Assessment of Large-Diameter Ductile Iron Pipeline Joint to Transverse Loading using Distributed Fiber Optic Sensing

Abstract

Buried pipelines, especially segmented ones in the water networks, face natural hazard events like earthquakes or landslides. Vulnerabilities in connections between pipe segments are a concern. While new connection joints are emerging, the performance of these systems, especially for large-diameter joints, remains inadequately evaluated. The study conducts a 4-point bending test on a 24-inch NS-type ductile iron pipe manufactured by Kubota Corporation that are extensively instrumented with distributed fiber optic sensors. These sensors measure the continuous strain development of the pipelines in the longitudinal and circumferential directions to capture the actual behavior of the pipes. Overall, this study provides insights into the behavior of large-diameter ductile iron pipes under transverse loading conditions and can inform future improvements to pipeline design, which can ultimately reduce the risk of damage to pipelines from seismic events.