Faculty Publications
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Item Explosive energy is the most commonly used form of energy to fragment rock mass/overburden and mineral deposits in the mines. Fragmentation obtained in the blasting process influences the downstream costs like loading cost, transportation cost, processing cost, etc. Among the various factors which influence the rock fragmentation, initiation system is one of the most important because presently much research is going on in this area of rock blasting. Some field studies were taken up with conventional detonating cord initiation and shock-tube-based NONEL initiation systems to study the influence of initiation systems on rock fragmentation. Fragmentation analysis was done using the boulder count method and image analysis. It was found that the shock-tube initiation gives 33% less boulders and 31% lesser K50 value compared to detonating cord initiation. © 2004 Taylor & Francis Ltd.(Taylor and Francis Ltd., Shock tube initiation for better fragmentation: A case study) Sastry, V.R.; Ram Chandar, K.2004Item Induced stresses in blasting gallery panel during depillaring based on field instrumentation(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2012) Kumar Reddy, S.; Sastry, V.R.Selection of a suitable mining method for economical and safe underground extraction of a thick coal seam is an extremely delicate process and brings a number of geo-technical parameters into consideration. In fact, single lift working of full thickness of a thick coal seam has always a verge over the multi slice working due to favorable economics and high production and productivity. Charbonnage de France (CdF) proposed Blasting Gallery (BG) for extraction of virgin thick seams as well as developed pillars in thick seams in single lift. The method was very successful resulting in 85% of extraction with high productivity. But, this method experienced strata control problems during final extraction. Due to strata problems, the method was not successful at East Katras Colliery where overriding of the pillars occurred in one panel. Two BG panels (BG 2/2 and BG 1/10 panels) at GDK No. 8 Incline, Singareni Collieries Company Ltd. (SCCL) were also closed prematurely due to strata problems. In this paper, strata monitoring data of stress cells in pillars of a blasting gallery panel is analyzed for the induced stresses in a Blasting Gallery panel during depillaring in specific geo-mining and working conditions of a underground mine in Southern part of India. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Generation and accuracy assessment of digital elevation model using digital photogrammetry and differential global positioning system techniques(CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2016) Sastry, V.R.; Venkat Reddy, D.; Garimella, G.; Adithya, N.; Saiprasad, S.A.Blasting can be considered as the most crucial process in an opencast mine. It is therefore important for mining engineers to understand the effect of geological discontinuities and blast design parameters on the results of blasting. Bench height and burden are very important parameters affecting stiffness of bench. Joints alter the results of blasting, by making explosive energy utilization ineffective. Modern tools like high speed videography reveal many aspects of fragmentation process, which otherwise are difficult to visualize and understand. An attempt is made through this paper to present some of the research results of model scale studies, coupled with field study results related to bench height and joints in order to improve blast results. © 2016 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Response of Strata and Buildings to Blast Induced Vibrations in the Presence and Absence of a Tunnel(Springer International Publishing, 2016) Rebello, N.E.; Shivashankar, R.; Sastry, V.R.Blast induced vibrations form an inevitable and major part of modern day construction. The changes that happen to the strata or buildings surrounding the blast are evident in a fraction of a second. Effect of damage is more pronounced in the absence/presence of the tunnel. The vibration produced due to blast may be induced due to a deep underground explosion, a surface explosion or even an in-tunnel explosion. In this study the above three situations are numerically modeled by a Distinct Element software 3DEC (3.0). Soil properties are varied representing soft and stiff strata. Further, three velocity time histories of 2, 45 and 85 Hz are used as an input in the model and are applied at three different boundaries of the model. Results of the analysis reveal that the response of building in softer strata and lower frequencies led to greater magnification of velocities and displacements compared to response of buildings in stiff strata. Presence of the tunnel led to reduction of peak velocity (PV’s) and displacements at the building top due to damping effect. PV’s at the top floor were greater than the PV’s at the bottom floor and there was an upliftment of the soil mass at the ground level. However, the upliftment in the presence of the building was lower than the upliftment in the absence of the building. Stress in the tunnel lining increased in the presence of the building, however percentage reduction of stress depends on the number of building stories. © 2016, Springer International Publishing Switzerland.Item A Critical Comparison of Regression Models and Artificial Neural Networks to Predict Ground Vibrations(Springer International Publishing, 2017) Ram Chandar, K.; Sastry, V.R.; Hegde, C.Blasting is important and an essential prerequisite in any opencast mine for fragmenting hard deposits. Blasting always produces unwanted effects like ground vibrations, noise and fly rock; among which ground vibrations effect is more on surrounding structures. Propagation of ground vibrations can lead to destruction of surrounding structures. Prediction of ground vibrations especially in terms of peak particle velocity is beneficial as opposed to conventional data monitoring techniques which can be expensive as well as time consuming. This paper uses predictors to estimate the intensity of ground vibrations and compares different methods of prediction methods like linear regression, multiple linear regression, non linear regression (NLR) and artificial neural networks. Intensity of ground vibrations generated from blasting operations was monitored in three different mines of limestone, dolomite and coal; obtaining about 168 ground vibration recordings in total. The statistical modelling or data-driven modeling has shown promise in the prediction of blast vibrations. Proposed a system of introducing site specific rock parameters like poison’s ratio, uniaxial compressive strength of rock and Young’s modulus to improve the correlation coefficient using statistical modelling (commonly called feature engineering in machine learning circles). © 2016, Springer International Publishing Switzerland.Item SEM and XRD investigations on lithomargic clay stabilized using granulated blast furnace slag and cement(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2019) C. Sekhar, D.; Nayak, S.Lithomargic clay soil is found along the western coast of southern India extending from Cochin to Goa below hard lateritic soil varying in large depths. This soil is problematic as it loses its strength upon saturation and is mainly consisting of silt size particles. Granulated blast furnace slag is a by-product from the iron industry available in large quantities. Since it has high percentage of CaO (i.e. 30–45%), it has latent hydraulic properties. Laboratory experiments were conducted to improve the strength properties of lithomargic clay by replacing soil with varying percentages of GBFS. Lithomargic clay stabilised with 25% GBFS was found to be the optimum. Further addition of 2 and 4% cement to the optimised slag–soil mix improves the strength properties significantly. SEM and XRD analyses were carried out to observe the microstructural changes in the stabilised soil. The reason for the improvement in strength was established through SEM and XRD. C-S-H, C-A-S-H and few other similar compounds were responsible in improving the strength properties by filling the voids between the soil particles. From the quantitative EDS analysis, it was concluded that the strength improvement was due to the increase in Ca:Si ratio and decrease in Al:Ca ratio. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group.Item Parametric Analysis of Mine Bench Blasting using High Speed Video Camera(World Researchers Associations, 2025) Channabassamma, N.; Akhil, A.; Rama, S.V.; Kumar, T.A.; Sahana, P.This study presents a comprehensive parametric analysis of mine bench blasting through the utilization of high-speed video camera technology. Mine bench blasting is a critical operation in the extraction of minerals and understanding its parameters is essential for optimizing safety, efficiency and environmental impact. The research employs a high-speed video camera, specifically the S-Motion Model by AOS Technologies, Switzerland, capable of recording at 1000 frames per second. Here we carried out the sensitive parametric analysis like dependency of burden rock movement on ejection of stemming gaseous, stemming ratio, stemming height and total explosive charge using Proanalyst image processing software. Through the analysis, we identified key trends and correlations that contribute to control rock movement, stemming gas ejection and optimizing explosive charge distribution. This comprehensive understanding provides valuable insights for improving the overall effectiveness and precision of future blasting operations, thereby contributing to enhanced operational outcomes and safety in mining or construction activities. © 2025, World Researchers Associations. All rights reserved.Item Evaluating Blast Fragmentation: A Comparative Study of Electronic and Shock-Tube Initiation Systems in a Limestone Mine(World Researchers Associations, 2025) Vinith Kumar, P.V.; Raina, A.K.; Balamadeswaran, P.; Sambasivam, V.S.; Saravanan, K.; Chandar, K.R.Explosive energy is the most widely used method for fragmenting rock masses and mineral deposits in mining operations. The fragmentation achieved during blasting significantly impacts downstream operations including loading, transportation, crushing and processing costs. Among the various factors affecting blast fragmentation, the initiation system plays a crucial role. A study was carried out to compare the performance of electronic detonators with shock-tube detonators, in terms of fragmentation in a limestone mine. Field experiments were conducted to assess the fragment size using digital image analysis technique (DIAT). The results indicated that electronic initiated blasts produced finer average fragment sizes (k50) ranging from 0.31-0.44 m, while as in non-electric shock-tube (NeSt) initiated blasts produced larger fragmentation with k50 values between 0.39-0.51 m. The analysis revealed that average k50 values of blasts initiated with electronic detonator were 20% less than that of non-electric shock tube (NeSt) initiated blasts. This is primarily due to precise delays planned and executed for the rock mass that aid in proper fragmentation. © 2025, World Researchers Associations. All rights reserved.Item Development of an equation to predict blast induced ground vibrations of open cast lime stone mine by using Multiple Linear Regression (MLR)(World Researchers Associations, 2025) Appani, R.; Harsha, V.; Subrahmanyam, S.K.V.This study focuses on predicting ground vibrations generated by blasting activities in open cast limestone mining by integrating blast design parameters with conventional variables. Blasting is a critical operation for the effective removal of overburden and mineral extraction, but it can lead to significant adverse effects, particularly ground vibrations, which pose challenges for both mining and environmental engineers. Conventional methods for estimating these vibrations typically focus on the distance from the blast site and the maximum charge per delay as key independent variables. Recognizing the substantial impact of blast design on vibration levels, this research employs multiple linear regression analysis to incorporate additional factors such as blast design elements. By developing a more comprehensive predictive model, the study aims to enhance the accuracy of ground vibration forecasts, ultimately contributing to safer and more sustainable mining practices. © 2025, World Researchers Associations. All rights reserved.Item Influence of Stiffness Ratio and Powder Factor on Burden Rock Movement in Blasting Operations: A Case Study on Limestone Mines(World Researchers Associations, 2025) Channabassamma, N.; Akhil, A.; Rama, S.V.In opencast mining, blasting is a critical operation that significantly impacts the efficiency and costeffectiveness of material removal. This study focuses on optimizing the use of explosive energy to move the burden, thereby reducing reliance on mechanical methods. Effective blast design involves strategically utilizing energy within a blast hole, considering factors such as explosive type, quantity, detonation timing and blast hole geometry. Given the rapid nature of blasting, high-speed video cameras are employed to capture the blast progression on a millisecond scale, providing essential data for analyzing blast dynamics. This research evaluates the influence of blast design parameters, specifically the stiffness ratio (the ratio of bench height to the burden) and powder factor (the amount of explosive per unit volume of rock), on the movement of burden rock in a limestone mine. By examining these parameters, the study aims to optimize blast designs to achieve improved fragmentation, reduced fly rock and minimized ground vibrations, ultimately enhancing the efficiency and cost effectiveness of mining operations. © 2025, World Researchers Associations. All rights reserved.