摘要
基于3种不同纤维混凝土材料试验,结合数字图像相关(DIC)技术得到理论研究所需的损伤本构参数,通过建立围岩–隧道结构数值模型,采用以应力强度因子和稳定安全系数为解析理论基础的有限元位移法,分析隧道二衬为常规混凝土和不同类型纤维混凝土工况下,不同裂缝位置、深度、宽度、倾角、车速和围岩等级等参数对带缝衬砌结构稳定性的影响规律。结果表明:衬砌裂缝在车载下呈剪压受力模式,相比于常规混凝土,纤维混凝土可有效提高带缝衬砌结构在车载过程中的结构稳定性,降低裂缝尖端的应力集中现象,其中玻璃纤维能力最强,混合纤维其次,PVA纤维最弱。同时,裂缝从拱脚至拱顶对衬砌结构稳定性的影响呈爬坡趋势,且相比于裂缝宽度,裂缝深度和倾角对车载下带缝衬砌结构的稳定性影响更为明显,拱顶裂缝倾角θ=45°时结构稳定性最差,以此为分界线的0°<θ<45°区域比45°<θ<90°更为危险,且其危险程度都随车速的增大而增大。当隧道洞周围岩为强度较低的V级时,纤维混凝土对结构稳定性的强化效果大幅降低,此时θ=45°的拱顶斜裂缝在裂缝深度较浅时结构就容易进入危险状态,工程中需特别注意此类情况的裂缝修复。
The three different damage parameters for fiber concrete are determined for theoretical researches based on the fiber concrete tests with the digital image correlation(DIC)technology,and the mechanics model for surrounding rock-tunnel structure is also obtained.On the basis of the finite element displacement method expressed by stress intensity and stability factor with analytical solution,the influences of different crack location,depth,width,angle,surrounding rock grades on the structural stability of lining cracks are analyzed under the cases of conventional concrete and different types of fiber concrete for secondary lining.The results show that lining cracks are subjected the compression and shear stress under the train excitation loads.Compared with the conventional concrete,the fiber concrete can effectively enhance the structural stability of the cracked lining,and reduce the stress concentration at crack tip during the dynamic loads of train.Among them,the glass fiber concrete has the strongest reduction effect,the mixed fiber is the second,and the PVA fiber is the weakest.Furthermore,the influence of cracks from arch foot to arch roof on the stability of lining structure tends to climb status,and compared with the crack width,the crack depth and inclination angle are more obvious for the effect of stability of lining structure under train loads.For the case of the inclination angleθ=45°for crack in arch roof of lining tunnel,the stability of lining structure is weakest.Takingθ=45°as the dividing line,the area of 0°<θ<45°is more dangerous than the area of 45°<θ<90°,and the danger increases with the increase of train speed.Moreover,when the rock around the tunnel is grade V with low strength,the reinforced effect of fiber concrete on the structural stability is greatly reduced.At this moment,even if the depth of crack in arch roof of tunnel lining is very small,the tunnel lining structure also will enter a dangerous status,so special attention should be paid to the repair of such cracks in the engineering practice.
作者
张治国
张孟喜
冯驹
马伟斌
王志伟
程志翔
ZHANG Zhiguo;ZHANG Mengxi;FENG Ju;MA Weibin;WANG Zhiwei;CHENG Zhixiang(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China;Department of Civil Engineering,Shanghai University,Shanghai 200444,China;State Key Laboratory for Track Technology of High-speed Railway,China Academy of Railway Sciences,Beijing 100081,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第S01期2927-2943,共17页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41977247,41772331)
高速铁路轨道技术重点实验室基金项目(2018YJ181)
关键词
隧道工程
隧道衬砌
车载
纤维混凝土试验
有限元位移法
稳定安全系数
tunnelling engineering
tunnel lining
train load
fiber concrete tests
finite element displacement method
stability factor
作者简介
张治国(1978–),男,博士,2001年毕业于武汉理工大学交通土建工程专业,现任教授,主要从事地下工程施工影响控制方面的研究工作。E-mail:zgzhang@usst.edu.cn
