Abstract: The aim of this study is to investigate the sorrounding rock stability of soft rock tunnel under high geostress. The vibration velocity of rock mass near blasting at different distances from the blast face was analyzed by using numerical simulation software ANSYS/LSDYNA and field monitoring data. Meanwhile, the blasting damage effect on surrounding rock under different number of blastings was studied. Results demonstrated: (1) In the area near blasting, the peak vibration velocity of particles in the tunnel was larger in vertical direction than that in radial direction and axial direction sequently. The vibration velocity in vertical direction in the bottom and sidewall of tunnel were larger than that in tunnel crest, and far more greater than those in arch shoulder and arch foot. (2) The peak joint vibration velocity was found in the unexcavated area of the tunnel, and the vibration velocity of particles in the unexcavated area of the tunnel decayed more slowly. (3) With the increase in the number of blasting, the acoustic velocity at different depths of the surrounding rock showed a trend of gradual decay; but the blasting vibration had a limited damage to the surrounding rock in terms of damage range.

Key words: surrounding rock safety, blast vibration, numerical simulation, acoustic velocity, damage effect