Numerical Simulation Of The Propagation Of Stress Wave In Jointed Rock Mass

With the rapid development of traffic engineering in our country,the mountain tunnel project appears in large number,and the drilling and blasting method is the most commonly used excavation method.Rock mass contains joints and other weak rock discontinuity structural planes.The existence of these weak rock discontinuity structural planes will affect the effect of blasting to rock and exacerbate the attenuation of stress waves.Studying the propagation law of stress wave in jointed and fractured rock mass can guide the drilling and blasting,improve the utilization ratio of explosive energy and enhance the blasting effect to rock.In this paper,the influence of joints on propagation and attenuation of stress wave and the influence of joint geometry size and joint filling on attenuation effect of vibration are studied by using ANSYS/LS-DYNA software.The main research contents and results are as follows:The law of propagation and attenuation of stress waves through the rock joints,whose joint thickness and joint filling are different,were studied.The influence of joint width and filling on the propagation and attenuation of stress wave is given.The distribution of stress induced by explosion in the jointed rock were studied when the angle between the rock joint and the horizontal direction is different.Influence of stress distribution on the effect of smooth blasting is given.The law of propagation and attenuation of stress waves through the rock joints were studied when amount of explosive charge are different.The influence of amount of explosive charge on the propagation and attenuation of stress wave is given.A numerical model is established based on the engineering background.By using the numerical model,the attenuation law of seismic wave through joint was studied when the length of the joint along the direction of the working face excavation,the joint length in the vertical direction and the joint filling are different.The law can be used to control the blasting vibration influence on neighborhood tunnel.