Recently, the application of deep hole presplit blasting (DHPB) in underground-engineering excavation has increased, but the research on deformation characteristics and failure mechanism of DHPB is relatively less, and lack of relevant numerical simulation verification. Owing to the above situation, the deformation characteristics and failure mechanism of DHPB are obtained through numerical simulation and model testing of samples under horizontal compressive stress, compressive vertical stress and no compressive stress, and the shape analysis of presplit cracks after presplit blasting. This work demonstrates when presplit blasting is performed in underground engineering, the angle between the connection orientations of the blasthole and the compressive stress orientation should be avoided at 90° as far as possible. When the deep confining pressure is not uniform, the orientation of the minimum principal stress should be at an angle of 90° to the orientation of the blasthole connecting line as far as possible. Furthermore, the orientation of the maximum principal stress should be consistent with the orientation of the blasthole connecting line as far as possible.

近年来，深孔预裂爆破（DHPB）在地下工程开挖中的应用有所增加，但对深孔预裂爆破变形特征及破坏机理的研究相对较少，缺乏相关的数值模拟验证。针对上述情况，通过对试样在水平压应力、竖向压应力和无压应力下的数值模拟和模型试验，以及预裂爆破后的预裂裂纹形状分析，得到了DHPB的变形特征和破坏机制。本文论证了在地下工程中进行预裂爆破时，应尽量避免爆破孔连接方向与压应力方向的夹角为90°。当深部围压不均匀时，最小主应力方向应尽量与炮孔连线方向成90°角。此外，最大主应力方向应尽量与爆破孔连线方向一致。