Large-Scale Fault Rupture Tests on Pipelines Reinforced with Cured-in-Place Linings

Abstract

Cured-in-place linings (CIPLs) are flexible fiber-reinforced polymer linings used to rehabilitate aging pipelines in situ. They also can strengthen utilities against transient and permanent ground deformation caused by earthquakes, thus providing added value through seismic retrofitting. This paper presents the results of full-scale fault rupture tests to characterize the debonding, axial elongation, and bending performance of pipelines with circumferential cracks and weak joints strengthened with CIPLs and subjected to abrupt ground deformation. The results of finite-element simulations were compared with the experimental fault rupture response of jointed pipelines with and without CIPL reinforcement. The results of a numerical model that accounts for debonding between the lining and pipe as Mode II fracture propagation were in good agreement with full-scale fault rupture test results. Recommendations are made for applying the modeling and experimental results for in situ strengthening of underground utilities against earthquakes and other sources of permanent ground deformation.