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针对深埋圆形隧洞,计算2种不同开挖方式下围岩的开裂范围及裂纹扩展长度,分析围岩开裂过程中的能量耗散规律,并采用可释放弹性应变能指标,判定岩爆发生的等级和位置。研究结果表明:与隧道掘进机开挖引起的准静态卸荷相比,钻爆法开挖诱发的瞬态卸荷加剧了围岩开裂效应,导致开裂过程中能量耗散值增大,使得开挖卸荷后围岩可释放弹性应变能减小,发生时滞型岩爆的风险降低;但由于受瞬态卸荷过程中能量高聚集特性的影响,可释放弹性应变能提高,钻爆法开挖发生即时型岩爆的风险增大。
According to the deep circular tunnel, the cracking range and crack propagation length of surrounding rock under two different excavation methods were calculated. The energy dissipation law during the cracking process of surrounding rock was analyzed. The rock burst was determined by using the releasable elastic strain energy index Rank and position. The results show that compared with the quasi-static unloading caused by excavation of tunnel boring machine, the transient unloading induced by the drilling and blasting method aggravates the cracking effect of surrounding rock and leads to the increase of energy dissipation value during cracking, After excavation and unloading, the elastic strain energy of surrounding rocks can be reduced and the risk of delayed rock burst decreases. However, the elastic strain energy can be increased due to the high energy accumulation during transient unloading, There is an increased risk of immediate rockburst during excavation.