文章编号：1004－5422(2021)04－0418－07 

DOI:10.3969/j.issn.1004-5422.2021.04.014

基于西原模型的浅埋隧道围岩变形分析

邱洪志^1,2，吴启红¹，唐然¹

（1.成都大学  建筑与土木工程学院，四川  成都  610106；

2.中国科学院、水利部成都山地灾害与环境研究所/山地灾害与地表过程重点实验室，四川  成都  610041；）

摘  要：以某浅埋山岭隧道围岩变形失稳为研究对象，基于西原模型及Mohr-Coulomb屈服准则在FLAC^3D中的二次开发应用，对浅埋隧道在开挖条件下围岩的变形进行分析.结果表明：应用西原模型计算围岩的位移时，可以考虑时间效应对围岩变形的影响，其塑性区主要形成于隧道开挖过程中和初支结构施工阶段，在仰拱浇筑完成后达到基本稳定.另外，塑性区形态受隧道埋深的影响，随着浅埋隧道埋深增加，开挖后围岩塑性区形态由近似半椭圆形向蝶形转变，当埋深小于2倍硐室宽度时，围岩塑性区近似半椭圆形并贯穿至地表.将本研究计算结果与监测数据对比分析发现，该计算结果的累积变形值略大于实际监测结果值，这是因为监测工序稍晚于开挖工序.对浅埋隧道围岩变形规律的研究是基于工程实例开展的，其成果对同类工程的设计与施工具有一定的指导意义.

关键词：西原模型；超浅埋隧道；围岩变形；现场监测

中图分类号：U451+.2                 文献标识码：A

Deformation Analysis of Surrounding Rock in Shallow Tunnel Based on Nishihara Model

QIU Hongzhi^1,2, WU Qihong¹, TANG Ran¹

(1.School of Architecture and Civil Engineering,Chengdu University,Chengdu 610106,China;

2.Key Laboratory of Mountain Hazards and Earth Surface Processes,Chinese Academy of Sciences/ 

Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China)

Abstract：In order to guarantee the safe construction and operation in the mountain tunnel portal section,gully section and valley section,the paper studies the instability and deformation of surrounding rock of a shallow mountain tunnel.Based on Nishihara model and Mohr Coulomb yield criterion,the deformation of surrounding rock of a shallow mountain tunnel under excavation condition is analyzed by secondary development and application in FLAC^3D.The results show that: when using Nishihara model to calculate the displacement of surrounding rock,the influence of time effect on the deformation of surrounding rock can be considered.The plastic zone is mainly formed in the process of tunnel excavation and the construction stage of primary support structure,and the inverted arch is basically stable after pouring.In addition,the shape of plastic zone is affected by buried depth of the tunnel.With the increase in the buried depth of the shallow tunnel,the shape of plastic zone of surrounding rock changes from semi ellipse to butterfly after excavation.The buried depth is twice as large as the width of the chamber.The plastic zone of surrounding rock is semi ellipse,and the plastic zone runs through the surface.Finally,by comparing the calculation results of this method with the monitoring data,it is found that the cumulative deformation value of the calculation results is slightly larger than that from the actual monitoring results,because the monitoring process lags behind the excavation process.The research on the deformation law of surrounding rock of shallow tunnel is based on engineering examples,and the research results have certain guiding significance for the design and construction of similar projects.

Key words：Nishihara model; shallow burial tunnel；surrounding rock deformation; field monitoring