Investigation of mechanical properties of corroded concrete pipes after cured-in-place-pipe (CIPP) rehabilitation under multi-field coupling

•The full-scale test of concrete pipes after CIPP rehabilitation was carried out.•A numerical model of concrete pipes after CIPP rehabilitation was established.•The mechanical properties of the pipe-liner composite structure were studied.•Various cover depths, traffic loads and fluid loads were considered. The pipeline is mainly subjected to soil load, fluid load and traffic load, the mechanical properties of corroded concrete pipes after cured-in-place-pipe (CIPP) rehabilitation under multi-field coupling have not been revealed. In this paper, a 3D numerical model of buried concrete pipes after CIPP rehabilitation under the coupled effects of the soil load, traffic load and fluid load were established based on the results of the full-scale test. The influence of cover depth, traffic load and fluid load on the maximum principal stress of the pipeline, vertical displacement of the pipeline, the von Mises stress of the CIPP liner and the circumferential bending moment of pipe-liner composite structure were analyzed. Results showed that the cover depth and traffic load have a greater influence on the crown, invert, and springline of the pipe and has a lesser influence on the shoulder and haunch of the pipe; The stress and the circumferential bending moment of the pipeline is mainly caused by the soil load, the vertical displacement of the pipeline and the von Mises stress of CIPP liner is mainly caused by the traffic load, and the fluid load has little effect on the pipe-liner composite structure.