软岩隧道预应力锚固系统中钢带的结构效应研究  

Study on Structural Effect of Steel Belt of Prestressed Anchorage System for Soft Rock Tunnel

作　　者：李金津 汪波[1] 喻炜 郭新新 LI Jinjin;WANG Bo;YU Wei;GUO Xinxin(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;College of Environmental and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]西南交通大学交通隧道教育部重点实验室,四川成都610031 [2]成都理工大学环境与土木工程学院,四川成都610059

出　　处：《防灾减灾工程学报》2023年第1期41-49,共9页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(U2034205);国家自然科学基金项目(51878571)资助。

摘　　要：预应力锚固系统为核心的变形主动控制技术为隧道挤压大变形的治理开辟了新途径,作为其中协同支护的钢带,其受力特性及结构效应未明确。鉴于此,在分析钢带主要结构形式的基础上,理论分析与数值仿真结合,开展了软岩隧道预应力锚固系统中钢带的结构效应研究。研究结果表明:基于单跨简支梁理论,得到随钢带惯性矩增大,围岩(跨中)挠度和最大主应力均呈现“先急后缓再平”的减小趋势,以此建议软岩隧道优先采用W形钢带、且惯性矩>2.92E-01cm^(4);通过建立“预应力锚杆+钢带”与围岩作用模型,发现较单一预应力锚杆支护,钢带协同预应力锚杆支护具有更优的围岩变形控制效果和更佳的围岩应力改善功效,同时,锚杆的受力减小,相互间也更趋均匀。The active deformation-control technology with the prestressed anchorage system as the core has opened a new way for the treatment of large extrusion deformation.As the steel belt for the cooperative support,its mechanical characteristics and structural effects are not clear.In view of this,based on analyzing the main structural forms of the steel belt,the method of combining theoretical analysis and numerical simulation is used to study the structural effect of steel belt in the prestressed anchorage system of soft rock tunnel.The results show that:based on the single-span simply supported beam theory,it is obtained that with the increase of the moment of inertia of the steel belt,the deflection of the surrounding rock(mid-span)and the maximum principal stress show a decreasing trend of"first sharp,then gentle and then flat";it is suggested that the W-shaped steel belt with the moment of inertia>2.92E-01cm^(4)should be preferred for soft rock tunnels;by establishing the interaction model of‘prestressed bolt+steel belt’and surrounding rock,it is obtained that compared with the support of single prestressed bolt,the prestressed bolt support with the synergy of steel belt has better surrounding rock displacement control and surrounding rock stress improvement effects,and the bolt force is reduced and more uniform.The research results help deepen the understanding of the importance of steel belts in the prestressed anchorage system.

关 键 词：软岩隧道 预应力锚杆 协同作用 钢带 惯性矩 

分 类 号：U45[建筑科学—桥梁与隧道工程] X947[交通运输工程—道路与铁道工程]