【摘要】 针对双江口水电站大型地下厂房，采用数值仿真探究了高地应力条件下开挖卸荷对围岩变形与破坏的影响。通过微震监测技术，对厂房爆破开挖过程微震事件的时空活动特征进行了监测与分析，并与数值模拟结果进行了对比。结果表明，地下厂房开挖初期，拱顶围岩易出现拉应力集中，拱肩及拱脚处压应力集中显著，需要重点关注拱顶、拱肩及拱脚部位。微震事件的发生与现场施工活动密切相关，随着开挖卸荷强度增大，围岩应力调整趋于剧烈，微震事件发生的频率及强度显著上升。微震事件空间分布特征受不良结构面影响显著，在高应力卸荷作用下，构造面周边微震事件聚集现象明显，易形成局部损伤破坏区。更多还原

【Abstract】 Based on the large underground powerhouse of Shuangjiangkou Hydropower Station, a numerical simulation was carried out to investigate the impact of excavation unloading on surrounding rock deformation and damage under high ground stress conditions.Through microseismic monitoring technology, the spatiotemporal evolution characteristics of microseismic events during the blasting excavation process were monitored and analyzed, and a study was conducted in conjunction with the numerical simulation results.The results show that, at the initial stage of the underground powerhouse excavation, the arch crown surrounding rock is prone to tensile stress concentration, and significant compressive stress concentration occurs at the arch shoulders and arch feet.The special attention is needed on the arch crown, arch shoulders, and arch feet.The occurrence of microseismic events is closely related to on-site construction activities.As the intensity of excavation unloading increases, the adjustment of surrounding rock stress becomes more intense, and the frequency and intensity of microseismic events significantly increase.The spatial distribution of microseismic events is significantly affected by adverse structural planes.Under the action of high-stress unloading, the microseismic events around the structural plane are obviously concentrated, and prone to form local damage and destruction zones.更多还原