软弱破碎深埋隧道围岩渐进性破坏试验研究  

EXPERIMENTAL RESEARCH OF PROGRESSIVE DAMAGE OF SURROUNDING ROCK FOR SOFT FRACTURED DEEP TUNNEL

作　　者：李英杰[1,2] 张顶立[1] 宋义敏[3] 房倩[1] 陈峰宾[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]辽宁工程技术大学力学与工程学院,辽宁阜新123000 [3]中国矿业大学力学与建筑工程学院,北京100083

出　　处：《岩石力学与工程学报》2012年第6期1138-1147,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：铁道部重大项目(2009G005–B);国家重点基础研究发展计划(973)项目(2010CB732100)

摘　　要：利用相似模型试验对深埋隧道围岩渐进性破坏特征进行研究。相似模型针对大断面、软弱破碎、深埋铁路隧道围岩。模型材料选择重晶石、石英砂、凡士林按一定比例配制而成。采用自主研发的平面应变模型试验台、气囊加载装置和千斤顶加载装置作为加载系统。利用白光散斑方法监测系统监测加载过程中隧道围岩表面应变场演化规律,利用压力盒监测加载过程中围岩压力的变化。试验结果分析表明:(1)隧道拱腰处在逐渐加载过程中形成剪切的V型楔形体,拱顶没有破坏但产生较大拉伸变形。拱腰处的剪切破坏范围逐渐扩大到拱顶,最终在拱顶上方形成剪切的拱形裂纹。(2)拱腰近洞壁一定范围内径向压力先增加后减小说明该处存在松动区,围岩深处存在切向压力升高区对应压力拱拱体;拱顶上方近洞壁存在径向压力减小区域对应松动区,围岩深处最大主应力方向发生偏转,该处对应压力拱位置;深埋隧道围岩受力分区特征为松动区–压力拱拱体–原岩应力区。The characteristics of rock progressive damage of deep tunnel are studied by using similarity model test.The similarity model is based on big section,soft fractured,deep railway tunnel.The barite,quartz sand and petroleum jelly are mixed in a fixed proportion as similar material.The self-developed test rig of plane strain model is adopted.In this device,the gas bag loading and lifting loading are used as loading system.The evolution of the strain field on rock surface during loading is monitored using the white light digital speckle correlation method（DSCM）.The rock pressure change is monitored using pressure cells.The experimental results show that：（1） The shear V-shaped wedge form gradually deep from the tunnel arch sides and it has no damage in the crown of the arch but greater tensile deformation.Shear failure at the arch sides gradually expand to the crown of the arch and the shear arch crack forms over the crown of the arch.（2） Radial compression increases first and then decrease within a certain range of arch sides close to the tunnel wall,where is loosen zone.Tangential stress increased deep in the arch sides,and it is as the main resistance to pressure corresponding the pressure arch body;Radial compression decrease within certain range of the crown of the arch,where is loosen zone.The maximum principal stress direction changes far from the crown of the arch,and which is corresponding the pressure arch body.The surrounding rock show loosen zone-the pressure arch body-original stress zone after loading.

关 键 词：隧道工程 深埋隧道 渐进性破坏 机制 压力拱 数字散斑方法 

分 类 号：U45[建筑科学—桥梁与隧道工程]