-, Febrianti (2017) Analisis Local Buckling Pipa Bawah Laut 20 inch pada saat Instalasi dengan Metode S-Lay di Blok DA dan BH, Selat Madura. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Pipa bawah laut telah terbukti efisien dan efektif karena pelaksaan tranportasinya tidak tergantung oleh cuaca, namun proses instalasi pipa bawah laut sangat bergantung pada kondisi lingkungan seperti gelombang dan arus yang mengenai pipa secara langsung yang berpengaruh dengan gerakan barge. Sebelum dilakukan proses instalasi, dilakukan analisis besar tegangan terlebih dahulu agar diketahui pipa berada dalam kondisi yang diijinkan. Pada penelitian ini, metode instalasi yang sesuai adalah metode S-Lay, dimana pipa akan dianalisis ketika proses instalasi akibat beban dinamis. Beban dinamis berpengaruh pada kejadian buckling yang mengakibatkan kegagalan ketika proses instalasi. Permodelan barge dilakukan dengan bantuan software MOSES dan analisis dinamis instalasi pipa dilakukan dengan bantuan software OFFPIPE. Jika telah didapatkan tegangan yang terjadi pada pipa, analisis dilanjutkan dengan perhitungan local buckling berdasarkan DNV OS F-101 (2013) untuk mengetahui apakah terjadi local buckling. Dari hasil analisis yang dilakukan, pipa mengalami tegangan maksimum sebesar 81.66% SMYS pada kedalaman 109 m dengan gelombang datang arah 0o, sehingga keseluruhan tegangan yang terjadi pada pipa tidak melebihi tegangan izin dan dapat disimpulkan bahwa semakin besar kedalaman air laut maka semakin besar tegangan yang diterima oleh pipa. Nilai unity check terbesar untuk local buckling bernilai 0.738 pada kedalaman 109 m, maka tidak terjadi local buckling di sepanjang 27 km pipeline.
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Subsea pipeline
s
have proven to be efficient and effective since their transport
operat
ions are not depend on weather, however the installation processes are very
dependent on environmental conditions
such as waves and currents that affect
pipelines directly which will also affect the barge motion. Prior to the installation
process, stress
analysis will be the first to analyzed to know whether the
stress
that
occurs on pipeline is save
or not
. In this study, with 109 m water depth, the most
appropriate installation method is using S
-
Lay and the pipeline will be analyzed
due to dynamic load. The dynamic load will determine that pipeline will occur
any buckling that resulting to failure. Barge
model will
be modeled with MOSES
while for the dynamic analysis will be modeled with OFFPIPE. When the stress
number that occurs on pipeline is available, the analysis will be continue to local
buckling
analysis
using DNV OS
-
F101 (2013)
to know the occuran
ce of local
buckling along the 27 km pipeline. From this study, the maximum stress
is
81.66% SMYS or 365.84 MPa in 109 m water depth
with
0
o
wave
direction
, so
the
stress along 27 km pipeline is bellow the allowable
values
based on DNV OS
-
F101 (2013) whic
h 87% SMYS or 389.74 MPa.
The highest unity check value for
local buckling analysis is 0.738 in 109 m water depth.
In conclusion
the deeper
the water the greater stress will occur on the pipeline and there is no occurance of
local buckling along the 27 km
pipeline.
| Item Type: | Thesis (Undergraduate) |
|---|---|
| Uncontrolled Keywords: | Installation, Pipeline, Stress, Strain, Overbend, Sagbend, dan Local Buckling. |
| Subjects: | T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures |
| Divisions: | Faculty of Marine Technology (MARTECH) > Marine Engineering > 36202-(S1) Undergraduate Thesis |
| Depositing User: | Febrianti . . |
| Date Deposited: | 05 Oct 2017 03:33 |
| Last Modified: | 06 Mar 2019 07:40 |
| URI: | http://repository.its.ac.id/id/eprint/45266 |
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