Influence of Optimal Intensity Measures Selection in Engineering Demand Parameter of Fixed Jacket Offshore Platform

Abstract

This research identifies the significant optimal intensity measures (IM) for seismic performance assessments of the fixed offshore jacket platforms. A four-legged jacket platform for the oil and gas operation is deployed to investigate the seismic performance. The jacket platform is applied with nonlinearly modeled using finite element (FE) software OpenSees. A total of 80 ground motions and 21 different IMs are incorporated for numerical analyses. Nonlinear time-history analyses are performed to obtain the jacket structure’s engineering demand parameters (EDP): peak acceleration and displacement at the top of the structure. Four important statistical parameters: practicality, efficiency, proficiency, and coefficient of determination, are then calculated to find the significant IMs for seismic performance of the jacket structure. The results show that acceleration-related IMs: effective design acceleration (EDA), A95 parameter, and peak ground acceleration (PGA) are optimal IMs, and the acceleration-related IMs have good agreements with the acceleration-related EDP.

Determining Factors of Fixed Offshore Platform Inspections in Indonesia

“…Fixed offshore platforms are one of the most used types of offshore platforms; about 95% of the world's offshore platforms use a fixed platform [21]. There has been a significant increase in offshore structures, mainly in the renewable energy field [1]. These fixed platforms consist of a topside, jacket, and pile [22].…”

“…Fixed offshore structures are commonly used for various purposes in offshore industries, especially oil exploration [1,2]. Since the first commercial production in 1971 of offshore areas, until now, Indonesia has had 613 units of fixed offshore platforms: 54.65% of these are more than 20 years old and 24.63% are 16-20 years old [3].…”

Optimal Intensity Measures for Probabilistic Seismic Stability Assessment of Large Open-Pit Mine Slopes under Different Mining Depths

“…Several evaluation criteria have been proposed to determine the best IM for seismic risk assessment of various structures, including correlation, efciency, practicality, profciency, sufciency, relative sufciency, and hazard computability. To date, these criteria and extensive studies are mainly focused on buildings [22,23], bridges [24], dams [25], storage tanks [26], tunnels [27,28], ofshore platform [29,30], and nuclear power plant [31,32]. Due to the space constraints, an elaboration of the work about optimal IM for above-given structures is not shown herein.…”