Abstract
Water delivery pipelines are usually constructed into a composite structure through installing steel or plastic liners into a finished tunnel and filling the annular space with cementirics material, for improving its hydraulic performance, prevention of water leakage and protection of the lining. However, many recent failure accidents of pipelines indicate that the buckling failure of the internal liners is still an important structural concern. In this study, fifteen specimens of composite pipes are tested under water pressure with the aim to clarify the buckling mechanism and improve the current design method. The experimental results clarified the acting condition of water pressure, the effects of filling material and construction faults on the buckling critical pressure, and the buckling mechanism. Based on the experimental results, the problems in the existing buckling design were discussed and an improved design method was proposed.
