Structural deterioration in the roof in an underground mine can easily cause roof fall, and deterioration is difficult to detect. When drilling holes for roof bolts, there is a relationship between the vibration of th...Structural deterioration in the roof in an underground mine can easily cause roof fall, and deterioration is difficult to detect. When drilling holes for roof bolts, there is a relationship between the vibration of the drill rod and the properties of the rock being drilled. This paper analyzes transverse, longitudinal, and torsional vibrations in the drill rod by using vibration theory. Characteristic indexes for three kinds of vibration are determined. Using the finite element analysis software ABAQUS, a model for drill rod vibration during the drilling of roof bolt holes was established based on the geological and mining conditions in the Guyuan Coal Mine, northern China. Results from the model determined that the transverse and the longitudinal vibration decrease as the rock hardness decreases. In descending order, sandstone,sandy mudstone, mudstone, and weak interbeds cause progressively less vibration when being drilled.The ranking for strata that cause decreasing torsional vibration is slightly different, being, in descending order, mudstone, sandstone, sandy mudstone, and weak interbeds. These results provide a theoretical basis for predicting dangerous roof conditions and the presence of weak interbeds to allow for adjusting bolt support schemes.展开更多
With rampant growth and improvements in drilling technology,drilling of blast holes should no longer be viewed as an arduous sub-process in any mining or excavation process.Instead,it must be viewed as an important op...With rampant growth and improvements in drilling technology,drilling of blast holes should no longer be viewed as an arduous sub-process in any mining or excavation process.Instead,it must be viewed as an important opportunity to quickly and accurately measure the geo-mechanical features of the rock mass on-site,much in advance of the downstream operations.It is well established that even the slightest variation in lithology,ground conditions,blast designs vis-à-vis geologic features and explosives performance,results in drastic changes in fragmentation results.Keeping in mind the importance of state-of-the-art measurement-while-drilling(MWD) technique,the current paper focuses on integrating this technique with the blasting operation in order to enhance the blasting designs and results.The paper presents a preliminary understanding of various blasting models,blastability and other related concepts,to review the state-of-the-art advancements and researches done in this area.In light of this,the paper highlights the future needs and implications on drill monitoring systems for improved information to enhance the blasting results.展开更多
基金the National Natural Science Foundation of China (Nos.51104055,51274087,51604094 and 51674098)
文摘Structural deterioration in the roof in an underground mine can easily cause roof fall, and deterioration is difficult to detect. When drilling holes for roof bolts, there is a relationship between the vibration of the drill rod and the properties of the rock being drilled. This paper analyzes transverse, longitudinal, and torsional vibrations in the drill rod by using vibration theory. Characteristic indexes for three kinds of vibration are determined. Using the finite element analysis software ABAQUS, a model for drill rod vibration during the drilling of roof bolt holes was established based on the geological and mining conditions in the Guyuan Coal Mine, northern China. Results from the model determined that the transverse and the longitudinal vibration decrease as the rock hardness decreases. In descending order, sandstone,sandy mudstone, mudstone, and weak interbeds cause progressively less vibration when being drilled.The ranking for strata that cause decreasing torsional vibration is slightly different, being, in descending order, mudstone, sandstone, sandy mudstone, and weak interbeds. These results provide a theoretical basis for predicting dangerous roof conditions and the presence of weak interbeds to allow for adjusting bolt support schemes.
文摘With rampant growth and improvements in drilling technology,drilling of blast holes should no longer be viewed as an arduous sub-process in any mining or excavation process.Instead,it must be viewed as an important opportunity to quickly and accurately measure the geo-mechanical features of the rock mass on-site,much in advance of the downstream operations.It is well established that even the slightest variation in lithology,ground conditions,blast designs vis-à-vis geologic features and explosives performance,results in drastic changes in fragmentation results.Keeping in mind the importance of state-of-the-art measurement-while-drilling(MWD) technique,the current paper focuses on integrating this technique with the blasting operation in order to enhance the blasting designs and results.The paper presents a preliminary understanding of various blasting models,blastability and other related concepts,to review the state-of-the-art advancements and researches done in this area.In light of this,the paper highlights the future needs and implications on drill monitoring systems for improved information to enhance the blasting results.
