Effectiveness of concrete grouting method for deep-sea pipeline repairs

Abstract

This study aims to assess the effect of a concrete grouted layer on the collapse pressure of pipes under external pressure. The system consists of a concrete grouting layer and a high-strength plastic jacket. Six specimens with varying degrees of defects are tested to obtain their collapse pressures under external pressure, and four specimens are then repaired. The results show that the repair method restores the collapse pressure of the pipe to 39.15%–100% that of the undamaged pipeline. In addition, a numerical model is established and validated, and systematic parametric studies are conducted to supplement the test results. The experimental and numerical results show that the ultimate collapse pressure of the pipe is significantly influenced by the repair measures of the concrete grouted layer. Based on the parametric study, the main parameters that affect the collapse pressure of the repaired pipes are identified. The relationship between the collapse pressure and the geometry of the concrete grouted layer is analysed, and optimal parameters for the concrete grouted layer are obtained. The results show that installing concrete reinforcement is an effective technology for the rapid repair of defective pipes.