摘要
针对小净距隧道中岩墙的对拉锚杆加固,基于中岩墙受力特点和Mohr-Coulomb准则建立对拉锚杆加固力学模型,通过数值模拟和工程应用研究对拉锚杆加固后中岩墙的力学特征。结果表明:对拉锚杆对中岩墙施加水平约束后,与中岩墙组成复合结构,可改善其力学参数,提高其抗压强度;对拉锚杆的预应力和间排距是决定加固效果的重要参数;使用对拉锚杆加固后,中岩墙位移明显减小,主应力增大,顶部应力卸载区减小甚至消失,底部应力集中区增大;中岩墙中部对拉锚杆轴力大于顶部和底部且持续增大,顶部和底部的对拉锚杆存在预应力损失现象。研究成果可为对拉锚杆加固设计提供理论依据。
Based on the mechanical characteristics of the middle rock wall and Mohr-Coulomb criterion,a mechanical model of the counter-pulled bolts reinforcement was established for the middle rock wall between neighborhood tunnels.The mechanical characteristics of the middle rock wall after the counter-pulled bolts reinforcement were studied through numerical simulation and engineering application. The results show that after the horizontal restraint is applied to the middle rock wall by the counter-pulled bolts,and the composite structure is formed with the middle rock wall,which improves its mechanical parameters and thus increases the compressive strength;the pre-stress and inter-row distance of the counter-pulled bolts are important parameters to determine the reinforcement effect;the displacement of the middle rock wall is significantly reduced,the main stress is increased,the stress unloading zone at the top is reduced or even disappears,and the stress concentration zone at the bottom is increased after the reinforcement with counter-pulled bolts. The stress of the counter-pulled bolts in the central part is greater than that in the top and bottom parts and continues to increase. Pre-stress loss exists in the top and bottom counter-pulled bolts. The research results can provide a theoretical basis for the design of counter-pulled bolts reinforcement.
作者
王浩
杨新安
WANG Hao;YANG Xin’an(Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201804,China;College of Transportation Engineering,Tongji University,Shanghai 201804,China)
出处
《铁道建筑》
北大核心
2022年第10期106-111,共6页
Railway Engineering
基金
中国铁路总公司科技研究开发计划(2017G007-A)。
关键词
小净距隧道
铁路隧道
数值模拟
对拉锚杆
中岩墙
力学特征
加固机理
neighborhood tunnel
railway tunnel
numerical simulation
counter-pulled bolts
middle rock wall
mechanical characteristics
reinforcement mechanism
