Faculty Publications

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    An Enhanced IoT and LoRa-Based Communication System for Underground Mines
    (Springer Science and Business Media Deutschland GmbH, 2023) Kumar Reddy, S.K.; Naik, A.S.
    The mining industry is well known for valuable minerals all over the world and the way to get minerals is by mining below the surface. Real-time monitoring of environmental parameters from underground mines is a very complex task to ensure safety. Accidents in the underground area are due to hazardous toxic gas spread beyond the threshold limit value at excavations. These mine gases are a threat to both mine workers’ health and the mine environment and are also very hard for miners to detect. Automation in the mining industry reduces hazardous accidents while improving efficiency and productivity. Adopting the Internet of Things (IoT) with Long Range (LoRa) wireless communication technology to build a robust long-range wireless communication system to monitor environmental parameters and hazardous events. To ensure a safe mine environment for mineworkers at the mine site, Artificial Intelligence techniques are an add-on to automation systems to build predictive modeling for an intelligent early warning alert system. However, current solutions are limited to monitoring, low computing power and processing capability, battery lifetime, suitable at the laboratory level, or reports events in a few cases. The proposed system is comprised of the IoT-based sensor modules, communication protocols, Long-Range (LoRa), and machine learning technologies to establish safe, reliable communication from the underground mine to the surface area. A reliable, robust, and cost-effective communication system should be required that monitors environmental parameters and predicts reports of unusual events by adopting new technology. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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    Effect of Surcharge on Analysis of Anchored Sheet Piles Embedded in Cohesionless Soil
    (Springer Science and Business Media Deutschland GmbH, 2025) Dinesh, G.; Nayak, S.; Kumar Reddy, S.K.
    An anchored sheet pile wall is a flexible retaining structure stabilized by anchors placed at a specific depth to resist external forces. The design of these walls is influenced by two key factors: the embedment depth into the foundation soil and the maximum bending moment experienced by the wall. This study presents design charts for anchored sheet piles in cohesionless soil subjected to surcharge loads. Both the conventional free earth support method and finite element analysis using PLAXIS 2D were employed. Multiple scenarios were simulated in PLAXIS 2D using the Mohr–Coulomb model, with an internal friction angle of 34° for the soil and a combination of fixed base boundary conditions. The study also examined different water table positions at the surface, middle, dredge level, and deep below the surface and generated design charts for embedment depth (D) and maximum bending moment (Mmax). Results revealed that the conventional free earth support method tends to overestimate the maximum bending moment. In contrast, the finite element analysis, with detailed mesh refinement and boundary conditions, provided a better assessment of soil–structure interaction, yielding more reliable outcomes. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
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    A Systematic Review on Implementation of Internet-of-Things-Based System in Underground Mines to Monitor Environmental Parameters
    (Springer, 2024) Naik, A.S.; Kumar Reddy, S.K.; Raj, G.R.
    The automation in the mining industry by adopting Internet of Things (IoT) technology is great potential to improve safety and efficiency. The mining industry is recognized globally for its valuable resources (gold, coal, iron ore, etc.) which are obtained by mining below the surface. The productivity and safety of mine personnel are impacted by several environmental parameters in underground mines, such as toxic gases, flammable gases, elevated levels of carbon dioxide (CO2), and decreased levels of oxygen (O2) concentrations. The presence of these gases is a significant issue and needs to be dealt with suitably. There are various methods to monitor the percentage of gases and provide a suitable course of action in case of an increase in the threshold limit of gases. Each system has its limitations. Wireless monitoring systems are indispensable in underground mines. This paper presents the methodology to adopt IoT in underground mines to measure environmental parameters in underground mine areas, the structure of installation of sensors in underground mines, threshold limits of gases, and underground mine disasters which were caused by gas explosion accidents. Further, it evaluates wireless sensor networks (WSNs) techniques ZigBee and LoRa for underground mines applications. Subsequently, it proposed a real-time industrial safety system in underground mines with its working, effectiveness, and scope are discussed. © The Institution of Engineers (India) 2023.
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    Stability Assessment and Optimal Excavated Design of a Rock Slope in an Opencast Limestone Mine
    (Books and Journals Private Ltd., 2023) Kumar Reddy, S.K.
    The stability of rock slopes in an opencast limestone mine throughout the mining process was investigated using the limit equilibrium approach (SlopeW). The optimal excavation method with a substantially steeper slope angle of 450 rather than 350 was successfully accomplished at the critical geological section of the pit slope under numerous geologically disturbed area such as joints, faults and folds on a geotechnical basis in order to ensure adequate stability against any failure while working in the mine. The primary objective of this paper is to use the limit equilibrium approach in the SlopeW programme to predict the slope’s safety factor and critical failure surface geometry due to the imposed of a surcharge loading of dump on top of the open pit slope for a 110m deep rock cut in the limestone mine. Geotechnical studies covering field geological mapping, laboratory experiments on rock samples cored from exploration drilling and different rock blocks retrieved straight from the mine were used to determine the physico-mechanical characteristics of the rock components, and numerical analysis using limit equilibrium technique (SlopeW) was carried out. It is also recommended that no activity or construction take place on the top of the pit slope crest in order to prevent further slope failures in old scheme and shifting dump 25m away from the top of pit slope for future safe workings in the mine. © 2023, Books and Journals Private Ltd.. All rights reserved.
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    Monitoring and Prediction of Slope Failure Instability in a Limestone Mine
    (Books and Journals Private Ltd., 2023) Kumar Reddy, S.K.
    In a mining operation, maintaining safe and cost-effective slope geometries is critical. Monitoring has often proven to be a valuable method in dealing with potential slope instability when design analysis and engineering judgment have dictated conservative and usually more expensive problem solutions. Unexpected pit wall collapses could have a significant impact on the safety and profitability of an openpit operation. As a result, a well-planned and executed monitoring programme can permit operation with a lower theoretical margin of safety. Monitoring provides an important check on design parameters and can measure the effects of corrective actions, which lead to increased significant production and reduced economic losses. Often, early warning of impending failure can be established. In this paper, a slope failure of a pit wall stability on the north side of a limestone mine which leads to stopping the workings by the regulatory body was studied. A comprehensive slope monitoring strategy has been implemented to improve safety and mine more economically using different slope monitoring techniques like visual inspection, prism monitoring, piezometer and wireline extensometers are also used to predict the instability of the failure area of a limestone mine. All of these monitoring tools offer primary monitoring, which is used to determine the riskiness of a failure area or zone. It gives early warning of further failure or instability if the slope is detected in challenging conditions. Today’s mining regulations place a strong emphasis on the proactive identification and mitigation of risks to employees and the operation. This paper focuses on reducing operational and safety risks through an approved monitoring programme. Based on slope monitoring results of the failure area, remedial measures to improve the stability of the workings are presented for a limestone mine. © 2023, Books and Journals Private Ltd.. All rights reserved.
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    Analysis of Fault’s Effect on the Highwall Stability of Medapalli Open Pit Coal Mine
    (Springer Science and Business Media Deutschland GmbH, 2023) Kumar Reddy, S.K.
    Mining operations can have a significant impact on the stability of the surrounding area. One example is the Medapalli open pit coal mine in southern India. The mine is a large excavation working at a depth of 165 m that can reach up to 200 m. The western side highwall has locked-up coal reserves in the mine, but concerns about the geologically disturbed regions have resulted in complications and significant challenges. Surface tension cracks around the excavation became visible in 2018, prompting intensive monitoring, protective measures, and numerous geotechnical analyses. The area, however, has a rich tectonic history, with faults interacting with soil movements. Proper geotechnical investigations were used in this work to analyse the stability of the highwall due to faults' effects on the area's reaction due to mining operations. The findings in the study highlighted the significance of flaws in the ground movement due to improper design of the highwall fault interaction area. The presence of the fault increases the likelihood of tensile cracks and subsidence at the highwall's surface level, significantly worsening the mining activities in the area. The analysis reveals that complex geological features, such as the presence of faults roughly parallel to the highwall slope profile, can exacerbate the mining operations in the surrounding environment. The recommended slope design with protective measures towards the west side disturbed highwall area helps safely excavate the western side highwall locked-up coal reserves in the Medapalli open pit mine. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
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    Physicomechanical Properties and Characterization of Gold Ore Tailings and the Utilization in Manufacturing of Geopolymer Concrete with Class F Fly Ash and Recycled Coarse Aggregates
    (American Society of Civil Engineers (ASCE), 2023) Lokesha, E.B.; Mangalpady, M.; Kumar Reddy, S.K.; Srinivasa, A.S.
    The mining industry generates a large amount of waste, particularly in the form of tailing dumps, which creates major environmental difficulties such as air pollution, water pollution, soil erosion, and acid mine drainage. Previous studies confirmed that the mine waste could be used in making building materials, such as bricks, tiles, concrete blocks, pavement blocks, and precast concrete elements. However, gold ore tailings (GOTs) are recognized as major mine residues in the mining industry. In this study, GOTs were utilized as partial replacement material (0%, 5%, 10%, 15%, 20%, 25%, and 30% by weight) to fine aggregates such as river sand (RS) and low calcium fly ash (FA) as binder material in the manufacture of geopolymer concrete (GPC) along with recycled coarse aggregates. The GPC samples were cast and cured at room temperature until the curing ages; subsequently, the compressive strength of the samples was determined. This study demonstrated that the RS can be partially substituted in the manufacture of GPC by GOTs up to 15% with a slump value of 38.6 mm and the maximum compressive strength of 35.8 MPa. The mineralogical and chemical composition of raw materials (i.e., GOTs and FA) was analyzed using X-ray diffraction (XRD) and X-ray fluorescence (XRF), respectively. The XRD analysis revealed that the quartz has the highest peak intensity of 55% in GOTs and 50% of corundum in FA. The XRF analysis exhibited that GOTs and FA have high silicon oxides up to 39% and 38%, respectively. The crushed GPC samples were analyzed using field emission scanning electron microscopy to observe the morphological changes. The GPC sample comprised 15% GOTs exhibited denser and compacted microstructures. © 2023 American Society of Civil Engineers.
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    Development of Regression Model and Optimization of Mechanical Properties of Geopolymer Concrete Prepared Using Gold Ore Tailings
    (American Society of Civil Engineers (ASCE), 2023) Lokesha, E.B.; Mangalpady, M.; Kumar Reddy, S.K.; Srinivasa, A.S.
    In this study, 11 mix proportions of geopolymer concrete (GPC) beam and cylinder samples were prepared by partially replacing the class F fly ash (FA) as the binder with ground granulated blast furnace slag (GGBFS) in steps from 10% to 100%, along with gold ore tailings (GOTs) [as a partial substitute to the river sand (RS) in steps from 5% to 30%] and recycled coarse aggregates (RCAs). The laboratory tests demonstrated a maximum split tensile strength of 5.99 MPa and flexural strength of 7.98 MPa for Sample GOT-11-15 (11 indicates Mix Proportion-XI and 15 indicates 15% of GOTs) of Mix Proportion-XI. In addition to the previous 11 mix proportions, one more set of cylinders and beams was prepared using FA, GOTs, and natural coarse aggregates (NCAs), which are designated as Mix Proportion-XII. For Mix Proportion-XII, the highest split tensile strength of 4.17 MPa and flexural strength of 6.13 MPa was achieved for Sample GOT-15 (15 indicates 15% of GOTs). Among the 12 types of mix proportions, Sample GOT-0 of Mix Proportion-XII (i.e., FA 100%, GOT 0%, and NCAs 100%) showed a maximum slump value of 89.3 mm. Sample GOT-1-0 of Mix Proportion-I (i.e., FA 100%, GOT 0%, and RCA 100%) exhibited the maximum slump of 65.3 mm. The field emission scanning electron microscopy (FESEM) analysis indicated that silicon (Si) and aluminum (Al) were the two main constituents of the GOTs and FA. In addition, this analysis revealed the existence of uneven forms of quartz particles in GOTs and the spherical shapes of the FA particles that adhered to the RCAs. The multiple regression analysis exhibited the root mean square (R2) values of 89.0% and 85.5%, respectively, for the split tensile and flexural strengths. The p-value for the developed model was <0.05; therefore, the developed model was considered significant and the best-fit model. © 2023 American Society of Civil Engineers.
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    Development of a Novel Real-Time Environmental Parameters Monitoring System Based on the Internet of Things with LoRa Modules in Underground Mines
    (Springer, 2023) Kumar Reddy, S.K.; Naik, A.S.; Raj, M.G.
    The mining industry relies on extracting valuable minerals through underground mining. Many industries have implemented automation to enhance workplace safety, optimize operations, improve responses to events, and achieve cost-effectiveness. A real-time communication and monitoring system is indispensable in underground mines to prevent significant hazards and improve safety in underground mines. However, the environmental conditions of underground mines are affected by toxic, flammable, combustible gases and dust. The harmful gases are a significant concern as they can cause gas explosions. Internet of Things (IoT) enabled real-time communication system with Long Range (LoRa) transceiver module is designed and developed to measure the underground mine environmental parameters, temperature, and humidity. The LoRa-based proof of concept (POC) system is tested and evaluated at the surface level and in two underground mines. The LoRa module radio waves range test is carried out to measure the received signal strength indicator (RSSI) value at the surface level. In addition, the developed system is tested and evaluated at different positions of underground mines to measure environmental parameters in straight and curved tunnels. The experimental results represent successful IoT with LoRa-based wireless communication between underground mine tunnels to the surface, wireless transmission of parameters at the straight tunnels, and curved tunnels of underground mines. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.
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    RTEPMS: Real-Time Environmental Parameters Monitoring System Using IoT-Based LoRa 868-MHz Wireless Communication Technology in Underground Mines
    (Institute of Electrical and Electronics Engineers Inc., 2024) Naik, A.S.; Kumar Reddy, S.K.; Raj, M.G.
    In underground mining, the real-time monitoring of environmental parameters plays a pivotal role in ensuring the safety of mining operations and personnel. This article explores the integration of Long Range (LoRa) wireless communication technology and the Internet of Things (IoT) to bolster safety measures and prevent potential accidents within underground mines. The environmental parameters in underground mines include Oxygen (O2), Carbon Dioxide (CO2), Carbon Monoxide (CO), Methane (CH4), Nitric Oxide (NO), Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2), Hydrogen Sulfide (H2S), Ethylene Oxide (EO), Temperature and Humidity. Currently, underground mines in India use portable multi-gas detector devices to measure environmental parameters. HPD13A LoRa 868 MHz based Real Time Environmental Parameters Monitoring System (RTEPMS) is designed and developed to facilitate real-time data collection in underground mines. In addition, the developed RTEPMS system is tested and evaluated at the open surface level and in one of the underground mines in India. The experimental results represent successful LoRa-based wireless communication established in an underground mine with data acquisition and real-time processing. Major parameters exceeding threshold limits in the underground mine environment include O2, CO, CO2, NO2, and EO. The data correlation between LoRa-based RTEPMS and multi-gas detector devices is 69.47% for CO2 and 72.38% for CO, while the values for CH4 and H2S are nearly zero, indicating their presence in underground mines is almost negligible. The RTEPMS is an affordable solution for smaller and less affluent underground mines. It alerts mine workers if environmental parameters exceed threshold limits during emergencies. © 2013 IEEE.