Mechanical sensitivity analysis of pipe-liner composite structure under multi-field coupling

Cured-in-place pipe (CIPP) has become one of the most widely used pipeline trenchless rehabilitation technologies because it has the advantages of needing no grouting, rapid curing, and short construction time. However, previous research has not yet revealed the mechanical sensitivity of pipe-liner composite structures. In this paper, a numerical model for a pipe-liner composite structure under multi-field coupling of the traffic load, earth pressure and water flow was first established based on an Abaqus, Fluent and mesh-based parallel code coupling interface (MpCCI). Then, the maximum principal stress of the pipeline, vertical displacement of the pipeline, von Mises stress of the CIPP liner and vertical displacement of the CIPP liner were selected as evaluation indicators, and the CIPP thickness, cover depth, traffic load, corrosion width, corrosion depth, and water quantity were selected as sensitive factors of the pipe-liner composite structure. Finally, the mechanical characteristics of the pipe-liner composite structure were analysed under condition of different sensitive factors; moreover, the sensitivity of the sensitive factors was ranked based on the sensitivity coefficient. The research results are consistent with previous research providing a theoretical basis for the optimal design of wall thicknesses for CIPPs.