Analisis Umur Kelelahan Pada Struktur Kaki Jacket Platform Akibat Scouring, Studi Kasus : Fasilitas Migas Di Perairan Indramayu

Arianto, Jeremia Jakim (2026) Analisis Umur Kelelahan Pada Struktur Kaki Jacket Platform Akibat Scouring, Studi Kasus : Fasilitas Migas Di Perairan Indramayu. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Fenomena scouring atau pengikisan tanah di sekitar pondasi merupakan salah satu faktor yang dapat menurunkan kapasitas dukung tanah dan memengaruhi respons struktur jacket platform terhadap beban lingkungan. Penelitian ini bertujuan untuk menganalisis pengaruh kedalaman maximum scouring terhadap kinerja struktur tripod wellhead platform melalui analisis in-place serta evaluasi umur kelelahan (fatigue life). Analisis dilakukan menggunakan dua pendekatan, yaitu metode cumulative damage secara global menggunakan perangkat lunak SACS dan metode fracture mechanics secara lokal menggunakan ANSYS. Hasil analisis in-place menunjukkan bahwa struktur masih memenuhi kriteria kekuatan dengan nilai Unity Check kurang dari 1,0 pada kondisi maximum scouring sedalam 1,14 m, meskipun terjadi redistribusi beban yang meningkatkan konsentrasi gaya pada beberapa sambungan struktur. Berdasarkan analisis cumulative damage, sambungan kritis berada pada Joint 605 dengan fatigue life sebesar 7,72 tahun, sehingga belum memenuhi target design service life selama 20 tahun. Selanjutnya, analisis fracture mechanics pada sambungan kritis dengan asumsi retak permukaan semi-elips menunjukkan prediksi kegagalan akibat perambatan retak terjadi setelah 15,56 tahun. Hasil penelitian ini menunjukkan bahwa kondisi maximum scouring memberikan pengaruh signifikan terhadap umur kelelahan struktur sehingga perlu dipertimbangkan dalam evaluasi integritas struktur lepas pantai selama masa operasinya.
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Scouring around foundation elements is one of the major factors that reduces soil bearing capacity and influences the structural response of offshore jacket platforms subjected to environmental loading. This study aims to investigate the effect of maximum scour depth on the structural performance of a tripod wellhead platform through in-place analysis and fatigue life assessment. The fatigue assessment was conducted using two approaches: the global cumulative damage method implemented in SACS software and the local fracture mechanics approach using ANSYS. The in-place analysis indicates that the structure still satisfies the strength requirement with a Unity Check value below 1.0 under the maximum scour condition of 1,14 m, although load redistribution increases the stress concentration in several structural joints. Based on the cumulative damage analysis, the critical joint is Joint 605 with a predicted fatigue life of 7.72 years, which does not satisfy the required 20-year design service life. Furthermore, the fracture mechanics analysis performed on the critical joint assuming a semi-elliptical surface crack predicts structural failure after 15.56 years. These findings demonstrate that maximum scouring significantly affects the fatigue performance of the jacket platform and therefore should be considered in offshore structural integrity assessments throughout its service life.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Jacket Platform, Scouring, Cumulative Damage, Fracture Mechanics, Umur Kelelahan, Jacket Platform, Scouring, Cumulative Damage, Fracture Mechanics, Fatigue Life.
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA347 Finite Element Method T Technology > TA Engineering (General). Civil engineering (General) > TA455.S6 Soil (Materials of engineering and construction) T Technology > TA Engineering (General). Civil engineering (General) > TA645 Structural analysis (Engineering) T Technology > TA Engineering (General). Civil engineering (General) > TA658 Structural design
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User:	Jeremia Jakim Arianto
Date Deposited:	22 Jul 2026 02:06
Last Modified:	22 Jul 2026 02:06
URI:	http://repository.its.ac.id/id/eprint/136134

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