含锚岩体岩爆的能量演化机理和定量化预测研究

This project aims at studying the rockburst of hard rock in deep tunnel anchored with rock bolt. In this project, experimental study of rockburst of anchored rock specimen under multiaxial stress condition will be first conducted using a new true-triaxial rockburst testing system. By analyzing the energy evolution of bolt-rock composite, the interaction between bolt and hard rock and kinetic energy releasing will be described, and the mechanism of rockburst in anchored rock mass will be further revealed. Then, according to the experimental study, discrete element constitutive model, which can reflect the continuous-discontinuous deformation behavior and energy evolution of anchored rock mass, will be established; and the discrete element numerical simulation method for quantitatively predicting rockburst of anchored rock mass will be proposed. Based on the feedback analysis of physical test and field case, the proposed methods will be verified and improved. Finally, energy evolution of rockburst in anchored surrounding rock mass in deep tunnel under complicated stress and boundary conditions will be deduced to further reveal the mechanism of rockburst in anchored rock mass. This project will provide an effective method for reasonable prediction of rockburst in deep tunnel.

本项目针对深埋隧洞锚杆支护条件下硬岩岩爆地质灾害机理不清和预测困难的问题，采用新型真三轴岩爆试验系统，系统开展多轴应力下含锚岩样岩爆过程的试验研究，通过分析岩爆孕育过程中锚杆与硬岩复合体的能量演化特征，阐释了锚杆与硬岩的相互作用机制和动能释放规律，揭示含锚岩石的岩爆发生机制，由此建立反映含锚岩体连续-非连续变形行为特征与能量释放特征的离散元本构模型，进而提出含锚岩体岩爆定量化预测的离散元数值模拟方法，在基于室内试验和现场实例反馈分析的基础上，验证和完善提出模型与方法，推演复杂条件下深埋隧洞含锚围岩的岩爆能量演化过程，进一步揭示其机理。为深埋隧洞岩爆地质灾害的合理预测提供有效手段。

本项目针对深埋隧洞锚杆支护条件下硬岩岩爆地质灾害机理不清和预测困难的问题，系统开展含锚岩体岩爆研究。采用新型真三轴岩爆试验系统，开展多轴应力下含锚岩样岩爆过程的试验研究，获得了含锚岩体岩爆弹射过程和特征，分析了岩爆过程中岩石的力学特性、变形特征、能量变化规律和声发射信号特征，阐释了含锚岩体岩爆过程中的裂纹演化规律和动能释放机理，揭示了锚杆对岩爆的影响。开展含锚岩体岩爆数值模拟研究，提出了含锚岩体岩爆弹射过程离散元数值模拟方法，进一步获得了更复杂应力和锚杆支护条件下的岩爆特征，并揭示不同锚杆间距条件下的岩爆发生模式。采用聚脲、高丙酸、玄武岩纤维布和砂浆作为提高表层抗拉强度的支护材料，开展真三轴岩爆试验研究，发现通过提高岩石表层抗拉强度可有效抑制岩爆的发生或降低岩爆的烈度。此外，还开展了不同初始损伤对岩爆特征影响的试验研究和不同动力扰动方向对岩爆特征影响的试验研究。本课题成果可为深埋隧洞岩爆地质灾害机理认识提供科学依据，并为其合理预测提供有效手段。