Research on reinforcement design method of composite profiles for rail transit tunnels

Abstract

With the increasing service life of rail transit tunnels and the continuous changes in the surrounding soil, structural defects in tunnels have become increasingly prominent, posing significant risks to tunnel integrity and the operational safety of rail systems. This study focuses on the reinforcement design method utilizing prefabricated composite profiles for rail transit tunnels, aiming to clarify their application performance and advantages in tunnel engineering. Through literature review and case studies, existing problems and limitations in current tunnel reinforcement design method ologies are critically evaluated. A novel reinforcement design approach based on composite profiles is proposed. The findings indicate that this method offers notable advantages in enhancing the structural stability and durability of tunnels. Furthermore, a quantitative classification mechanism for shield tunnel defects is established. Based on the tunnel defect composite index(TDCI), tunnel defects are categorized into five levels. Corresponding reinforcement schemes, including prefabricated composite profile reinforcement and pre-reinforcement strategies, are developed according to defect severity. Using tunnel section scanning data, prefabricated components of the composite profiles are manufactured and assembled on-site. These components are anchored and bonded to the tunnel lining through bolts and structural adhesive, followed by grout injection, to achieve effective reinforcement. This study provides robust technical support for the structural reinforcement of shield tunnels.

Keywords

tunnel defect classification / prefabricated composite profiles / tunnel reinforcement design / TDCI score / reinforcement scheme