CP Protiction on Piles

Abstract: A new liquefied natural gas (LNG) receiving terminal was constructed on the site of a decommissioned facility; construction basis of the LNG receiving terminal project included an effort to extend the life of the existing jetty structure and associated berths. A comprehensive integrity evaluation of the existing jetty structure confirmed that it was feasible and economical to refurbish the jetty for future service as a loading dock for the LNG terminal. The design life of the new facility was 30 years. The primary means for extending the life of the jetty was select replacement of severely degraded components, concrete repair works, and application of cathodic protection (CP). Life extension of the jetty presented a number of significant design and execution challenges. These include the scope of the retrofit work and the constraints required to safely apply CP to pre - stressed concrete. The jetty included a mix of pre - stressed concrete piles, partially coated steel piles and concrete support structures located in and above the splashzone. In an effort to extend the life of the jetty, the piles and other support structures were retrofitted with an impressed current CP system. Use of impressed current system required addressing significant design challenges including avoidance of hydrogen effects on pre - stressed tendons, and the CP monitoring of hundreds of submerged piles and atmospheric zones. This paper will discuss the basic jetty design as well as concrete u rebar corrosion protection needs. The CP design basis which included dividing the jetty structure into several distinct zones to assist with CP design will also be covered.

Keywords: LNG Jetty, Cathodic Protection and Corrosion

Edition: Volume 12 Issue 3, March 2023,

Pages: 524 - 526