DESIGN AND RELIABILITY ANALYSIS OF FOUR LEGGED OFFSHORE STRUCTURE IN NATUNA SEA

• Main Author: Fathurridho Hermanto, Mochammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/41902
• Institution: Institut Teknologi Bandung

An offshore platform is a building built offshore to support the activities of the oil and gas industry. Types of offshore platforms vary according to the function and shape of the structure. The type of offshore platform in this final project is jacket platform remains as a wellhead platform. Offshore platforms need to be well designed to meet the design limit state. Analysis that needs to be done are in- place, seismic and fatigue. In-place analysis considering the structure is already in the field with the result of member unity check and joint can unity check, deflection and pile capacity. Seismic analysis considers the dynamic load of earthquakes in the field with the results of members unity check and joint can unity check and pile capacity. Fatigue analysis of wave dynamics discusses structure response to wave force during design life with service life results. In design, many factors are approved in several parameters such as wave parameters and structural responses. With the choice of design parameters, it is necessary to analyze the reliability of the structure. Structure satisfactory performance cannot be assured. However, satisfactory performance probabilities can be determined by reliability analysis. Besides probability of satisfying satisfactory performance, another result that can be obtained is the reliability index. In this final project the reliability analysis is carried out based on the reserve strength ratio results of the pushover analysis. All analyzes were carried out based on API RP- 2A WSD design standards and several other standards. Structure and loads modeling is done using SACS 5.6 software. The final results of in-place and seismic analysis meet API RP-2A WSD design standards. The results of fatigue analysis gave a service life of 51.6419 years. The structure has high reliability with a reliability index of 6.25.