摘要
为研究正断层错动作用下矿山法隧道的受力变形机理,以胶州湾第二海底隧道穿越沧口断裂为工程背景,采用自研的大比尺穿越断层隧道结构破坏加载试验装置,针对设置柔性连接变形缝和变形缝间距对隧道结构抗错断效果的影响,开展几何相似比为1∶40的矿山法隧道穿越倾角70°的正断层错动模型试验,对错动试验过程中的隧道变形、应变分布、围岩接触压力和破坏特性等关键指标进行监测,分析获得了正断层错动作用下隧道变形和力学响应规律。研究结果表明:(1)隧道在正断层错动作用下,呈现纵向拉弯+竖向挤压的受荷模式,在下盘邻近断层面处拱顶部位和上盘邻近断层面处仰拱部位出现脱空区;(2)隧道开裂主要以纵向贯通裂缝为主,近断层面处衬砌还出现了部分斜向裂缝和环向裂缝;(3)节段间的连接形式和节段长度不会根本上改变隧道在断层错动作用下的受荷模式和变形模式,但节段间刚度越小,节段长度越小,结构对于地层强制位错的适应性就更好;(4)相比于刚性连接,节段间的柔性连接吸收了大部分地层强制位错,有效降低衬砌节段的荷载和变形,使结构趋于安全。
In order to study the mechanism of force and deformation of mining tunnel under the action of normal fault dislocation,taking the Qingdao No.2 submarine tunnel crossing the F3 Cangkou Fault as a project,the self-developed large-scale tunnel structure failure loading test device through the fault is used to meet the working conditions of different segment connection forms(rigid connection,hinged connection)and different segment widths.carry out a model test of normal fault dislocation with a mining method tunnel crossing dip angle of 70°with a geometric similarity ratio of 1∶40.The key indicators such as tunnel deformation,strain distribution,surrounding rock contact pressure and failure characteristics during the dislocation test were monitored,and the laws of tunnel deformation and mechanical response under the action of normal fault dislocation were analyzed and obtained.The research results show that:(1)Under the action of normal fault dislocation,the tunnel presents a load mode of longitudinal tension and bending+vertical compression.(2)A void appears in the area.The tunnel cracks are mainly longitudinal through cracks,and some oblique cracks and circumferential cracks also appear in the lining near the fault plane.(3)The connection form and segment length between segments will not fundamentally change the load mode and deformation mode of the tunnel under the action of fault dislocation,but the smaller the inter-segment stiffness,the smaller the segment length,and the structural impact on the formation.(4)Compared with the rigid connection,the flexible connection between the segments absorbs most of the forced dislocation of the stratum,effectively reduces the load and deformation of the lining segment,and the structure tends to be safer.
作者
武哲书
孙文昊
陈峻博
王天强
王琦
陈立保
WU Zheshu;SUN Wenhao;CHEN Junbo;WANG Tianqiang;WANG Qi;CHEN Libao(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;National Local Joint Engineering Research Center for Underwater Tunnel Technology,Wuhan 430063,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道标准设计》
北大核心
2024年第1期146-154,共9页
Railway Standard Design
基金
中铁第四勘察设计院集团有限公司科研开发课题(2019K037)
中国博士后科学基金资助项目(2021M693698)。
关键词
海底隧道
矿山法隧道
断层错动
正断层
模型试验
铰接设计
脱空区
subsea tunnel
mining tunnel
fault dislocation
normal fault
model test
articulation design
void area
