Analysis Of Static And Dynamic Mechanical Properties Of Coal Rock Fractures

China's coal resources are rich,the output is huge,has a huge energy potential.In this paper,the static and dynamic mechanical properties of coal rock fractures are analyzed respectively.Among them,the analysis of static mechanical characteristics includes the study of the influence of fracture on coal seam filling mining;The analysis of dynamic mechanical characteristics includes the study of the impact of explosive blasting on the range of rock fracture zone and crushed zone.In this paper,3DEC software based on discrete element method and ANSYS-LSDYNA software based on nonlinear dynamic finite element analysis were used for numerical simulation research,and the following results were obtained:(1)Using 3DEC software and its built-in discrete fracture network model of containing crackes coal strata modeling,the different parameters for crack filling mining strata movement deformation law of coal seam,the influence of the results showed that the strata containing crackes,stable subsidence zone in overlying strata subsidence degree deepening,volume decreases,and the rock alienation when cracks increase in the number,the overburden subsidence intensity increased;With the increase of the average fracture dip Angle,the maximum subsidence decreases first and then increases.When the average fracture dip Angle is close to horizontal or vertical,the overburden subsidence shifts to the final mining line or the cut hole,and the overburden subsidence reaches the maximum value in the stable subsidence area.(2)ANSYS-LSDYNA software was used for rock blasting process under the influence of different initial stress numerical simulation research,through the observation records of different time rock stress nephogram and explosion source different distances away from the unit stress change curve,come to a conclusion: when there is the initial stress of rock under the action of blasting crack expand impeded,narrow fracture zone,crushed zone formed mainly depends on the effect of early explosion stress wave,while the explosion stress is greater than the initial stress,so to crush the influence can be neglected;With the increase of the initial stress,the range of the rock fracture zone is gradually reduced under the influence of blasting,and the range of the crushed zone has little change.(3)ANSYS-LSDYNA software was used for carbon dioxide crack model,using powder instead of liquid carbon dioxide in the liquid storage tube,different explosive charge conditions,carbon dioxide for the crack of the rock crack machine effect and scope,through the observation records of different plane moment by blasting rock stress nephogram and release hole unit stress change curve of different distance apart,get the conclusion that with the increase of explosive charge,the effect of rock under explosion stress,rock blasting release hole unit under different distance apart the peak stress increased.When the charge amounts were 200 g,250g and 300 g,the range of the crushed zone and the fracture zone increased.The release holes in the crushed zone were about 20 cm,20cm-25 cm and25cm-30 cm respectively,and the release holes in the fracture zone were about 50 cm,50cm-60 cm and 60 cm respectively.