多次爆破作用下巷道围岩累积损伤演化与破裂特征

为研究多次爆破作用下巷道围岩累积损伤演化与破裂特征，建立考虑扰动效应的时效损伤本构模型.二次开发扰动效应的时效损伤本构模型，并建立数值模型验证了开发程序的正确性.将本构模型应用于深部巷道多次爆破开挖的数值模拟中，研究围岩累积损伤演化特征与破裂特征.结果表明：地应力对巷道围岩爆破累积损伤有抑制作用，地应力越大，抑制作用越明显；围岩的损伤程度随爆破扰动次数的增加呈现非线性累积特征，围岩损伤范围也随着爆破荷载作用次数的增加而扩大；巷道围岩近区在多次爆破荷载作用下损伤严重，巷道围岩表层出现破裂现象.

Cumulative Damage Evolution and Fracture Characteristics of Tunnel Surrounding Rock Under Multiple Blasting Action

In order to study the cumulative damage evolution and fracture characteristics of tunnel surrounding rock under multiple blasting action, a time-dependent damage constitutive model considering disturbance effect was established. The time-dependent damage constitutive model based on the disturbance effect was redeveloped, and the numerical model was established to verify the correctness of the development program. The constitutive model was applied to the numerical simulation of multiple blasting excavation of deep tunnel, and the cumulative damage evolution and fracture characteristics of surrounding rock were studied. The results show that the in-situ stress restrains the cumulative damage of tunnel surrounding rock of blasting, and the greater in-situ stress results in the more obvious restraining effect. The damage degree of surrounding rock presents nonlinear cumulative characteristics with the increase of blasting disturbance times, and the damage range of surrounding rock also expands with the increase of blasting load times. The surrounding rock near the tunnel is seriously damaged by multiple blasting loads, and the surface of tunnel surrounding rock is broken.