{"title":"Investigations on mechanical behavior of longitudinal joints in segmental tunnel linings reinforced with epoxy bonded-bolted steel plates","authors":"Xian Liu , Jianyu Hong , Zhen Liu","doi":"10.1016/j.tust.2025.106724","DOIUrl":null,"url":null,"abstract":"<div><div>For shield tunnel linings reinforced with epoxy bonded-bolted steel plates, the mechanical behavior of longitudinal joints is a key factor affecting the overall load-bearing capacity and durability of the structure. However, current research and design efforts mostly remain at the conceptual or qualitative analysis stage, with insufficient consideration of the collaborative mechanical behavior of components such as steel plates, epoxy adhesive, and chemical anchors. The corresponding design method is also missing. Therefore, to thoroughly investigate the mechanical behavior and failure process of longitudinal joints reinforced with epoxy bonded-bolted steel plates and to quantify the contributions of steel plates, epoxy adhesive, and chemical anchors to the joint’s mechanical performance, in this study, full-scale joint tests under positive and negative bending moments and develop three-dimensional refined nonlinear finite element models of the longitudinal joints are conducted. By conducting parameter attribution analysis, the key factors affecting the macroscopic mechanical performance indicators of the joint are identified, the roles of steel plates, epoxy adhesive, and chemical anchors are also revealed. The research provides a theoretical basis for the design and application of shield tunnel structures reinforced with epoxy bonded-bolted steel plates. The study results are as follows: (1) The failure of longitudinal joints reinforced with epoxy bonded-bolted steel plates can be divided into three stages: elastic stage, stress redistribution stage, and ultimate failure stage. (2) The bearing capacity of the reinforced joints is mainly determined by the dimensions of the steel plates and the shear performance of the epoxy adhesive interface, while stiffness is determined by the steel plate dimensions. Ductility depends on the steel plate dimensions, epoxy adhesive shear performance, and chemical anchors. (3) Under positive bending moments, the steel plates share the stress of the bolts, while under negative bending moments, they strengthen the intrados concrete of the joint. (4) The epoxy adhesive connects the steel plates and longitudinal joint, with tension-shear composite failure occurring under positive bending moments and compression-shear composite failure under negative bending moments. (5) After the epoxy adhesive interface fails, the chemical anchors promptly share the interface load, providing additional safety reserves.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"163 ","pages":"Article 106724"},"PeriodicalIF":6.7000,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tunnelling and Underground Space Technology","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0886779825003621","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
For shield tunnel linings reinforced with epoxy bonded-bolted steel plates, the mechanical behavior of longitudinal joints is a key factor affecting the overall load-bearing capacity and durability of the structure. However, current research and design efforts mostly remain at the conceptual or qualitative analysis stage, with insufficient consideration of the collaborative mechanical behavior of components such as steel plates, epoxy adhesive, and chemical anchors. The corresponding design method is also missing. Therefore, to thoroughly investigate the mechanical behavior and failure process of longitudinal joints reinforced with epoxy bonded-bolted steel plates and to quantify the contributions of steel plates, epoxy adhesive, and chemical anchors to the joint’s mechanical performance, in this study, full-scale joint tests under positive and negative bending moments and develop three-dimensional refined nonlinear finite element models of the longitudinal joints are conducted. By conducting parameter attribution analysis, the key factors affecting the macroscopic mechanical performance indicators of the joint are identified, the roles of steel plates, epoxy adhesive, and chemical anchors are also revealed. The research provides a theoretical basis for the design and application of shield tunnel structures reinforced with epoxy bonded-bolted steel plates. The study results are as follows: (1) The failure of longitudinal joints reinforced with epoxy bonded-bolted steel plates can be divided into three stages: elastic stage, stress redistribution stage, and ultimate failure stage. (2) The bearing capacity of the reinforced joints is mainly determined by the dimensions of the steel plates and the shear performance of the epoxy adhesive interface, while stiffness is determined by the steel plate dimensions. Ductility depends on the steel plate dimensions, epoxy adhesive shear performance, and chemical anchors. (3) Under positive bending moments, the steel plates share the stress of the bolts, while under negative bending moments, they strengthen the intrados concrete of the joint. (4) The epoxy adhesive connects the steel plates and longitudinal joint, with tension-shear composite failure occurring under positive bending moments and compression-shear composite failure under negative bending moments. (5) After the epoxy adhesive interface fails, the chemical anchors promptly share the interface load, providing additional safety reserves.
期刊介绍:
Tunnelling and Underground Space Technology is an international journal which publishes authoritative articles encompassing the development of innovative uses of underground space and the results of high quality research into improved, more cost-effective techniques for the planning, geo-investigation, design, construction, operation and maintenance of underground and earth-sheltered structures. The journal provides an effective vehicle for the improved worldwide exchange of information on developments in underground technology - and the experience gained from its use - and is strongly committed to publishing papers on the interdisciplinary aspects of creating, planning, and regulating underground space.