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Das K.C.,Indian Institute of Technology Kharagpur | Deb D.,Indian Institute of Technology Kharagpur | Jha A.K.,Central Mine Planning and Design Institute Ltd
Geosystem Engineering | Year: 2013

The stability of underground structure made especially in jointed rock mass is of the utmost important to designer, engineers and operators. Rock bolting is generally being practised to reinforced excavation walls and roofs by minimizing the movement of rock joints. In this study, a numerical procedure has been developed in extended finite element framework (XFEM) to analyze the behaviour of grouted bolt intersected by a joint. A solid finite element intersected by a bolt and a joint along any arbitrary direction is termed as 'doubly enriched' element. Nodes of an doubly enriched element have additional degrees of freedom for determining displacements, stresses developed in the bolt rod as well as the displacements jump and traction along the joint. The paper also provides verifications of this procedure by solving two known examples (i) direct shear test performed on a bolted joint sample-experimental verification and (ii) reinforcement of a joint located in the vicinity of a circular tunnel-analytical verification. © 2013 Copyright Taylor and Francis Group, LLC. Source

Mani D.,CSIR - Central Electrochemical Research Institute | Patil D.J.,CSIR - Central Electrochemical Research Institute | Dayal A.M.,CSIR - Central Electrochemical Research Institute | Prasad B.N.,Central Mine Planning and Design Institute Ltd
Marine and Petroleum Geology | Year: 2015

This study investigates the source rock characteristics of Permian shales from the Jharia sub-basin of Damodar Valley in Eastern India. Borehole shales from the Raniganj, Barren Measure and Barakar Formations were subjected to bulk and quantitative pyrolysis, carbon isotope measurements, mineral identification and organic petrography. The results obtained were used to predict the abundance, source and maturity of kerogen, along with kinetic parameters for its thermal breakdown into simpler hydrocarbons.The shales are characterized by a high TOC (>3.4%), mature to post-mature, heterogeneous Type II-III kerogen. Raniganj and Barren Measure shales are in mature, late oil generation stage (Rr%Raniganj=0.99-1.22; Rr%Barren Measure=1.1-1.41). Vitrinite is the dominant maceral in these shales. Barakar shows a post-mature kerogen in gas generation stage (Rr%Barakar=1.11-2.0) and consist mainly of inertinite and vitrinite. The δ13Corg value of kerogen concentrate from Barren Measure shale indicates a lacustrine/marine origin (-24.6--30.84‰ vs. VPDB) and that of Raniganj and Barakar (-22.72--25.03‰ vs. VPDB) show the organic provenance to be continental. The δ13C ratio of thermo-labile hydrocarbons (C1-C3) in Barren Measure suggests a thermogenic source.Discrete bulk kinetic parameters indicate that Raniganj has lower activation energies (δE=42-62kcal/mol) compared to Barren Measure and Barakar (δE=44-68kcal/mol). Temperature for onset (10%), middle (50%) and end (90%) of kerogen transformation is least for Raniganj, followed by Barren Measure and Barakar. Mineral content is dominated by quartz (42-63%), siderite (9-15%) and clay (14-29%). Permian shales, in particular the Barren Measure, as inferred from the results of our study, demonstrate excellent properties of a potential shale gas system. © 2015 Elsevier Ltd. Source

Roy S.,National Institute of Rock Mechanics | Adhikari G.R.,National Institute of Rock Mechanics | Renaldy T.A.,National Institute of Rock Mechanics | Jha A.K.,Central Mine Planning and Design Institute Ltd
Journal of Environmental Science and Technology | Year: 2011

Blasting is one of the essential operations at surface coal mines but it emits large amount of dust into the atmosphere. Prediction of dust concentrations can help in air quality management in mining. In this study, particulate matter generated due to blasting was monitored in different seasons at a large opencast coal mines in India. Blast design parameters, moisture content of the benches and distance of dust samplers from blast locations were recorded. Unlike ambient dust monitoring for industrial activities, blast monitoring was carried out for a period of dust accumulation at various locations in the downwind direction. Blast site varied from one location to other in the mine. Based on the observations of many blasts, monitoring period was determined. Scatterplots and correlation matrices for different variables were plotted. Stepwise regression procedure was carried out for selection of most influencing variables. Incorporating selected variables, multiple regression and neural network models were developed for prediction of particulate matter. The performance of the multiple regression models was assessed. For the development of neural network models, a feed forward with back propagation learning algorithm was used to train the network. The performance of neural network was determined in terms of correlation coefficient (R) and Mean Square Error (MSE). The optimum number of hidden neurons was found out for obtaining the lowest value of MSE and the highest value of R. The results indicated that the network can predict particulate concentrations better than multiple regression models. © 2011 Asian Network for Scientific Information. Source

Majumdar P.,Central Mine Planning and Design Institute Ltd
Journal of Mines, Metals and Fuels | Year: 2010

The increasing consumption, coupled with the rising cost and scarcity of diesel has made it all the more necessary to scrutinize its use and find out opportunities for its conservation to the maximum extent possible. Dumpers take much share of diesel consumption, need attention and topmost priority for its conservation. The areas needing attention include loading and waiting time, speed and haul road condition, pay load, restrictions of unnecessary movement and maintenance. Proper action should be taken to prevent the diesel leakage. Because leaks in diesel lines mostly remain undetected/unattended till maintenance is taken up. A correct approach to information system is to link the consumption data with different output data. Only the comprehensive data and its analysis will enable the user to achieve effective conservation that is, efficient utilization of inputs to produce maximum output. Source

Ranjan R.,Central Mine Planning and Design Institute Ltd
Journal of Mines, Metals and Fuels | Year: 2011

The important elements which should be considered as per the World Bank suggestion for the best practice of mine closure planning should begin at the feasibility stage and contain at least the six elements. These include clarity about time lines and costs, specifics about the expected final landform and surface rehabilitation, risk assessment to help set priorities for preparatory work, cost-benefit analysis of different options, a management plan for how closure will be implemented and proposals for post-closure monitoring arrangements. Mine closure plans should be integrated with annual mining plans, especially regarding environmental protection. The World Bank suggests the issues in a closure plan which includes environmental protection and reclamation, disposal of asset and legal framework. The final mine closure plan activities will continue to its life cycle and till the area is restored to an acceptable level. After the closure, the reclaimed leasehold area and any structure thereon, which is not to be utilized by the mine owner shall be surrendered to the state government concerned. Source

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