Abstract:
In mining, tunneling and other engineering projects, stratified rock formations are commonly encountered. Particularly in blasting operations, the presence of bedding structures significantly influences crack propagation during rock fracturing. Therefore, accurate understanding of the mechanical behavior of stratified rocks and the evolution patterns of plastic zones under blasting loads is crucial for engineering construction. This study employed Brazilian splitting disc tests and acoustic wave measurements to determine the tensile strength of layered slate, summarized acoustic anisotropic characteristics including P−wave velocity, waveform, and frequency spectrum, and explored the intrinsic relationship between P−wave velocity and tensile strength of layered slate. Numerical simulations were conducted to verify and investigate damage patterns in bedded rock masses under pre−splitting blasting at different bedding angles, with particular focus on damage characteristics. Experimental results show that: 1) Bedding angles significantly affect rock tensile strength and P−wave velocity characteristics − tensile strength decreases logarithmically with increasing bedding angle while increasing exponentially with P−wave velocity; 2) Larger acoustic wave incidence angles correspond to higher P−wave velocities, smoother waveforms, and better rock integrity; 3) Bedding angles influence blast−induced damage zones, with larger angles between borehole connecting lines and bedding planes resulting in more extensive damage areas. These findings provide important theoretical guidance for stability control of stratified rock masses and optimization of blasting parameters in engineering practice.