Experimental Study On The Loosening Radius Of The Deep-hole Blasting

Directing at how to Experimental study on the loosening radius of the deep-hole blasting. First,the paper introduced application and research status on the deep-hole blasting,analysed on the present situation at home and abroad, points out deficiency of study on the loosening radius of the deep-hole blasting,proposed the necessity of the paper study,and made clear the its main contents. Subsequently,analysis and the summary on explosion theory and antireflection mechanism based on predecessors' research. According to the nonlinear theory and finite element numerical,with the aid of the ANSYS/LS-DYNA finite element analysis software,based on coal-rock mass of the coal seam No.7 face of Pansan Colliery, Huanan,built four calculation models and studied dynamic process on transmission of stresswave and impact on stress distribution in the coal-rock mass. Dynamically simulated the development,growth and transfixion of coal-rock mass with the damage mechanics model,and according to results ,qualitatively analyzed the impact of observation drilling,number and hole arrangement of blast hole on loosening results.The simulation shows that observation drilling were beneficial to the main crack growth;Judging from the effect of crack growth;Double blast hole is superior to single-hole;Because blast hole spacing on the communication between the cracks with the width and length has the opposite effect,a reasonable hole spacing is the width and length in a certain balance point;In this paper, the range of the effective loosening radius of the coal seam No.7 was 3 ~ 3.5m.The spot test shows that the range of the effective loosening radius of the coal seam No.7 was 3 ~ 3.5m.Finally, founded that the results of the analysis of both the basic line were consistent by comparing the numerical simulation results and field test results . This paper describes the numerical model simulation of the simplified design and parameter selection is reasonable. Furtherly, illustrated that the use of LS-DYNA software to provide a useful reference and guidance for the deep-hole blasting in the actual engineering design.