Microvibration blasting process of metro double-line large-span tunnel

Abstract

The invention discloses a microvibration blasting process of a metro double-line large-span tunnel. The process is characterized in that a blasting mode using a carbon dioxide phase change cracker as a blasting device achieves a tunnel excavation purpose through the quick expansion effect of liquid-state carbon dioxide in a pipe; the length of the cracker controls the drilling depth to be not smaller than 1.5 m and the aperture to be not bigger than 63 mm; peripheral eye precracking guide holes are drilled; the hole distance is 10-50 cm; and the hole depth is smaller than the depth of cracking holes by 20-30 cm. The microvibration blasting process of the metro double-line large-span tunnel has the following advantages: the blasting mode using the carbon dioxide phase change cracker as the blasting device achieves the tunnel excavation purpose through the quick expansion effect of liquid-state carbon dioxide in the pipe. The process is suitable for vibration reduction blasting construction of urban metro mined tunnels, and is more prominent in effect on the vibration reduction blasting construction aspect of cross super / first-grade risk source, large-span and small-gap tunnels.

Description

technical field [0001] The invention relates to the field of blasting and excavation of urban shallow-buried subway tunnels, in particular to a micro-vibration blasting process for a subway double-track long-span tunnel. Background technique [0002] Tunnel blasting has entered the urban area from the field, and has entered the stage of protective blasting and excavation from the simple pursuit of footage in the past. The vibration hazards caused by tunnel excavation and blasting have attracted more and more attention. First, the excessive excavation of tunnel blasting Vibration may damage the surrounding rock and affect the stability of the tunnel; second, the tunnel will pass through various surface and underground buildings. In order to ensure the safety of urban residents and various buildings and avoid unnecessary claims and disputes, the tunnel Blasting vibration control is even more important. [0003] Liquid carbon dioxide phase change fracturing technology is a bla...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to adopt a new type of physical blasting method in view of the fact that the existing explosive blasting vibration velocity value cannot meet the requirements of construction and environmental protection.

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