Research On Vibration And Control Of Existing Railway Tunnel Caused By Super Close Blasting

The vibration performance of existing tunnel under the blasting of super close range is a research worthy of study.This paper analyzed the vibration performance of existing railway tunnel structure under the influence of blasting construction of super close range tunnel which relies on the actual railway tunnel project and wavelet packet energy analysis method.Combining blast vibration measurement data of existing ultra-distinguished tunnels,based on wavelet packet energy analysis,numerical analysis,rock mechanics,structural dynamics,using MATLAB,ANSYS software,etc.,analysis of blasting vibration at ultra-close distance from the perspective of blasting seismic wave propagation energy The blasting seismic effect of ultra-short distance is studied in terms of energy distribution,energy attenuation characteristics of the frequency bands of the blasting seismic wave,and the energy response of the existing tunnel structure to different frequency bands.The blasting vibration damping measures are discussed and some effective methods are proposed.The main research content is as follows:(1)The monitoring and analysis of blasting vibration of existing railway tunnels under ultra-close distance conditions was carried out,and the main vibration directions of existing railway tunnel structures at different locations under the influence of super-distance blasting earthquakes were obtained.The energy distribution of the main vibration direction of the existing railway tunnel was calculated by wavelet packet decomposition,and the energy distribution characteristics of each frequency band of the tunnel and the frequency band where the main frequency of the vibration was located were calculated,and then the vibration signals of different maximum doses and different burst distances were calculated.The distribution of energy characteristics of frequency bands was studied.(2)Based on structural dynamics and structural seismic theory,the energy response coefficients of different frequency bands of the existing tunnel structure are deduced,the response distribution law of the tunnel structure to different frequency bands is obtained,and the existing frequency bands of the existing tunnel structure are analyzed based on the measured data.The attenuation characteristics of energy;studied the vibration velocity and frequency attenuation of the existing tunnel particle,and obtained the vibration velocity,frequency distribution and attenuation law of the existing tunnel structure.(3)Based on the finite element analysis of ANSYS,the near-distance blasting excavation conditions were simulated and analyzed.The most dangerous cross sections under the blasting conditions of several existing conditions of the existing tunnel were analyzed,and the dynamic response under the influence of blasting vibration under different working conditions was obtained..The results show that the main stress in different positions of the existing tunnel section is different.The relationship between the main stress change trend and its decay time and the blast center distance is analyzed.(4)According to the characteristics of blasting vibration and its propagation law and engineering practice of existing railway tunnels,the blasting vibration control and shock absorption measures are discussed,and some effective existing tunnel damping technologies and methods are proposed.It is recommended to choose reasonable blasting equipment.,Explosives types and charge structure,and guttering methods,using differential control blasting and designing vibration-reducing holes,active control measures based on the analysis of vibration characteristics of existing railway tunnel structures,and research results on existing railways at ultra-short distances Tunnel blasting shock absorption measures have some reference significance.