Numerical Study on Mechanical Properties of Corroded Concrete Pipes before and after Cured-in-Place-Pipe Rehabilitation

Cured-In-Place-Pipe (CIPP) rehabilitation technology is widely utilized in pipeline rehabilitation projects and has exhibited favorable results. Nevertheless, the mechanical characteristics of pipelines after CIPP rehabilitation and the effectiveness of CIPP rehabilitation in repairing these mechanical characteristics remain unknown. To address these issues, a three-dimensional numerical model of a corroded concrete pipe before and after CIPP rehabilitation was established in the present study. To authenticate the accuracy of the numerical model, the numerical simulation data were compared with the full-scale test data from prior research, and the comparison outcomes show that the numerical model formulated in this study is reasonable and reliable. To appraise the repair effectiveness of CIPP rehabilitation, the mechanical properties of a corroded pipe, a CIPP-repaired pipe, and a normal pipe under traffic load were computed and compared, and the comparison outcomes demonstrate that the stress in the pipe bell, stress in the pipe spigot, vertical displacement of the pipe crown, and vertical displacement of the pipe invert were reduced by 39.8%, 16.7%, 24.7%, and 24.4%, respectively, after CIPP rehabilitation. Moreover, a series of three-dimensional numerical models were constructed to scrutinize the impacts of factors such as corrosion degree, corrosion angle, and traffic load on the mechanical properties of corroded pipelines before and after CIPP rehabilitation. The findings indicate that the stress on the pipe escalates with increasing corrosion degrees and diminishes with increasing corrosion angles; there are no noteworthy differences between the vertical displacement of the pipe and the von Mises stress of the CIPP liner for diverse corrosion degrees and corrosion angles; the amplification of the traffic load will augment the stress and displacement of the pipe and increase the rotation of the pipe, resulting in a significant upsurge in the stress of the CIPP liner at pipe joints. When the traffic load magnitude rises from 0.7 MPa to 1 MPa, the stress and displacement of the pipe and the von Mises stress of the CIPP liner were increased by 18.9%, 42.3%, and 42.1%, respectively.