Pub Date : 2020-07-01DOI: 10.22044/JME.2020.9814.1901
K. S. Shah, M. Hashim, K. Ariffin, N. F. Nordin
The stability analysis of rock slopes is a complex task for the geotechnical engineers due to the complex nature of the rock mass in a tropical climate that often has discontinuities in several forms, and consequently, in several types of slope failures. In this work, a rock mass classification scheme is followed in a tropical environment using the Rock Mass Rating (RMR) and Geological Strength Index (GSI) combined with the kinematic investigation using the Rocscience Software Dips 6.0. The Lafarge quarry is divided into ten windows. In the RMR system, the five parameters uniaxial compressive strength (UCS), rock quality designation (RQD), discontinuity spacing, discontinuity condition, and groundwater conditions are investigated. The RMR values range from 51 to 70 (fair to good rock mass), and the GSI values range from 62 to 65 (good to fair rock mass). There is a good and positive correlation between RMR and GSI. The kinematic analysis reveals that window A is prone to critical toppling, window H to critical wedge-planar failure, and window G to critical wedge failure. From the results obtained, it can be concluded that the kinematic analysis combined with the rock mass classification system provides a better understanding to analyze the rock slope stability in a tropical climate compared with considering the rock mass classification system individually.
{"title":"A Preliminary Assessment of Rock Slope Stability in Tropical Climates: A Case Study at Lafarge Quarry, Perak, Malaysia","authors":"K. S. Shah, M. Hashim, K. Ariffin, N. F. Nordin","doi":"10.22044/JME.2020.9814.1901","DOIUrl":"https://doi.org/10.22044/JME.2020.9814.1901","url":null,"abstract":"The stability analysis of rock slopes is a complex task for the geotechnical engineers due to the complex nature of the rock mass in a tropical climate that often has discontinuities in several forms, and consequently, in several types of slope failures. In this work, a rock mass classification scheme is followed in a tropical environment using the Rock Mass Rating (RMR) and Geological Strength Index (GSI) combined with the kinematic investigation using the Rocscience Software Dips 6.0. The Lafarge quarry is divided into ten windows. In the RMR system, the five parameters uniaxial compressive strength (UCS), rock quality designation (RQD), discontinuity spacing, discontinuity condition, and groundwater conditions are investigated. The RMR values range from 51 to 70 (fair to good rock mass), and the GSI values range from 62 to 65 (good to fair rock mass). There is a good and positive correlation between RMR and GSI. The kinematic analysis reveals that window A is prone to critical toppling, window H to critical wedge-planar failure, and window G to critical wedge failure. From the results obtained, it can be concluded that the kinematic analysis combined with the rock mass classification system provides a better understanding to analyze the rock slope stability in a tropical climate compared with considering the rock mass classification system individually.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":"11 1","pages":"661-673"},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46052697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.22044/JME.2020.9446.1852
D. Mohammadi, R. Mikaeil, J. Sharif
The blasting method is one of the most important operations in most open-pit mines that has a priority over the other mechanical excavation methods due to its cost-effectiveness and flexibility in operation. However, the blasting operation, especially in surface mines, imposes some environmental problems including the ground vibration as one of the most important ones. In this work, an evaluation system is provided to study and select the best blasting pattern in order to reduce the ground vibration as one of the hazards in using the blasting method. In this work, 45 blasting patterns used for the Sungun copper mine are studied and evaluated to help determine the most suitable and optimum blasting pattern for reducing the ground vibration. Additionally, due to the lack of certainty in the nature of ground and the analyses relating to this drilling system, in the first step, a combination of the imperialist competitive algorithm and k-means algorithm is used for clustering the measured data. In the second step, one of the multi-criteria decision-making methods, namely TOPSIS (Technique for Order Performance by Similarity to Ideal Solution), is used for the final ranking. Finally, after evaluating and ranking the studied patterns, the blasting pattern No. 27 is selected. This pattern is used with the properties including a hole diameter of 16.5 cm, number of holes of 13, spacing of 4 m, burden of 3 m, and ammonium nitrate fuel oil of 1100 Kg as the most appropriate blasting pattern leading to the minimum ground vibration and reduction of damages to the environment and structures constructed around the mine.
爆破方法是大多数露天矿最重要的开采方法之一，由于其成本效益和操作灵活性，在其他机械开挖方法中具有优先地位。然而，爆破作业，特别是露天矿山爆破作业，带来了一些环境问题，其中地面振动是最重要的环境问题之一。本文提出了一种评价体系，用于研究和选择最佳爆破方式，以减少地面振动这一爆破方法使用中的危害之一。本文对孙郡铜矿45种爆破方式进行了研究和评价，以确定减少地面振动的最合适和最优爆破方式。此外，由于地面性质和与该钻井系统相关的分析缺乏确定性，在第一步中，将帝国主义竞争算法和k-means算法相结合用于对测量数据进行聚类。第二步，采用多准则决策方法之一，即TOPSIS (Order Performance Technique for Similarity to Ideal Solution)进行最终排序。最后，对所研究的爆破模式进行了评价和排序，最终选定了27号爆破模式。钻孔直径16.5 cm，孔数13个，间距4 m，装料3 m，硝酸铵燃料油1100 Kg为最合适的爆破方式，使地面震动最小，减少对矿山周围环境和构筑物的破坏。
{"title":"Investigating and Ranking Blasting Patterns to Reduce Ground Vibration using Soft Computing Approaches and MCDM Technique","authors":"D. Mohammadi, R. Mikaeil, J. Sharif","doi":"10.22044/JME.2020.9446.1852","DOIUrl":"https://doi.org/10.22044/JME.2020.9446.1852","url":null,"abstract":"The blasting method is one of the most important operations in most open-pit mines that has a priority over the other mechanical excavation methods due to its cost-effectiveness and flexibility in operation. However, the blasting operation, especially in surface mines, imposes some environmental problems including the ground vibration as one of the most important ones. In this work, an evaluation system is provided to study and select the best blasting pattern in order to reduce the ground vibration as one of the hazards in using the blasting method. In this work, 45 blasting patterns used for the Sungun copper mine are studied and evaluated to help determine the most suitable and optimum blasting pattern for reducing the ground vibration. Additionally, due to the lack of certainty in the nature of ground and the analyses relating to this drilling system, in the first step, a combination of the imperialist competitive algorithm and k-means algorithm is used for clustering the measured data. In the second step, one of the multi-criteria decision-making methods, namely TOPSIS (Technique for Order Performance by Similarity to Ideal Solution), is used for the final ranking. Finally, after evaluating and ranking the studied patterns, the blasting pattern No. 27 is selected. This pattern is used with the properties including a hole diameter of 16.5 cm, number of holes of 13, spacing of 4 m, burden of 3 m, and ammonium nitrate fuel oil of 1100 Kg as the most appropriate blasting pattern leading to the minimum ground vibration and reduction of damages to the environment and structures constructed around the mine.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":"11 1","pages":"881-897"},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46996991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.22044/JME.2020.9139.1804
M. Shenavar, M. Ataee-Pour, M. Rahmanpour
Production scheduling in underground mines is still a manual process, and achieving a truly optimal result through manual scheduling is impossible due to the complexity of the scheduling problems. Among the underground mining methods, sub-level caving is a common mining method with a high production rate for hard rock mining. There are limited studies about long-term production scheduling in the sub-level caving method. In this work, for sub-level caving production scheduling optimization, a new mathematical model with the objective of net present value (NPV) maximization is developed. The general technical and operational constraints of the sub-level caving method such as opening and developments, production capacity, sub-level mining geometry, and ore access are considered in this model. Prior to the application of the scheduling model, the block model is processed to remove the unnecessary blocks. For this purpose, the floating stope algorithm is applied in order to determine the ultimate mine boundary and reduce the number of blocks that consequently reduces the running time of the model. The model is applied to a bauxite mine block model and the maximum NPV is determined, and then the mine development network is designed based on the optimal schedule.
{"title":"A New Mathematical Model for Production Scheduling in Sub-level Caving Mining Method","authors":"M. Shenavar, M. Ataee-Pour, M. Rahmanpour","doi":"10.22044/JME.2020.9139.1804","DOIUrl":"https://doi.org/10.22044/JME.2020.9139.1804","url":null,"abstract":"Production scheduling in underground mines is still a manual process, and achieving a truly optimal result through manual scheduling is impossible due to the complexity of the scheduling problems. Among the underground mining methods, sub-level caving is a common mining method with a high production rate for hard rock mining. There are limited studies about long-term production scheduling in the sub-level caving method. In this work, for sub-level caving production scheduling optimization, a new mathematical model with the objective of net present value (NPV) maximization is developed. The general technical and operational constraints of the sub-level caving method such as opening and developments, production capacity, sub-level mining geometry, and ore access are considered in this model. Prior to the application of the scheduling model, the block model is processed to remove the unnecessary blocks. For this purpose, the floating stope algorithm is applied in order to determine the ultimate mine boundary and reduce the number of blocks that consequently reduces the running time of the model. The model is applied to a bauxite mine block model and the maximum NPV is determined, and then the mine development network is designed based on the optimal schedule.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":"11 1","pages":"765-778"},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44631324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.22044/JME.2020.9939.1923
A. Alimoradi, B. Maleki, A. Karimi, M. Sahafzadeh, S. Abbasi
The exploration methods are divided into the direct and indirect categories. Among these, the indirect geophysical methods are more time- and cost-effective compared with the direct methods. The target of the geophysical investigations is to obtain an accurate image from the underground features. The Induced polarization (IP) is one of the common methods used for metal sulfide ore detection. Since metal ores are scattered in the host rock in the Zarshouran mine area, IP is considered as a major exploration method. Parallel to IP, the resistivity data gathering and processing are done to get a more accurate interpretation. In this work, we try to integrate the IP/RS geophysical attributes with borehole grade analyses and geological information using the cuckoo search machine-learning algorithm in order to estimate the silver grade values. The results obtained show that it is possible to estimate the grade values from the geophysical data accurately, especially in the areas without drilling data. This reduces the costs and time of the exploration and ore reserves estimation. Comparing the results of the intelligent inversion with the numerical methods, as the major tools to invert the geophysical data to the ore model, demonstrate a superior correlation between the results.
{"title":"Integrating Geophysical Attributes with New Cuckoo Search Machine-Learning Algorithm to Estimate Silver Grade Values–Case Study: Zarshouran Gold Mine","authors":"A. Alimoradi, B. Maleki, A. Karimi, M. Sahafzadeh, S. Abbasi","doi":"10.22044/JME.2020.9939.1923","DOIUrl":"https://doi.org/10.22044/JME.2020.9939.1923","url":null,"abstract":"The exploration methods are divided into the direct and indirect categories. Among these, the indirect geophysical methods are more time- and cost-effective compared with the direct methods. The target of the geophysical investigations is to obtain an accurate image from the underground features. The Induced polarization (IP) is one of the common methods used for metal sulfide ore detection. Since metal ores are scattered in the host rock in the Zarshouran mine area, IP is considered as a major exploration method. Parallel to IP, the resistivity data gathering and processing are done to get a more accurate interpretation. In this work, we try to integrate the IP/RS geophysical attributes with borehole grade analyses and geological information using the cuckoo search machine-learning algorithm in order to estimate the silver grade values. The results obtained show that it is possible to estimate the grade values from the geophysical data accurately, especially in the areas without drilling data. This reduces the costs and time of the exploration and ore reserves estimation. Comparing the results of the intelligent inversion with the numerical methods, as the major tools to invert the geophysical data to the ore model, demonstrate a superior correlation between the results.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":"11 1","pages":"865-879"},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43329906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.22044/JME.2020.9444.1851
S. Akbari, S. Zare, H. Chakeri, H. M. N. Abad
Evaluation of the interaction between a new and the existing underground structures is one of the important problems in urban tunneling. In this work, using FLAC3D, four numerical models of single- and twin-tube tunnels in urban areas are developed, where the horizontal distance between the single- and twin-tube tunnels are varied. The aim is to analyze the effects of the horizontal distances, considering various criteria such as the deformation of linings, the forces and moments exerted on the twin-tube tunnels and their safety factors, the subsidence that occur on the surface and the nearby buildings, the stability of the single-tube tunnel, and the stability of the pillar lying between the single- and twin-tube tunnels. Considering the above-mentioned criteria, the results obtained indicate that the interaction between the single- and twin-tube tunnels is virtually negligible in the distance more than three times the single-tube tunnel diameter. Also the stability of the pillar lying between the tunnels makes the distance to be chosen at least 1.5 times the single-tube tunnel diameter.
{"title":"A 3D Finite-Difference Analysis of Interaction between a Newly-Driven Large Tunnel with Twin Tunnels in Urban Areas","authors":"S. Akbari, S. Zare, H. Chakeri, H. M. N. Abad","doi":"10.22044/JME.2020.9444.1851","DOIUrl":"https://doi.org/10.22044/JME.2020.9444.1851","url":null,"abstract":"Evaluation of the interaction between a new and the existing underground structures is one of the important problems in urban tunneling. In this work, using FLAC3D, four numerical models of single- and twin-tube tunnels in urban areas are developed, where the horizontal distance between the single- and twin-tube tunnels are varied. The aim is to analyze the effects of the horizontal distances, considering various criteria such as the deformation of linings, the forces and moments exerted on the twin-tube tunnels and their safety factors, the subsidence that occur on the surface and the nearby buildings, the stability of the single-tube tunnel, and the stability of the pillar lying between the single- and twin-tube tunnels. Considering the above-mentioned criteria, the results obtained indicate that the interaction between the single- and twin-tube tunnels is virtually negligible in the distance more than three times the single-tube tunnel diameter. Also the stability of the pillar lying between the tunnels makes the distance to be chosen at least 1.5 times the single-tube tunnel diameter.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":"11 1","pages":"809-823"},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48598430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.22044/JME.2020.9520.1863
M. Ansari, M. Hosseini, A. Beydokhti
Rock abrasivity, as one of the most important parameters affecting the rock drillability, significantly influences the drilling rate in mines. Therefore, rock abrasivity should be carefully evaluated prior to selecting and employing drilling machines. Since the tests for a rock abrasivity assessment require sophisticated laboratory equipment, empirical models can be used to predict rock abrasivity. Several indices based on five known methods have been introduced for assessing rock abrasivity including rock abrasivity index (RAI), Cerchar abrasivity index (CAI), Schimazek’s abrasivity factor (F-abrasivity), bit wear index (BWI), and LCPC abrasivity coefficient (LAC). In this work, 12 rock types with different origins were investigated using the uniaxial compressive strength (UCS), Brazilian test for tensile strength, and longitudinal wave velocity and LCPC tests, and microscopic observations were made to obtain a correlation for estimating the LCPC abrasivity coefficient by conducting the conventional rock mechanics tests. Using the equivalent quartz content, velocity of longitudinal waves, and rock brittleness index, a linear correlation was obtained with a coefficient of determination (R2) of 93.3% using SPSS in order to estimate LAC.
{"title":"A Correlation for Estimating LCPC Abrasivity Coefficient using Rock Properties","authors":"M. Ansari, M. Hosseini, A. Beydokhti","doi":"10.22044/JME.2020.9520.1863","DOIUrl":"https://doi.org/10.22044/JME.2020.9520.1863","url":null,"abstract":"Rock abrasivity, as one of the most important parameters affecting the rock drillability, significantly influences the drilling rate in mines. Therefore, rock abrasivity should be carefully evaluated prior to selecting and employing drilling machines. Since the tests for a rock abrasivity assessment require sophisticated laboratory equipment, empirical models can be used to predict rock abrasivity. Several indices based on five known methods have been introduced for assessing rock abrasivity including rock abrasivity index (RAI), Cerchar abrasivity index (CAI), Schimazek’s abrasivity factor (F-abrasivity), bit wear index (BWI), and LCPC abrasivity coefficient (LAC). In this work, 12 rock types with different origins were investigated using the uniaxial compressive strength (UCS), Brazilian test for tensile strength, and longitudinal wave velocity and LCPC tests, and microscopic observations were made to obtain a correlation for estimating the LCPC abrasivity coefficient by conducting the conventional rock mechanics tests. Using the equivalent quartz content, velocity of longitudinal waves, and rock brittleness index, a linear correlation was obtained with a coefficient of determination (R2) of 93.3% using SPSS in order to estimate LAC.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":"11 1","pages":"799-808"},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41581851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.22044/JME.2020.9775.1897
H. Fattahi
The tensile strength (σt) of a rock plays an important role in the reliable construction of several civil structures such as dam foundations and types of tunnels and excavations. Determination of σt in the laboratory can be expensive, difficult, and time-consuming for certain projects. Due to the difficulties associated with the experimental procedure, it is usually preferred that the σt is evaluated in an indirect way. For these reasons, in this work, the adaptive network-based fuzzy inference system (ANFIS) is used to build a prediction model for the indirect prediction of σt of sandstone rock samples from their physical properties. Two ANFIS models are implemented, i.e. ANFIS-subtractive clustering method (SCM) and ANFIS-fuzzy c-means clustering method (FCM). The ANFIS models are applied to the data available in the open source literature. In these models, the porosity, specific gravity, dry unit weight, and saturated unit weight are utilized as the input parameters, while the measured σt is the output parameter. The performance of the proposed predictive models is examined according to two performance indices, i.e. mean square error (MSE) and coefficient of determination (R2). The results obtained from this work indicate that ANFIS-SCM is a reliable method to predict σt with a high degree of accuracy.
{"title":"A New Method for Predicting Indirect Tensile Strength of Sandstone Rock Samples","authors":"H. Fattahi","doi":"10.22044/JME.2020.9775.1897","DOIUrl":"https://doi.org/10.22044/JME.2020.9775.1897","url":null,"abstract":"The tensile strength (σt) of a rock plays an important role in the reliable construction of several civil structures such as dam foundations and types of tunnels and excavations. Determination of σt in the laboratory can be expensive, difficult, and time-consuming for certain projects. Due to the difficulties associated with the experimental procedure, it is usually preferred that the σt is evaluated in an indirect way. For these reasons, in this work, the adaptive network-based fuzzy inference system (ANFIS) is used to build a prediction model for the indirect prediction of σt of sandstone rock samples from their physical properties. Two ANFIS models are implemented, i.e. ANFIS-subtractive clustering method (SCM) and ANFIS-fuzzy c-means clustering method (FCM). The ANFIS models are applied to the data available in the open source literature. In these models, the porosity, specific gravity, dry unit weight, and saturated unit weight are utilized as the input parameters, while the measured σt is the output parameter. The performance of the proposed predictive models is examined according to two performance indices, i.e. mean square error (MSE) and coefficient of determination (R2). The results obtained from this work indicate that ANFIS-SCM is a reliable method to predict σt with a high degree of accuracy.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":"11 1","pages":"899-908"},"PeriodicalIF":0.8,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41427295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-30DOI: 10.22044/JME.2020.9527.1864
A. Zarghami, K. Shahriar, K. Goshtasbi, A. A. Dehkharghani
Calculation of the specific charge and specific drilling before blasting operation play a significant role in blasting pattern design and reduction of the final extraction cost of minerals. Information from Sungun, Miduk and Chah-Firouzeh copper mines in Iran was assessed, and found that there is a significant relationship between specific charge and specific drilling with hole diameter, bench height, uniaxial compressive strength and joint set orientation and tested this model in Sungun copper mine. Due to insufficient consideration during the design of the blast pattern and because of the high hardness in the rock in some parts of the mine, lots of destructive events such as boulders, back break, bench toe, high specific charge and high specific drilling, fly rock and ground vibration in the blast operation were observed. The specific charge and specific drilling are the most important technical and economic parameters in designing the blasting pattern and play an important role in reducing the cost of blasting. The blasting cost could be largely controlled by the accurate examination and computation of these parameters. Based on this model, an increase in the rock strength and the angle between the bench face and the main joint set will increase the specific charge and specific drilling. On the other hand, the specific charge and specific drilling will decrease when the hole diameter increases in every range of uniaxial compressive strength.
{"title":"A new technical and economic model to calculate specific charge and specific drilling using hole diameter, height bench, uniaxial compressive strength, and joint set orientation","authors":"A. Zarghami, K. Shahriar, K. Goshtasbi, A. A. Dehkharghani","doi":"10.22044/JME.2020.9527.1864","DOIUrl":"https://doi.org/10.22044/JME.2020.9527.1864","url":null,"abstract":"Calculation of the specific charge and specific drilling before blasting operation play a significant role in blasting pattern design and reduction of the final extraction cost of minerals. Information from Sungun, Miduk and Chah-Firouzeh copper mines in Iran was assessed, and found that there is a significant relationship between specific charge and specific drilling with hole diameter, bench height, uniaxial compressive strength and joint set orientation and tested this model in Sungun copper mine. Due to insufficient consideration during the design of the blast pattern and because of the high hardness in the rock in some parts of the mine, lots of destructive events such as boulders, back break, bench toe, high specific charge and high specific drilling, fly rock and ground vibration in the blast operation were observed. The specific charge and specific drilling are the most important technical and economic parameters in designing the blasting pattern and play an important role in reducing the cost of blasting. The blasting cost could be largely controlled by the accurate examination and computation of these parameters. Based on this model, an increase in the rock strength and the angle between the bench face and the main joint set will increase the specific charge and specific drilling. On the other hand, the specific charge and specific drilling will decrease when the hole diameter increases in every range of uniaxial compressive strength.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41739311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-20DOI: 10.22044/JME.2020.9581.1872
V. Sarfarazi
In this paper, interaction between semi-circular space and neighboring joint with and without Presence of Rock Bolt is investigated using Particle Flow Code. For this purpose, firstly calibration of PFC was performed using both of the Brazilian experimental test and uniaxial compression test. Secondly, numerical model with dimension of 100mm *100 mm was prepared. A semi-circular space with radius of 25 mm was situated below the model. A joint with length of 40 mm was situated above the space. Joint opening was 2mm. Joint angle related to horizontal direction was 0°, 15°, 30°, 45°, 60° and 75°. Totally, 6 different configurations of semi-circular space and neighboring joint were prepared. These models tested with and without presence of vertical rock bolts by biaxial test. The Rock bolt length was 50 mm. The value of lateral force was fixed at 2 MPa. Axial force was applied to the model till final failure was occurred. The results shows that presence of rock bolts change the failure pattern of numerical model. In absence of rock bolt, two tensile wing cracks initiate from joint tip and propagate diagonally till coalescence from model boundary. Also several shear bands were initiated in the left and right sides of the tunnel. In presence of rock bolt, several shear bands were initiated in the left and right sides of the tunnel. The compressive strength with presence of rock bolt was more than that without presence of rock bolt. The failure stress has minimum value when joint angle was 45°.
{"title":"Behavior of Tunnel and Neighboring Joint with and without Presence of Rock Bolt under biaxial loads; Particle Flow Code Approach","authors":"V. Sarfarazi","doi":"10.22044/JME.2020.9581.1872","DOIUrl":"https://doi.org/10.22044/JME.2020.9581.1872","url":null,"abstract":"In this paper, interaction between semi-circular space and neighboring joint with and without Presence of Rock Bolt is investigated using Particle Flow Code. For this purpose, firstly calibration of PFC was performed using both of the Brazilian experimental test and uniaxial compression test. Secondly, numerical model with dimension of 100mm *100 mm was prepared. A semi-circular space with radius of 25 mm was situated below the model. A joint with length of 40 mm was situated above the space. Joint opening was 2mm. Joint angle related to horizontal direction was 0°, 15°, 30°, 45°, 60° and 75°. Totally, 6 different configurations of semi-circular space and neighboring joint were prepared. These models tested with and without presence of vertical rock bolts by biaxial test. The Rock bolt length was 50 mm. The value of lateral force was fixed at 2 MPa. Axial force was applied to the model till final failure was occurred. The results shows that presence of rock bolts change the failure pattern of numerical model. In absence of rock bolt, two tensile wing cracks initiate from joint tip and propagate diagonally till coalescence from model boundary. Also several shear bands were initiated in the left and right sides of the tunnel. In presence of rock bolt, several shear bands were initiated in the left and right sides of the tunnel. The compressive strength with presence of rock bolt was more than that without presence of rock bolt. The failure stress has minimum value when joint angle was 45°.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44677170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-09DOI: 10.22044/JME.2020.9304.1860
A. Ghanizadeh, Abouzar Yarmahmoudi, H. Abbaslou
Due to economical and environmental issues, utilization of mineral wastes, e.g. iron ore mine tailing (IOMT), as road materials can be recommended as a sustainable alternative. In the present study, mechanical properties, as well as resistance to freezing and thawing cycles (F-T) of low plasticity clay soil stabilized with different percentages of Portland cement (0, 6, 9, 12 and 15%) and different IOMT content (0, 10, 20, 30 and 40%) has been investigated. To this end, unconfined compressive strength (UCS), initial elastic modulus (E0), and indirect tensile strength (ITS) at different curing times of 7, 14, 18, and 56 days for different admixtures was determined to select optimum mix design for stabilization of clayey subgrade soil. This study shows that by increasing the percentage of cement, strength parameters such as UCS, E0, and ITS increases while increasing IOMT does not show a specific trend to increase strength parameters. Evaluation of strength parameters at different curing time showed that in short-term curing times (7 and 14 days), iron ore mine tailing has a positive effect on the strength parameters, while in long-term curing times (28 and 56 days), iron ore mine tailing has a negative effect on the strength parameters. In total, it was found that 12% of the Portland cement and 10 to 40% of the IOMT passes the UCS and F-T criteria for stabilization of low plasticity clay soils, while clay soil (without IOMT) requires at least 15% of Portland cement for stabilization.
{"title":"Mechanical Properties of Low Plasticity Clay Soil Stabilized with Iron Ore Mine Tailing and Portland cement","authors":"A. Ghanizadeh, Abouzar Yarmahmoudi, H. Abbaslou","doi":"10.22044/JME.2020.9304.1860","DOIUrl":"https://doi.org/10.22044/JME.2020.9304.1860","url":null,"abstract":"Due to economical and environmental issues, utilization of mineral wastes, e.g. iron ore mine tailing (IOMT), as road materials can be recommended as a sustainable alternative. In the present study, mechanical properties, as well as resistance to freezing and thawing cycles (F-T) of low plasticity clay soil stabilized with different percentages of Portland cement (0, 6, 9, 12 and 15%) and different IOMT content (0, 10, 20, 30 and 40%) has been investigated. To this end, unconfined compressive strength (UCS), initial elastic modulus (E0), and indirect tensile strength (ITS) at different curing times of 7, 14, 18, and 56 days for different admixtures was determined to select optimum mix design for stabilization of clayey subgrade soil. This study shows that by increasing the percentage of cement, strength parameters such as UCS, E0, and ITS increases while increasing IOMT does not show a specific trend to increase strength parameters. Evaluation of strength parameters at different curing time showed that in short-term curing times (7 and 14 days), iron ore mine tailing has a positive effect on the strength parameters, while in long-term curing times (28 and 56 days), iron ore mine tailing has a negative effect on the strength parameters. In total, it was found that 12% of the Portland cement and 10 to 40% of the IOMT passes the UCS and F-T criteria for stabilization of low plasticity clay soils, while clay soil (without IOMT) requires at least 15% of Portland cement for stabilization.","PeriodicalId":45259,"journal":{"name":"Journal of Mining and Environment","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48858529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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