Seismic analysis of jacket platform against peak ground acceleration: A case study of a four-legged jacket platform

A platform jacket is a part of the structure of a marine building that has the function of supporting the upper structure. Jacket platform locations are generally built in offshore areas, so they are prone to environmental loads such as waves, wind, currents, and earthquakes. Seismic analysis of the platform jacket was carried out to evaluate the strength of the structure in the event of an earthquake. Modelling and analysis in this study were carried out using the Element software up to SACS. This study aims to analyze the strength of the jacket platform when receiving earthquake loads with a gradual increase in peak ground acceleration (PGA). This research is expected to contribute to the development of a platform jacket that is safe against seismic loads and provide insights related to the design behaviour of platform jackets against earthquake loads. The study's results showed a decrease in the strength of the platform jacket with the increase in PGA, with unity check (UC) results in the analysis of members that continued to increase as PGA increased. The minimum UC occurs at a PGA of 0.05g by 0.17, while for UC, the maximum is 0.99 at a PGA of 0.30g.