Research On Energy Evolution And Instability Of Rock Mass Under Blasting Load

During the drill excavation of deep tunnels,the blasting load will cause the target rock body to be effectively broken,and will also cause different degrees of damage to different degrees of damage,and severely affect the tunnel stability.The essence of blasting and broken rock is the blasting load to the rock mass,thereby driving the rock bulge failure.Therefore,the explosive load is carried out,and the decline in decline is made of high-efficiency use of blasting energy and reduced blasting negative impacts.This paper uses explicit dynamics software,analyzes the time and space distribution characteristics and evolution laws of each substance energy in a single hole blasting system,and studies the side pressure coefficients under the highlands stress and blast load coupling.Dynamic response of surrounding rock energy and the developmental characteristics of rupture tape.The main research work and the conclusions are as follows:(1)Based on a stream solid coupling algorithm,establish a single hole unpoupling cost reduction numerical test model,analyzed the feasibility of the numerical methods used in this article,and studied the non-coupling coefficient pair Effects of the pressure,energy evolution,and explosive crack extension.The results show that under the same explosives,the strain energy of the rock mass,the strain rate and peak pressure,the peak pressure,the area of the explosion crack is negatively related,and it is given Change formula with the non-coupling coefficient.When the non-coupling coefficient is less than 3,change the no-coupling coefficient of the drug,the peak pressure,rock body strain energy,and the explosion area are significantly reduced as the inclination of the non-coupling coefficient;and when the coupling coefficient is greater than 3 Changing the non-coupling coefficient has a small change amplitude.(2)The numerical model of the blasting disturbance of the adjacent tunnel was established.The effects of different side pressure coefficients ? and prefabricated cracking angle ? on tunnel surrounding rock strain air evolution characteristics and unstability rupture was analyzed.The results show that when ? is less than 1,the variable energy release area appears at the bottom of the tunnel;when the ? is greater than 1,the variable energy release area begins to transfer to the tunnel,and the larger the lambda,the larger the range of strain energy release area.The strain energy density of the bursting on the side surrounding rock increases with the increase in crack angle ?.Blasting load under the tunnel surrounding rock response time curve appears to fluctuate "double peak",and the final stability value is greater than the initial value.When the vertical in-situ stress is constant,the area of the "V-shaped" crack formed by blasting disturbance on the side of the tunnel to blast decreases with the increase of the crack inclination Angle ? and the lateral pressure coefficient ?.(3)The stress relief blasting test of Hanji-Weihe Qinling water transfer tunnel is taken as the engineering background.The numerical calculation models of three kinds of stress relief blasting schemes for light,medium and strong rockburst are established.The stability of tunnel surrounding rock and the characteristics of stress and energy release under each scheme are evaluated.the value calculation model for the three stresses of mild,medium and strong rock bursts was established,and the various programs were evaluated.The results show that the stress release at the vault of the tunnel face is the largest and the stress release at the side wall is the least after the stress relief blasting.When the stress environment and the mechanical properties of surrounding rock are the same,the effect of blasting scheme with light rock burst stress relief on the stability of surrounding rock is the least,while that with strong rock burst stress relief blasting is the largest.Three different stress relief blasting schemes can form a continuous fracture zone along the tunnel contour in the surrounding rock in the tunnel face.