堡镇隧道高地应力炭质页岩的变形破坏机制  

Deformation mechanism of black batt with high stress in Baozhen tunnel

作　　者：田四明[1,2] 

机构地区：[1]铁道部工程设计鉴定中心,北京100844 [2]铁道部经济规划研究院,北京100038

出　　处：《北京交通大学学报》2013年第1期21-26,共6页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：铁道部科技研究开发计划项目资助(2004G021-C);铁道部科技开发计划重大项目资助(2009G005;2011G019-A)

摘　　要：宜万铁路堡镇隧道围岩变形量大、变形速率快、持续时间长,且在时空效应上具有明显的不对称性和不均匀性.针对隧道施工中出现的炭质页岩大变形、围岩和支护结构扭曲折断和破坏等问题,基于现场监测数据的统计分析和掌子面素描,运用工程地质学和结构力学相关理论,分析高地应力炭质页岩的变形破坏机制,探讨了层状岩层和软弱夹层对隧道围岩稳定性的影响,揭示了高地应力炭质页岩变形破坏的力学机制.研究结果表明:堡镇隧道炭质页岩变形破坏形式主要有沿层理的挤出变形、斜顶形成的梁柱弯折变形、片帮、片(冒)落、相切于开挖轮廓线墙角的泥质夹层引起的底鼓和软弱夹层引起的侧墙整体变形等;变形破坏特征主要有共生性、不均匀和分区性、不对称性、集中性和软弱夹层对大变形的控制性等;变形机制具有多样性、共存性和相互转化等特征.Large amount of deformation,high deformation rate,long deformation duration and obvious dissymmetry and non-uniformity in space-time effect are primary characteristics of rock mass around Baozhen Tunnel for Yiwan Railway.Aiming at the problems occurring in construction of the tunnel,including large deformation of carbonaceous shale,distortion and fracture of surrounding rock and support structure,based on statistical analysis of field monitoring data and geological sketch of tunnel heading,deformation and failure mechanism of carbonaceous shale have been analyzed by engineering geology and structural mechanics,affection of rock stratification and soft interlayer on stability of surrounding rock has been discussed,deformation and failure mechanism of carbonaceous shale under high ground stress has been uncovered in the paper.The research results indicate that deformation and failure forms of carbonaceous shale around Baozhen Tunnel principally involve extrusion deformation along bedding,bending deformation of rock beam,rib fall,inbreak,bottom squeeze of muddy interlayer,deformation of sidewall provoked by weak interlayer.Deformation and failure characteristics principally include symbiosis,non-uniformity,zonation,dissymmetry,concentricity and domination of weak interlayer on large deformation.The deformation mechanism presents diversity,coexistence and reciprocal transformation.

关 键 词：隧道工程 炭质页岩 变形机制 破坏特征 软弱夹层 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]