Massive strata frequently met in Indian coalfields have been the most important single factor con... more Massive strata frequently met in Indian coalfields have been the most important single factor controlling the development and mechanization of mines. Under the programme of development of equivalent Material Mines Modelling Technique, a model was constructed to simulate massive coal measure formation. Different mining parameters were investigated in this model with a view to chacking the reproducibility of the field conditions in the laboratory.
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1991
Strata control problems in underground coal mining account for highest fatal and serious injuries... more Strata control problems in underground coal mining account for highest fatal and serious injuries to workers. These problems are due to operational, geological and geo-technic parameters. Efforts are being made in various Indian coal mines to replace conventional timber supports by boltings, stitchings, hydraulic/friction props, chocks and shield supports for safety. Operation in and around faulted zones in Kamptee and Kanhan coalfield of Central India posed most serious challenge to safety of miners. Evaluation of orientation, throw and frequency of faults along with cleats and joints were studied with a view to evolving safe and economic system of supports and method of mining. Faults are the main geo-structural features disturbing bord and pillar and longwall workings. The fault throw up to the working height could be tackled without major change in layout and hence were called small throw faults. Over 20faults of throw within a metre to 60 m were observed in depth for gouge thickness and associated strata control problems. Faults with 10 m throw and above in creased face cleat and mjor joint frequency from 11m-1 to 16 m-1 and above and 4 m-1 to 10 m-1reswpectively within 5 to 50 m of its position. Orientation of face cleat and major joint west was also influenced by such faults which were classified as major faults. Entries along the major and the minor faults suffered from severe strata control problems. For better roof condition, drivages shouid be laid 20-45° across the faults; reinforcement of supports by way of stitchings and use of M.S. cross-bars along with conventional supports should be installed immediately in the faulted zones to avoid deterioration of exposed strata.
Stability of waste dump is now gaining importance due to increasing depth and size of mine. Manag... more Stability of waste dump is now gaining importance due to increasing depth and size of mine. Management of dump nearby mining areas is one of the most critical and crucial task for mine management due to limited land and other governing laws related to environment and forest conservation. In this paper, a study was conducted to establish the effect of slope angle on the stability of waste dump for accommodation of flyash is carried out. Based on numerical simulation, it was found that the dump slope of 60 m height with 36° slope can be critically stable with 20% flyash randomly mixed with overburden materials whereas flatter slopes provide higher factor of safety. Keeping other parameters constant, the optimum slope of 32° is the best possible to accommodate the mine dump for its long term stability. These findings were further supported by study of maximum velocity vectors and shear strain rates in every case and the extent of damage zone due to tensile pull. It is hoped that this t...
Rockfall is a critical problem in the hilly regions. The Lengpui-Aizawl highway has witnessed man... more Rockfall is a critical problem in the hilly regions. The Lengpui-Aizawl highway has witnessed many rockfalls and other types of landslide events in the past few years. This highway is imperative to the area as it links the Lengpui airport with the city. Most of the rock slopes along this highway are prone to rockfall, thus requires proper investigation. In this study, an investigation into the rockfall hazard was carried out on the nine rock slopes using the rockfall hazard rating system (RHRS) approach along NH-44A. Based on an extensive field investigation, the analysis shows that two out of nine slopes are more hazardous than the others as the RHRS score for these slopes is higher than 500. Furthermore, rockfall simulations were performed for hazardous slope to quantify the risk in terms of bounce height, velocity, kinetic energy and maximum reach of falling rock blocks. The simulation result reveals that vehicles on the roadway are under continuous threat. The potential falling blocks have a kinetic energy of 196 kJ which is enough to damage the buildings, vehicles and fatalities.
Elastic parameters such as Young’s modulus and Poisson’s ratio are significant to demarcate the d... more Elastic parameters such as Young’s modulus and Poisson’s ratio are significant to demarcate the damage zone around circular opening of tunnels. In the present study, a three dimensional finite difference numerical code, FLAC3D has been employed to study the effect of elastic parameters (E and v) on the radial displacement along the longitudinal direction around circular tunnel in hydrostatic field conditions. The tunnel is assumed to be driven in a homogeneous, isotropic, linear elastic rock mass. The results are compared with work done by previous researchers. Also, volumetric strain around tunnel and its behavior near the tunnel face have also been investigated to examine the failure behavior near the tunnel face. The material properties incorporated in the numerical model were taken in the range of common Indian rocks strength properties where most of the tunneling activities are going on. The empirical equation based on influence of Young’s modulus and Poisson’s ratio on radial deformation along the longitudinal axis of tunnel has been provided. Also, the relations between elastic parameters (E and v) and radial displacement has been proposed for future use in similar rock conditions.
AbstractThermal conductivity is a very important property of rocks which determines the rate of h... more AbstractThermal conductivity is a very important property of rocks which determines the rate of heat transfer between two adjacent layers of rock. Temperature-dependent thermal properties of Ganurgarh shale are analyzed and presented over a temperature range from air dried to 900 °C. Physico-mechanical properties, porosity, density and P-wave velocity are determined as per ISRM standards. In addition, changes in internal microstructure are studied using scanning electron microscopy (SEM). Thermal conductivity is predicted using P-wave velocity and porosity of Ganurgarh shale. The effect of temperature on the microstructure, porosity, and mineralogical composition of shale and dependency of thermal conductivity on porosity of shale is discussed. It has also been found that as temperature increases, porosity of Ganurgarh shale increases up to 2.3 times of its initial porosity because of thermal cracking which also acts as barrier of heat flow and hence thermal conductivity decreases. Uncertainties of measured quantities are calculated and the total combined expanded uncertainty for thermal conductivity value of Ganurgarh shale at 95 % confidence level is less than 6 %. All the results obtained using a state-of-the-art single hot guarded parallel plate apparatus.
This paper presents field investigations and numerical analyses of the landslide, affecting Malin... more This paper presents field investigations and numerical analyses of the landslide, affecting Malin village of Pune district in Maharashtra, India. The Malin village was wiped out due to Malin landslide, occurred on July 30, 2014; however, only a primary school and few houses remained safe during the event, and mass of the people buried in debris of slide. To study the causes of the event, field study has been carried out. Representative samples of slope-forming geomaterials (soil/rock) have been collected at three locations of the hill viz. L1 (bottom of the hill), L2 (middle of the hill) and L3 (top of the hill) along with massive and vesicular basalt for the determination of the geotechnical properties in the laboratory. The estimated geotechnical properties have been used for numerical modeling of the hill slope that has been performed to calculate factor of safety, maximum displacement, displacement direction and accumulated maximum shear strain with the help of numerical programs based on limit equilibrium method and finite element method approaches, respectively. This study shows that the hill slope was unstable with FoS < 1 and prone to failure. It was triggered by various man-made and natural factors like heavy rainfall, unscientific construction activities at the top of the hill and along the hill, unplanned cultivations and lack of drainage system. Also, the results of the numerical analysis can be successfully implemented to minimize/reduce impact and frequency of landslide in the area of similar morphology.
Artificial neural networks (ANNs) are rapidly gaining popularity in the area of oil exploration. ... more Artificial neural networks (ANNs) are rapidly gaining popularity in the area of oil exploration. This article discusses the importance of ANNs to petroleum engineers and geoscientists and its advantages over other conventional methods of computing. ANNs can assist geoscientists in solving some fundamental problems such as formation, permeability prediction, and well data interpretation from geophysical well log responses with a
Beijing East Road No.1 tunnel in Guiyang city has the most complexity in arround, so prediction a... more Beijing East Road No.1 tunnel in Guiyang city has the most complexity in arround, so prediction and control the blasting vibration is the most important task. In order to improve the accuracy of the prediction of the blasting vibration to mitigate the possible hazard in tunnel construction, studied on method of predicting peak particle velocity (PPV) using support vector machine (SVM) and established regression prediction model based on SVM. Comparisons between the predicted PPV using the empirical equation regression and SVM was made, find that the SVM gives much better prediction of PPV than does the empirical equation regression.
Massive strata frequently met in Indian coalfields have been the most important single factor con... more Massive strata frequently met in Indian coalfields have been the most important single factor controlling the development and mechanization of mines. Under the programme of development of equivalent Material Mines Modelling Technique, a model was constructed to simulate massive coal measure formation. Different mining parameters were investigated in this model with a view to chacking the reproducibility of the field conditions in the laboratory.
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1991
Strata control problems in underground coal mining account for highest fatal and serious injuries... more Strata control problems in underground coal mining account for highest fatal and serious injuries to workers. These problems are due to operational, geological and geo-technic parameters. Efforts are being made in various Indian coal mines to replace conventional timber supports by boltings, stitchings, hydraulic/friction props, chocks and shield supports for safety. Operation in and around faulted zones in Kamptee and Kanhan coalfield of Central India posed most serious challenge to safety of miners. Evaluation of orientation, throw and frequency of faults along with cleats and joints were studied with a view to evolving safe and economic system of supports and method of mining. Faults are the main geo-structural features disturbing bord and pillar and longwall workings. The fault throw up to the working height could be tackled without major change in layout and hence were called small throw faults. Over 20faults of throw within a metre to 60 m were observed in depth for gouge thickness and associated strata control problems. Faults with 10 m throw and above in creased face cleat and mjor joint frequency from 11m-1 to 16 m-1 and above and 4 m-1 to 10 m-1reswpectively within 5 to 50 m of its position. Orientation of face cleat and major joint west was also influenced by such faults which were classified as major faults. Entries along the major and the minor faults suffered from severe strata control problems. For better roof condition, drivages shouid be laid 20-45° across the faults; reinforcement of supports by way of stitchings and use of M.S. cross-bars along with conventional supports should be installed immediately in the faulted zones to avoid deterioration of exposed strata.
Stability of waste dump is now gaining importance due to increasing depth and size of mine. Manag... more Stability of waste dump is now gaining importance due to increasing depth and size of mine. Management of dump nearby mining areas is one of the most critical and crucial task for mine management due to limited land and other governing laws related to environment and forest conservation. In this paper, a study was conducted to establish the effect of slope angle on the stability of waste dump for accommodation of flyash is carried out. Based on numerical simulation, it was found that the dump slope of 60 m height with 36° slope can be critically stable with 20% flyash randomly mixed with overburden materials whereas flatter slopes provide higher factor of safety. Keeping other parameters constant, the optimum slope of 32° is the best possible to accommodate the mine dump for its long term stability. These findings were further supported by study of maximum velocity vectors and shear strain rates in every case and the extent of damage zone due to tensile pull. It is hoped that this t...
Rockfall is a critical problem in the hilly regions. The Lengpui-Aizawl highway has witnessed man... more Rockfall is a critical problem in the hilly regions. The Lengpui-Aizawl highway has witnessed many rockfalls and other types of landslide events in the past few years. This highway is imperative to the area as it links the Lengpui airport with the city. Most of the rock slopes along this highway are prone to rockfall, thus requires proper investigation. In this study, an investigation into the rockfall hazard was carried out on the nine rock slopes using the rockfall hazard rating system (RHRS) approach along NH-44A. Based on an extensive field investigation, the analysis shows that two out of nine slopes are more hazardous than the others as the RHRS score for these slopes is higher than 500. Furthermore, rockfall simulations were performed for hazardous slope to quantify the risk in terms of bounce height, velocity, kinetic energy and maximum reach of falling rock blocks. The simulation result reveals that vehicles on the roadway are under continuous threat. The potential falling blocks have a kinetic energy of 196 kJ which is enough to damage the buildings, vehicles and fatalities.
Elastic parameters such as Young’s modulus and Poisson’s ratio are significant to demarcate the d... more Elastic parameters such as Young’s modulus and Poisson’s ratio are significant to demarcate the damage zone around circular opening of tunnels. In the present study, a three dimensional finite difference numerical code, FLAC3D has been employed to study the effect of elastic parameters (E and v) on the radial displacement along the longitudinal direction around circular tunnel in hydrostatic field conditions. The tunnel is assumed to be driven in a homogeneous, isotropic, linear elastic rock mass. The results are compared with work done by previous researchers. Also, volumetric strain around tunnel and its behavior near the tunnel face have also been investigated to examine the failure behavior near the tunnel face. The material properties incorporated in the numerical model were taken in the range of common Indian rocks strength properties where most of the tunneling activities are going on. The empirical equation based on influence of Young’s modulus and Poisson’s ratio on radial deformation along the longitudinal axis of tunnel has been provided. Also, the relations between elastic parameters (E and v) and radial displacement has been proposed for future use in similar rock conditions.
AbstractThermal conductivity is a very important property of rocks which determines the rate of h... more AbstractThermal conductivity is a very important property of rocks which determines the rate of heat transfer between two adjacent layers of rock. Temperature-dependent thermal properties of Ganurgarh shale are analyzed and presented over a temperature range from air dried to 900 °C. Physico-mechanical properties, porosity, density and P-wave velocity are determined as per ISRM standards. In addition, changes in internal microstructure are studied using scanning electron microscopy (SEM). Thermal conductivity is predicted using P-wave velocity and porosity of Ganurgarh shale. The effect of temperature on the microstructure, porosity, and mineralogical composition of shale and dependency of thermal conductivity on porosity of shale is discussed. It has also been found that as temperature increases, porosity of Ganurgarh shale increases up to 2.3 times of its initial porosity because of thermal cracking which also acts as barrier of heat flow and hence thermal conductivity decreases. Uncertainties of measured quantities are calculated and the total combined expanded uncertainty for thermal conductivity value of Ganurgarh shale at 95 % confidence level is less than 6 %. All the results obtained using a state-of-the-art single hot guarded parallel plate apparatus.
This paper presents field investigations and numerical analyses of the landslide, affecting Malin... more This paper presents field investigations and numerical analyses of the landslide, affecting Malin village of Pune district in Maharashtra, India. The Malin village was wiped out due to Malin landslide, occurred on July 30, 2014; however, only a primary school and few houses remained safe during the event, and mass of the people buried in debris of slide. To study the causes of the event, field study has been carried out. Representative samples of slope-forming geomaterials (soil/rock) have been collected at three locations of the hill viz. L1 (bottom of the hill), L2 (middle of the hill) and L3 (top of the hill) along with massive and vesicular basalt for the determination of the geotechnical properties in the laboratory. The estimated geotechnical properties have been used for numerical modeling of the hill slope that has been performed to calculate factor of safety, maximum displacement, displacement direction and accumulated maximum shear strain with the help of numerical programs based on limit equilibrium method and finite element method approaches, respectively. This study shows that the hill slope was unstable with FoS < 1 and prone to failure. It was triggered by various man-made and natural factors like heavy rainfall, unscientific construction activities at the top of the hill and along the hill, unplanned cultivations and lack of drainage system. Also, the results of the numerical analysis can be successfully implemented to minimize/reduce impact and frequency of landslide in the area of similar morphology.
Artificial neural networks (ANNs) are rapidly gaining popularity in the area of oil exploration. ... more Artificial neural networks (ANNs) are rapidly gaining popularity in the area of oil exploration. This article discusses the importance of ANNs to petroleum engineers and geoscientists and its advantages over other conventional methods of computing. ANNs can assist geoscientists in solving some fundamental problems such as formation, permeability prediction, and well data interpretation from geophysical well log responses with a
Beijing East Road No.1 tunnel in Guiyang city has the most complexity in arround, so prediction a... more Beijing East Road No.1 tunnel in Guiyang city has the most complexity in arround, so prediction and control the blasting vibration is the most important task. In order to improve the accuracy of the prediction of the blasting vibration to mitigate the possible hazard in tunnel construction, studied on method of predicting peak particle velocity (PPV) using support vector machine (SVM) and established regression prediction model based on SVM. Comparisons between the predicted PPV using the empirical equation regression and SVM was made, find that the SVM gives much better prediction of PPV than does the empirical equation regression.
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Papers by Prof. T N Singh