Analisis Lateral Buckling Pada Subsea Pipeline Di Perairan Laut Jawa

Azzam, Fadhil Muhammad (2025) Analisis Lateral Buckling Pada Subsea Pipeline Di Perairan Laut Jawa. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Lateral buckling adalah bentuk ketidakstabilan struktural yang umum terjadi pada pipa bawah laut akibat ekspansi aksial termal yang tertahan oleh friksi tanah dasar laut. Ketika gaya aksial melebihi ambang tertentu, pipa dapat mengalami pembengkokan lateral secara tiba-tiba, yang berpotensi menimbulkan kerusakan struktural. Penelitian ini menganalisis perilaku buckling pipa melalui pendekatan analitik menggunakan metode Hobbs berdasarkan DNV-RP-F110 dan simulasi metode elemen hingga (FEA), dengan mempertimbangkan tiga variasi koefisien gesekan tanah (μ = 0.2, 0.35, dan 0.5). Hasil screening menunjukkan bahwa gaya aksial efektif (EAF) melebihi gaya inisiasi buckling (S∞) pada seluruh kondisi, menandakan potensi buckling tinggi. Lokasi kritis bergeser dari KP 6.8 (μ = 0.2) ke KP 4.1 (μ = 0.35) hingga KP 2.9 (μ = 0.5). Dari ketiga kondisi, μ = 0.35 dipilih untuk simulasi FEA karena posisi kritisnya sesuai dengan hasil pemindaian side scan sonar yang menunjukkan deformasi lateral aktual sebesar ±4.55 m. Hasil simulasi menunjukkan displacement lateral maksimum ±4.57 m dan tegangan von Mises hingga 298 MPa, melebihi batas leleh material API 5L X42. Pipeline gagal memenuhi kriteria Load-Controlled Condition (LCC) pada seluruh kondisi, dan hanya aman terhadap Displacement-Controlled Condition (DCC) pada μ ≤ 0.35. Temuan ini menegaskan pentingnya mitigasi struktural dan validasi kondisi lapangan untuk menjaga integritas jangka panjang pipa bawah laut.
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Lateral buckling is a common structural instability in subsea pipeline caused by restrained thermal axial expansion due to seabed friction. When axial forces exceed a certain threshold, the pipeline may deform laterally, potentially leading to structural failure. This study analyzes buckling behavior using the Hobbs analytical method based on DNV-RP-F110 and Finite Element Analysis (FEA), considering three soil friction coefficients (μ = 0.2, 0.35, and 0.5). Screening results indicate that the effective axial force (EAF) exceeds the buckling initiation force (S∞) in all scenarios, confirming high buckling potential. The critical location shifts from KP 6.8 (μ = 0.2) to KP 4.1 (μ = 0.35) and KP 2.9 (μ = 0.5). The μ = 0.35 condition was selected for FEA simulation since the predicted critical location matches side scan sonar observations, which recorded actual lateral deformation of ±4.55 m. The simulation yielded a lateral displacement of ±4.57 m and von Mises stress of up to 298 MPa, exceeding the yield strength of API 5L X42. The pipeline failed to meet Load-Controlled Condition (LCC) in all cases and only satisfied the Displacement-Controlled Condition (DCC) at μ ≤ 0.35. These findings emphasize the need for structural mitigation and field validation to ensure long-term subsea pipeline integrity.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Subsea Pipeline, Lateral Buckling, Friksi Tanah, Metode Hobbs, Simulasi Elemen Hingga.
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA347 Finite Element Method T Technology > TJ Mechanical engineering and machinery > TJ930 Pipelines (General). Underwater pipelines. T Technology > TN Mining engineering. Metallurgy > TN879.5 Petroleum pipelines
Divisions:	Faculty of Marine Technology (MARTECH) > Offshore Engineering > 54040-(S1) Undergraduate Thesis
Depositing User:	Fadhil Muhammad Azzam
Date Deposited:	27 Jul 2025 08:21
Last Modified:	27 Jul 2025 08:21
URI:	http://repository.its.ac.id/id/eprint/121704

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