Analysis of the vibration impact of railway tunnel blasting excavation on existing highway tunnels

Abstract

Prior to tunnelling by drilling and blasting, a proper assessment of the impact of blasting and excavation vibrations on the adjacent existing buildings (structures) is the basis for ensuring the safe operation and maintenance of the adjacent existing buildings (structures). Based on the Zijing yaoshan Railway Tunnel under the existing Guibin highway tunnel, the Midas GTX software was used to perform non-linear time history analysis, taking into account the damping effect of the blast wave, to study the impact of tunnel blasts on existing structures. The simulation results show that the maximum vibration velocity occurs at the left wall position of the tunnel, with a size of 0.71cm/s, which meets the requirement of particle vibration velocity less than 10cm/s in the specification; Due to the plane intersection angle between the Guibin highway tunnel and the Zijing yaoshan tunnel excavated by blasting, the entire Guibin highway tunnel leans to the right, causing the left side of the Guibin highway tunnel to be affected by the blasting shock wave earlier than the right side. The vibration velocity distribution shows that the vibration velocity at the measurement point on the left side of the tunnel section is significantly higher than that on the right side; Analyzing the development curve of blasting vibration speed, the development curve can be divided into three stages, namely the rising stage, the falling stage, and the stable attenuation stage, and analyzing the characteristics of each stage.