Roof fall is one the most hazardous phenomenon in underground coal mines. It has been a cause maj... more Roof fall is one the most hazardous phenomenon in underground coal mines. It has been a cause major accident throughout in Indian coal mines. Besides endangering the lives of the miners roof fall can also cause blockades and as well as lead to damages to machinery and other devices. Thus prediction of roof fall becomes a necessity owing to the ever increasing demand of raw materials and any delays caused due to sudden roof fall need to be averted. In this study, the fuzzy logic was applied to predict roof fall rate in coal mines. Six parameters i.e. Slake durability, immediate roof thickness, structural feature value, RQD, and span were used as input in the fuzzy model an one out put i.e. stand up time was used. The fuzzy model was developed using expert knowledge of mining field using a database of 42 values of roof conditions from Indian coal mines The comparison between obtained results from model and actual roof fall rate showed that the fuzzy model can predict roof fall rate re...
Journal of The Institution of Engineers (India): Series D, 2015
ABSTRACT In this paper, a mathematical model has been formulated for calculating the factor of sa... more ABSTRACT In this paper, a mathematical model has been formulated for calculating the factor of safety of a slope. Corresponding computer code has also been developed. Limit equilibrium method (moment equilibrium) has been adopted for calculating the net resulting driving and resisting forces. The probable slip circle region has been divided into radial slices for the simulation process. In this approach, the inter-slice shear forces are zero. Thus, the calculation process becomes simpler as compared to that with vertical slices. The slope stability analyses were done. Validation of the present program was done with existing limit equilibrium based methods. Various models were prepared and analysed with varying geometry and soil strength parameters. These models were also analysed with other limit equilibrium methods like Bishop, Janbu and Spencer method. The results were found to be in agreement with the results of other limit equilibrium methods for the same dump soil properties and slope parameters.
International Journal of Mining Science and Technology, 2014
ABSTRACT The present paper discusses the effects of small plants on the dump mass reinforcement a... more ABSTRACT The present paper discusses the effects of small plants on the dump mass reinforcement and slope stability. The roots of smaller plants (such as grasses and shrubs) do not go deep. However, they stabilize the slope by binding the upper layer of dump slope. Shear strength of the dump mass with and without root reinforcement is determined by laboratory shear box instrument. The increased cohesion (apparent cohesion) of upper layer of the dump mass due to plants is determined by fabricated shear box. The kinetic behavior of the dump has been investigated using the FLAC software. The factor of safety has been calculated in order to determine the possible effect of small plants on the stability of the dump slope. It is observed that the small plants do not significantly improve the factor of safety (FOS) of slope. However, it could be useful for early stabilization. The grasses quickly bind the upper surface, whereas shrubs too immensely strengthen the stability of the dump in the initial stage.
Journal of The Institution of Engineers (India): Series D, 2012
ABSTRACT Shear strength of the dump material is very important in the stability analysis of slope... more ABSTRACT Shear strength of the dump material is very important in the stability analysis of slope. Determination of shear strength of dump or vegetated dump is very complicated and also requires large size of specimen so that it represents the true behaviour of dump mass with and without vegetation. Large size shear box (1.5 × 1.5 × 0.75 m) and small shear boxes (0.3 × 0.3 × 0.15 m) have been fabricated and used for the present study. Various types of plants have been grown in the mine waste dump in the laboratory. The grasses increased cohesion of the dump mass up to 27 kPa whereas the shrubs increased the cohesion up to 32 kPa in given conditions. The increased cohesion depends on the depth of root and age of tree. It generally varies from 10 to 80 kPa or more depending on the age of the tree.
Various predictor equations have been proposed to determine the peak particle velocity (PPV), a f... more Various predictor equations have been proposed to determine the peak particle velocity (PPV), a function of distance (R) and maximum safe charge per delay (Qmax). PPVs calculated by using these predictor equations give results close to observed values in the field. ...
ABSTRACT The present paper discusses the impact of the geometrical parameters of the coal rib and... more ABSTRACT The present paper discusses the impact of the geometrical parameters of the coal rib and the mine dump on the stability of the coal rib. The geometrical parameters such as the slope angle, the height of dragline dump, the height of main dump, the gradient of seam and the thickness of coal rib have been considered as input to the numerical model for the stability analysis of the coal rib. Sensitivity analysis has been performed based on the results of the analysis in term of factor of safety of the coal rib. The input parameters have been classified in terms of significance (i.e. very high significance, high significance medium significance and low significance). The factor of safety is more influenced by highly significant parameters. The height and the slope angle of dragline dump and the thickness of the coal rib are highly significant parameters for the stability of the coal rib. The gradient of the seam is a medium significant parameter whereas, height of main dump and the number of dragline cut dump are low significant parameters for stability of coal rib.
Roof fall is one the most hazardous phenomenon in underground coal mines. It has been a cause maj... more Roof fall is one the most hazardous phenomenon in underground coal mines. It has been a cause major accident throughout in Indian coal mines. Besides endangering the lives of the miners roof fall can also cause blockades and as well as lead to damages to machinery and other devices. Thus prediction of roof fall becomes a necessity owing to the ever increasing demand of raw materials and any delays caused due to sudden roof fall need to be averted. In this study, the fuzzy logic was applied to predict roof fall rate in coal mines. Six parameters i.e. Slake durability, immediate roof thickness, structural feature value, RQD, and span were used as input in the fuzzy model an one out put i.e. stand up time was used. The fuzzy model was developed using expert knowledge of mining field using a database of 42 values of roof conditions from Indian coal mines The comparison between obtained results from model and actual roof fall rate showed that the fuzzy model can predict roof fall rate re...
Journal of The Institution of Engineers (India): Series D, 2015
ABSTRACT In this paper, a mathematical model has been formulated for calculating the factor of sa... more ABSTRACT In this paper, a mathematical model has been formulated for calculating the factor of safety of a slope. Corresponding computer code has also been developed. Limit equilibrium method (moment equilibrium) has been adopted for calculating the net resulting driving and resisting forces. The probable slip circle region has been divided into radial slices for the simulation process. In this approach, the inter-slice shear forces are zero. Thus, the calculation process becomes simpler as compared to that with vertical slices. The slope stability analyses were done. Validation of the present program was done with existing limit equilibrium based methods. Various models were prepared and analysed with varying geometry and soil strength parameters. These models were also analysed with other limit equilibrium methods like Bishop, Janbu and Spencer method. The results were found to be in agreement with the results of other limit equilibrium methods for the same dump soil properties and slope parameters.
International Journal of Mining Science and Technology, 2014
ABSTRACT The present paper discusses the effects of small plants on the dump mass reinforcement a... more ABSTRACT The present paper discusses the effects of small plants on the dump mass reinforcement and slope stability. The roots of smaller plants (such as grasses and shrubs) do not go deep. However, they stabilize the slope by binding the upper layer of dump slope. Shear strength of the dump mass with and without root reinforcement is determined by laboratory shear box instrument. The increased cohesion (apparent cohesion) of upper layer of the dump mass due to plants is determined by fabricated shear box. The kinetic behavior of the dump has been investigated using the FLAC software. The factor of safety has been calculated in order to determine the possible effect of small plants on the stability of the dump slope. It is observed that the small plants do not significantly improve the factor of safety (FOS) of slope. However, it could be useful for early stabilization. The grasses quickly bind the upper surface, whereas shrubs too immensely strengthen the stability of the dump in the initial stage.
Journal of The Institution of Engineers (India): Series D, 2012
ABSTRACT Shear strength of the dump material is very important in the stability analysis of slope... more ABSTRACT Shear strength of the dump material is very important in the stability analysis of slope. Determination of shear strength of dump or vegetated dump is very complicated and also requires large size of specimen so that it represents the true behaviour of dump mass with and without vegetation. Large size shear box (1.5 × 1.5 × 0.75 m) and small shear boxes (0.3 × 0.3 × 0.15 m) have been fabricated and used for the present study. Various types of plants have been grown in the mine waste dump in the laboratory. The grasses increased cohesion of the dump mass up to 27 kPa whereas the shrubs increased the cohesion up to 32 kPa in given conditions. The increased cohesion depends on the depth of root and age of tree. It generally varies from 10 to 80 kPa or more depending on the age of the tree.
Various predictor equations have been proposed to determine the peak particle velocity (PPV), a f... more Various predictor equations have been proposed to determine the peak particle velocity (PPV), a function of distance (R) and maximum safe charge per delay (Qmax). PPVs calculated by using these predictor equations give results close to observed values in the field. ...
ABSTRACT The present paper discusses the impact of the geometrical parameters of the coal rib and... more ABSTRACT The present paper discusses the impact of the geometrical parameters of the coal rib and the mine dump on the stability of the coal rib. The geometrical parameters such as the slope angle, the height of dragline dump, the height of main dump, the gradient of seam and the thickness of coal rib have been considered as input to the numerical model for the stability analysis of the coal rib. Sensitivity analysis has been performed based on the results of the analysis in term of factor of safety of the coal rib. The input parameters have been classified in terms of significance (i.e. very high significance, high significance medium significance and low significance). The factor of safety is more influenced by highly significant parameters. The height and the slope angle of dragline dump and the thickness of the coal rib are highly significant parameters for the stability of the coal rib. The gradient of the seam is a medium significant parameter whereas, height of main dump and the number of dragline cut dump are low significant parameters for stability of coal rib.
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