强震作用下岩体破坏深度及对隧道围岩压力的影响  

Failure Depth of Rock Mass under Strong Earthquake and Its Influence on Surrounding Rock Pressure of Tunnel

作　　者：赵玉报[1] 陈寿根[1] 周泽林[1] 涂鹏[1] 

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031

出　　处：《防灾减灾工程学报》2015年第6期833-838,共6页Journal of Disaster Prevention and Mitigation Engineering

基　　金：中央高校基本科研业务费专项资金项目(SWJTU11ZT33);教育部创新团队发展计划项目(IRT0955)资助

摘　　要：5·12地震后,震区岩体受到了不同程度的破坏,产生了大量松动岩体,对新建隧道围岩压力产生了较大的影响。为研究地震力对岩体的破坏深度以及震裂松散岩体对隧道围岩压力的影响,基于波动理论和摩尔库伦准则,分析了地震力对岩体破坏的极限深度,推导出解析公式,并通过波速测试结果对震裂松散岩体的松动深度进行了探讨,最后就松散岩体对隧道围岩压力的影响进行了理论分析。研究结果表明:1地震力对岩体破坏有一极限深度,隧道埋深越浅,岩体越易产生破坏;2岩体破坏极限深度与岩体力学参数及地震水平震动速度有关,汶川地震震区岩体的极限破坏深度最大达112m;3汶川地震震后,不同松动程度的岩体分别占破坏岩体深度的20%、30%和50%;4震裂松散岩体对围岩竖向松动压力有较大影响,主要原因为震裂松散体的存在,改变了震后岩体的深浅埋分界深度,在震后松散岩体中修建隧道应按等效埋深来确定深浅埋分界深度。After″5.12″earthquake,the rock mass in seismic zone was subjected to different degrees of damage to form a lot of loose rock mass.Meanwhile surrounding rock pressure of tunnel was greatly affected.Based on wave theory and Mohr-coulomb failure criterion,the limiting failure depth of rock mass was explored.Using the derived analytical formulas,the failure depth of rock masses was calculated.Finally,the division of loose depth was analyzed through in-situ wave velocity tests and comparative analysis of different results.The results show that：（1）There is a limiting failure depth of rock mass,the more shallow of buried depth of tunnel,the more vulnerable to damage.（2）The limiting failure depth is closely related to mechanical parameters of rock mass and seismic horizontal velocity,and the maximal failure depth is 112 min seismic area of Wenchuan M8.0Earthquake.（3）The percentage of different degree of looseness is20%,30% and 50%.（4）Loose rock mass has great influence on the vertical loose pressure of surrounding rock.

关 键 词：岩体破坏 地震力作用 松动岩体 围岩压力 

分 类 号：U451[建筑科学—桥梁与隧道工程]