摘要
文章基于33座隧道68个监测断面的282根锚杆轴力的统计数据,探讨了锚杆轴力的整体分布特征及围岩级别对其的影响规律,讨论了隧道锚杆轴力的时程变化特征及空间分布规律,研究了锚杆轴力与锚杆长度的关系,分析了隧道开挖半径对锚杆轴力最大值位置的影响规律,从而揭示了锚杆中性点与隧道开挖半径的关系。结果表明:锚杆长度越长和围岩等级越高,锚杆轴力达到最大值的时间越久,且轴力时程曲线分为快速增大阶段、缓慢上下波动阶段、趋于稳定3个阶段;从空间分布规律角度看,锚杆轴力的分布较为离散,但其最大值常出现在拱肩和拱腰;随着锚杆长度增长,轴力出现较大值的案例所占比例增大;锚杆中性点位置随着隧道开挖半径的增大而呈现线性增大关系。
Based on the statistical data of axial forces of 282 anchor bolts in 68 monitoring sections of 33 tunnels,this paper investigates the overall distribution characteristics of the axial force of anchor bolts and the influence law of surrounding rock grades on it,discusses the time-history variation characteristics and spatial distribution law of the axial force of anchor bolts,studies the relationship between the axial force and the length of anchor bolts,as well as analyzes the influence law of tunnel excavation radius on the position of maximum axial force of anchor bolts,thus revealing the relationship between the neutral point of anchor bolts and the tunnel excavation radius.The results show that:the longer the anchor bolt length and the higher the surrounding rock grade,the longer it takes to reach the maximum axial force value of anchor bolts,and the time-history curve of the axial force is divided into three stages:the rapid increase stage,slow fluctuation stage and stabilization stage;from the perspective of spatial distribution law,the distribution of the axial force of anchor bolts is relatively discrete,but the maximum value often appears at the tunnel spandrel and haunch;the proportion of occurrence of the larger axial force increases with the increase of anchor bolt length;and the neutral point position of anchor bolts increases linearly with the increase of tunnel excavation radius.
作者
李鹏飞
黄靖络
陈柯屹
童磊
LI Pengfei;HUANG Jingluo;CHEN Keyi;TONG Lei(Key Laboratory of Urban and Engineering Safety and Disaster Reduction of the Ministry of Education,Beijing University of Technology,Beijing 100124;Zhejiang Province Institute of Architectural Design and Research,Hangzhou 310006)
出处
《现代隧道技术》
CSCD
北大核心
2021年第5期227-236,共10页
Modern Tunnelling Technology
基金
国家自然科学基金资助项目(51778025,51978019)。
关键词
隧道工程
锚杆轴力
现场监测
中性点
空间分布
Tunnel engineering
Anchor bolt axial force
Field monitoring
Neutral point
Spatial distribution
