Research On The Influence Of Explosion Excavation Of Following Hole Of Bias Tunnels

Drilling and blasting is the most commonly used excavation method in the tunnel,which can cause the blasting vibration to adversely affect the surrounding rock and structure around the tunnel.Based on the Xiaonong high-speed Maanshan tunnel project,this paper studies the influence of the rear-hole blasting construction on the first hole in the small-distance bias tunnel.According to the related theory of rock blasting,to simulate the blasting vibration and establish related calculation and analysis three dimensional numerical model,the research analyzes the small clear distance bias tunnel after tunnel during blasting excavation,first at the beginning of the tunnel under the condition of different law of dynamic response of the structure.The following are the main research topics and results for this article:(1)Through comparison and analysis on the bias tunnel hole blasting excavation,after early ahead of the tunnel supported structure dynamic response law of every key point,get bias tunnel at the beginning of the first hole in vibration under the influence of the structure of the most unfavorable position for the wall and the arch waist position.(2)This paper studies the dynamic response law of the initial tunnel under the condition of different distance and different surrounding rock under the bursting load of the tunnel after excavation.The results show that the larger the spacing of the bias tunnel is,the more obvious the attenuation effect of the initial tunnel is,and the reasonable tunnel spacing under the blasting vibration should be larger than 1.5 times.(3)The response of the tunnel to the initial structure of the initial tunnel is analyzed and analyzed.The results show that when the depth of the tunnel is different,the deviation of the tunnel on the tunnel The influence of the bias angle on the blasting vibration is different,and the influence of the bias angle is different.At the same time,the influence of the bias angle on the blasting vibration is different.In the deep case,the reasonable excavation order of the small-distance deviation tunnel under the influence of blasting vibration.(4)The vibration response law of the initial anchorage structure of the tunnel is studied under the condition of different face spacing.The results show that the vibration velocity of the initial support of the first tunnel is reduced with the distance between the two faces of the small-distance deviation of the tunnel.When the distance between the face and the face is more than a certain range,The influence of the initial vibration isnot obvious,and the reasonable longitudinal spacing of the small pitch deviation tunnel under the blasting vibration is obtained.