International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 09 Issue: 06 | June 2022 www.irjet.net p-ISSN: 2395-0072 © 2022, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 1113 A Theoretical Study on Strata Behaviour and Ground Control in Coal Mines Jannela Yernaidu 1 , Vinay Kumar Patel 1 , Abhishek Kumar Tripathi 2 1 Department of Mining Engineering, Bhagwanth University, Sikar Road, Ajmer-305004, Rajasthan, India 2 Department of Mining Engineering, Aditya Engineering College, Surampalem, Andhra Pradesh, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract – The mining activities are one of the main causes to strata movement and lack of its knowledge leads to various mining hazards such as roof fall, inrush of ground water, rock burst, coal bump, sub surface deformation and damages to the buildings or structures on the surface. The movement of strata affects the life of men, material, and machines during the course of mining operations. Therefore, a detailed study on the investigation and monitoring of strata behaviour and its control is becomes one of the key concern in the field of mining. In this paper a theoretical attempt has been made to understand the mechanics of the ground movement that occurred during any mining operations. The behaviour of the ground movement can be predicted by measuring the intensity of load on the strata. Thus, the paper focused on the application of geotechnical instruments such as vibrating- wire type stress cells, load cells, Tell– Tale type borehole extensometers and convergence stations on the measurement of load Key Words: Strata behaviour, Ground control, Roof fall, Borehole extensometer 1. INTRODUCTION The progress in the state of the art, technology in many branches of engineering is quite rapidly in recent years (Adomavicius et. al.2005). In the case of underground coal mining industry, a slow progress was observed during the last one decade, due to its complex and hazardous environment. Nevertheless, a few advancements in the availability and adaptability of the modern mining machinery was observed. These advancements in the underground coal mining are also limited due to the inadequate technology of strata control (suitable designs of workings and support systems) (Minggao et. al. 1994). The Board and Pillar mining method is the most widely used technology in the scenario of Indian coal mining industry. This method of coal winning has the negative impact on roof maintenance. During the operation of this method a large portion of roof is exposed to the external load which degrades the strength of the roof. Roof fractures and roof fall occur in this method of workings when the roadways are being driven due to time dependent deformation or during the extraction of pillars. This reduces the safety and increase the probability of roof fall. Therefore, it is required to implement various innovative technologies for the extraction process by this method (Rogers M. et. al. 1995). The factors influencing coal mining involves geological distribution in ore blocks, depth of deposit, and geology of deposits, and sustainable mining operation which improves the support system installation which is originated by the study of strata mechanics (Kang et. al. 2010). In earlier days of mining, due to less investment in mining equipment and technology there was limited possibility of quantification coal with good qualitative possible. However, now-days, with improved technology of mining and instrumentation, such as numerical models and computer applications analysis of data, investigators gained enhanced satisfaction through observational approaches (Von Kimmelmann et. al. 1984). The mining industry in the recent scenario requires more innovative changes in the instrumentation adopts for their safer and appropriate extraction. India has large resources of coal deposits of underground mining and lots of coal was blocked in existing underground mines. These blocked coal needs to be extracted by the installation of proper strata reading instruments (Zhang J et. al. 2010). Moreover, the accidents which mainly occurred in the underground mines are due to the strata deformation and it is the one of the important factors for these accidents. 2. MATERIAL AND METHODS Generally, the problem of ventilation and strata control poses a very big challenge to the mining employees to work coal at greater depths at 450-600m (Noack K et. al. 1998). Obviously, the strata on the face, and in the adjoining areas (in front and behind), must require attention so that no uncontrolled failure of ground takes place. In order to understand proper strata control measures, it is important to understand the mechanics of the movement of ground, which usually occurs as a result of mining operations. In addition to strata control problems, ventilation also poses a great challenge to the mining fraternity for designing innovative methodologies of implementation of environmental control measures in mines. The yield-pillar gate road system provides no significant protection to the tailgate corner of the active longwall face from side-abutment stresses (Guo H et. al. 2008). Yield pillar systems succeed when abutment loads are shifted off gate road pillars, thereby avoiding potentially hazardous stress concentrations, and onto the panel edge