Blast Vibration Response of Tunnel Influenced by Confining Pressure and Surrounding Rock Type

Abstract

Based on the finite element model of the tunnel, dynamic response of tunnel is studied influenced by different confining pressure and different surrounding rock types under of blasting vibration under blast vibration load. The results show that when the confining pressure increases, the maximum horizontal and vertical vibration velocity, stress and displacement increase, and the horizontal vibration amplitudes are less than the vertical vibration amplitudes. With the decreasing of the rock type, the vertical vibration velocity peak value increases, and vertical direction vibration velocity is more sensitive for the rock stress state. With the increase of depth of surrounding rock, the confining pressure increases, and the vertical velocity response signal of surrounding rock increases, and the response signal is more sensitive to the change of stress of surrounding rock compared with the horizontal vibration velocity peak.