摘要
运营隧道出现开裂、渗漏水、腐蚀等严重病害时,对衬砌病害的治理不仅要考虑支护结构的受力状况,还需考虑支护材料的性能。基于某病害隧道二次衬砌置换项目,开展了多尺度聚丙烯纤维混凝土(Multi-scale Polypropylene Fiber Reinforced Concrete,MPFRC)的二次衬砌现场浇筑试验,对衬砌强度、隧道表观、初期支护与二次衬砌接触压力、混凝土应变等进行长期观测与数据采集,研究了纤维混凝土二次衬砌结构的受力特性。结果表明:纤维对混凝土的强度提升明显,抗压、劈裂抗拉和抗折强度分别增长了7.51%、11.45%和26.95%;普通混凝土段与纤维混凝土段初期支护与二次衬砌最大接触压力均在拱脚,分别为282.63 kPa和231.83 kPa;二次衬砌纤维混凝土的应变相比于普通混凝土要小约45.45%,其应变-时间曲线相对平缓、数值更加稳定;MPFRC提高了衬砌强度的安全性,研究成果可为类似工程的病害预防与治理提供参考。
When lining cracking,water leakage,corrosion and other diseases occur in operating tunnels,the treatment of lining diseases should not only consider the stress condition of the supporting structure,but also the performance of the supporting materials.Based on a tunnel secondary lining replacement project,a field test of the secondary lining of Multi-scale Polypropylene Fiber Reinforced Concrete(MPFRC)was carried out.The long-term observation and data collection were carried out on the lining strength,tunnel appearance,contact pressure between the primary support and the secondary lining,and concrete strain.The mechanical characteristics of the fiber-reinforced concrete secondary lining structure were studied.The results show that the strength of fiber to concrete is obviously improved under the condition of this ratio,and the compressive strength,split tensile strength and flexural strength have increased by 7.51%,11.45%and 26.95%,respectively.Secondly,the maximum contact pressures of the ordinary concrete section and the fiber-reinforced concrete section are both at the arch foot,which are 282.63 kPa and 231.83 kPa,respectively.Thirdly,the strain amplitude of fiber-reinforced concrete is about 45.45%smaller than that of ordinary concrete,its strain curve is relatively flat,and the value is more stable.MPFRC enables the safety of lining structures to be enhanced.The research can provide a reference for the disease control of similar projects.
作者
孙德彬
杨沛文
任联玺
梁宁慧
刘鎏
Sun Debin;Yang Peiwen;Ren Lianxi;Liang Ninghui;Liu Liu(CCCC Asset Management Co.,Ltd.,Beijing 100013,P.R.China;CCCC Road and Bridge Construction Co.,Ltd.,Beijing 101107,P.R.China;Shanghai Tunnel Engineering and Rail Transit Design&Research Institute,Shanghai 200235,P.R.China;School of Civil Engineering,Chongqing University,Chongqing 400045,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2023年第3期833-843,共11页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(50334060)
国家科技支撑计划子课题(2006BAJ27B05)。
关键词
运营隧道
聚丙烯纤维混凝土
试验研究
二次衬砌
强度安全系数
highway tunnel
polypropylene fiber reinforced concrete
experimental research
secondary lining
strength safety factor
