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

作　　者：邓志云 林鹏[2] 马翔 夏勇 李子昌 DENG Zhiyun;LIN Peng;MA Xiang;XIA Yong;LI Zichang(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China;Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710032,China;Power China Chengdu Engineering Co.,Ltd.,Chengdu 610072,China;Technological Innovation Center of Hydropower,Wind,Solar and Energy Storage of Tibet Autonomous Region,Chengdu 610072,China;Sichuan Energy Internet Research Institute,Tsinghua University,Chengdu 610213,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]清华大学水利水电工程系,北京100084 [3]西安热工研究院有限公司,西安710032 [4]中国电建集团成都勘测设计研究院有限公司,成都610072 [5]西藏自治区水风光储能源技术创新中心,成都610072 [6]清华四川能源互联网研究院,成都610213

出　　处：《清华大学学报(自然科学版)》2025年第3期495-508,共14页Journal of Tsinghua University(Science and Technology)

基　　金：北京交通大学人才基金项目(2024XKRC035);国家自然科学基金项目(12102230);中国华能集团有限公司总部科技项目(HNKJ21-H74);西藏自治区清洁能源科技重大专项项目(XZ202201ZD0003G);陕西省科技计划项目(2023-YBGY-278)。

摘　　要：该文针对深埋隧洞衬砌结构开裂问题,提出了采用玄武岩纤维混凝土(basalt fiber reinforced concrete,BFRC)提升衬砌结构承载能力的方法。首先,对0~0.5%纤维体积率的BFRC试件进行拉压力学特性试验,获得最优纤维掺量,验证了素混凝土和最优掺量纤维混凝土损伤塑性(concrete damaged plasticity,CDP)模型参数;其次,采用数值模拟法建立了岩衬结构围岩-初期支护整体承载模型和二衬支护模型,获得了深埋隧洞二衬支护特性曲线,揭示了混凝土裂缝扩展规律;最后,定量分析了配筋率、二衬厚度和纤维混凝土对二衬正常使用及极限状态承载力的影响。研究结果表明:相较于素混凝土B0,0.2%纤维体积率的BFRC轴拉强度和劈拉强度最大增幅分别为12.81%和14.79%,0.5%纤维体积率的BFRC弯曲强度最大增幅为31.68%,综合考虑纤维体积率最优掺量选用0.2%;随着配筋率和二衬厚度的增加,二衬0.30 mm裂缝荷载P_(0.30)和极限状态承载力均呈线性增加,配筋率每增加0.10%,P_(0.30)平均增加约5.40%,二衬厚度每增加0.10 m,P_(0.30)平均增加约11.18%;掺入纤维可有效提升混凝土的抵抗裂缝扩展能力,混凝土初始开裂荷载和P_(0.30)可分别提升38.64%和5.54%。该文研究结果可为深埋隧洞岩衬结构设计和纤维混凝土应用提供参考。[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 fiber-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 fiber-reinforced concrete accurately simulated the peak ten

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 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]