高地应力条件下隧洞围岩流变损伤机制数值模拟研究  

Numerical Simulation of the Rheological Damage Mechanism of a Surrounding Rock Mass with High Ground Stress

作　　者：孙金山[1] 左昌群[1] 姜清辉[2] 谢妮[1] 蒋楠[1] 

机构地区：[1]中国地质大学(武汉)工程学院,武汉430074 [2]武汉大学土木建筑工程学院,武汉430072

出　　处：《现代隧道技术》2016年第5期35-42,共8页Modern Tunnelling Technology

基　　金：国家自然科学基金资助项目(41102196;51379194);湖北省自然科学基金资助项目(2012FFB06502)

摘　　要：高地应力条件下深部地下洞室的围岩均具有流变性,可能发生流变损伤甚至断裂,但该过程目前无法直接观测。为此,文章以锦屏二级水电站引水隧洞大理岩为研究对象,在三轴强度实验和流变损伤实验数据基础上,通过在颗粒流数值模拟方法中引入应力腐蚀模型,建立了能反映岩样短期和长期强度特征的数值模型。数值实验表明,不同应力状态下大理岩的微裂纹开裂类型、开裂方向、分布特征和扩展过程等呈现不同的规律,且随着围压的提高流变损伤效应将逐渐减弱。在岩石试样的损伤流变特征分析基础上,构建了锦屏二级电站引水隧洞的有限元数值模型,阐明了隧洞开挖过程中围岩的损伤演化机制。With high ground stress, a tunnel＇s surrounding rock reveals rheological behaviors and damage--it may even break up. However, the evolution process of internal damage has not yet been directly observed. Taking the marble mass around the JINPINC Ⅱ Hydropower Station diversion tunnel as a research subject, and based on tri-ax- ial strength test results and data from the analysis of a rheological damage experiment, a numerical model is estab- lished to reflect the short-term and long-term strength features of the marble specimen by introducing the parallel- bonded stress corrosion model （PSC） into the particle flow numerical simulation method. The tri-axial compressive creep numerical experiments show that the cracking type, cracking direction, distribution characteristics and exten- sion process of the micro-cracks in the marble specimen present various patterns under different stress states, and the rheological damage effect of the marble will gradually decrease with an increase of the confined stress. Based on an analysis of the theological damage characteristics of the marble specimen, a finite element （FEM） numerical mod- el of the Jinping Ⅱ Hydropower station diversion tunnel was built and the theological damage evolution mechanism of the surrounding rock during tunnel excavation was elucidated.

关 键 词：隧洞 围岩 流变损伤 颗粒流 数值模拟 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]