大面积腐蚀隧道衬砌结构的新型加固技术及承载能力分析

Zha Xicao, Lei Mingfeng, Sun Ningxin, Li Yongheng, Liu Linghui, Duan Lian, Wang Lichuan

School of Civil Engineering, Central South University, Changsha 410075, China.

MOE Key Laboratory of Engineering Structures of Heavy Haul Railway (Central South University), Changsha 410075, China.

Materials (Basel). 2023 Apr 4;16(7):2871. doi: 10.3390/ma16072871.

Affected by the erosive environment, tunnel lining concrete in the long-term service zprocess often exhibits engineering diseases such as concrete corrosion degradation and loss of strength, decreasing the stability of the tunnel lining structure and the traffic safety. Based on HTG tunnel project, the basic distribution rule of tunnel lining corrosion and macro mechanical properties of corroded concrete were explored in this paper through engineering disease site investigation. Then, on this basis, aiming at large-scale corrosion of tunnel lining structure, two reinforcement and repair schemes are proposed, corrugated steel plate reinforcement method and channel steel reinforcement method. Indoor component tests are carried out on the two reinforcement schemes. The failure characteristics and stress and deformation law of tunnel lining members after reinforcement and repair were verified. The analysis showed that the failure process of the reinforced specimens on the tensile side could be divided into the non-cracking stage and the working stage with cracks, and the cracking load and failure load of the specimens were significantly increased. The bearing capacity of the reinforced specimens was divided into the ultimate bearing capacity against cracking and the ultimate bearing capacity during failure. Finally, the calculation methods of the bearing capacity of the channel steel reinforcement method and the corrugated steel plate reinforcement method were derived. Comparative analysis shows that the results of numerical simulation, experimental testing and theoretical simplification methods are close to each other, and the maximum deviation is less than 8%. The established method for calculating the bearing capacity of corroded components after reinforcement is reliable and can be used for the design calculation of corroded lining reinforcement.

受侵蚀环境影响，长期服役过程中的隧道衬砌混凝土常出现混凝土腐蚀劣化、强度损失等工程病害，降低了隧道衬砌结构的稳定性和交通安全。本文以HTG隧道工程为依托，通过工程病害现场调查，探究了隧道衬砌腐蚀的基本分布规律及锈蚀混凝土的宏观力学性能。在此基础上，针对隧道衬砌结构的大面积腐蚀问题，提出了两种加固修复方案，即波纹钢板加固法和槽钢加固法。对两种加固方案进行了室内构件试验，验证了加固修复后隧道衬砌构件的破坏特征及应力变形规律。分析表明，受拉侧加固试件的破坏过程可分为无裂缝阶段和有裂缝工作阶段，试件的开裂荷载和破坏荷载均显著提高。加固试件的承载力分为抗裂极限承载力和破坏时的极限承载力。最后，推导了槽钢加固法和波纹钢板加固法的承载力计算方法。对比分析表明，数值模拟、试验测试和理论简化方法的结果较为接近，最大偏差小于8%。所建立的加固后锈蚀构件承载力计算方法可靠，可用于锈蚀衬砌加固的设计计算。