基于脆性缓冲理念的隧道抗错断方法及模型试验  

Method and model experiment of resisting dislocation of tunnel based on the brittle buffer concept

作　　者：曹俊 崔臻[1,2] 张翔宇 张佳威 CAO Jun;CUI Zhen;ZHANG Xiangyu;ZHANG Jiawei(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [2]中国科学院大学,北京100049

出　　处：《清华大学学报（自然科学版）》2024年第7期1116-1125,共10页Journal of Tsinghua University(Science and Technology)

基　　金：国家重点研发计划“川藏铁路”重点专项2023年度青年科学家项目(2023YFB2390400);云南省重大科技专项计划项目(202102AF080001);国家自然科学基金资助项目(52079133,52379112);水利部重大科技项目(SKS-2022103)。

摘　　要：针对许多隧道面临的穿越活动断层挑战,该研究提出一种基于脆性缓冲理念的隧道抗错断方法。通过设计并实施模型试验,验证脆性缓冲结构在抗错断方面的有效性。研究结果表明:当断层发生错动时,采用脆性缓冲结构的隧道设计理念是可行的。通过观察破坏模式发现,脆性缓冲材料的粉碎和衬砌的部分脱空作用可有效分散局部剪切破坏,显著降低断层带区域衬砌的损坏程度。在上盘区域,拱顶处的脆性缓冲结构被压碎,与此同时,拱底处脱空。下盘区域的拱顶处脱空,而拱底的脆性缓冲结构被压碎。这种变形模式有效分散了断层位置的局部剪切变形,显著减轻了衬砌的损坏。在50 mm厚缓冲结构的保护下,即使错动位移达到100 mm,相当于实际情况下的4 m位移,衬砌模型表现出的损坏较小,突显了脆性缓冲结构在保护隧道结构完整性方面的强大性能。此外,从应变监测数据分析可以看出,衬砌的应变峰值并不出现在断层破碎带内,而是迁移至离断层位置较远的区域,显著减轻了断层破碎带内的应变集中现象。该研究为跨越活动断层带的隧道设计提供了重要的理论依据和实践指导,为抗错断方案的选择提供了参考。[Objective]Tunnels are integral to transport infrastructure and often face the formidable challenge of traversing active fault zones during construction.The active fault zones indicate potential geological disturbances,leading to structural damage and posing a severe threat to tunnel safety.Therefore,this study aims to propose a method of resisting dislocation of tunnel based on the brittle buffer concept to enhance the structural integrity of tunnels when confronted with displacements induced by fault activities.The method involves strategically filling the space between the primary and secondary linings with brittle and compressible materials,which serve as buffers to absorb and mitigate localized displacements caused by fault activities,thus protecting the tunnel from substantial damage.[Methods]To rigorously study and validate the effectiveness of the proposed brittle buffer structure in resisting fault displacements,a comprehensive indoor model experiment was designed and implemented.Scaling down the size according to a 40:1 geometric similarity ratio and using similar materials for the surrounding rock,lining,and buffer structures,tunnel model was cast in the laboratory,simulating fault movements within the model box.The analysis focused on the deformations and failure characteristics of the models under different fault loads,confirming the effectiveness of the brittle buffer structure.[Results]Observations of tunnel deformation and failure modes after fault movements revealed distinct patterns.In the hanging wall of the fault,the brittle buffer structure at the arch top was crushed,accompanied by void formation at the arch bottom.Meanwhile,in the footwall of the fault,the arch top exhibited voiding,whereas the brittle buffer structure at the arch bottom was crushed.This deformation pattern effectively dispersed local shear deformations at the fault location,markedly mitigating damage to the lining.Impressively,under the protection of a 50-mm buffer structure,the lining model showed minimal damage even with

关 键 词：隧道工程 活动断层 模型试验 脆性材料 

分 类 号：U452.28[建筑科学—桥梁与隧道工程]