关键词: 球状缺陷岩石　, PFC^2D　, 破坏特征　, 力学性能　, 损伤分析

Abstract: Spherical defects are among the major defects in rock masses,and their size and spatial distribution signifi cantly affect rock mass stability.To investigate the influence of spherical defects on the mechanical properties,fracture evolu tion process,and failure characteristics of rocks,standard specimen models containing a single spherical defect of varying sizes and at different positions were constructed using PFC2D software,and uniaxial compression simulations were performed.The axi al compression results of intact specimens (without holes) were compared with those of single-hole specimens under different conditions.The results indicate that the position of the hole has a significant influence on the peak strength,failure strain,and crack propagation path of the single-hole specimen.When the hole diameter is 3 mm,the peak stress of specimens with holes located near the longitudinal axis is higher than that of specimens with holes deviating from the axis at the same horizontal lev el.The specimen reaches the maximum peak stress when the hole is located at the center.As the hole diameter increases from 1 mm to 5 mm,the peak strength of the specimen generally decreases.The hole boundary and loading ends are the main regions for crack initiation and propagation.Specimens with different hole positions exhibit different failure modes,including shear fail ure,tensile failure,and combined shear-tensile failure.When the hole is located near the axis,crack initiation occurs relatively later,the final number of cracks is larger,and the failure degree is more pronounced.

Key words: spherical defective rocks,PFC2D,destruction characteristics,mechanical properties,damage analysis