| Summary: | When the two-lane tunnel in the mountainous area is excavated by the drilling and blasting method,the construction of the rear tunnel will inevitably produce unfavorable vibration effects,thus affecting the safety and stability of the preceding tunnel.Therefore,the vibration test and analysis of adjacent tunnel blasting is of great significance for the safe construction of double-line tunnels.In this paper,based on the two-line tunnel project of the Xingyan Expressway,the following conclusions ard drawn by conducting on-site vibration tests on its tunnel axis:①The relationship between the three directions of vibration intensity in the adjacent tunnel test area is:vertical direction > horizontal radial > horizontal axis,and the size relationship is relatively fixed.As the blasting distance increases,the difference in vibration intensity between the three directions gradually decreases.②The clamping of cutting hole is the biggest and the blasting vibration intensity is the biggest.③The blasting vibration waveforms of different types of blastholes have a phenomenon of rapidly increasing from the initial value to the peak value of the vibration velocity,and the attenuation process is relatively slow,and this phenomenon is particularly noticeable in the blasting of the cut hole.④In the double-line tunnel blasting construction,reducing the maximum single-stage dose of the cut hole,increasing the detonator section,decomposing the tunnel excavation section,and controlling the blasting scale are effective ways to reduce the blasting vibration.
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