Study On The Influence Of Blasting Construction On Adjacent Tunnel And Adjacent Tunnel

Since twenty-first Century,the rapid improvement of China's comprehensive national strength has brought about a new upsurge in the construction of high-speed rail,highway and other transportation.Our country is vast in territory,and the mountains and the terrain are complex in the west,and there is a huge number of tunnels in the construction of traffic engineering.In the process of tunnel construction,often appear in the construction of the tunnel and adjacent existing tunnel intersection,blasting construction in tunnel construction inevitably caused by blasting vibration,adjacent tunnels intersect,affect the stability and the safety of the structure.This paper takes Chongqing city as mother mountain for one small spacing tunnel through a plurality of existing railway tunnel as the background,field monitoring and numerical simulation calculation method of tunnel blasting construction in tunnel construction of forced vibration are studied by theoretical analysis,and study the surrounding rock grade,tunnel space,blasting charge and other factors impact on the existing tunnel of forced vibration,the main research contents and achievements are as follows:(1)The blasting construction of the tunnel under construction(left hole),blasting vibration under railway tunnel field monitoring,processing and analysis of monitoring data,get the variation diagram of measuring point vibration velocity and displacement,according to China's "blasting safety regulations" requirement,in the construction of the tunnel(left),the tunnel under blasting vibration velocity is less than the allowable safety vibration velocity range,the tunnel structure is in a safe and stable state;(2)The blasting construction process simulation,a numerical analysis model of blasting vibration adjacent and crossing tunnels,calculated the tunnel structure node in a blasting vibration velocity in the circulation variation,by proximity,cross tunnel velocity distribution,blasting face the maximum vibration velocity and displacement of nodes in the tunnel structure the greater the distance and velocity,the smaller.Therefore,it is necessary to pay close attention to the safety and stability of the tunnel face in the actual construction;(3)To establish the numerical model of tunnel blasting vibration with small spacing,of different grade of surrounding rock,tunnel space,blasting charge under the adjacent small spacing tunnel blasting vibration law,obtained the safety distance between the tunnel blasting construction of small spacing under different rock classes,and the design of charge amount has been adjusted,the construction design of blasting parameters optimization;(4)The general situation of relying on the actual project site,set up the tunnel and cross tunnel blasting vibration numerical model of small spacing,respectively.The effect of the surrounding rock grade,blasting charge and other factors on the tunnel blasting vibration velocity,the minimum distance between tunnel blasting construction under different rock classes at the cross,and the blasting design of the existing installation the dosage was adjusted to optimize,these results can provide reference for similar engineering.