为研究结构面倾角对深埋隧洞岩爆破坏机制的影响, 选取云南某深部矿山的深部矿井灰岩, 预制成含圆孔的立方体试件(100 mm×100 mm×100 mm, 圆孔=50 mm)模拟地下隧洞结构, 利用预制裂隙模拟结构面, 使用高速摄像系统监测不同试件的岩爆孕育演化过程; 利用PFC软件模拟了不同试样的压缩试验, 分析了含不同倾角结构面隧洞的破坏模式和应力–应变特征。研究结果表明: 结构面使围岩内部应力和能量的传播路径发生了改变, 其附近岩体应力集中, 使岩爆提前发生; 结构面显著增强了岩爆烈度, 灰岩中的围岩破坏形式主要表现为剧烈的剪切弹射。随结构面倾角的改变, 围岩破坏程度发生变化; 当结构面倾角为0°和180°时, 围岩破坏程度较弱; 当结构面倾角为90°时, 隧洞围岩破坏最为严重; 结构面倾角对圆形隧洞应力特征影响显著, 根据试验数据构建了结构面倾角与圆形隧洞应力特征(_max/_c)间的理论关系式。研究结果可为地下岩体工程灾害防治与岩爆预测等提供参考。

To investigate the influence of structural plane dip angles on the rockburst mechanism in deep-buried tunnels, limestone samples from a deep mine in Yunnan, China, were prepared into cubic specimens (100 mm×100 mm×100 mm) with a central hole (=50 mm) to simulate underground tunnel. Prefabricated fissures were introduced in limestone samples to replicate structural planes. A high-speed camera system was employed to monitor the initiation and evolution processes of rockburst in specimens with varying inclination angles of structural plane. Additionally, compression tests on these specimens were simulated using PFC software to analyze the failure modes and stress-strain characteristics of tunnel structures under different inclination angles of structural plane. The results show that structural planes alter the transfer paths of stress and energy within the surrounding rock, leading to localized stress concentration in adjacent rock mass and triggering premature rockburst. Structural planes significantly amplify rockburst intensity, with intense shear ejection as the dominant failure mode of limestone surrounding rock. The degree of surrounding rock damage varies with the inclination angle of structural planes. Minimal damage occurs with the inclination angles of 0° and 180°, while the most severe damage is observed at an inclination angle of 90°. Furthermore, the inclination angle of structural planes exerts a pronounced influence on the stress characteristics of circular tunnels. Based on experimental data, the stress characteristic parameter of circular tunnels (_max/_c) was quantified in terms of inclination angle of structural plane.