Propagation and failure characteristics of stress wave of full anchor solid under dynamic load

Abstract

Dynamic stresses severely disrupt and distort deep shaft roadways. It is critical to understand the stress wave propagation and damage characteristics of anchor support body under dynamic loads. On the basis of the SHPB test equipment, the stress wave propagation law of solid anchor specimens under varied impact air pressures was investigated, and the laminar cracking strength of anchor solids was determined using the one-dimensional stress wave theory. The stress wave propagation of anchor solid specimens exposed to dynamic load impact was simulated using the ABAQUS numerical simulation software. The strain and time sequence features of the anchor solid along the axial direction at various cross-sections were examined. The findings demonstrate that ① as the impact air pressure rises, the spatial attenuation amplitude and attenuation coefficient steadily increase. Moreover, there is a discernible strain reinforcing effect as the laminar fracture strength of the solid anchor specimen is strongly associated with the impact air pressure. ② The peak strain of the surrounding rock at the tail and middle of the anchor is somewhat greater than the peak strain of the surrounding rock, however the peak strain of the surrounding rock quickly increases at the anchor end due to the net tensile stress. ③ The dynamic responses of anchor rod, anchor agent and wave are time-ordered, with the anchor rock and anchor agent being the first to receive the compressive stress wave and the anchor rod being the first to receive the compressive stress wave. The anchor rod generates a tensile stress wave that follows behind the anchor rock, protecting the anchor specimen from synergistic damage. ④ The peak strain of the anchor and rock at the tail of the anchor is somewhat greater than the peak strain of the surrounding rock. Anchor rod, anchor agent and wave have a strain start interval of 0. And the peak strain of the anchor increases as the stress wave is transferred to the middle and end of the anchorage, and the larger the impact air anchor is, the anchor end is severely damaged, and the non-synergistic effect gradually increases.

Keywords

• dynamic load action
• anchor solid
• stress wave propagation law
• layer cracking strength
• strain-time sequence features