Study On Fracture Characteristics Of Fine Sandstone At Medium To High Strain Rates

In order to accurately control the ultra-deep hole expansion and blasting effect,improve the working efficiency of the coal mining face when passing through large structures,and control production costs,dynamic and static mechanical experiments were carried out on the rock sample-fine sandstone in the structure of the mining area,and the detailed analysis and comparison The failure process of fine sandstone under static load and dynamic load,the failure mechanism and strength characteristics of fine sandstone under medium and high strain rate were studied,and the strain rate effect and compressive strength of fine sandstone under dynamic load were obtained.Its failure mode dominated by tensile stress,combined with the existing numerical simulation results,designed and optimized the on-site blasting scheme.The blasting results reached the expected effect,which verified the rationality and reliability of the fine sandstone mechanics experimental results in this paper,which can be ultra-deep holes.The design of blasting scheme provides corresponding theoretical basis.The main research contents and conclusions of this article are:(1)Investigate the scene,take the required rock samples,process the rock samples according to the experimental requirements,use the RMT test system to conduct static experiments,and analyze the failure mode of the fine sandstone under static load,which is uniaxial The shock compression experiment provides a reference.(2)the large-diameter SHPB experimental system was selected to perform a uniaxial compression impact test on the fine sandstone specimens,and the fracture mode and strength characteristics were analyzed.The stress-dominated failure mode provides corresponding theoretical basis for numerical simulation and on-site ultra-deep hole blasting.(3)According to the research on the failure mode and strength characteristics of the fine sandstone under dynamic load,combined with the existing numerical simulation results,the on-site blasting scheme was designed.The ultra-deep hole blasting has made the cutting unit consumption of the shearer of the working face obvious Reduced,the experimental effect reached expectations,and verified the rationality and reliability of the theoretical research results.The paper has 36 figures,15 tables and 60 references.