College of Science, Qingdao University of Technology
College of Geosciences and Engineering, North China University ofWater Resources and Electric Power
State Key Laboratory of Geotechnical Mechanics and Engineering, Institute of Rockand Soil Mechanics, Chinese Academy of Sciences
College of Civil Engineering, Qingdao University of Technology

深部硬岩工程开挖过程中,洞壁围岩常常因结构面的存在发生岩爆地质灾害,造成人员伤亡和设备损毁等事故。通过采用有限元、离散元相耦合的 GDEM 数值仿真技术研究了边墙含竖向结构面的数目和尺度对深部硬岩直墙拱形隧道在开挖卸荷作用下,围岩裂化扩展行为、应力、位移、片状块体速度等力学运动特征的影响,以此揭示围岩板裂化、结构面型岩爆之间的演化机制。结果表明:开挖卸荷后,含多结构面数目隧道的破坏模式及强度与结构面控制效应有关 (洞壁径向距离 1.5 m 范围内结构面的作用影响大),且结构面具有主导控制岩爆爆坑边界的作用,而多节理岩板裂化的演化机制为切应力不均匀分布,致使岩板实际承载偏心受压,产生二阶弯矩效应,诱发强烈的张拉板裂型岩爆,呈现出“平底锅状”C 字型的爆坑;围岩破坏强度与岩板的尺度效应有关且结构面具有削弱应力向径向深部围岩转移的阻碍作用,从而不断加剧结构面围岩之间卸荷应力波的相互反射,增大了岩板内的应力积聚与能量积累。且尺度不同,其切应力调整分布演化差异大,大尺度高柔度的三节理岩板,其端部载荷强度高、岩板的屈曲效应较明显,导致径向内部岩板易屈曲失稳而引发边墙围岩板端部的剪断失稳破坏,诱发强烈岩爆。而中小尺度的三节理岩板,柔度小不易失稳,且载荷作用小,裂纹易沿结构面尖端扩展贯通破坏,呈现为脱落型静态脆性破坏,形成小 V 型破坏断口。为深部硬岩地下岩体工程设计和稳定性分析提供了理论支撑,也加深了对结构面诱发岩爆灾害的了解。

In the process of deep underground rock excavation, the surrounding rock of cave wall often causes some rockburst geological disasters due to the weakening of structural plane. In order to reveal the influence of the existence ofstructural plane on the rockburst induction mechanism, in this paper, adopting the finite element and discrete elementcoupled GDEM numerical simulation technology, the influences of the number and scale of vertical structural planes onthe mechanical characteristics of rock cracking propagation, stress, displacement and slab velocity of deep hard rockstraight arch tunnel under excavation and unloading are studied, and the evolutionary mechanism between wall crackingand structural plane rockburst is revealed. Results indicate that the failure modes and intensity for the surrounding rockwith multiple structural planes are associated with the controlling effect of the structural plane, especially within 1.5 maway from the tunnel side, and the weak plane can act as the boundary of the rockburst cater. The uneven distribution ofthe tangential stress and the eccentric compression of the rock plates separated by the weak plane will induce intense slabbing rockburst. The size of the structural plane will also affect the intensity of the surrounding rock failure, and the stresstransfer to the deep rockmass will be impeded. Three-jointed rock slab with large scale and high flexibility has high endload strength and obvious buckling effect of rock slab, which leads to radial internal rock slab buckling and triggeringshear instability failure at the end of side wall surrounding rock slab and strong rock burst. However, with the small andmedium scale three-jointed slab, the flexibility of the rock plate is small and the rock plate is stable, leading to the quasistatic brittle failure of the surrounding rock, and forming a small V-type destructive fracture port. This paper providessome theoretical support for the design of safety and stability of underground rock mass engineering, and also deepens theunderstanding of rockburst disaster phenomenon.

国家自然科学基金资助项目(51879135);山东省泰山学者青年专家资助项目、山东省青创团队科技支持计划资助项目(2019KJG002)

周雄,孟凡震,岳祝凤,等. 基于 GDEM 的结构面型岩爆孕育演化机制[J]. 煤炭学报,2023,48(5):2207−2223.

ZHOU Xiong,MENG Fanzhen,YUE Zhufeng,et al. Evolution and mechanism of rockburst induced by struc-tural plane based on gdem[J]. Journal of China Coal Society,2023,48(5):2207−2223.