PURPOSE: A last method for center hole of tunnel is provided to minimize transmission of the vibration according to the blasting and noise. CONSTITUTION: A first smooth blasting(21) is formed in the central part of the tunnel free surface. 4 second smooth blastings(22) are parallelly separated with the first smooth blasting from the first smooth blasting. 4 primary blast balls(23) are arranged in the first smooth blasting surrounding in the form of square. The first blast balls are obliquely dug to the backend of the first smooth blasting. The second bursts are obliquely dug to the backend of the first smooth blasting. Third bursts are parallelly dug with second smooth blasting. Explosive successively explodes from the first blast ball to the third burst.
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