软弱地层大断面浅埋隧道围岩与初支结构协调变形规律研究  

Study on the Coordinated Deformation between Primary Support and Rock Mass of Shallow Large Cross-section Tunnel in Soft Ground

作　　者：任博[1] 王碧剑[2] 肖晓 REN Bo;WANG Bijian;XIAO Xiao(Shaanxi Vocational and Technical College,Xi’an,Shaanxi 710000,China;Xi’an University of Architectural Science and Technology,Xi’an,Shaanxi 710000,China;College of Construction Engineering,Jilin University,Changchun,Jilin 130000,China)

机构地区：[1]陕西职业技术学院,陕西西安710000 [2]西安建筑科技大学,陕西西安710000 [3]吉林大学建设工程学院,吉林长春130000

出　　处：《公路工程》2019年第6期104-108,共5页Highway Engineering

基　　金：吉林省交通厅科技项目(2014-4-1-10-2)

摘　　要：在软弱地层下修建大断面浅埋隧道,围岩变形通常面临着变形时间长及变形量大的问题,因此找到支护与围岩之间的变形协调关系是避免大变形给隧道工程建设带来不良影响的关键。首先分析了软弱地层大断面隧道产生大变形的原因及当前设计施工中普遍存在的问题,基于已有大变形隧道的研究资料统计,提出了隧道围岩与支护结构协调变形的关系假定,分析认为整体沉降与支护闭合前的挠曲变形是大变形的主要来源。得到了考虑时空效应下的隧道台阶法施工开挖变形过程,台阶法施工中大变形包含整体沉降与支护挠曲变形两部分,上台阶初支变形为下沉,同时侧墙支护发生挠曲。基于该变形特点进一步提出大变形的应对措施,克服了传统预留变形量的局限性,可为后续类似工程提供参考和施工指导。During the construction of the shallow large cross-section tunnel in soft ground,the rock mass deformation are always characterized by long duration and considerable value.Hence,the key to avoid adverse impact of large deformation on tunnel engineering is to identify the deformation coordination relationship between support structure and rock mass.This paper firstly analyses main causes responsible for large deformation of the tunnels constructed in soft ground,and then the common problems during design and construction phase are discussed.Based on the collected large deformation data,the coordinated deformation hypothesis between rock mass and support structure is put forward.It is considered that the main large deformation comes from the overall settlement and deflection before support closure.Considering the space-time effect,the deformation process of the tunnel excavated by bench method is obtained,that is,the large deformation in bench method construction includes two parts:the whole settlement and the support deflection.The primary support deformation of the upper step is subsided while the side wall is deflected.Based upon the deformation characteristics,the measures to deal with large deformation are further obtained,which overcomes the limitation of the traditional reserved deformation,and it can provides reference and construction guidance for future similar projects.

关 键 词：软弱地层 大断面浅埋隧道 协调变形 台阶法 预留变形 

分 类 号：U45[建筑科学—桥梁与隧道工程]