深埋地下洞室岩爆发生的岩体条件数值分析  

Numerical Analysis of the Rock Mass Conditions for Rock Burst Occurrences in Deep Underground Caverns

作　　者：赵红亮[1,2] 周又和[1,2] 

机构地区：[1]兰州大学土木工程与力学学院,兰州730000 [2]西部灾害与环境力学教育部重点实验室.兰州730000

出　　处：《现代隧道技术》2015年第5期32-39,共8页Modern Tunnelling Technology

基　　金：国家自然科学基金项目(No.41272326);高等学校博士学科点专项科研基金(No.20100211120030);兰州大学中央高校基本科研业务费专项资金(lzujbky-2015-174);兰州大学博士后基金(No.870870)

摘　　要：岩体的结构与性质是岩爆发生与否的物质基础,也是岩爆发生的主要内因。深埋地下隧洞中的岩爆灾害主要产生于坚硬的弹脆性围岩中。强度高、原生节理裂隙少、岩体完整性好等岩体条件非常有利于岩石积累弹性应变能。为定量分析岩体条件对围岩潜在岩爆可能性的影响,文章针对锦屏Ⅱ级水电站深埋地下隧洞工程实例,采用岩石单轴抗压强度表征围岩的强度,采用地质强度指标GSI刻划岩体的完整性程度;保持围岩应力水平条件不变,选取不同的岩石单轴抗压强度和不同的地质强度指标,通过数值模拟方法分别计算围岩应力集中部位在开挖过程中的应力变化特征及最终应力状态。数值计算结果揭示,深埋地下隧洞的强岩爆主要倾向于出现在强度高、岩石单轴抗压强度达到120 MPa以上、岩体完整性好、地质强度指标GSI值在55以上的Ⅱ级围岩。Structural properties of rock masses are the material basis and main factors for rock burst occurrences. In deep tunnels, most rock bursts occur in hard surrounding rock characterized by elasto-friability. Sound condi- tions for rock masses, such as high strength, fewer original joint fissures and good integrality, are conducive to e- lastic strain energy accumulation in rock masses. In order to quantitatively analyze the irLfluence of rock mass conditions on the possibility of rock bursts in surrounding rocks, and using the deep tunnel of the Jinping II hy- dropower station as an example, the uniaxial compressive strength of a rock mass is selected to represent the strength of the surrounding rock and the geological strength index （GS1） is selected to represent the integrality of the surrounding rock mass. With an unchanged surrounding rock geo-stress, different uniaxial compressive strengths and various geological strength indexes, the stress behaviors and ultimate stress state at the stress con- centration zones during tunnel construction are calculated by a numerical simulation. The numerical calculation results indicate that intense rock bursts mostly occur in surrounding rock masses of Class II characterized by high strength （uniaxial compressive strength〉 120 MPa） and good integrality （geological

关 键 词：深埋隧洞 岩爆 岩石强度 岩体完整性 形成条件 数值模拟 

分 类 号：U453.2[建筑科学—桥梁与隧道工程]