Blasting and Shock-absorbing Technologies for High-speed Railway Tunnel Side-crossing Buildings
As the high-speed railway network becomes more dense,tunnels will inevitably cross underneath or sideways through buildings(structures).Under the premise of ensuring the vibration safety of buildings(structures),improving the tunneling efficiency is the key and the difficulty of the construction.Taking the tunnel side-crossing the buildings as the engineering background,this paper studied the composite working method of upper-step mechanical excavation+middle and lower-step controlled blasting by the numerical calculation,and it was compared with the upper-step controlled blasting method.The results showed that the higher the elevation of the building,the more obvious the vibration,indicating that the elevation had an amplification effect on the vibration velocity with amplification factors of more than 2 times,and monitoring the vibration velocity of the top of the building should be the focus in the construction.Compared with the upper-step controlled blasting method,the composite working method could reduce the shock by over 50%.This composite method of upper-step mechanical excavation+middle and lower-step controlled blasting can not only enhance the excavation efficiency but also reduce the vibration effect on the surface buildings to the maximum extent,and it has high promotion and application values.