Numerical Simulation Study on Damage Law of Surrounding Rock in Blasting Excavation of Ultra-deep Shaft

This study aims to analyze the damage evolution law of the surrounding rock mass in an ultra-deep shaft under blasting load. To achieve this, a numerical simulation method is adopted based on the blasting construction practice of Xiling Auxiliary Shaft in Sanshandao Gold Mine. The simulation utilizes a restart technology based on ANSYS/LS-DYNA and adopts the equivalent explosion load method according to the blasting design scheme. The surrounding rock mass damage of the ultra-deep shaft is calculated under four different ground stresses(15 MPa, 30 MPa, 45 MPa, and 60 MPa) and four different side pressure coefficients(1.0, 1.25, 1.5, and 2.0). Furthermore, this study analyzes the damage effect on the shaft's surrounding rock mass and investigates how ground stress and side pressure coefficient influence the extent of damage to the surrounding rock. The numerical results demonstrate that as ground stress increases from 15 MPa to 60 MPa, there is a significant inhibition in the damage area with a decrease in radius from 5.75 m to 3.4 m. Additionally, it is observed that with an increase in lateral pressure coefficient, there is anisotropy in terms of blasting damage area distribution where greater ground stress leads to concentrated damage areas.