考虑劣化效应与注浆加固的隧道围岩黏弹塑性大变形分析  

Large viscoelastic-plastic deformation analysis of tunnel surrounding rock considering deterioration effect and grouting reinforcement

作　　者：张帅 王俊杰 ZHANG Shuai;WANG Junjie(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Materials Science and Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学材料科学与工程学院,重庆400074

出　　处：《铁道科学与工程学报》2023年第12期4690-4700,共11页Journal of Railway Science and Engineering

基　　金：重庆市建设科技计划项目(城科字2022第8-12号);重庆市自然科学基金创新发展联合基金(市教委)A类项目(2022NSCQ-LZX0133)。

摘　　要：高地应力软岩中开挖隧道时,由于应力释放、流变效应等原因容易引发围岩大变形、支护结构侵限等工程问题,通过分析围岩大变形的变形机理,提出“加长锚杆+喷射混凝土(含钢拱架)+环向(滞后)注浆”的支护形式。其中,加长锚杆可以有效改善围岩自身条件并使围岩挤压变形逐步释放,环向(滞后)注浆可以提高围岩参数并控制围岩松动变形。通过建立的深埋圆形隧道围岩力学模型,借助Mohr-Coulomb屈服准则与Maxwell黏性体,得到考虑围岩强度参数与刚度参数(弹性模量E)同时劣化的深埋圆形隧道围岩黏弹塑性解析式,借助FLAC-3D有限差分软件进行验证后,对相关影响因素进行分析。研究结果表明:计算高地应力软岩隧道围岩变形量时,适当考虑强度参数与刚度参数同时劣化后得到的围岩变形值更符合实际。采用“加长锚杆+喷射混凝土(含钢拱架)+环向(滞后)注浆”的支护形式对围岩大变形有一定的控制效果,注浆后的围岩总变形量与未注浆时相比下降了40%,注浆后的围岩变形量仅占总变形量的20%。残余黏聚力c"、残余内摩擦角φ"、残余弹性模量E"取值越小时,围岩变形量越大,其中残余弹性模量E"的取值对围岩变形影响最大。缩小锚杆间距、增加初期支护厚度、增大注浆区围岩参数均能降低围岩变形量。Engineering problems such as large deformation of surrounding rock and invasion of supporting structure commonly occur during tunnel excavation in soft rocks with high ground stress due to stress release,rheological effect,and other reasons.By analyzing the deformation mechanisms of large deformation of the surrounding rock,the support form of“lengthened bolt+shotcrete(including steel arch)+circumferential(hysteretic)grouting”was proposed.The lengthening bolt can effectively improve the surrounding rock conditions and gradually release the surrounding rock extrusion deformation.The circular(hysterical)grouting can improve the surrounding rock parameters and control the surrounding rock loosening and deformation.Based on the mechanical model of the surrounding rock of the deep-buried circular tunnel and with the help of the Mohr-Coulomb yield criterion and Maxwell viscous body,the viscoelastic-plastic analytical formula of the surrounding rock of the deep-buried circular tunnel was obtained,which considers the deterioration of both the strength parameter and the stiffness parameter(elastic modulus E).After the verification by FLAC3D finite difference software program,the relevant influencing factors were analyzed.The results show that when calculating the deformation of soft rock tunnel with high ground stress,the deformation value of surrounding rock obtained by considering the deterioration of strength parameter and stiffness parameter at the same time is more practical.The support form of“lengthened bolt+shotcrete(including steel arch)+circumferential(delayed)grouting”has certain control effect on large deformation of surrounding rock.The total deformation of surrounding rock after grouting decreases by 40%compared with that without grouting,and the deformation of surrounding rock after grouting only accounts for 20%of the total deformation.The smaller the values of residual cohesion c″,residual internal friction Angleφ″,and residual elastic modulus E″,the larger the surrounding rock deformation

关 键 词：隧道围岩 劣化效应 注浆加固 黏弹塑性 围岩大变形 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]