RELIABILITY ANALYSIS OF 4-LEGGED AND 3-LEGGED OFFSHORE FIXED PLATFORM WITH STATIC PUSHOVER LOAD BY WSD AND LRFD METHOD

• Main Author: NABIYL (NIM: 25515305), NABIGH
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29438
• Institution: Institut Teknologi Bandung

<p align="justify"> The most common reference in Indonesia is the standard of American Petroleum Institute (API) RP 2A, consists of two methods: WSD (Working Stress Design) and LRFD (Load and Resistance Factor Design). The API standard was developed based on water conditions in the Gulf of Mexico that are relatively more extreme than Indonesian waters. There is a need for further study on the relevance of API standards to Indonesian waters condition, by reviewing the value of reserve strength ratio (RSR) and reliability index value (&#946;). Case study of offshore platform structures of 4-Legged and 3-Legged jacket types in Natuna Sea waters. The analysis of the ultimate limit by the static pushover method results in a minimum RSR value of 4-legged offshore platform structure at either a 0-degree combination of WSD or LRFD loading and on the 3-Legged offshore structure structure at 270 degrees in either the combination of WSD or LRFD loading. Reliability index value (&#946;) offshore platform structure 4-Legged case study is 1.030529 for LRFD and 1.08404 for WSD and for 3-Legged case study is 1.028141 for LRFD and 1.044226 for WSD conditions. The RSR value and &#946; values of the case study platform are well above the minimum requirements, ie, the RSR value of 0.8 and the &#946; value of 3.71, it can be because the value of Unity Check optimization result of structure almost all close to 1 . Thus, it can be concluded that the application of API RP 2A WSD and API RP 2A LRFD standards in offshore platform planning in the Natuna Sea waters is less effective. There needs to be an adjustment of coefficients related to the condition of the waters at the offshore platform of the case study. <p align="justify">