Numerical analysis of straight and curved underground pipeline performance after rehabilitation by cured-in-place method

Abstract

Underground pipelines are prone to damage by corrosion in Taiwan due to the humid climate and the aging and overuse of pipelines. No-dig technologies are necessary, as the cities in Taiwan are highly populated. Rehabilitation methods, including the cured-in-place pipe (CIPP) method, provide an alternative to the new no-dig installation methods, which are comparatively more expensive. In this study, the numerical analysis software ABAQUS was used to simulate straight-line and curved underground pipelines damaged by corrosion. After calibration by small-scale physical modeling in the laboratory, numerical models were applied to the analysis of the mechanical behavior of straight-line and curved underground pipelines. To analyze the performance of the CIPP rehabilitation method, different scenarios for straight-line and curved pipelines were considered. These included before- and after-rehabilitation, different internal pressures and surface loading conditions, and different liner deformabilities and pipe-liner interface strengths. The results suggest that the CIPP method can reinforce damaged pipes by reducing stress concentration and differential displacement near the corrosion void. However, proper liner thickness, liner material properties, and pipe-liner interface strength are essential for well-designed CIPP rehabilitation. Keywords: Straight-line pipeline, Curved pipeline, No-Dig, Rehabilitation, Cured-in-place-pipe, Soil-pipe interaction