Original Research Paper
Blessing Olamide Taiwo; Gebretsadik Angesom; Yewuhalashet Fissha; Yemane Kide; Enming Li; Kiross Haile; Oluwaseun Augustine Oni
Abstract
Rock blast production rate (BPR) is one of the most crucial factors in the evaluation of mine project's performance. In order to improve the production of a limestone mine, the blast design parameters and image analysis results are used in this work to evaluate the BPR. Additionally, the effect of rock ...
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Rock blast production rate (BPR) is one of the most crucial factors in the evaluation of mine project's performance. In order to improve the production of a limestone mine, the blast design parameters and image analysis results are used in this work to evaluate the BPR. Additionally, the effect of rock strength on BPR is determined using the blast result collected. In order to model BPR prediction using artificial neural networks (ANNs) and multivariate prediction techniques, a total of 219 datasets with 8 blasting influential parameters from limestone mine blasting in India are collected. To obtain a high-accuracy model, a new training process called the permutation important-based Bayesian (PI-BANN) training approach is proposed in this work. The developed models are validated with new 20 blast rounds, and evaluated with two model performance indices. The validation result shows that the two model results agree well with the BPR practical records. Additionally, compared to the MVR model, the proposed PI-BANN model in this work provides a more accurate result. Based on the controllable parameters, the two models can be used to predict BPR in a variety of rock excavation techniques. The study result reveals that rock strength variation affects both the blast outcome (BPR) and the quantity of explosives used in each blast round.
Review Paper
Devraj Dhakal; Salad Omar Abdi; Kanwarpreet Singh; Abhishek Sharma
Abstract
The highway contributes significantly to human existence by providing safe, dependable, and cost-effective services that are environmentally friendly and promote economic progress. Highway projects need extensive planning to prevent work revisions, save time and cost, and increase job efficiency. Without ...
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The highway contributes significantly to human existence by providing safe, dependable, and cost-effective services that are environmentally friendly and promote economic progress. Highway projects need extensive planning to prevent work revisions, save time and cost, and increase job efficiency. Without a doubt, Highway transportation system must be constantly updated to keep up with technology breakthroughs, environmental change, and rising client needs. Incorporating Remote Sensing (RS) and Geographic Information Systems (GISs) has the potential to go beyond the limitations of RS, which typically collects information about the earth and its peripheries from space, and does not alter, analyze, calculate, query or display geographic engineering maps. Over the last few decades, the fusion of RS and GIS has shown promise, and the researchers are employing it in different stages of the Highway Planning and Development Process (HPDP) such as optimal route analysis, geometric design, operation and management, traffic modeling, accident analysis, and environmental impact analysis (noise pollutions, air pollutions). This paper gives an overall review of the use of RS and GIS on HPDP at various stages of their lifecycles.
Original Research Paper
Ankit Kumar; Ravi Kumar Sharma
Abstract
Granular pile anchor is a new technique that is commonly used to improve the pull-out resistance of expansive soil like soft clay, loose sand, and black cotton soil. Using the Abaqus software, this work presents a numerical investigation to estimate the pull-out capacity of granular pile anchor ...
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Granular pile anchor is a new technique that is commonly used to improve the pull-out resistance of expansive soil like soft clay, loose sand, and black cotton soil. Using the Abaqus software, this work presents a numerical investigation to estimate the pull-out capacity of granular pile anchor in soft clay. By applying a specified displacement of 10% of D (pile diameter) on the granular pile anchor, the effects of length, diameter, angle of inclination (α), and number of GPA at varying spacing values on uplift capacity is examined. Additionally, L/D ratios of both individual and group piles are examined using various variables. The study uses expansive soil and GPA of unit weight 17 kN/m3 and 22 kN/m3, poisson’s ratio of 0.4 and 0.3, modulus of elasticity 4 MPa, and 11 MPa, respectively, for the estimation of uplift capacity. The cohesion value for the expansive clay is 25 kPa, and the angle of shearing resistance for GPA is 36˚. According to the numerical study, both for a single pile and for piles placed in a group, with increases in pile length and diameter, the granular pile anchor's pull-out capability improves. For a pile placed in group the value of the pull-out capacity shows optimum result when spacing (S) is 2.5D. Additionally, the uplift capacity of the granular pile anchor increases with an increase in angle inclination (α) from 0˚ to 10˚, and then decreases from 10˚ to 15˚. The efficiency of GPA is examined, which assists in the choice of the different granular pile anchor parameters.
Original Research Paper
Ali Nouri Qarahasanlou; Abbas Barabadi; Meisam Saleki
Abstract
Implementing maintenance protocols for industrial machinery is essential since a well-thought-out plan may support and improve machinery dependability, production quality, and safety precautions. Implementing a maintenance plan that considers the equipment's actual functional behavior and the effects ...
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Implementing maintenance protocols for industrial machinery is essential since a well-thought-out plan may support and improve machinery dependability, production quality, and safety precautions. Implementing a maintenance plan that considers the equipment's actual functional behavior and the effects of failures will be easier and more practical. Engineers must consider environmental conditions when studying in hostile environments such as mine. The major goal of this study is to create a mining equipment maintenance program that is as effective as possible while incorporating risk and performance indicators and taking environmental factors into account. The study uses the “reliability-centered maintenance” method, which combines the reliability operating index and risk. The Cox model also includes the risk factors associated with environmental conditions in the reliability analysis. The proposed approach was implemented in a 5-758 Komatsu dump-truck case study at the Sungun copper mine in Iran. The reliability-centered maintenance approach is implemented for dump-truck in three scenarios based on risk factors: 1- baseline, 2- First semi-annual, cheap maintenance, and 3- second semi-annual, expensive maintenance. All failure modes are low-risk, making corrective maintenance appropriate. In Scenario 1, electrical-electrical, electrical-start, mechanical, and pneumatic-related failures are low-risk, making corrective maintenance suitable. In Scenario 2, corrective maintenance is recommended for pneumatic-related failure. In Scenario 3, the fuel-related failure has a high criticality number and failure intensity, indicating a high-risk situation. Time-based preventive maintenance is the most appropriate strategy for this scenario.
Original Research Paper
Demet Demir Shahin; Ebrahim Kavoos Oghloo; Ali Osman Yilmaz
Abstract
Today, energy produced from coal is economical compared to other sources but it faces a very serious waste problem. However, these wastes are evaluated by using them as mineral additives in cement, which leads to lower cement costs, saving resources, producing environmentally friendly cement, reducing ...
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Today, energy produced from coal is economical compared to other sources but it faces a very serious waste problem. However, these wastes are evaluated by using them as mineral additives in cement, which leads to lower cement costs, saving resources, producing environmentally friendly cement, reducing CO2 gas, and producing high-strength cement. In this work, the pozzolanic properties of different types of fly ash (Afşin Elbistan C type and Çayırhan F type) are investigated. The fly ashes used in the study are first subjected to the milling process (10, 20, 30, 45, and 60 minutes), and then the 28 and 90-day pozzolanic activity index tests of the milled and unmilled ashes are performed. The results obtained show that the 28-day pozzolanic activity value of the ashes subjected to 20-, 30-, 45-, and 60-minute milling times are higher than the value specified in the standard, compared to the unmilled and 10 min milled fly ash. In addition, for all fly ash samples, the 90-day pozzolanic activity index results show that while the pozzolanic activity index value of Çayırhan (ÇYH) fly ash is higher than the standard value, that of Afşin Elbistan (AE) fly ash is lower than standard. The outcomes of the present study show that the mechanical properties of the fly ash are generated by the burning of coal increase after milling process, and thus can be used as a mineral additive. With the effect of grinding, both fly ash increase the pozzolanic activity. The results are determined with the experimental results obtained.
Original Research Paper
Kamar Samir; Ahmed Niazy El-Barkooky; Mohamed El-Sharkawi; Mohamed Saleh Hassan Hammed
Abstract
The Precambrian rock assemblages of Umm Tawat area in the North Eastern Desert of Egypt have a distinctive ENE-trending exposure of Hammamat sediments (HS) between the Gebel Gattar granitic pluton and the volcanoclastic succession of Gebel El Dokhan. The present work applies the Landsat-8 data and image ...
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The Precambrian rock assemblages of Umm Tawat area in the North Eastern Desert of Egypt have a distinctive ENE-trending exposure of Hammamat sediments (HS) between the Gebel Gattar granitic pluton and the volcanoclastic succession of Gebel El Dokhan. The present work applies the Landsat-8 data and image processing techniques such as spectral signature, principal component analysis, decorrelation stretch, and band ratios to map the various Precambrian rock units and the lithofacies of the HS and their geological contacts. The recognized mappable units of this assemblage are fully identified by their spectral signature, field verification, lineament analysis, and petrographic description. The resultant high-resolution lithological map based on the maximum likelihood algorithm demonstrates ten fully discriminated mappable units of younger granitoid and HS lithofacies units besides the Dokhan volcanics and metagabro-diorite rock units. The identified five HS lithofacies units are brownish gray conglomerate and sandstone HSf1, a green conglomerate with dominant volcanic fragments HSf2, fine-grained sediments of graywacke and silty-mudstone HSf3, interbedded conglomerates and siltstone with uranium enrichments related to the intrusive contact HSf4, and thermally metamorphosed pelitic sediments HSf5. Remote sensing techniques have been applied for the first time to reveal detailed facies variation of the Hammamat sediments of Umm Tawat. Finally, the results aforementioned above are imported to the Arc GIS database to update the geologic map with precise rock unit boundaries.
Original Research Paper
Vivek Sharma; Pardeep Kumar; Ravi Kumar Kumar Sharma
Abstract
Himachal Pradesh state is located in seismically active western Himalayas (India) and its seven districts are in seismic zone V and other in zone IV as per the seismic code of India. Ninety% area of Hamirpur district, the studied area, lies in zone V. Peak ground acceleration (PGA) is one of the most ...
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Himachal Pradesh state is located in seismically active western Himalayas (India) and its seven districts are in seismic zone V and other in zone IV as per the seismic code of India. Ninety% area of Hamirpur district, the studied area, lies in zone V. Peak ground acceleration (PGA) is one of the most important seismic response parameters in structural seismic design, largely influenced by the sub-soil and input seismic motion characteristics. In the present work, the primary objective is to identify the areas in the district that are prone to amplification of peak ground acceleration and can be delineated for infrastructural planning. Peak ground acceleration is one of the most important parameters used in seismic design of the structures. It is estimated using the computer programme ProShake, wherein the soil parameters from 181 borehole profiles up to 30 m depth and software in-built standard earthquake input motions of magnitude 6.9, 7.0, and 7.2 used as the input parameters. The output peak ground acceleration range from 0.24 g to 0.72 g at the ground surface and from 0.21 g to 0.54 g at a depth of 10 m. There is an attenuation of peak ground acceleration at 30 m depth. The estimation of peak ground acceleration will play an important role in delineating the starta having higher peak ground acceleration amplification. This information can be effectively used for planning of important infrastructure projects like hospitals, educational institutions, and commercial establishments in an economical way in the studied area.
Original Research Paper
Farouk Sayed; Mohamed Saleh Hassan Hammed; Ahmed Gaber Shided; Ahmed Wagih Hussein
Abstract
The northwestern margin of the Red Sea is developed as several rift-related fault blocks. These fault blocks comprise two mega tectono-stratigrahicsuccessions; the Pre-riftsuccessioncould be sub-divided intothe Precambrian Basement rocks and theUpperCretaceous-Lower Eocenedeposits,whilst the Syn-rift ...
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The northwestern margin of the Red Sea is developed as several rift-related fault blocks. These fault blocks comprise two mega tectono-stratigrahicsuccessions; the Pre-riftsuccessioncould be sub-divided intothe Precambrian Basement rocks and theUpperCretaceous-Lower Eocenedeposits,whilst the Syn-rift sequence includesthe Oligocene to Quaternary deposits. Lithologic differentiation of these rock units being encountered in thestudied area is accomplishedutilizing different remote sensing imagery enhancement techniques of the OLI data (Landsat-8) aided with field verification. Spectral signature analysis of different rock units, false-color composite, band-ratio, principle component analysis, minimum noise fraction, and independent component analysis are powerful tools in discrimination of the main rock units.The maximum likelihood distance supervised classificationtechnique is a robust tool in the identification of the contact between the different rock units. Radiometrically terrain corrected (RTC) DEM data extracted from PALSAR with a spatial resolution of 12.5m is utilized for the construction of a 3D perspective view image of the studied area. The present study offers a unique method for lithologic discrimination of main rock unitsutilizing OLI images, and introduces an enhanced high-resolution structural map of the studied area aided with field verification.
Original Research Paper
Kashitij Guleria; Ravi Kumar Sharma
Abstract
This paper discusses the applications of industrial waste like waste foundry sand (10%, 20%, 30%, and 40%) and calcium carbide residue (3%, 6%, 9%, and 12%) blended with polypropylene fibre (0.25%, 0.50%, 0.75%, and 1%) for soil stabilization. The purpose of this study is to develop a composite of clayey ...
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This paper discusses the applications of industrial waste like waste foundry sand (10%, 20%, 30%, and 40%) and calcium carbide residue (3%, 6%, 9%, and 12%) blended with polypropylene fibre (0.25%, 0.50%, 0.75%, and 1%) for soil stabilization. The purpose of this study is to develop a composite of clayey soil mixed with different additives, so it can be used for improving the geotechnical properties of the clayey soil. Multiple tests are conducted including differential free swell, Atterberg's limits test, compaction tests, unconfined compression test (UCS), and California-bearing ratio test (CBR) on clay soil individually and in different combinations and proportions with additive mixed with each other. The optimum percentage for the additives is found by performing differential free swell index and Atterberg limits test. The results demonstrate that the inclusion of additives in the clayey soil decreases the differential free swell and plasticity index of the composite but raises the composite UCS and CBR values. The maximum increase in the UCS and CBR values is obtained for optimum combination of C:PP:WFS:CC::76.25:0.75:20:3. Based on the CBR values, the thickness of flexible pavement is designed using the IITPAVE software. The results of the software analysis show a reduction in the pavement thickness for various values of commercial vehicles per day (1000, 2000, and 5000) for all combinations. The maximum reduction in layer thickness and construction costs is noticed for C:PP:WFS:CC:76.25:0.75:20:3. To further examine the improvement in the geotechnical properties of soil, calcium carbide residue, and waste foundry sand can be blended with nano-additives for potential uses.
Original Research Paper
kausar Sultan shah; Naeem Abbas; Li Kegang; Mohd Hazizan bin Mohd Hashim; Hafeez Ur Rehman; Khan Gul Jadoon
Abstract
The rocks in the studied area are prone to deterioration and failure due to frequent exposure to extreme temperature variations and loading conditions. In the context of rock engineering reliability assessment, understanding the energy conversion process in rocks is critical. Therefore, this research ...
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The rocks in the studied area are prone to deterioration and failure due to frequent exposure to extreme temperature variations and loading conditions. In the context of rock engineering reliability assessment, understanding the energy conversion process in rocks is critical. Therefore, this research work aims to assess the energy characteristics and failure modes of pink and white-black granite subjected to uniaxial compression loading at various temperatures. Samples of pink and white-black granite are heated to a range of temperatures (0 °C, 200 °C, 400 °C, 600 °C, 900 °C, and 1100 °C), and their failure modes and energy characteristics including total energy, elastic energy, and dissipated energy are studied by testing preheated samples under uniaxial compression. The results show that the dissipation energy coefficient initially rises rapidly, and then falls back to its minimum value at the failure stage. The micro-structures of granite rock directly affect its elastic and dissipation energy. Axial splitting failure mode is observed in most of the damaged granite specimens. After heating granite to 600 °C, the effect of temperature on the failure mode becomes apparent.
Original Research Paper
Kaustubh Sinha; Priyangi Sharma; Kanwarpreet Singh; Sushindra Kumar Gupta; ABHISHEK SHARMA
Abstract
Land surface temperature (LST) is one of the most important geological features of any area in the present times. During the study, the information regarding the land surface temperature is calculated using the Arc-GIS software. The LANDSAT 8 (2022) and LANDSAT 4-5 (2001 and 2011) satellite images are ...
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Land surface temperature (LST) is one of the most important geological features of any area in the present times. During the study, the information regarding the land surface temperature is calculated using the Arc-GIS software. The LANDSAT 8 (2022) and LANDSAT 4-5 (2001 and 2011) satellite images are used for the calculation of LST. From the LST maps of years 2001 and 2011, a significant rise is noticed; this is due to the rapid increment in the population of the said area. A gradual increment in the LST is present between the second period of 2011-2022. A connection between the LST and the specific humidity has also been drawn in this aspect. The specific humidity in the region has seen a significant increment in the concerned time period. Overall, it is observed that the LST of the area has increased rapidly from the -12 ˚C minimum temperature in 2001 to 27 ˚C in 2022; this is because of the human activity in the area, which has ultimately catered towards the degradation of the climatic condition and environment like LST.
Original Research Paper
Bijan Afrasiabian; Kaveh Ahangari; Ali Noorzad
Abstract
High-level vibrations caused by blasting operations in open-pit mining can exert adverse effects such as destruction of surrounding surface structures. Therefore, it is essential to identify the factors effective in mitigating the damaging effects of ground vibration in open-pit mines, and monitor them. ...
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High-level vibrations caused by blasting operations in open-pit mining can exert adverse effects such as destruction of surrounding surface structures. Therefore, it is essential to identify the factors effective in mitigating the damaging effects of ground vibration in open-pit mines, and monitor them. This study investigates the effects of some of the most important blast design parameters in a row of blast holes. According to the advantages of numerical methods, the 3D discrete element method is employed for this purpose. The Peak Particle Velocity (PPV) values are measured along the central hole at the distances of one meter. The results obtained demonstrate that an increase in the blast damage factor and inter-hole delay time results in higher PPV values. However, the increased delay time has no remarkable effect on reducing the development of the blast damage zone. On the other hand, as the decoupling increases, the PPV values diminish, leading to substantial reductions in the ground vibration and rock mass damage. It is also observed that the elimination of sub-drilling does not significantly reduce ground vibrations. The analysis of the results obtained from the numerical modeling show that the discontinuities of the rock mass act as a filter, which could decrease the wave energy by more than 90%. Moreover, it is found that the direction of the discontinuities also affects the emission of waves caused by the blast. The PPV values are reduced, and the damaged zone is less developed if the discontinuities are opposite of the slope surface.
Case Study
Hasan Alizadeh; Mahnaz Nedaei; Negar Tirandaz
Abstract
One of the significant negative factors involved in exploiting granite stones as ornamental stones is the presence of heterogeneous fractures within the rock mass. Joints can either be destructive or beneficial in the production granite piles and building stone mines depending on their characteristics. ...
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One of the significant negative factors involved in exploiting granite stones as ornamental stones is the presence of heterogeneous fractures within the rock mass. Joints can either be destructive or beneficial in the production granite piles and building stone mines depending on their characteristics. This work focuses on evaluating the joints in the Divchal mine area of Kelardasht, north Iran. To get to that point, the main faults are surveyed from the aerial photograph, geological and tectonic maps, and field observations. According to this implementation, a density map of faults is provided for the entire studied area. The characteristics of the main joints including the length, slope, number, and orientation are collected in the mine area. The volumetric percentage of joints ( ) and joint set spacing ( ) parameters are computed at specific stations to identify suitable locations for granite extraction. The findings of this work suggest that the lower the value of ( < 10), the larger the blocks can be extracted. On the other hand, at the high values, the width of the extraction block increases. These conditions are typically found in locations far from the main faults where the density of joints is low, and as a result, the distance between joints is higher. The values > 60 indicate a crushed rock mass, and are typically observed in clay-free shear zones. It is recommended that the opening of the working face be avoided in situations near the main faults due to the fragmentation of rocks and denser joint spacing.
Original Research Paper
Hadi Bejari; Jafar Khademi Hamidi
Abstract
This work aims to investigate the effect of water saturation on cutting forces and chipping efficiency by performing a series of small-scale linear cutting tests with a chisel pick on twelve low- and medium-strength rock samples. The peak and mean cutting force acting on the chisel pick are measured ...
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This work aims to investigate the effect of water saturation on cutting forces and chipping efficiency by performing a series of small-scale linear cutting tests with a chisel pick on twelve low- and medium-strength rock samples. The peak and mean cutting force acting on the chisel pick are measured and recorded under dry and saturated cutting conditions by the strain sensors that are embedded in the dynamometer. Also the amplitude of cutting force fluctuations in dry and saturated cutting conditions is compared by the standard deviation measurement of cutting force data, and its relationship with the size of cutting fragments is investigated. The results obtained show that the peak cutting force is reduced in saturated conditions compared to dry conditions. The mean cutting force in the synthetic sample cutting test is unchanged or in some cases increase, while in the natural samples it decreases. The relative increase in the mean cutting force in synthetic rock specimens is due to the paste state of fine materials produced from saturated cutting and chisel pick clogging. A strong correlation is found between the standard deviation of cutting force data and the average size of rock debris, indicating that the standard deviation of cutting force data is a useful measure for evaluating the chipping efficiency. The present study's findings reveal that to have an efficient excavation system in field operations, it is necessary to consider the presence of water and saturated conditions in designing the cutting machine's operating parameters and predicting the performance of mechanical excavators.
Original Research Paper
vahab sarfarazi; Mohammad Omidi manesh; nima babanouri; amir rezaei
Abstract
This work presents the hollow center cracked disc (HCCD) test and the cracked straight through Brazilian disc (CSTBD) test of oil well cement sheath using the experimental test and Particle Flow Code in two-dimensions (PFC2D) in order to determine mode I fracture toughness of cement sheath. The tensile ...
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This work presents the hollow center cracked disc (HCCD) test and the cracked straight through Brazilian disc (CSTBD) test of oil well cement sheath using the experimental test and Particle Flow Code in two-dimensions (PFC2D) in order to determine mode I fracture toughness of cement sheath. The tensile strength of cement sheath is 1.2 MPa. The cement sheath model is calibrated by outputs of the experimental test. Secondly, the numerical HCCD model and CSTBD model with diameter of 100 mm are prepared. The notch lengths are 10 mm, 20 mm, 30 mm, and 40 mm. The tests are performed by the loading rate of 0.018 mm/s. When the notch length in CSTBD is 40 mm, the external work is decreased 48%, related to the maximum external work of model with notch length of 10 mm (0.225 KN*mm decreased to 0.116 KN*mm). When the notch length in HCCD is 30 mm, the external work is decreased 33%, related to the maximum external work of model with notch length of 10 mm (0.06 KN*mm decreased to 0.04 KN*mm). The fracture energy is largely related to the joint length. The fracture energy is decreased by increasing the notch length. In constant to the notch length, the fracture energy of the CSTBD model is more than the HCCD model. Mode I fracture toughness is constant by increasing the notch length. The HCCD test and the CSTBD test yield a similar fracture toughness due to a similar tensile stress distribution on failure surface. The experimental outputs are in accordance to the numerical results.
Original Research Paper
Mohammad Rezaei; Milad Ghasemi
Abstract
Resource estimation and determining the grade distribution is one of the most important stages in planning and designing the open-pit and underground mines. In this work, a new mythology is used for resource estimation of the Angouran underground mine based on the optimized integration of the indicator ...
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Resource estimation and determining the grade distribution is one of the most important stages in planning and designing the open-pit and underground mines. In this work, a new mythology is used for resource estimation of the Angouran underground mine based on the optimized integration of the indicator kriging (IK), simple kriging (SK), and inverse distance weighted (IDW) methods. For this purpose, waste blocks are first removed from the block model using the IK method. Then the amount of mineral resource is estimated using the SK and IDW methods. Indeed, variograms are developed to estimate the grade of zinc minerals in the three used methods. Variograms analysis in three directions prove that the studied resource is anisotropic. Also the validation results confirm that the correlation coefficients between the measured and estimated zinc values by the SK and IDW methods equal to 0.76 and 0.75, respectively. Knowing this satisfactory result, a 3D model of the resource is prepared using the IK method, in which the ore and waste sections of the Angouran underground mine are separated definitely. According to the above methodology, the calculated resource of the Angouran underground mine using the SK method is achieved 1373962.5 tons with an average grade of 30.11%, whereas the estimated amount of this resource is attained 1349325 tons with an average grade of 31.88% using the IDW approach. The verification results show that the suggested methodology based on the optimized integration of the IK, SK, and IDW methods can be successfully applied for resource modeling and grade estimating of the Angouran underground mine.
Original Research Paper
Mehdi Hosseini; Alireza Dolatshahi; Esmaeel Ramezani
Abstract
This work investigates the effect of adding micro-silica as a pozzolan and a replacement for part of concrete cement when placing concrete in an acidic environment. Two types of ordinary concrete and concrete-containing micro-silica are constructed. The specimens are subjected to 0, 1, 5, and 10 cycles ...
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This work investigates the effect of adding micro-silica as a pozzolan and a replacement for part of concrete cement when placing concrete in an acidic environment. Two types of ordinary concrete and concrete-containing micro-silica are constructed. The specimens are subjected to 0, 1, 5, and 10 cycles for two hours inside two types of acidic water containing sulfuric and nitric acid with pH = 3 and normal water with pH = 7. Mechanical properties including Brazilian tensile strength and uniaxial compressive strength, and physical properties including effective porosity, water absorption, and the longitudinal wave velocity of specimens are determined after the mentioned number of cycles. Thr results show that by decreasing the pH and increasing the number of cycles, the effective porosity and water absorption increase, and the velocity of longitudinal waves, Brazilian tensile strength, and uniaxial compressive strength of concrete decrease. Replacing 10% of micro-silica as a part of concrete cement has boosted the durability of concrete in corrosive conditions containing sulfuric and nitric acid more than ordinary concrete.
Original Research Paper
Sajjad Aghababaei; Hossein Jalalifar; Ali Hosseini; Farhad Chinaei; Mehdi Najafi
Abstract
In this work, two rock engineering system (RES)-based models are presented, the first model to predict the roof failure when a longwall face advances toward a pre-driven recovery room (PDRR) and the second model to select the type of recovery room method for longwall mining. For the first model, an international ...
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In this work, two rock engineering system (RES)-based models are presented, the first model to predict the roof failure when a longwall face advances toward a pre-driven recovery room (PDRR) and the second model to select the type of recovery room method for longwall mining. For the first model, an international database of 43 case histories from the pre-driven rooms including technical parameters and type of corresponding operation outcome of each case history is considered. In this regard, a vulnerability index (VI) that refers to the risk of roof failure is calculated for each case history and the VIs are compared with the type of the corresponding outcomes. The obtained results indicate that the calculated VIs have a good adaptation with the corresponding outcomes. This approach could be used to analyze the risk of failure in PDRR, and determine the critical VI that specifies the boundary between the hazard range and the safe range that leads to an accurate operational planning. In the following, a method called multi-options RES-based model (MORESM) is adopted for the selection of recovery room methods in longwall operation. By this model, selecting the optimum option from several options in terms of many effective parameters on the system is possible. Based on the evaluations, CRR, PDRR3, and PDRR2&3 are the suitable options for the case study. This model could introduce the suitable option based on geotechnical conditions but the final decision depends on the economic policy of the managing team.
Original Research Paper
amir rezaei; vahab sarfarazi; nima babanouri; Mohammad Omidi manesh; shirin jahanmiri
Abstract
Non-persistent joints are geologic occurrences in rocks that weaken pillars because they are present within them. Using practical tests and numerical models, it has been determined how edge notches affect the way pillars break. Gypsum samples that are notched and have dimensions of 70 mm by 70 mm by ...
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Non-persistent joints are geologic occurrences in rocks that weaken pillars because they are present within them. Using practical tests and numerical models, it has been determined how edge notches affect the way pillars break. Gypsum samples that are notched and have dimensions of 70 mm by 70 mm by 50 mm are created. Gypsum's Young modulus, Poisson ratio, compressive strength, and tensile strength are 5.5 GPa, 0.27, 8 MPa, and 1.1 MPa, respectively. 10-, 20-, and 30-degree notch angles are used. The model receives an axial stress at a rate of 0.05 mm/min. On a rock pillar, numerical simulation is carried out concurrently with an experimental test. The findings indicate that the joint angle is mostly responsible for the failure process. The fracture pattern and failure mechanism of the pillars are connected to the compressive strengths of the specimens. At the notch points, two significant splitting tensile fractures spread vertically until coalescing with the top and lower boundaries of the models. On the left and right sides of the pillar, two rock columns are also taken out. The overall number of cracks rises as sample loading increases. The model's deformation at the start of loading reflect a linear elastic behavior, and the number of fractures steadily grows. When the number of cracks increases, the curve becomes non-linear, and the force being applied peaks. When the sample can no longer tolerate the applied force, a dramatic stress decrease occurs. The macro-failure over the whole model is what leads to the greater stress decrease following the peak load. In actuality, the reduced stress reduction is accompanied by more overall fractures. Similar findings are shown in both the experimental testing and numerical modeling.
Original Research Paper
Ali Nouri Qarahasanlou; Alireza Dolatshahi
Abstract
Engineers use various methods to evaluate the performance of concrete structures under dynamic loads, including numerical simulations, laboratory experiments, and field tests. By combining the results of these methods, the engineers can develop a comprehensive understanding of the behavior of concrete ...
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Engineers use various methods to evaluate the performance of concrete structures under dynamic loads, including numerical simulations, laboratory experiments, and field tests. By combining the results of these methods, the engineers can develop a comprehensive understanding of the behavior of concrete structures under dynamic loads and use this information to design more resilient structures capable of withstanding these loads. In this work, four models of the concrete lining of the circular tunnel are simulated to investigate the effect of the pre-cracked in the tunnel's concrete lining under an internal explosion loading. A crack in three different locations at angles of 0, 45, and 90 on the horizontal axis of the tunnel is investigated and analyzed. The coupled Eulerian-Lagrangian method and the constitutive behavior, such as concrete damage plasticity for concrete and Drucker-Prager for soil, allows a more accurate simulation of the internal explosion loading scenario. The selection of Trinitrotoluene and the Jones-Wilkins-Lee equation of state for the explosive provides a realistic representation of the behavior of the explosive material. The modeling results show that in an internal explosion, by examining three different locations of a crack in the concrete, the occurrence of a crack in the crown of the tunnel is more critical than two crack locations. Hence, the existence of a crack with a length of 100 cm and a depth of 15 cm in the crown of the tunnel increases the tensile damage zone by 16.59% compared to the case where there is no crack.
Original Research Paper
Myong Nam Sin; Un Chol Han; Sung Il Jon; Hyon Hyok Ri
Abstract
Anthracite coal seam of Democratic People’s Republic of Korea was broken into particles to be soft due to geological tectonic actions through several stages in the Mesozoic era. Because the folds and faults have excessively developed and the shape of coal seam is very complicated, it is impossible ...
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Anthracite coal seam of Democratic People’s Republic of Korea was broken into particles to be soft due to geological tectonic actions through several stages in the Mesozoic era. Because the folds and faults have excessively developed and the shape of coal seam is very complicated, it is impossible to extract the anthracite coal by longwall mining system, and coal has been mainly mined by entry caving mining system. The aim of this work is to assess effectiveness of new combination of flying squirrel search algorithm (SSA) and artificial neural-network (ANN) for back-analysis of time-depending mechanical parameters of anthracite coal based on timber loads and displacements measured in the coal face entry. The case study deals with a coal face entry in Sinchang Coal Mine located in the Unsan County, South Pyongan Province, DPR Korea. To verify the good performance of new combination of the SSA and ANN, the comparison studies between proposed back-analysis method and other methods with the same purpose, are conducted using data measured in coal face entry. The mean absolute error (MAE) of weighted error norm of ANN-SSA is relatively smaller in comparison with other methods, which is 2.49. The new back-analysis is the good method to determine the suitable time-dependent mechanical parameters of anthracite coal surrounding the entry in very soft coal seam.
Original Research Paper
Enayatallah Emami Meybodi; fatemeh taajobian
Abstract
Due to the challenge of finding identical rock samples with varying grain sizes, investigating the impact of texture on rock material has been given less attention. However, macroscopic properties such as compressive strength, tensile strength, and modulus of elasticity can indicate microscopic properties ...
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Due to the challenge of finding identical rock samples with varying grain sizes, investigating the impact of texture on rock material has been given less attention. However, macroscopic properties such as compressive strength, tensile strength, and modulus of elasticity can indicate microscopic properties like intergranular resistance properties influence rock fracture toughness. In this work, both the experimental and numerical methods are used to examine the effect of grain size on the mechanical properties of sandstone. Uniaxial compressive strength and indirect tensile tests are conducted on sandstone samples with varying grain sizes, and the particle flow code software is used to model the impact of grain dimensions on intergranular properties. Flat joint model is applied for numerical modeling in the particle flow code© software. The aim of this work is to validate the numerical model by peak strength failure and stress-strain curves to determine the effect of grain size on the mechanical behavior. The results show that increasing grain size significantly decrease compressive strength, tensile strength, and modulus of elasticity. The impact of the change in grain size is more significant on compressive strength than on the other two properties. The correlation coefficient for tensile strength and grain size is R2 = 0.57, while for modulus of elasticity and grain size, it is R2 = 0.79. The PFC software helps calibrate intergranular properties, and investigate the effect of changing grain size on these properties. Overall, this study offers valuable insights into the relationship between the grain size and the mechanical properties of sandstone, which can be useful in various engineering applications, especially in petroleum geo-mechanics.
Original Research Paper
IMRAN KHAN; Ravi Kumar Sharma
Abstract
An experimental study is carried out to improve the bearing capacity of soils by using geotextile. In the present study geotextile (tire reinforcement) is used as geotextile, whereas sand is used as a soil medium. This research work presents the results of laboratory load tests on model square footings ...
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An experimental study is carried out to improve the bearing capacity of soils by using geotextile. In the present study geotextile (tire reinforcement) is used as geotextile, whereas sand is used as a soil medium. This research work presents the results of laboratory load tests on model square footings supported on reinforced sand beds. A total of twenty-seven load tests are conducted to evaluate the effects of single layer reinforcement placed below square model footings. The parameters of the testing program of the research work are the depth of reinforcement, the plan area of reinforcement, and the number of reinforcements. From the experimental data, it is indicated that there is an optimum reinforcement depth at which the bearing capacity is the highest. Also, the optimum size of reinforcement is found to be 1.5 B×1.5 B irrespective of the type of reinforcing materials used. The bearing capacity of reinforced sand is also found to increase with the number of reinforcement layer and reinforcement size when the reinforcement is placed within a certain effective zone with high relative density. The optimum placement position of geotextile is found to be 0.5B to 0.75B from the base of the footing .The tests are done at two different relative densities, i.e., 40% and 60%. The bulk unit weight of sandy soil is 14.81 KN/m³. Maximum gain in load carrying capacity is obtained when depth of reinforcement/width of footing (Dr/B) is 0.5 at relative density of 40% and 0.75 at a relative density of 60%.In addition, the data indicate that increasing reinforcement beyond a certain value would not bring about further increase in the bearing capacity of the soil.
Original Research Paper
Lokeshwar Singh Dilta; Ravi Kumar Sharma
Abstract
This study highlights the results from a series of analytical model experiments that investigate the behaviour of a strip footing supported by hollow steel piles installed to stabilize a clay slope. The effects of changing the pile diameter, pile length, spacing between piles, slope angle, the position ...
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This study highlights the results from a series of analytical model experiments that investigate the behaviour of a strip footing supported by hollow steel piles installed to stabilize a clay slope. The effects of changing the pile diameter, pile length, spacing between piles, slope angle, the position of the pile row from the top of slope, and the footing placement are all examined. After determining the load-carrying capacity of unstabilized slopes, it is compared with the load-carrying capacity of stabilized slopes. The results are then analysed to see how each parameter affects the load carrying capacity of strip footing. The results of unstabilized cases reveal that the load carrying capacity of a footing decreases as the slope angle increases and increases when the footing is positioned away from the slope. In addition, the findings imply that by reinforcing clay slope with a sequence of hollow steel piles significantly enhances the load carrying capacity of strip footing. As the distance between piles is decreased and their length is increased, the bearing capacity of the footing increases, and this improvement is enhanced by increasing the diameter of the piles. When the row of pile is positioned away from the top of the slope, the footing’s load carrying capacity decreases. Also positioning the footing a quite distance apart from the crest slope shows reduction in bearing capacity ratio.
Case Study
Smily Vishwakarma; Dr Dharmendra; Deven Singh
Abstract
The present study is based on data collection from some of the WWTPs (wastewater treatment plants) of the Himachal Pradesh region, and to investigate the range of physico-chemical characteristics of conventional WWTPs, which receive wastewater from different zones in different cities in Himachal Pradesh. ...
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The present study is based on data collection from some of the WWTPs (wastewater treatment plants) of the Himachal Pradesh region, and to investigate the range of physico-chemical characteristics of conventional WWTPs, which receive wastewater from different zones in different cities in Himachal Pradesh. Five parameters are measured and analyzed in this research work. They are pH, suspended solids (mg/L), biological oxygen demand (mg/L), chemical oxygen demand (mg/L), and oil and grease (mg/L). The parameters are compared seasonally to help improve the performance, and operational conditions of WWTPs are with the standard parameters range according to APHA (American Public Health Association), standard examination methods of water, and wastewater seasonal in parameters. Seasonal variations in physico-chemical properties are noticeable. The study analyzes the physico-chemical parameters of wastewater from various Sewage Treatment Plants (STPs) across six districts in Himachal Pradesh, India, revealing variations in water quality across different seasons and locations. The study highlights the need for proper treatment and management of wastewater to prevent environmental pollution and protect public health. The findings could be useful for the policy-makers and authorities responsible for wastewater management in the region.
Original Research Paper
Ankit Verma; Akhilesh Nautiyal
Abstract
Roads are said to be the backbone of the development of any nation. In the developing nations like India, it is the primary mode of transportation, which makes its significance much higher. Highway geometric alignment is an important aspect for maintaining road safety and the effective movement of traffic ...
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Roads are said to be the backbone of the development of any nation. In the developing nations like India, it is the primary mode of transportation, which makes its significance much higher. Highway geometric alignment is an important aspect for maintaining road safety and the effective movement of traffic on any road. Highway geometry features are meant to be picked, sized, and placed in order to achieve various design goals including sight distance, car stability, driver convenience, drainage, economic growth, and aesthetic qualities. Due to the rapid increase in the growth of traffic in the past few years, it has become important to ensure safe design alignment to serve the future needs efficiently and economically. A case study of NH-05 is used in the present work to design the existing highway to improve its geometric features by considering future forecasted traffic and covering all safety measures given by the Indian Road Congress (IRC) recommendations. The OpenRoads software was used as a designing tool, and all designs were made keeping the design speed at 50 kmph. The roadway width has been decided to be 13.0 m, with the carriageway width set at 7.5 m and the width of the shoulder at 2.4 m. The cross-slope or camber has been determined to be 2.4% for bituminous surfaces and 3.6% for earthen surfaces, with a maximum super-elevation of 7%. Thus the results obtained can be used to solve the traffic congestion problems, particularly due to the high traffic volume, and enhance road safety.
Original Research Paper
Zohreh Nabavi; Mohammad Mirzehi; Hesam Dehghani; Pedram Ashtari
Abstract
Back-break is one of the adverse effects of blasting, which results in unstable mine walls, high duration, falling machinery, and inappropriate fragmentation. Thus, the economic benefits of the mine are reduced, and safety is severely affected. Back-break can be influenced by various parameters such ...
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Back-break is one of the adverse effects of blasting, which results in unstable mine walls, high duration, falling machinery, and inappropriate fragmentation. Thus, the economic benefits of the mine are reduced, and safety is severely affected. Back-break can be influenced by various parameters such as rock mass properties, blast geometry, and explosive properties. Therefore, during the blasting process, back-break must be accurately predicted, and other production activities must be done to prevent and reduce its adverse effects. In this regard, a hybrid model of extreme gradient boosting (XGB) is proposed for predicting back-break using gray wolf optimization (GWO) and particle swarm optimization (PSO). Additionally, validation of the hybrid model is conducted using XGBoost, gene expression programming (GEP), random forest (RF), linear multiple regression (LMR), and non-linear multiple regression (NLMR) methods. For this purpose, the data obtained from 90 blasting operations in the Chadormalu iron ore mine are collected by considering the parameters of the blast pattern design. According to the results obtained, the performance and accuracy level of hybrid models including GWO-XGB (R2 = 99, RMSE = 0.01, MAE = 0.001, VAF = 0.99, a-20 = 0.98), and PSO-XGB (99, 0.01, 0.001, 0.99, 0.98) are better than the XGBoost (97, 0.185, 0.132, 0.98, 95), GEP (96, 0.233, 0.186, 0.967, 0.935), RF (97, 0.210, 0.156, 0.97, 0.94), LMR (96, 0.235, 0.181, 0.964, 0.92), and NLMR (96, 0.229, 0.177, 0.968, 0.93) models. Notably, the GWO-XGB hybrid model has superior overall performance as compared to the PSO-XGB model. Based on the sensitivity analysis results, hole depth and stemming are the essential effective parameters for back-break.
Original Research Paper
Mohammadhossein Dehghani Firoozabadi; Mohammad Fatehi Marji; Abolfazl Abdollahipour; Alireza Yarahamdi Bafghi; Yousef Mirzaeian
Abstract
The presence of pores and cracks in porous and fractured rocks is mostly accompanied by fluid flow. Poroelasticity can be used for the accurate modeling of many rock structures in the petroleum industry. The approach of the stress to the value of the fracture stress and the effect of pore pressure on ...
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The presence of pores and cracks in porous and fractured rocks is mostly accompanied by fluid flow. Poroelasticity can be used for the accurate modeling of many rock structures in the petroleum industry. The approach of the stress to the value of the fracture stress and the effect of pore pressure on the deformation of rock are among the effects of fluid on the mechanical behavior of the medium. Due to the deformation-diffusion property of porous media, governing equations, strain-displacement, and stress-strain relationships can be changed to each other. In this study, constitutive equations and relationships necessary to investigate the behavior and reaction of rock in a porous environment are stated. Independent and time-dependent differential equations for an impulse and point fluid source are used to obtain the fundamental solutions. Influence functions are obtained by using the shape functions in the formulation of the fundamental solutions and integrating them. To check the validity and correctness of provided formulation, several examples are mentioned. In the first two examples, numerical application and analytical solution are used at different times and in undrained and drained conditions. In times 0 (undrained response of medium) and 4500 seconds (drained response of medium), there is good coordination and agreement between the numerical and analytical results. In the third example, using the numerical application, a crack propagation path in the wellbore wall is obtained, which is naturally in the direction of maximum horizontal stress.
Review Paper
Alireza Dolatshahi; Hamed Molladavoodi
Abstract
The structure's response to the region's prevailing loading conditions guides the engineers in estimating the resilience of the structural materials and their reinforcement. One of the main concerns in designing rock structures is paying attention to the size effect phenomenon. The size effect influences ...
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The structure's response to the region's prevailing loading conditions guides the engineers in estimating the resilience of the structural materials and their reinforcement. One of the main concerns in designing rock structures is paying attention to the size effect phenomenon. The size effect influences the nominal strength, brittleness, load capacity, stress intensity factor, the characteristics of the fracture process zone at the crack tip, and the way and path of crack propagation. Therefore, studying the size effect law will make a guideline for correct decision-making, design, and implementation of efficient support systems. As a comprehensive review, this work investigates specimen size effect on the rock's mechanical and fracture properties. With a comprehensive look at this issue, it explains the essential points that help the engineers design rock structures. During the investigations carried out in this work, it is shown that the specimen size affects the fracture and mechanical properties of the rock. The severity of this phenomenon depends on various factors such as the brittleness index, the shape of the notch or crack length, and the size of the particles that create the rock. In concrete, it depends on the additive boosting materials in the concrete.
Original Research Paper
Avinash Chandan; ABHISHEK SHARMA
Abstract
Due to disposal concerns, an enormous quantity of personal protective equipment (PPE) waste from the COVID-19 pandemic constituted a severe health and environmental risk. During the pandemic, the usage of protective suits increased dramatically raising concerns about how to dispose of them to safeguard ...
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Due to disposal concerns, an enormous quantity of personal protective equipment (PPE) waste from the COVID-19 pandemic constituted a severe health and environmental risk. During the pandemic, the usage of protective suits increased dramatically raising concerns about how to dispose of them to safeguard the environment. This research work uses shredded face masks (SFM) to stabilise clayey soil for sub-grade usage. Shredded face masks are added to clayey soil to investigate consistency limits, compaction characteristics, unconfined compressive strength (UCS), and California bearing ratio (CBR). Laboratory experiments demonstrate that clayey soil geo-technical characteristics such differential free swell, consistency limits, UCS, and CBR values have improved. Based on the CBR results, the IITPAVE software is used to design flexible pavement thickness, which was reduced for various commercial vehicles per day for all combinations. Cost analysis is also done to determine the total cost for a 1000-meter stretch. The results show that addition of SFM to clayey soils strengthen the geo-technical properties of clayey soil as the UCS values increase for all curing periods of 3, 7, and 28 days with a maximum improvement of 64% for 28 days curing for 1% SFM content. Also, the CBR value is found to be increased from 1.96% to 6.72%.
Original Research Paper
Yeluri Sesha Choudary; Karan Singh; T S Ramesh Babu; Garikapati Deepthi
Abstract
The efficiency of geo-polymer mortar is analyzed by replacing fine aggregates with different ratios of copper slag and crumb rubber. Properties such as flow value, setting time, strengthening properties, density, and water absorption are studied for different factors, i.e. molarities of sodium hydroxide ...
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The efficiency of geo-polymer mortar is analyzed by replacing fine aggregates with different ratios of copper slag and crumb rubber. Properties such as flow value, setting time, strengthening properties, density, and water absorption are studied for different factors, i.e. molarities of sodium hydroxide (8, 10, and 12 M), various ratios of alkali-activator solution (1, 2, and 3), and the effect of pre-treating rubber. The results indicate that the increase in molarity increases the compressive strength, setting time, and flow value of mortar. It is observed that NaOH of 12 M and an alkali activator ratio of 2 show high compressive strength, which is 71.79 N/mm2. The rubber treated with alkali improves the bonding between the binder and the rubber, which leads to an increase in the material's strength by 7% for 1 hour and 10% for 24 hours, and density by about 1.5%. It is suggested that the optimum mix with 50% copper slag, 10% rubber with pre-treatment for a period of 1 hour, 12 M NaOH, and alkali activator ratio 2 provide excellent results among all mixes. In conclusion, the findings indicate that the produced mortar contributes to economic and ecological improvement.
Review Paper
Debasmita Basu; Smriti Mishra
Abstract
Although mine closure problems have been researched in the past, little to no research has been dedicated to the post-reclamation impacts of abandoned mine closure. Even though reclamation has been an age-old identified technique, stakeholders’ perception has played an important role in defining ...
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Although mine closure problems have been researched in the past, little to no research has been dedicated to the post-reclamation impacts of abandoned mine closure. Even though reclamation has been an age-old identified technique, stakeholders’ perception has played an important role in defining the implementation procedure. Therefore, this study intends to identify the various implementation procedures through a rigorous literature assessment of 112 publications, identified from various sources. Theoretical and practical complications have been identified in the fields of environmental, socio-cultural and economic impacts of mine closure. The study unveiled that the most implemented reclamation strategy was intensive and non-intensive recreation/tourism-based reclamation techniques. Thus the study paves the way for the incorporation of an interdisciplinary strategy through cooperation between various stakeholders and research fields for the long-term viability of a mining site restoration.
Original Research Paper
Yahia ElSayed Khamis; Shady Galal El-Rammah; Adel M Salem
Abstract
The rate of penetration plays a key role in maximizing drilling efficiency, so it is essential for the drilling process optimization and management. Traditional mathematical models have been used with some success to predict the rate of penetration in drilling. Due to the high complexity and non-linear ...
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The rate of penetration plays a key role in maximizing drilling efficiency, so it is essential for the drilling process optimization and management. Traditional mathematical models have been used with some success to predict the rate of penetration in drilling. Due to the high complexity and non-linear behavior of drilling parameters with the rate of penetration, these mathematical models cannot accurately and comprehensively predict the rate of penetration. Machine learning (ML) seems to be an attractive alternative to model this complicated physical process. This research paper introduces new data-driven models used to predict ROP using different parameters such as (depth, weight on bit (WOB), revolution per minute (RPM), Torque (T), standpipe pressure (SPP), flow in pump (pumping flow rate(Q), mud weight, hours on bit (HOB), revolutions on bit, bit diameter, total flow area (TFA), pore pressure, overburden pressure, and pit volume). Data-driven models are built using two different machine learning techniques, using 1771 raw real field data. The coding is built using the python programming language. The k-nearest neighbors (KNN) model predicting ROP for the training dataset show a correlation coefficient (R2) of 0.94. The multi-layer perceptron (MLP) model predicting ROP for the training dataset show a correlation coefficient (R2) of 0.98. We can conclude that MLP has a better accuracy, and removing outliers enhances model performance.
Original Research Paper
Rahul Shakya; Manendra Singh
Abstract
Due to fast urbanization, there is a shortage of above-ground surfaces. Thus to reduce this shortage of above-ground surface, underground tunnels are constructed beneath the structure for transportation purposes. As a result, it is critical to understand how earthquakes affect underground tunnels, so ...
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Due to fast urbanization, there is a shortage of above-ground surfaces. Thus to reduce this shortage of above-ground surface, underground tunnels are constructed beneath the structure for transportation purposes. As a result, it is critical to understand how earthquakes affect underground tunnels, so that people's lives can be saved and service levels can be maintained. Underground constructions cannot be considered entirely immune to the impacts of ground shaking, as evidenced by the Kobe earthquake (1995), the Chi-Chi earthquake (1999), and the Niigata earthquake (2004), when some underground structures were severely damaged. A typical section at Chandani Chowk of DMRC (Delhi Metro Rail Corporation) tunnels, New Delhi, India, has been analyzed by using the finite element method. Response of the soil tunnel system for the Uttarkashi earthquake (1991) has been found out in the form of maximum forces induced in the RC liner of the tunnel, displacement, induced acceleration and stresses. The results have been compared with the available closed-form solutions. Parametric studies by considering different parameters such as effect of contraction (volume loss), influence of boundary conditions and damping, effect of interface condition between soil and tunnel, effect of displacement time history and effect of a nearby building have also been conducted. Forces in RC liners and stress concentration obtained in the present study are well-matched to those obtained by available closed formed solutions. The vertical stress concentration and volume loss depend upon the soil medium's constitutive behavior. The section under consideration was safe against the 1991 Uttarkashi earthquake. It can also be observed that, due to the presence of the building, the axial force and bending moment increased in tunnel’s liner, and the value of all three forces reduced as the position of the building was away from the tunnel. Shear force and bending moment were maximum for full slip condition between soil and tunnel lining however the effect of the interface condition on the displacement was negligible after a certain value of the interface condition.
Original Research Paper
Vaibhav Sharma; Andy Kwame Yeboah; Joshua Asare; Natillio Pillay; Jaspreet Singh
Abstract
The presence of any underground cavity in the soil stratum can seriously harm the structural performance of the overlying facility. These may develop because of mining, tunneling, water, and gas networks or outdated channels. In the present investigation, a circular void is considered, and its effect ...
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The presence of any underground cavity in the soil stratum can seriously harm the structural performance of the overlying facility. These may develop because of mining, tunneling, water, and gas networks or outdated channels. In the present investigation, a circular void is considered, and its effect on the surface strip footing (in the form of ultimate load (UL), ultimate settlement (US), footing tilting, and footing horizontal displacement (HD)) is studied using numerical simulation. The variable parameters are load eccentricity (e), load inclination (α), and geogrid reinforcement location (u). It is observed that as the load inclination and eccentricity increases, the UL decreases. For instance, in the unreinforced soil, u/B = 0, at load inclination of α = 0°, 10°, 20°, and 30°, the UL is 249, 200, 142, and 97 kN/m, respectively. Moreover, as the geo-grid location is changed, the UL first increases when placed near the footing (u/B = 0.10), and thereafter, starts to decrease as the distance between footing and geo-grid increases. For instance, the UL is 249, 278, 267, 260, 259, and 256 kN/m when e/B = 0.0, α = 0°, and u/B varies from 0 to 0.5 with an increment of 0.1. The tilting increases as the eccentricity is increased; for example, u/B = 0.0 for α = 0°; the tilting values are 0°, 0.12°, 0.31°, and 0.61°. Moreover, as the load eccentricity increases, the HD decreases (for u/B = 0.1 and α = 10°, the HD is 4.20, 3.5, 3.00, and 2.60 mm, respectively.
Original Research Paper
Jitendra Pandey; Dheeraj Kumar; Sumit kumar Chaudhari; Ajay Khalkho; Jai Krishna Pandey
Abstract
Detection and mapping of the Jharia coal mine fire through the integration of satellite-based observed data with ground thermography data have been used and described in this work. This assimilation has been achieved using three types of data set viz., Landsat satellite images, topographical area map, ...
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Detection and mapping of the Jharia coal mine fire through the integration of satellite-based observed data with ground thermography data have been used and described in this work. This assimilation has been achieved using three types of data set viz., Landsat satellite images, topographical area map, and ground temperature survey of different fire-affected sites of Jharia Coalfields (JCF). Thermal anomaly, as observed from the satellite imagery, is one of the most important characteristics of the coal fire detection process. It has been used as a prime indicator for the fire area's extent and intensity. Ground thermographic measurement has also been conducted to further substantiate the thermal anomaly. The obtained amalgamated data is plotted on topographical maps of different sites of JCF. The study reveals that around 70% of the total coal mines of JCF are in grip of either surface fire or sub-surface fire or both surface and sub-surface fire. About 93% of fires detected in the year 1988 were shifted to new locations or in a dormant condition, whereas the remaining about 7% of fires were still burning at the same locations mostly due to the shifting of these fires from the upper coal seam to the lower coal seam or vice versa. The temperature detected by satellite data was 10 to 15 times lower than the actual fire condition measured on the ground during field observation. The study concludes that the detection of several years long-standing fire conditions historical satellite data will be the best option to delineate the fire condition.
