【摘要】 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。更多还原

【Abstract】 For a case of circular deep-buried tunnel,cracking extent and extending length in surrounding rock masses under blasting and TBM methods are calculated,and energy dissipation during the cracking of surrounding rock masses is analyzed. In addition,based on the index of releasable strain energy,rank and position of rockbursts are determined. Results show that,compared with the quasi-static unloading of in-situ stress caused by tunnel boring machine excavation,the transient release of in-situ stress induced by blasting excavation aggravates the cracking in surrounding rock masses,and enlarges the energy dissipation during this process. This minifies the releasable strain energy after the excavation unloading and brings down the risk of time delayed rockbursts;while during the transient release of in-situ stress,influenced by high aggregation of energy,the releasable strain energy is enhanced,and the risk of immediate rockbursts is enlarged for the blasting excavation.更多还原