摘要
研究目的:全风化红砂岩和砂质黄土互层地层在我国有较广泛的分布,其敏感脆弱的工程地质特性严重影响隧道工程建设。本文以蒙华铁路阳城隧道为依托工程进行拓展性研究,采用室内试验、数值模拟、现场监测等多种方式深入探讨岩层倾角对土砂互层地层隧道围岩稳定性的影响。研究结论:(1)随着岩层倾角增大,拱顶及左、右拱腰位移呈现互异的变化规律,且具有不同的变形机理;对于拱顶而言,45°为破坏模式转换临界,位移取得最小值43.7 mm;根据左、右拱腰变形差异性,分为非对称变形缓慢发展区、非对称变形快速发展区、非对称变形稳定区、非对称变形弱化区和非对称变形二次发展区五个阶段;(2)拱顶及左、右拱肩处支护结构在不同地层倾角下均有较大主应力,且波动幅度较大,左、右拱肩处应力差值的变化对隧道结构会产生不同程度的影响,当倾角为60°时,两处主应力差值取得最大值1.01 MPa;(3)随着岩层倾角变化,张拉塑性区和剪切塑性区存在不同的分布规律,实际工程中应做好相应抑变措施;(4)本研究结论可为不同岩层倾角产状下的土砂互层地区的隧道设计和施工提供借鉴。
Research purposes:The fully weathered red sandstone and sandy loess interbedded strata are widely distributed in China,and their sensitive and fragile engineering geological characteristics seriously affect the construction of tunnel engineering.Based on the Yangcheng tunnel of Menghua railway,this paper conducts an extensive study,and uses various methods such as laboratory test,numerical simulation and field monitoring to deeply discuss the influence of rock stratum dip angle on the stability of surrounding rock of the tunnel in soil-sand interbedded strata.Research conclusions:(1)With the increase of rock stratum dip angle,the displacement of the vault and the left and right arched waist presents different changing rules,and each part has different deformation mechanism;For the vault,45°is critical for failure mode conversion,and the minimum value of displacement is 43.7 mm;According to the differences of left and right arched waist deformation,it can be divided into five stages:the slow development area of asymmetric deformation,the fast development area of asymmetric deformation,the stable area of asymmetric deformation,the weakening area of asymmetric deformation and the secondary development area of asymmetric deformation.(2)The supporting structures of vault and left and right spandrel have large principal stress under different dip angle,and the volatility is bigger.The change of the stress difference at the left and right spandrel will have different degrees of influence on tunnel structure.When the dip angle is 60°,the maximum value of difference between the two principal stresses is 1.01 MPa.(3)With the change of rock stratum dip angle,the plastic zones of tension and shear have different distribution rules,and corresponding measures should be taken to control deformation in practical projects.(4)The research conclusions can be used for reference in tunnel design and construction in sand and soil interbedded areas with different dip angles.
作者
王志杰
李振
徐海岩
王如磊
夏勇
唐力
WANG Zhijie;LI Zhen;XU Haiyan;Wang Rulei;XIA Yong;TANG Li(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;China Railway Design Corporation,Tianjin 300142,China)
出处
《铁道工程学报》
EI
北大核心
2019年第9期54-59,84,共7页
Journal of Railway Engineering Society
基金
国家自然科学基金项目(51678498)
教育部创新团队发展计划项目(IRT0955)
关键词
铁路隧道
土砂互层地层
岩层倾角
围岩稳定性
数值模拟
现场监测
railway tunnel
interbedded beds of soil and sand
rock stratum dip angle
stability of surrounding rock
numerical simulation
field monitoring
