深部复合地层TBM隧道支护结构作用的透明岩体试验研究  

Experimental Study on TBM Tunnel Support Structure in Deep Composite Stratum Using Transparent Rock

作　　者：任超[1] 孙晓明[1] 李元海[2] 杜建明 REN Chao;SUN Xiaoming;LI Yuanhai;DU Jianming(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology,Beijing 100083,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology,Xuzhou,221116,China;Key Laboratory for Urban Underground Engineering of the Ministry of Education,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室(北京),北京100083 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [3]北京交通大学城市地下工程教育部重点实验室,北京100044

出　　处：《湖南大学学报（自然科学版）》2021年第1期59-69,共11页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(511174197);国家重点基础研究发展计划(“973”计划)项目(2014CB046905)。

摘　　要：针对深部复合地层TBM隧道模型试验研究中出现的掘进和开挖、围岩的变形和破裂、支护结构作用机理等关键问题,基于透明岩体试验的新方法,研制出满足试验需求的“复合地层”,并自主研发了掘进机模拟装置和TBM管片制作装置.在此基础上,运用数字照相量测技术,对比分析有、无支护下围岩内部的变形破裂情况,揭示了有、无支护下隧道围岩的变形破裂机制,并结合围岩变形破裂的特点,反推支护结构的作用.结果表明:1)在轴向加载、四周约束的前提下,深部复合地层TBM隧道围岩变形破裂机制为剪切滑移型(无支护)和扩容膨胀型+层状变形型(有支护).2)支护结构能遏制隧道周围变形的发展,大大减小围岩内部变形量,降低围岩的破碎程度,使围岩承载力提高2倍左右,并使围岩的应力状态由局部受拉剪变为整体竖向受压,减缓了应力集中程度,使得浅部围岩形成具有一定承载能力的承载区,并有效地抑制了底鼓,从而保护了隧道的稳定和安全.3)TBM隧道中两边墙拐角处会出现应力集中现象,在实际工程中可采用豆砾石回填灌浆、局部区域注浆加固等措施,以提高该薄弱环节的稳定性.Aiming at the key problems such as excavation,deformation and rupture of surrounding rock,and mechanism of support structure in the experimental study of deep composite stratum TBM tunnel,based on the new method of transparent rock mass test,a composite stratum was developed to meet the test requirements.Also,the tunnel boring machine(TBM)simulation experiment device and the TBM segment production device were developed.On this basis,digital photographic measurement technology was used to compare and analyze the deformation and fracture of surrounding rock with and without support,and it revealed the deformation and rupture mechanism of the surrounding rock with and without support.Combined with the deformation and fracture of the surrounding rock,the characteristics of the thrust structure were reversed.The research results show that:1)Under the premise of axial loading and surrounding constraints,the deformation and fracture mechanism of the surrounding rock on TBM tunnel in the deep composite stratum is shear-slip type(without support)and expansion type layer deformation type(with support).2)The supporting structure can restrain the development of deformation around the tunnel,greatly reducing the deformation of the surrounding rock,cutting down the degree of fragmentation of the surrounding rock and increasing the bearing capacity of the surrounding rock by about 2 times.Also,the stress state of the surrounding rock is changed from local tensile shear to overall vertical compression,which reduces the stress concentration and makes the shallow surrounding rock form a certain bearing capacity.Moreover,the bottom drum is effectively suppressed,thus protecting the stability and safety of the tunnel.3)Stress concentration occurs at the corners of the two walls in the TBM tunnel.In the actual project,measures such as backfilling grouting with bean gravel and local grouting reinforcement can be used to improve the stability of the weak link.

关 键 词：透明岩体 数字照相量测 支护结构 变形破裂 时空效应 复合地层 TBM 

分 类 号：U455.31[建筑科学—桥梁与隧道工程] U451.5[交通运输工程—道路与铁道工程]