考虑喷射混凝土耐热性能的高地温隧道支护结构研究  

Study on Supporting Structure of High Geothermal Tunnel Considering Heat Resistance of Shotcrete

作　　者：罗明睿 陶亮亮 曾艳华[1,2] 欧灶华 崔圣爱[2] 叶跃忠[2] LUO Mingrui;TAO Liangliang;ZENG Yanhua;OU Zaohua;CUI Shengai;YE Yuezhong(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Sichuan Yongyuan Engineering Design Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]西南交通大学交通隧道过程教育部重点实验室,四川成都610031 [2]西南交通大学土木工程学院,四川成都610031 [3]四川永元工程设计有限公司,四川成都610031

出　　处：《铁道学报》2024年第11期170-179,共10页Journal of the China Railway Society

基　　金：四川省交通运输科技项目(2018-ZL-02)。

摘　　要：为获得适用于高地温隧道的支护特征曲线,依托某隧道,模拟高地温环境,通过材料组配设计、室内试验等手段,对喷射混凝土耐热性能进行研究。结果表明:配合比为0.45,使用无碱速凝剂、单掺20%矿粉的喷射混凝土,在35℃养护下性能较好。与标准养护条件相比,28 d抗压强度提高了10%,劈拉强度提高了14%。对岩石表面湿润后的干热环境下,其与岩石的黏结强度较高,较标准条件下,强度提高了44%。单掺矿粉替代水泥可降低水化热,在高温环境中能略微提升混凝土的各项性能。喷射混凝土具有明显的时变特性,考虑其时变特性可有助于合理支护时机的选取。研究成果有助于解决高地温隧道的热害问题,亦可为工程中相似热害环境支护问题提供参考。In order to obtain the support characteristic curve applicable to high ground temperature tunnels,the thermal performance of shotcrete was studied by means of material composition design and indoor tests,relying on a tunnel and simulating a high ground temperature environment.The results show that the shotcrete with a mix ratio of 0.45,alkali-free quick-setting agent and 20%mineral powder alone has better performance under 35℃curing.Compared with standard curing conditions,the 28 d compressive strength and the splitting strength increase by 10%and 14%respectively.The bond strength of the shotcrete to the rock is higher for the dry thermal environment after wetting the rock surface,with a 44%increase in strength compared to the standard conditions.Single blended mineral powder instead of cement can reduce the heat of hydration,and slightly improve the properties of concrete in high temperature environment.As shotcrete has obvious time-varying characteristics,considering its time-varying characteristics can help the selection of reasonable support timing.The research results can help to solve the thermal damage problem in high ground temperature tunnels,and also provide reference for support problems under similar thermal damage environment in engineering.

关 键 词：高地温隧道 喷射混凝土外掺料 无碱速凝剂 力学性能 黏结强度 

分 类 号：U451[建筑科学—桥梁与隧道工程]