深部隧道爆破开挖诱发围岩损伤与扰动效应数值分析

现阶段，不同地应力条件下深部岩体受爆破作用的损伤破坏分析尚显不足。为了研究深部隧道围岩爆破开挖损伤破坏规律，基于有限元软件ANSYS/LS-DYNA，采用Riedel-Hiermaier-Thoma本构模型，对不同地应力环境下隧道爆破效果影响因素、围岩扰动范围等问题进行数值分析。结果表明：双向等压隧道的断面损伤程度与地应力水平呈负相关；随着地应力上升，地应力对隧道底板的损伤抑制作用渐为明显；隧道腰部围岩受爆破扰动较为突出，其应力和振动速度均随侧压力系数增大而大幅升高，且振动速度增幅超过40%，明显高于顶部围岩；在垂直应力20 MPa条件下，腰部测点应力、振动速度幅值随侧压力系数增加而增大的趋势较缓；当垂直应力升高至60 MPa时，侧压力系数对围岩扰动的影响较大。相关结论对实际工程施工具有重要指导意义，同时对隧道围岩稳定性监测与支护参数优化具有一定参考价值。

Numerical analysis of damage and disturbance effect of surrounding rocks induced by deep tunnel blast excavation

The damage and failure analysis of deep rock mass subjected to blasting under different crustal stress conditions is still insufficient at present. To explore the damage and failure law of surrounding rocks of deep tunnel during blasting excavation, based on the finite element software ANSYS/LS-DYNA, the Riedel-Hiermaier-Thoma constitutive model is adopted to carry out numerical analysis on the influencing factors of tunnel blasting effect and surrounding rock disturbance range under different crustal stress environments. The results show that the cross-section damage degree of the bidirectional isobaric tunnel is negatively correlated with the geostress level. With the increasing geostress, the damage of the tunnel floor is more significantly suppressed by geostress. The surrounding rocks at the waist of the tunnel is prominently disturbed by blasting, and its stress and vibration velocity increase significantly with the increasing lateral pressure coefficient, and the vibration velocity increases by more than 40%, much higher than that of the top surrounding rocks. Under the vertical stress of 20 MPa, the amplitudes of stress and vibration velocity at the waist measuring point increase slowly with the increasing lateral pressure coefficient. When the vertical stress rises to 60 MPa, the lateral pressure coefficient has a great influence on the disturbance of surrounding rocks. The relevant conclusions obtained are of important guiding significance for actual engineering construction, and are of certain reference value for monitoring the stability of tunnel surrounding rocks and optimizing support parameters.