清华大学学报（自然科学版）2025，Vol.65Issue(3)：495-508,14.DOI:10.16511/j.cnki.qhdxxb.2025.26.015
深埋隧洞纤维混凝土衬砌支护特性及应用
Support characteristics and application of fiber-reinforced concrete lining for deep-buried tunnels
摘要
Abstract
[Objective]To address the issue of cracking in the lining structures of deep-buried tunnels,this paper proposes the use of basalt fiber-reinforced concrete(BFRC)to improve the load-bearing capacity of lining structures.[Methods]Tension and compression tests were conducted on BFRC specimens with varying volume basalt fiber fractions ranging from 0 to 0.5％.The optimal fiber content was determined,and the concrete damage plasticity(CDP)model parameters for plain and fib er-reinforced concrete with the optimal fiber content were validated.Then,numerical simulations were employed to create an integrated bearing model of surrounding rock-initial support and a secondary lining support model.The use of solid and structural elements and a secondary lining support characteristic curve(SCC)for deep-buried tunnels were obtained,revealing the crack propagation characteristics of the concrete.A quantitative analysis was conducted on the effects of the reinforcement ratio,secondary lining thickness,and fiber-reinforced concrete on the normal and ultimate state load-bearing capacity of the secondary lining.[Results](1)Compared with those of plain concrete(B0),the maximum increases in the axial tensile strength and splitting tensile strength of BFRC with a fiber volume fraction of 0.2％were 12.81％and 14.79％,respectively.Furthermore,a maximum enhancement of 31.68％in the flexural strength of BFRC was noted when the fiber volume fraction was increased to 0.5％.The optimal fiber content was 0.2％.(2)The stress-strain curve of the BFRC could be fitted using peak compressive strength,peak compressive strain,and compressive shape parameters.The compressive shape parameter values for B0 and B0.2 were 6.50 and 3.00,respectively.The tensile stress-strain curve could be fitted using the peak tensile strength,peak tensile strain,and tensile shape parameter,with tensile shape parameter values for B0 and B0.2 being 3.00 and 1.86,respectively.(3)The CDP parameters for plain concrete and fib er-reinforced concrete accurately simulated the peak tensile and compressive strengths as well as the shapes of the tensile and compressive stress-strain curves.For compressive stress-strain curves,the error between numerical simulation and experimental fitting values at 0.50％compressive strain was 2.48％(2.01％)for B0(B0.2).For tensile stress-strain curves,the error at 0.04％tensile strain was 4.08％(1.68％)for B0(B0.2).(4)The SCC curve of the secondary lining exhibited rapid linear growth initially,slow growth in the middle,and a nearly horizontal trend in the later stages with increasing displacement.For class V surrounding rock,the secondary lining crack width showed slow linear growth in the initial stage and rapid linear growth after reaching approximately 0.10 mm.Higher reinforcement ratios effectively delayed crack propagation in the early stage,although increasing the reinforcement ratio beyond 0.6％or 0.8％was not economically reasonable.(5)Increases in reinforcement ratio and lining thickness resulted in almost linear increases in the 0.30 mm crack load and ultimate state load-bearing capacity.For every 0.1％increase in the reinforcement ratio,0.30 mm crack load increased by an average of 5.40％.In addition,for every 0.10 m increase in the secondary lining thickness,0.30 mm crack load increased by an average of 11.18％.Fiber addition considerably enhanced concrete resistance to crack propagation,especially in the early stages,increasing the initial cracking load by 38.64％and the 0.30 mm crack load by 5.54％.[Conclusions]This study provides theoretical and practical guidance for designing deep-buried tunnel lining structures and serves as a reference for applying fiber-reinforced concrete in secondary lining structures of deep-buried tunnels.关键词
深埋隧洞/二衬支护/纤维混凝土/最优纤维掺量/支护特性Key words
deep buried tunnel/second lining/fiber-reinforced concrete/optimal fiber content/support characteristics分类
交通工程引用本文复制引用
邓志云,林鹏,马翔,夏勇,李子昌..深埋隧洞纤维混凝土衬砌支护特性及应用[J].清华大学学报（自然科学版）,2025,65(3):495-508,14.基金项目
北京交通大学人才基金项目(2024XKRC035) （2024XKRC035）
国家自然科学基金项目(12102230) （12102230）
中国华能集团有限公司总部科技项目(HNKJ21-H74) （HNKJ21-H74）
西藏自治区清洁能源科技重大专项项目(XZ202201ZD0003G) （XZ202201ZD0003G）
陕西省科技计划项目(2023-YBGY-278) （2023-YBGY-278）
