摘要
鉴于隧道现行规范缺乏系统锚杆支护的承载能力分析方法,总安全系数法提出了锚−岩承载拱的荷载结构模型与承载力计算方法,在理论上实现了锚杆的量化设计,但缺少试验验证。基于此,从结构试验角度研制了大型隧道结构模型试验系统,开展了毛洞与不同间距系统锚杆支护下的锚−岩承载拱结构承载试验。通过监测围岩内部应力−应变、隧道位移与锚杆应变,分析了围岩与锚杆材料的破坏状态与破坏荷载,研究了锚−岩承载拱变形与受力特征、锚杆轴力分布。对比分析了模型试验的结构承载力与总安全系数法理论下锚−岩承载拱的计算承载力。研究结果表明:锚杆能有效地与围岩协同承载,显著增加围岩的侧限力,提高围岩抗压强度与承载能力;试验得到的锚−岩承载拱承载能力与理论计算结果较为吻合,表明了总安全系数法的锚−岩承载拱计算模型是合理的,并具有合适的安全性。
In view of the absence of bearing capacity analysis method for systematic bolt in the current specifications of tunnels,the total safety factor method proposes a load structure model of bolt-rock bearing arch.This method theoretically enables the quantitative design of bolts but lacks experimental verification.To address this,this paper develops a large-scale tunnel structure model experimental system from a structural experimental perspective.It conducts bearing experiments on bolt-rock bearing arch structures in unsupported tunnel and bolted tunnels with different spacings.By monitoring the stress and strain in the surrounding rock mass,tunnel displacement and bolt strain,the failure state and failure load of surrounding rock and bolt are analyzed.The deformation and force characteristics of the bolt-rock bearing arch and the distribution of bolt forces are investigated.The structural bearing capacity of the model experiment and the calculated bearing capacity of the bolt-rock bearing arch under the total safety factor method theory were compared and analyzed.The results show that the bolts can bear the load together with the surrounding rock mass,effectively increasing the confining stress of the surrounding rock mass and enhancing the compressive strength and bearing capacity.The experimental bearing capacity of the bolt-rock bearing arch is consistent with theoretical calculation results,proving the rationality of the bolt-rock bearing arch theory of the total safety factor method.This method is both safe and conservative.
作者
肖明清
徐晨
崔岚
盛谦
陈健
谢壁婷
晏庆明
XIAO Ming-qing;XU Chen;CUI Lan;SHENG Qian;CHEN Jian;XIE Bi-ting;YAN Qing-ming(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan,Hubei 430063,China;National and Local Joint Engineering Research Center for Underwater Tunnel Technology,Wuhan,Hubei 430063,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Marine Science and Technology,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2024年第6期1743-1754,共12页
Rock and Soil Mechanics
基金
中国铁建股份有限公司科研计划(2021-B18)
铁四院科技计划(2021K038)
国家自然科学基金面上项目(No.52279118)
中国科学院青年创新促进会项目(No.2023344)。
关键词
锚?岩承载拱
模型试验
承载能力
总安全系数法
bolt-rock bearing arch
model experiments
bearing capacity
total safety factor method
