隧道大变形机理及分类分级探讨  

Discussion on the Mechanism and Classification of Large Deformation in Tunnel Engineering

作　　者：张广泽[1] 冯君[1,2] 易勇进 柴春阳[1] 强新刚[1] 王振友[1] ZHANG Guangze;FENG Jun;YI Yongjin;CHAI Chunyang;QIANG Xingang;WANG Zhenyou(China Railway Eryuan Engineering Group Co.,Ltd.(CREEC),Chengdu 610031,China;School of Resource and Civil Engineering,Northeastern University,Shenyang 110004,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031 [2]东北大学资源与土木工程学院,沈阳110004

出　　处：《铁道标准设计》2020年第10期77-82,共6页Railway Standard Design

基　　金：四川省科技计划项目(2019YFG0047);中铁二院工程集团有限责任公司科技研究计划项目(KYY2019003(19-22),KYY2019004(19-22),KYY2018012(18-19))。

摘　　要：为研究隧道工程大变形发生的机理及等级,从区域地应力场、地层岩性、地质构造、松动圈扩展出发,对大变形的发生机理进行综合分析。在此基础上,对隧道大变形进行分类分级,并对控制技术进行探讨。得到以下结论:(1)隧道大变形的产生往往受到区域地应力场、地层岩性、地质构造及其挤压程度的共同影响;(2)根据大变形发生的构造部位,可以将大变形分为断层型、碎裂型和顺层型3种;断层型发生在区域断层带;碎裂型发生在褶皱核部、转折端以及构造节理密集带;顺层型发生在褶皱翼部,它以隧道轴向与岩层走向小角度相交为条件。缓倾岩层是顺层的特例,易发隧道底鼓;(3)工程前期现场资料缺乏的条件下,宜在最大主应力近于水平的前提下,根据地层岩性、地质构造、相对变形量,结合工程经验,参考相应规范及其他相关研究成果,进行综合判定;(4)大变形应采取"强支护、预加固、快封闭"的控制理念。To study the mechanism and grade of large deformation in tunnel engineering,this paper analyzes the mechanism of large deformation in tunnel engineering in terms of the regional geo-stress field,formation lithology,geologic structure and loose circle extension.On this basis,it categorizes the large deformation and discusses the deformation control technologies.The results show that:(1)Large deformation of tunnel is commonly caused by the joint influence of regional geo-stress field,formation lithology,geologic structure and its extrusion degree.(2)According to their locations in geo-structure,large deformations are categorized as fault type,shatter type and bedding type.Fault type occurs in regional fault zone;shatter type in fold core,hinge zone of fold and dense zone of structural joints;bedding type occurs in fold limb on condition that the tunnel axis is intersected with stratum strike by a small angle.Floor heave is likely to occur in flat dipping bed,which is a special case of bedding.(3)Due to the lack of site data at the early stage of the project,synthetic decision should be made based on formation lithology,geologic structure,relative deformation and engineering experience,and with reference to corresponding norms and relevant research findings on the premise that the maximum principal stress is nearly horizontal.(4)To deal with large deformation problem,the control concept of"strong support,pre-reinforcement,quick closing"should be adopted.

关 键 词：隧道工程 大变形机理 分类分级 区域应力场 地质构造 松动圈 

分 类 号：TU443[建筑科学—岩土工程] U451[建筑科学—土工工程]