential to cause erosion of pipes and valves. Separating grains from oil is a costly process. Oil and gas companies are motivated to reduce sand production during petroleum extraction. Hydraulic fracturing is one of the parameters that can influence sand production. However, understanding the complex interactions between hydraulic fracturing mechanisms and sand production around wellbores is critical for optimizing reservoir recovery and ensuring the integrity of production wells. This article explores the integrated simulation approach to model hydraulic fracturing processes and assess their effects on sand production. Two-dimensional models were created using the discrete element method in PFC2D software for this research. The fractures' length in the models varies based on the well's radius. The angle between two fractures at 90 and 180 degrees to each other was also modeled. In the first case, the length of the fracture is less than the radius of the well, in the second case, the values are equal and finally, the fracture length is assumed to exceed the well radius. The calibrated and validated results demonstrate the change in sand production rate in comparison to the unbroken state.
Original Research Paper
Environment
Asghar Azadehranjbar; Shahrzad khoramnejadian; Saeidreza Asemi Zavareh; Alireza Pendashteh
Abstract
Mining and minerals extraction and purification are critical in today’s world. However, these processes may have negative consequences on the environment. Xanthates which are essential in the floatation process are found to be significant polluting chemicals. In this manuscript, the effect of different ...
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Mining and minerals extraction and purification are critical in today’s world. However, these processes may have negative consequences on the environment. Xanthates which are essential in the floatation process are found to be significant polluting chemicals. In this manuscript, the effect of different parameters on the recovery of lead from Nakhlak lead mine was investigated considering the impact of used chemicals on the surrounding environment including air, soil and native plant species. The reason for this investigation was to achieve the optimal conditions for the minimum consumption of xanthates and other chemicals. The optimal recovery was obtained in the presence of xanthate (1 kg/t) and sodium silicate (0.4 kg/t). In addition, MIBC showed to be more efficient in the floatation process. Furthermore, it was observed that higher xanthate contents are required for the floatation of large particles. Therefore, smaller particles of feed can decrease xanthate consumption. A particle size of 100 µm showed the best floatation recovery with the least xanthate requirement.
Case Study
Exploration
Moslem Jahantigh; Hamid Reza Ramazi
Abstract
Fuzzy c-means (FCM) is an unsupervised machine learning algorithm. This method assists in integrating airborne geophysics data and extracting automatic geological map. This paper tries to combine airborne geophysics data consisting of aeromagnetic, potassium, and thorium layers to classify the lithological ...
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Fuzzy c-means (FCM) is an unsupervised machine learning algorithm. This method assists in integrating airborne geophysics data and extracting automatic geological map. This paper tries to combine airborne geophysics data consisting of aeromagnetic, potassium, and thorium layers to classify the lithological map of the Shahr-e-Babak area, a world-class porphyry area in the south of Iran. The resulting clusters with FCM show appropriate coincidence with the geological map of the study area. The clusters are adapted with high magnetic anomalies corresponding to the mafic volcanic rocks and the clusters with high radiometric signature associated with igneous rocks. The cluster is associated with low magnetic anomaly and low radioelements concentration representing sedimentary rocks. some clusters are associated with two or more lithological formations due to similar signatures of geophysics properties. The fuzzy score membership in all clusters is above 0.71 indicating a high correlation between geological signatures and multigeophysical data. This study shows geophysical signatures analyzed with the machine learning method can reveal geological units.
Review Paper
Rock Mechanics
Mohammad Reza Shahverdiloo; Shokroallah Zare
Abstract
The deformation modulus of rock mass is necessary for stability analysis of rock structures, which is generally estimated by empirical models with one to five input parameters/indexes. However, appropriate input parameter participation to establish a sound basis for a reliable prediction has been a challenging ...
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The deformation modulus of rock mass is necessary for stability analysis of rock structures, which is generally estimated by empirical models with one to five input parameters/indexes. However, appropriate input parameter participation to establish a sound basis for a reliable prediction has been a challenging task. In this study, the concept of the principal input parameters was developed based on an analytical method with an emphasis on in situ stress. Based on analytical methods, Young’s modulus of intact rock, the joint’s shear and normal stiffness, joint set spacing, and in situ stress are introduced as the main principal input parameters. A review of seventy empirical models revealed that most of them suffered from a lack of analytical parameters. Due to considering practical issues, the geological strength index (GSI) is replaced with joint set spacing; moreover, the in situ stress effect is perceived by combining Young’s modulus and joint stiffness with specific confining pressure and normal stress, respectively. The integration of the analytical base input parameters and practical issues enhanced the reliability of empirical models due to the reasonable prediction of the deformation modulus to numerical or analytical deformability analysis.
Original Research Paper
Exploitation
Mohammad Hossein Jalalian; Raheb Bagherpour; Mehrbod Khoshouei; S. Najmedin Almasi
Abstract
Diamond wire cutting is a common method to extract dimension stones, which depends on various factors, including the mechanical and physical properties of the stone, cutting specifications, and operational characteristics. Specific energy, production rate, efficiency, and wear of diamond beads are some ...
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Diamond wire cutting is a common method to extract dimension stones, which depends on various factors, including the mechanical and physical properties of the stone, cutting specifications, and operational characteristics. Specific energy, production rate, efficiency, and wear of diamond beads are some of the criteria that influence economic and environmental optimization of diamond wire cutting operations. In this study, the specific energy of the diamond wire cutting process was measured for 11 samples of Granite stones. By analyzing the impact of parameters such as stone density, porosity, and cutting rate on energy consumption, a linear regression model was developed with a correlation coefficient (R2) of 0.944 to predict specific energy for different types of stones. Statistical analyses, including ANOVA, have confirmed that the model accurately predicts specific energy values. Data from three new stone samples were used to validate the model, and their predicted energy values were compared with actual values. The model presented achieved an R2 value of 0.827, demonstrating its high accuracy. The results indicate that energy consumption in dimension stone cutting operation can be accurately predicted and characterized indirectly using high precision stone properties and operational parameters. This method can accurately and indirectly monitor energy consumption and cutting machine performance during the dimension stone cutting operation and can be used to optimize economic and environmental aspects of this process.
Original Research Paper
Rock Mechanics
Dariush Mohammadi; Kourosh Shahriar; Parviz Moarefvand; Ebrahim Farrokh
Abstract
The correct design of the cutterhead of a tunnel boring machine (TBM) plays a vital role in the efficient operation of the machine, as the cutterhead structure remains unchanged during the tunneling project. This paper aims to elucidate the fundamental principles in the design of the cutterhead opening ...
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The correct design of the cutterhead of a tunnel boring machine (TBM) plays a vital role in the efficient operation of the machine, as the cutterhead structure remains unchanged during the tunneling project. This paper aims to elucidate the fundamental principles in the design of the cutterhead opening in soft ground based on data obtained from TBM manufacturers. Initially, a comprehensive database of soft ground cutterheads from different TBM manufacturers across various projects and ground conditions was compiled. The most frequently used cutterhead configurations with diameters exceeding 5 meters were categorized into 36 distinct opening configurations based on a radial opening ratio curve and opening patterns per sector. Next, the performance parameters and particle flow characteristics of three Herrenknecht cutterhead designs featuring varying opening configurations in the central and circumference areas were analyzed using the Discrete Element Method (DEM) by considering material parameters for machine and soil and contact parameters between soil particles and soil particles-machine structures. Hertz–Mindlin model was assigned as the contact model for these elements. Additionally, three different cutterheads employed in Tehran metro projects in Iran were identified by monitoring the cutterhead torque and thrust force under same geotechnical conditions and operational parameters. Generally, a higher opening percentage in the central area of the cutterhead indicates good performance during excavation in cohesive soils. However, the higher opening percentage in circumferential areas is a better choice for effective excavated material removal around the cutterhead and tunnel in non-cohesive soils, weathered rocks, mixed and heterogeneous conditions.
Original Research Paper
Environment
Behnoosh Khataei; Farhad Qaderi; Farzad Mosavat
Abstract
The increase in the number of factories, the industrialization of human life, and the increasing use of industrial paints have caused an increase in dye wastewater and consequent environmental pollution. Discharging wastewater containing the dyes mentioned above, which are often carcinogenic, is a severe ...
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The increase in the number of factories, the industrialization of human life, and the increasing use of industrial paints have caused an increase in dye wastewater and consequent environmental pollution. Discharging wastewater containing the dyes mentioned above, which are often carcinogenic, is a severe threat to living organisms. In this research, a photocatalytic method (as an advanced oxidation method) using zinc oxide nanoparticles was investigated to treat the colored wastewater containing methylene blue. This type of nanoparticle is cheap (based on the used synthesis method), abundant and readily available, and low in toxicity. For this purpose, an evaluation of the optimal ratio between zinc acetate and polyvinylpyrrolidone for the synthesis of zinc oxide nanoparticles was carried out. Furthermore, the simultaneous decreasing and increasing effects of independent parameters (pH, irradiation time, methylene blue concentration, zinc acetate to PVP ratio) on the efficiency of the photocatalytic process and kinetic model were evaluated. The results showed that the best pollutant removal efficiency (91.7%) was obtained using the ratio of zinc acetate and polyvinylpyrrolidone equal to 33.67 in 60 minutes of irradiation time. This result shows that the lower ratio of zinc acetate to polyvinylpyrrolidone indicates higher dye removal.
