穿越土–岩交界面隧道围岩变形和衬砌受力特性研究  

Study on Deformation of Surrounding Rock and Stress Characteristics of Lining in Tunnels Passing through Soil-rock Interface

作　　者：杨治军 刘泾堂 胡金鑫 洪铭 Yang Zhijun;Liu Jingtang;Hu Jinxin;Hong Ming(Gansu Province Transportation Planning,Survey&Design Institute Co.,Ltd.,Lanzhou 730030,Gansu,China;School of High-way,Chang’an University,Xi’an 710064,Shaanxi,China)

机构地区：[1]甘肃省交通规划勘察设计院股份有限公司,甘肃兰州730030 [2]长安大学公路学院,陕西西安710064

出　　处：《岩土工程技术》2023年第6期649-655,共7页Geotechnical Engineering Technique

摘　　要：基于黄土隧道穿越土–岩交界面的工程实际,运用有限元数值计算手段,结合隧道施工过程中土–岩交界面分布规律,研究土–岩交界面空间分布位置对地表位移及洞内收敛变形特征的影响,得到衬砌结构力学特征与变化规律。研究结果表明,土–岩交界面位于拱底以下时,隧道开挖范围均为黄土,地表沉降与围岩变形均较大,衬砌拱顶附近受拉较大;土–岩交界面位于拱顶以上时,隧道开挖对地表沉降、围岩变形的影响基本不变;土–岩交界面位于拱肩附近时,拱顶衬砌拉应力最小,衬砌结构受力较为有利;土–岩交界面位于拱顶附近时,衬砌在拱腰处压应力显著增大,拱顶处拉应力也较大,此时衬砌结构受力最为不利。根据衬砌结构总位移特征,得到拱肩处锁脚锚杆打设角度可控制为15°~35°,拱腰与拱脚处锁脚锚杆角度控制为45°左右。研究成果可为隧道设计施工提供一定的理论依据。Based on the engineering practice of loess tunnel crossing soil-rock interface,finite element numerical calculation method combined with the distribution law of soil-rock interface during tunnel construction was used to study the influence of spatial distribution position of soil-rock interface on surface displacement and convergence deformation characteristics in tunnel,and the mechanical characteristics and variation law of lining structure were obtained.The results show that when the soil-rock interface is loc-ated below the arch bottom,the tunnel excavation range is loess,the surface settlement and surrounding rock deformation are large,and the tension near the arch top of lining is large.When the soil-rock interface is above the top,the influence of tunnel excavation on sur-face settlement and surrounding rock deformation is basically unchanged.When the soil-rock interface is located near the arch shoulder,the tensile stress of the vault lining is the smallest,and the lining structure is more favorable.When the soil-rock interface is located near the vault,the compressive stress of the lining at the arch waist increases significantly,and the tensile stress at the vault is also large.At this time,the stress of the lining structure is the most unfavorable.Further,according to the total displacement character-istics of the lining structure,the angle of the locking anchor at the arch shoulder can be controlled to 15°~35°,and the angle of the lock-ing anchor at the arch waist and the arch foot can be controlled to about 45°,which can provide a theoretical basis for tunnel design and construction.

关 键 词：土–岩交界面 数值计算 衬砌受力变形 锚杆角度 

分 类 号：U451[建筑科学—桥梁与隧道工程]