【摘要】 采取叠合式套拱方案,加固拱顶带纵向裂缝的隧道衬砌结构,并基于1∶10的相似模型试验,量化研究拱顶松动荷载作用下结构的破坏机制,即受力变形特征、裂缝发展过程、短期刚度衰减规律以及破坏模式,进而探讨补强结构的极限承载能力计算方法,并分析原衬砌裂缝深度对补强效果的影响。研究表明,地层抗力为10 MPa/m时,松动荷载下,补强结构的受力变形过程分3个阶段,以拱顶开裂、拱顶叠合面错开为分界点;主裂缝集中于拱顶、拱腰部位,整体破坏为延性破坏,破坏荷载由拱顶截面控制;补强结构的开裂荷载、短期刚度、破坏荷载与既有裂缝深度满足线性关系。更多还原

【Abstract】 Based on laboratory model test with 1∶10 geometric similarity factor,stacked inner lining has been taken to reinforce the structure with axial cracks on the top lining. With test data,we conclude the failure mechanism of reinforced lining under loose pressure,by analyzing its lateral deformation,development of main cracks,short-term stiffness of lining apex and final failure mode. In addition,we also quantitively study the influence of crack depth on the ultimate bearing capacity. It is important to note that the cracked tunnel works under loose load and the rock resistance coefficient is 10 MPa/m. The results show as follows:(1) the process of failure can be divided into three stages,namely,specimen crack stage,"arch crack-penetrated arch crack",penetrated arch crack-specimen fail.(2) The main cracks in on the vault and haunch,the overall failure mode is brittle failure.(3) There exist linear relationship between existed crack depth and crack moment,short term stiffness,ultimate load.更多还原