Experimental Performance Evaluation of Pipelines Rehabilitated with Cured-In-Place Pipe Liner under Earthquake Transient Ground Deformations

The cured-in-place pipe (CIPP) liner technology involves installation of flexible polymeric composite liners coated with thermosetting resin to the inner surfaces of existing pipelines. This innovative technology provides an efficient, economic, and environmentally friendly method for rehabilitation of structurally compromised underground pipelines without expensive and disruptive excavation. However, the unverified and unquantified seismic performance of CIPP liner-reinforced pipelines under earthquake transient ground deformations (TGD) remains a barrier to the deployment of this technology in seismically active regions. Full-scale quasi-static and dynamic tests were performed on five water-pressurized ductile iron (DI) pipelines, with 150-mm (6.0-in.) nominal diameter and 9.14-m (30-ft) nominal length, reinforced with one type of CIPP liner commonly used in engineering practice. This paper evaluates experimentally the behavior of the liner-strengthened DI pipelines under static loading and also quantifies their seismic response under TGD-induced tensile axial loads. The test results indicate that CIPP liner provides substantial longitudinal tensile stiffness and strength to the joints of DI pipelines and improves significantly their seismic behavior under high-intensity TGD.