公路隧道喷射型ECC物理力学性能及其喷层稳定性  

Physical and Mechanical Properties of Sprayable ECC in Highway Tunnels and its Spray Layer Stability

作　　者：胡时 李晓芳 蔡海兵[1] 韩辰悦 宋海清[1] HU Shi;LI Xiaofang;CAI Haibing;HAN Chenyue;SONG Haiqing(School of Civil Eng.and Architecture,Anhui Univ.of Sci.and Technol.,Huainan 232001,China;Shanxi Research Inst.for Clean Energy,Tsinghua Univ.,Taiyuan 030032,China;College of Civil Eng.,Tongji Univ.,Shanghai 200092,China;School of Urban Construction,Anhui Wenda Univ.of Info.Eng.,Hefei 231201,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]清华大学山西清洁能源研究院,山西太原030032 [3]同济大学土木工程学院,上海200092 [4]安徽文达信息工程学院城市建设学院,安徽合肥231201

出　　处：《工程科学与技术》2024年第3期109-121,共13页Advanced Engineering Sciences

基　　金：安徽理工大学高层次引进人才科研启动基金(2023yjrc76);安徽省高等学校科学研究项目(2022AH052853);国家自然科学基金项目(51778004)。

摘　　要：传统纤维增强水泥基复合材料(ECC)存在成本高、收缩大和应用场景局限等问题,且关于开挖扰动下公路隧道喷射型ECC层稳定性的研究尚不完善,此外缺乏对其工程应用后的监测评估。基于此,本文研究了公路隧道喷射型ECC的物理力学性能,分析了开挖扰动下围岩及喷射型ECC层的稳定性,并通过现场监测分析了其应用效果。结果表明:将脱硫石膏、混杂纤维、机制砂、膨胀剂和减缩剂引入ECC中,所研发的喷射型ECC物理力学性能满足公路隧道喷射混凝土的要求。基于数值模拟,当支护12 m后,喷射型ECC层的拉伸和压缩最大主应力较C25喷射混凝土(C25SC)层分别提高了36.8%、28.4%,并且其内侧拱顶的最大竖向位移较C25SC可降低3.15%,仅为1.23 mm。基于现场实测,在近似相同的围岩地质条件下,使用喷射型ECC较C25SC,能够降低10.26%的竖直沉降变形,此外其喷层表面未发现开裂、线状渗水等情况。因此,喷射型ECC在公路隧道支护领域具有广阔的应用前景。Traditional fiber-reinforced cementitious composites(ECC)are limited in application due to their high cost and considerable shrinkage.Additionally,research on the stability of sprayable ECC layers in highway tunnels under excavation disturbance remains incomplete,with inad-equate monitoring and evaluation following its engineering applications.This study investigates the physical and mechanical properties of spray-able ECC in highway tunnels.It analyzes the stability of the surrounding rock and the sprayable ECC layer under excavation and evaluates the ap-plication effectiveness through field monitoring.The results indicate that the physical and mechanical properties of sprayable ECC can meet the requirements for shotcrete in highway tunnels by incorporating desulfurized gypsum,hybrid fiber,manufactured sand,an expansion agent,and a shrinkage-reducing agent into the ECC mix.Based on numerical simulations,for a 12-m support,the peak tensile and compressive principal stresses of the sprayable ECC layer increase by 36.8%and 28.4%,respectively,compared to the C25 shotcrete(C25SC)layer.The maximum ver-tical displacement of the inner arch reduces by 3.15%compared to C25SC to only 1.23 mm.Based on on-site monitoring,under the same geolo-gical conditions of the surrounding rock,sprayable ECC minimizes the vertical settlement deformation by 10.26%compared to C25SC.In addi-tion,no cracking or linear seepage is observed on the surface of the sprayable ECC layer.Therefore,sprayable ECC holds broad application pro-spects in highway tunnel support with appropriate modifications.

关 键 词：喷射型ECC 公路隧道 物理力学性能 数值模拟 稳定性 

分 类 号：U454[建筑科学—桥梁与隧道工程]