Analisis Risk Based Inspection (RBI) Terhadap Subsea Pipeline Akibat Upheaval Buckling

Yumm, Cindy Diniharziany (2019) Analisis Risk Based Inspection (RBI) Terhadap Subsea Pipeline Akibat Upheaval Buckling. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pipeline memiliki risiko kegagalan yang perlu diperhitungkan salah satunya adalah upheaval buckling. Dalam tugas akhir ini penulis melakukan analisis risiko akibat upheaval buckling pada subsea pipeline dengan moda kegagalan downward required force terhadap total downward force (MK1) dan gaya aksial terhadap beban kritis Euler (MK2). Pipeline ini dimodelkan menggunakan software AUTOPIPE untuk mendapatkan defleksi dan displacement stress expansion ratio (SR) menggunakan codes ASME B31.8 Gas Transmission and Distribution Piping System. Kemudian probabilita kegagalan didapatkan dengan simulasi Monte Carlo. Untuk konsekuensi kegagalan didapatkan dengan metode semi-kuantitatif Risk Based Inspection (RBI), dengan kategori human fatalities (A1), environment (A2), dan property (A3). Dari hasil perhitungan didapat semua tegangan yang bekerja pada pipeline tergolong dibawah allowable stress yaitu, hoop stress sebesar 201.24 MPa, longitudinal stress sebesar -133.37 MPa, dan 291.77 MPa untuk combined stress. Namun untuk gaya aksial efektif bersifat kompresif sebesar -8001.24 kN yang akan menjadi driving force upheaval buckling. Untuk hasil perhitungan tingkat risiko kedua moda kegagalan mendapat tingkat yang sama dikarenakan kategori dari probabilita kegagalan yang terjadi berada pada kategori 2 dengan nilai 4.92x10-4 dan 5.06x10-4. Tingkat risiko kategori terhadap human fatalities (A1) adalah very low /2B, kategori terhadap environment (A2) adalah low /2C dan kategori terhadap property (A3) adalah very low /2B. Sehingga didapatkan interval inspeksi efektif sesuai dengan peringkat risiko akibat kedua moda kegagalan tersebut yaitu 8 tahun sekali dengan metode inspeksi yaitu Intelligent Pig (Geo Pig).
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Pipeline has a risk of failure that needs to be taken into account, one of which is upheaval buckling. In this final task the authors conducted a risk analysis due to upheaval buckling on the subsea pipeline with a downward required force failure mode for total downward force (MK1) and axial forces on Euler critical loads (MK2). This pipeline is modeled using AUTOPIPE software to obtain a deflection and displacement stress expansion ratio (SR) using ASME B31.8 Gas Transmission and Distribution Piping System codes. Then the probability of failure is obtained by a Monte Carlo simulation. For the consequences of failure obtained by the semi-quantitative method of Risk Based Inspection (RBI), in the categories of human fatalities(A1), environment(A2), and property(A3). From the calculation results, all the stresses acting in the pipeline are classified as below the allowable stress, namely hoop stress of 201,24 MPa, longitudinal stress of -133.37 MPa, and 291.77 MPa for combined stress. For effective axial forces it is compressive at -8001.24 kN which will be a driving force upheaval buckling. For the calculation of the risk level both modes of failure get the same level because the categories of failure probability that occur are in category 2 with values 4.92x10-4 and 5.06x10-4. The risk level of the human fatality (A1) category is very low / 2B, the environment category (A2) is low / 2C and the property damage category (A3) is very low / 2B. So that the effective inspection interval is obtained according to the risk rating due to the two modes of failure, namely once every 8 years with the inspection method, Intelligent Pig (Geo Pig).

Item Type: Thesis (Undergraduate)
Additional Information: RSKe 658.155 Yum a-1 2019
Uncontrolled Keywords: Upheaval Buckling, Risk Based Inspection, Pipeline, AUTOPIPE, Monte Carlo.
Subjects: T Technology > T Technology (General) > T174.5 Technology--Risk assessment.
T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures
Divisions: Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User: Yumm Cindy D.
Date Deposited: 07 Jun 2021 07:32
Last Modified: 22 Sep 2021 02:43
URI: http://repository.its.ac.id/id/eprint/60362

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