实验技术与管理2025，Vol.42Issue(12)：45-53,9.DOI:10.16791/j.cnki.sjg.2025.12.006
基于高性能潮喷纤维混凝土的隧洞支护结构强度离散性试验研究
Experimental study on the strength dispersion of high-performance fiber-reinforced web-mix shotcrete for tunnel support structures
摘要
Abstract
[Objective]The performance of concrete directly affects the stability and safety of tunnel support structures.However,shotcrete—widely used for tunnel initial support—has drawbacks such as low strength,poor uniformity,and limited durability.To address these issues,this study,based on an ongoing Tunnel Boring Machine(TBM)water diversion tunnel project in Xinjiang,conducts a full-scale test of a tunnel support structure using high-performance fiber-reinforced wet-mix shotcrete.The study examines strength differences and dispersion characteristics of the shotcrete on the inner and outer sides of the support structure.By comparing these results with those of dry-mix shotcrete,conventional wet-mix shotcrete,and cast concrete,the strength dispersion grade of the support structure constructed with high-performance fiber-reinforced wet-mix shotcrete used in this project is determined.[Methods]A rebound tester was used to measure the compressive strength of high-performance fiber-reinforced wet-mix shotcrete.Based on the average of the 16 rebound values in each measurement area,after discarding 3 maximum and 3 minimum values,the coefficient was corrected using the measured strength obtained through core-drilling sampling.The estimated strength values of each measurement area on the inner and outer sides of the structure were then organized,and the average strength,maximum value,minimum value,range,variance,standard deviation,coefficient of variation,and other indicators at different heights and in different strips were calculated and analyzed.[Results]The results indicate that the average compressive strength of the high-performance fiber-reinforced wet-mix concrete support structure on the inner side is 54.34 MPa,with good strength uniformity across different sections,and 83.3%of the strips exhibit low strength dispersion.For the outer side,the average compressive strength is 44.93 MPa,also showing relatively uniform strength distribution,with 58.3%of the strips classified as low dispersion.The inferior strength values and uniformity on the outer side compared to the inner side are primarily attributed to insufficient stiffness of the outer formwork and the shielding effect of the steel framework,leading to issues such as uneven aggregate distribution,lower compaction,and a surface layer of floating mortar.[Conclusions]Through improved techniques like pre-mixing water and admixtures(including water-reducing agents and accelerators)via single-tube injection,as well as extended nozzles,the high-performance fiber-reinforced wet-mix concrete support structure demonstrates significantly lower strength dispersion than conventional dry-mix or wet-mix concrete.These findings provide valuable insights for the construction and design of similar engineering structures in future projects.关键词
高性能混凝土/潮喷法/支护结构/强度均值/离散性Key words
high-performance concrete/wet-injection method/lining structure/mean intensity/discreteness分类
交通工程引用本文复制引用
ZHANG Huijian,YAN Zhicheng,WANG Lichuan,YU Ze,TAN Ling,LIU Zhiqiang,BAI Guogang,WANG Haiyan..基于高性能潮喷纤维混凝土的隧洞支护结构强度离散性试验研究[J].实验技术与管理,2025,42(12):45-53,9.基金项目
中铁十八局集团有限公司科技开发项目(CR18GK-25-22,G23-07-S) （CR18GK-25-22,G23-07-S）
国家自然科学基金项目(52178395) （52178395）
