University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Hydrothermal Gold Mineralization and Some Features of Ore Mineral at Onzon-Kanbani Area, Central Myanmar 95 103 68013 10.22059/ijmge.2017.240294.594691 EN Aung Tay Zar Department of Geological Engineering, Faculty of Engineering, University of Gadjah Mada, Yogyakarta 0000-0002-2742-5362 Journal Article 2017 08 22 Onzon-Kanbani area is a western flank of Mogok Metamorphic Belt where gold mineralization is hosted as auriferous quartz-vein with epithermal low-sulphidation characters. Mineralization is closely associated with NE-SW trending fracture or shear zone probably related to the dextral movement of the Sagaing Fault system. Mineralization related hydrothermal alteration is developed as narrow zones beside of the hydrothermal conduit as silicic alteration, sericite-illite alteration, and propylitic alteration. Dominant alteration minerals are quartz, ±adularia, sericite, chlorite, actinolite, epidote, illite, and smectite. The quartz dominant and base metal quartz-carbonate mineralization veins are characterized by open-spaced fracture filling with sharp-walled as well as minor amounts of disseminating nature are also found in marble. Gold occurs as free grains or locked within pyrite, sphalerite, galena, and gangue mineral quartz. In place, large electrum gold grains are associated with sphalerite and pyrite in the gold bearing quartz vein whereas fine-grained inclusions or blebs of native gold are observed in pyrite and sphalerite as disseminated specks. Gold and base metal mineralization are mostly deposited in Stage I ‘mineralization stage’. In place, ‘Stage II’ is a barren stage where veins are barren as quartz or calcite veins with very minor amounts of pyrite. At the last ‘Stage III’, some of the supergene minerals of hematite, goethite, and chalcocite are formed from primary sulphides by oxidation. Mineralogically, the correlation between gold (Au) and silver (Ag) is shown the positive nature as well as in copper (Cu) too. Otherwise, gold (Au) versus any other ore minerals of lead (Pb), zinc (Zn), tin (Sn) and antimony (Sb) are displayed negative correlations. The gold and other ore mineral content are suggested that higher grade mineralization of these metal ores has reduced from mineralization vein to outer alteration zones.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 The performance of bolt-reinforced and shotcreted in-stope pillar in a rockburst prone areas 105 117 68108 10.22059/ijmge.2018.251957.594715 EN Fhatuwani Sengani Rock Engineering Department, Technical Services, South Deep Gold mine, South Africa 0000-0003-4886-1072 Journal Article 2018 02 05 Historically, the design of the in-stope pillar in underground excavations has been based on empirical formulae and numerical modelling. Although these design methods have been extensively applied in several gold mines in South Africa, rockburst, in-stope pillar burst/failure are continuously reported as the major problem faced by mines. Therefore, this study attempts to compare the performance of the shotcreted and bolt-reinforced in-stope pillar with the bolt-reinforced in-stope pillars. Numerical modelling was simulated focusing on the major principal stresses ahead and along the de-stress cuts, damage along the in-stope pillar (yieldability of the in-stope pillar), and the rate of energy release along the in-stope pillar. Owing to that, seismic events with log P ≥1 were used through assessing their source mechanism, damaged area, rock mass response after the event, and source parameters for the events. The results of the study have shown that the in-stope pillar along different de-stress cuts was extensively yielding in the model. Very high-stress magnitudes were forecast in a zone ahead of the advancing face. Further results from a seismic point of view have shown that the estimated source mechanism from different case studies had a dominant double-couple component, and the steeply dipping nodal plane aligns well with the NNE-SSW to the dyke. Shear-type failure on the faults/dyke was the most probable source mechanism of the events. Visually, observation results have shown that most of the bolt-reinforced in-stope pillars resulted in extensive scaling and fracturing during the dynamic movement of the ground, while bolt-reinforced and shotcreted in-stope pillars were noted to have minor or no damage during the dynamic movement of the ground.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Computational and Programming Aspects of Transition Elements in a Three-dimensional Finite Element Program 119 123 68196 10.22059/ijmge.2018.241271.594697 EN Amin Chamani Department of Mining Engineering, Faculty of Engineering, University of Birjand, Birjand, Iran 0000-0001-6977-5427 Vamegh Rasouli Department of Petroleum Engineering, , University of North Dakota, ND, USA Journal Article 2017 09 13 The performance of any finite element (FE) structural analysis is directly related to the global number of nodes and degrees of freedom (DOF) of the discretized structure and mesh distribution attributes. It is obvious that the appropriate numerical analysis needs finer elements in the zone of interest, e.g. zone of high stress concentration and intensity, and coarser elements for farther portion of the structure. The transition element concept achieves this aim and with variable number of nodes of each element in the transition zone it creates coarser elements in the outward zones of the discretized structure. These elements have larger size with variable number of nodes per element and their number of nodes is between the number of nodes per elements of the inner and outer zones. In spite of the fact that the concept of transition element is not so new and dates back to the last few decades but to the authors' knowledge an obvious and clear programming strategy and the method of implementation in a FE program have not been depicted in particular in the related literature. In this study the main concept of transition element is completely presented with clear instances and the computational methodology of accounting for this subject is covered; then the programming strategy of the transition elements in a three-dimensional computer program of finite element method together with the related computer program parts in FORTRAN programming language are brought and finally a validating example is considered and the analogy between the results of the finite element program and analytical anticipation is made.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Investigating the Effect of Sedimentary Basin on Consolidation of Kerman Fine-Grained Soils 125 129 68220 10.22059/ijmge.2018.231642.594668 EN MohammadReza Aminizadeh Ferdowsi university of Mashhad Iman Aghamolaie Ferdowsi university of mashhad Gholam Reza Lashkaripour Ferdowsi University of Mashhad, Iran 1111222233334444 Mohammad Ghafoori Ferdowsi University of Mashhad Naser Hafezi Moghadas Ferdowsi University of Mashhad Journal Article 2017 04 20 In this research, the effects of a sedimentary basin, environmental conditions, and the passage of time were investigated on consolidation processes and engineering characteristics of fine-grained soils in Kerman city. For this purpose, the natural consolidation curves of soil samples extracted from different locations of Kerman city were compared with the Kerman city intrinsic consolidation line (ICL). To obtain the ICL, 25 soil samples were taken from several locations and depths of the study area and mixed with high water content equivalent 1.0 to 1.5 times their liquid limit. Then, one-dimensional consolidation tests were performed on reconstituted soils. Using the normalizing parameter (void index) proposed by Burland and the ICL of Kerman city deposits, the results of consolidation tests were plotted on Iv- Log(σ́v) space. To investigate the effects of the sedimentary basin on engineering properties of fine-grained deposits in Kerman city, natural sedimentation compression curves were compared with ICL of Kerman soils. This comparison was applied in three regions along the paths of rivers that supply the fine sediments of Kerman plain. The results have shown that soil structure and fabric have not been developed abundantly and the effect of sedimentary model has caused the compression.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Soil Arching Behind Retaining Walls under Active Translation Mode: Review and New Insights 131 140 68313 10.22059/ijmge.2018.264011.594754 EN Mohammad Hossein Khosravi UT 0000-0002-7600-5786 Mojtaba Bahaaddini Shahid Bahonar University of Kerman, Iran Ali Reza Kargar UT Thirapong Pipatpongsa Department of Urban Management, Kyoto University, Japan Journal Article 2018 08 18 Granular materials have a tendency to exhibit an arching effect by which the load is transferred from yielding parts to adjacent stationary parts. Retaining walls are among those structures that the soil arching plays an important role in the distribution of earth pressures. This paper briefly reviews the development of soil arching theory and its application to different geotechnical projects. Various arching-based theoretical formulations for estimation of lateral active earth pressure on the rigid retaining walls were reviewed and their validity was examined through comparisons with the filed data. It was concluded that, in spite of the conventional thought that the distribution of lateral earth pressure on the walls is linear; it is non-linear due to soil arching. Moreover, the maximum lateral stress does not appear at the toe of the wall; but at some heights, leading to a shift of the point of application of thrust from 33% to approximately 45% of the wall height measured from the bottom of the wall.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Comparison of pseudo-static, Newmark and dynamic response analysis of the final pit wall of Sungun copper mine 141 147 68703 10.22059/ijmge.2018.229315.594661 EN Hossain Noferesti Department of Mining Engineering, Faculty of Engineering, University of Birjand, Birjand, Iran Ayyoob Hazegh Department of Mining Engineering, Faculty of Engineering, University of Birjand, Birjand, Iran Journal Article 2017 03 06 Sungun Copper Mine is located in an area with a high level of seismic hazard. Most recently, the Ahar-Varzeqan earthquake with a magnitude of 6.2 on Richter scale occurred on August 11, 2012; at a distance about 40 kilometers away from the mine. Nevertheless, the seismic stability of the final pit wall has not been comprehensively reviewed. In this research, the southwestern wall of the final pit of Sungun Mine investigated by pseudo-static, Newmark and numerical methods. Besides, through the paper, it is tried to explain some of the difficulties in accomplishing and interpretation of results in a dynamic analysis of a mining slope. Pseudo-static analysis revealed that the final pit wall is unsafe against the design earthquake with a high probability of failure. Results of Newmark analysis proved that in the case of design earthquake a large failing region would form. Based on a dynamic numerical analysis of the pit wall, continuous earthquake-induced movements in the forward and downward directions observed, which might be a sign of pit wall instability. The effect of underground water drainage on pit wall stability was investigated in the numerical model. Resulted time histories of the drained pit wall displacements proved that merely water drainage is sufficient for protecting the pit wall against the design earthquake.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Tunnel design and construction process in difficult ground conditions with Analysis of Controlled Deformations (ADECO) approach; a Case Study 149 160 68704 10.22059/ijmge.2018.235548.594679 EN Majid Taromi Bsc Abbas Eftekhari Mining Engineering Department, Faculty of Engineering, Kashan University, Kashan, Iran. 0000-0001-8176-3840 Journal Article 2017 06 13 The 10.6 km long Sabzkuh water conveyance tunnel is currently under construction in High Zagros structural zone, located in western Iran, has used conventional (in section T1) and mechanized (in section T2) methods. The section T1 of the tunnel driven through alluvial geological units with great complexity in an area high potential for sliding and water-bearing fault which has made the excavation operation encounter many challenges. After excavation 35 m of the tunnel using conventional methods, geological problems and inappropriate method of tunnel excavation resulted in the tunnel collapse and failure in the tunnel inlet portal. After the incidence of the collapse, the Design and Construction Process (DCP) of tunnels was revised by using Analysis of Controlled Deformations in Rocks and Soils (ADECO-RS) in conjunction with the Sequential Excavation Method (SEM). The ground improvement in the portal and tunnel excavation continued in five phases including survey, diagnosis, therapy, operation, and monitoring. The application of this approach into construction of Part T1 of the tunnel increased the safety and minimized risks and costs despite geological complexities and hazards. Moreover, the excavation process with appropriate daily advance rate of 1 to 1.5 meters was achieved according to the predicted schedule.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Grade estimation of Zu2 Jajarm deposit by considering imprecise variogram model parameters based on the extension principle 161 165 68705 10.22059/ijmge.2018.238884.594687 EN Saeed Soltani University of Kashan 0000-0002-8390-1917 Abbas Soltani Department of mining engineering, University of Kashan, IR. Iran Emad Chamanifard Department of exploration and environmental geosciences, Lulea, Sweden Journal Article 2017 07 30 Nowadays, kriging has been accepted as the most common method of grade estimation in mineral resource evaluation stage. Access to the crisp assay data and a variogram model are the necessary means for the utilization of this method. Since fitting a crisp variogram model is generally difficult, if not impossible, the fitted theoretical model is usually tainted with uncertainty due to various reasons especially limitation of drill holes number. Although the geostatistical kriging model is incapable of taking into account the uncertainties, the fuzzy kriging method (presented based on the fuzzy concept) is capable of calculating the effects of uncertainties on the fitted model (and even on the assay data). To evaluate the Zu2 Jajarm mineral resource, effort was made to use Bardossy’s fuzzy kriging method (proposed based on the extension principle) instead of ordinary kriging because of high uncertainties tainted with fitted variogram model. Since no comprehensive software existed to be used for this method, the “FuzzyKrig” was developed for the required calculations. A key merit of the fuzzy kriging method compared with the general, simple, ordinary, and log- kriging is that it presents, as a parameter, the width of the fuzzy number of every block as a criterion for the evaluation of the uncertainties in the estimation process. The advantage of this parameter is that, unlike the estimation variance, it depends not only on the data arrangement, but also on the grade data and can, therefore, play a key role in risk management studies.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Developing a 3D stochastic discrete fracture network model for hydraulic analyses 167 175 68706 10.22059/ijmge.2018.244675.594704 EN ALI - HEYDARI mining engineering, faculty of mining petroleum and geophysics, university of Shahrood, IRAN 0000-0000-0000-0000 Seyed Esmaeil Jalali Faculty of Mining Engineering, Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran Mehdi Noroozi Faculty of Mining Engineering, Petroleum and Geophysics, Shahrood University of Technology, Shahrood, Iran Journal Article 2017 10 29 Fluid flow in jointed rock mass with impermeable matrix is often controlled by joint properties, including aperture, orientation, spacing, persistence and etc. On the other hand, since the rock mass is made of heterogeneous and anisotropic natural materials, geometric properties of joints may have dispersed values. One of the most powerful methods for simulation of stochastic nature of geometric characteristics of joins is three dimensional stochastic discrete fracture network (DFN) modelling. The current research is conducted to develop an applicable discrete fracture network model for hydraulic analyses. Also, DFN-FRAC3D software – which was proposed earlier for mechanical analysis - is developed to construct a hydraulic DFN. For this purpose, joint aperture parameter is added to other geometric features of model including orientation, spacing, persistence and intensity. In order to develop an accurate hydraulic DFN model, correlation between the joint aperture and length is also considered, that has not been observed in most previous studies. In this study, the software is developed for detection of connected joint networks. In order to test the performance of the provided simulator, a 3D hydraulic model for fracture network of rock mass in Mazino region is presented.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 The application of Committee machine with particle swarm optimization to the assessment of permeability based on thin section image analysis 177 185 68707 10.22059/ijmge.2018.223076.594649 EN Mahnaz Abedini Faculty of mining, petroleum and geophysics, Shahrood university of technology, Iran Mansur Ziaii Faculty of Mining, petroleum and Geophysics, Shahrood University of Technology Javad Ghiasi-Freez Iranian Central Oil Fields Company (ICOFC), Subsidiary of National Iranian Oil Company (NIOC) Tehran, Iran Journal Article 2016 12 27 Permeability is the ability of porous rock to transmit fluids and one of the most important properties of reservoir rock because oil production depends on the permeability of reservoirs. Permeability is determined using a variety of methods which are usually expensive and time consuming. Reservoir rock properties with image analysis and intelligent systems has been used to reduce time and money. This study presents an improved model based on the integration of petrographic data and intelligent systems to predict permeability. Petrographic image analysis was employed to measure the types of porosity including inter‌granular, intra‌granular, moldic, micro and optical, amount of cement, limestone, dolomite and anhydrite, types of texture and mean geometrical shape coefficient of pores. The permeability was first predicted using the three individual intelligent systems including a neural network (NN), a fuzzy logic (FL), and a neuro-fuzzy (NF) model, respectively. The mean squared error (MSE) of the NN, FL and NF methods are 0.0107, 0.0081 and 0.0080, which correspond to the R2 values of 0.8830, 0.9193 and 0.9136, respectively. Afterwards, two types of committee machine with intelligent systems (CMIS) were used to combine the predicted values of permeability from individual intelligent systems: simple averaging (SA) and weighted averaging (WA). In the WA, a particle swarm optimization (PSO) was employed to obtain the optimal contribution of each intelligent system. The MSE of the CMIS-SA and CMIS-WA are 0.0072 and 0.0066, which correspond to the R2 values of 0.9262 and 0.9260, respectively. These show that the CMIS-WA performed better than NN, FL, and NF models individually. In addition, a multiple linear regression (MLR) was used to compare with the other techniques. The R2 value between the core and MLR permeability is 0.8699. Thus, the integration of petrographic data and intelligent systems operated more accurate than the MLR model.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Implementation of Hyperbolic Tangent Function to Estimate Size Distribution of Rock Fragmentation by Blasting in Open Pit Mines 187 197 68708 10.22059/ijmge.2018.221013.594642 EN Moein Bahadori Department of Mining Engineering, Faculty of Engineering, University of Kashan, Kashan, Iran 0000-0002-7009-8862 Hassan Bakhshandeh Amnieh School of Mining, College of Engineering, University of Tehran, Tehran, Iran Journal Article 2016 11 22 Rock fragmentation is one of the desired results of rock blasting. So, controlling and predicting it, has direct effects on operational costs of mining. There are different ways that could be used to predict the size distribution of fragmented rocks. Mathematical relations have been widely used in these predictions. From among three proposed mathematical relations, one was selected in this study to estimate the size distribution curve of blasting. The accuracy of its estimates was compared to that of the RR (Rosin-Rammler), SveDeFo (The Swedish Detonic Research Foundation), TCM (Two Component Model), CZM (Crushed Zone Model), and KCO (Kuznetsov – Cunningham - Ouchterlony) relations. The comparison included assessing the accuracy (Regression, R) and precision (Mean Square Error, MSE) of the best possible fit between the mathematical relations to estimate the cumulative distribution of fragmented rocks that result from rock blasting in open pit mines (Miduk Copper Mine, Sirjan Gol-e-Gohar, and Chadormalu Iron Mines) using image analysis technique. The results showed that the power hyperbolic tangent function can estimate size distribution of hard rock fragmentation with more uniformity in fine and coarse-grained sizes (unlike soft and altered rocks with the non-uniform distribution in these regions), more accurately and with higher precision. Also, unlike the KCO, the absence of a second turning point for the largest block dimensions (Xm) in the proposed function, can guarantee the accuracy of estimations related to any range of inputs. Finally, due to the ability of the proposed relation to accurately estimate rock fragmentation distribution caused by blasting, the uniformity coefficient required for the relation is provided by a linear combination of the geometric blasting parameters, where R=0.855 and MSE=0.0037.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Comparative evaluation of Schmidt hammer test procedures for prediction of rocks strength 199 206 68724 10.22059/ijmge.2018.244154.594702 EN Amin Jamshidi Department of Geology, Faculty of Basic Sciences, Lorestan University, Khorramabad, Iran Rasool Yazarloo Department of Civil Engineering, Faculty of Engineering, Islamic Azad University of Gonbad Kavoos, Golestan, Iran Sahar Gheiji Department of Civil Engineering, Faculty of Engineering, Islamic Azad University of Qazvin, Qazvin, Iran Journal Article 2017 10 21 Uniaxial compressive and Brazilian tensile strengths (UCS and BTS) of rocks are considered important properties in the design of most the geotechnical projects that interact with rock such as slope stability and underground excavation. Measuring UCS and BTS using standard laboratory tests are time consuming, tedious and expensive. Moreover, it requires a large number of well-prepared rock cores that is often not, particularly in soft or highly jointed rock masses. For these reasons, indirect tests such as Schmidt hammer hardness (SH) can be used for prediction of UCS and BTS of rocks. There is a wide variation in the recommended SH test procedures by institutions and various researchers. The objective of this study is to evaluate the performance of SH testing procedures for prediction of UCS and BTS of rocks. For this, 22 sandstone samples from Qum Province, central Iran, were selected and their UCS, BTS and SH were determined. Using data analysis, correlation equations have been developed between UCS and BTS with SH. To check the validity of the correlation equations, a t–test was performed. Results showed that SH test procedures based on continuous impacts at a point reveals the lower values than that based on single impacts. Further, it was found that SH test procedures have different performance for prediction of UCS and BTS of rocks.

University of Tehran International Journal of Mining and Geo-Engineering 2345-6930 52 2 2018 12 01 Back analysis of inter-ramp slope failure in Teghout copper mine 207 214 68725 10.22059/ijmge.2018.242642.594700 EN Mostafa Asadizadeh Hamedan University of Technology 0000-0001-5944-0084 Nima Babanouri Hamedan University of technology Journal Article 2017 09 27 Slope stability is one of the most important issues in open pit mining design. The main purpose of any open pit mine design is to propose an optimal excavation configuration, considering safety, ore recovery and financial return. An accurate pit slope design which accounts for the mine geology, structural geology, rock mass properties, and hydrogeology models of the mine area, drastically enhances the whole mining operation. The present paper investigates the failure of an inter-ramp slope in the Teghout mine using the limit equilibrium and finite difference approaches. The geotechnical properties of the rock mass were obtained using field investigations and back analysis. In-situ shear strength parameters of the rock mass were back calculated using the limit equilibrium method. Utilizing sensitivity and probabilistic analyses, the internal friction angle and cohesion of the rock mass were obtained 33.5 degrees and 13.5 kPa, respectively. On the other hand, slope failure mechanism and the effect of the slope height and slope angle on the stability of pit slope were investigated using the finite difference method, and suitable slope angle was proposed.