深部硬岩的力学特性与支护要求

Mechanical Properties and Support Requirements of Hard Rock in Deep Engineering

以锦屏二级水电站深埋引水隧洞中白山组大理岩为典型,开展了常规三轴与真三轴加载试验、损伤控制加卸载试验,基于试验成果的综合分析,揭示了大理岩弹性变形特性、变形与强度的围压效应、脆延转换破坏特征及机制,并将其应用于指导深埋隧洞围岩支护设计,提出了快速提高围压、改变围岩破裂方式的深部硬岩工程支护设计理念,确立了及时进行表面支护、加固围岩、提高结构面抗剪强度及支护系统整体抗冲击能力的支护设计原则,研究结果对深入认识深部工程围岩的高应力破坏机制、针对性地制定岩体破坏防治策略具有重要指导意义。

The conventional and true triaxial loading tests and the damage control with loading-unloading tests were carried out for the marble of the Baishan formation in the Jinping II hydropower station. The results unveilthe elastic characteristics,the confining pressure effect of deformation and strength,the failure characteristicsand mechanism in the brittle-ductile transition of the marble,which helps to guide the support design ofsurrounding rock mass in deep tunnels. The support design concept including improving confining pressure assoon as possible and changing the cracking way of rock mass was proposed. Meanwhile,the support designprinciples including timely surface support,reinforcement of surrounding rock mass,improvement of the shearresistance of the structure planes and the overall impact resistance of the support system were presented. Thisstudy provides important guides for the profound understanding of the high stress failure mechanism and the specific solutions to the failure of the surrounding rock mass in deep engineering.