Studi Eksperimen Scouring pada Pipa Meletak dan In-Trench Akibat Gelombang Reguler

Rahayu, Novia Dwi (2017) Studi Eksperimen Scouring pada Pipa Meletak dan In-Trench Akibat Gelombang Reguler. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Jaringan pipa bawah laut merupakan salah satu fasilitas pendistribusian minyak dan gas bumi dari platform lepas pantai menuju pantai yang diangap lebih efisien. Namun, penggunaan pipa masih mempunyai kendala dimana peletakkan pipa akan mempengaruhi lingkungan sekitarnya. Pola aliran air akan berubah ketika terdapat struktur yang menghalangi aliran. Hal tersebut dapat menyebabkan penggerusan (scouring) di bagian bawah pipa yang mengakibatkan kondisi pipa freespan. Jika freespan terlalu panjang, maka akan terjadi kegagalan struktur dengan waktu singkat. Dalam tugas akhir ini akan dilakukan eksperimen mengenai scouring terhadap pipeline di flume tank Laboratorium Energi dan Lingkungan Laut Jurusan Teknik Kelautan FTK ITS. Model uji yang digunakan yaitu pipa berbahan PVC yang berukuran diameter 1,5 in. Ukuran d50 tanah yaitu 0.55 mm dengan specific gravity 2.8. Gelombang yang digunakan yaitu gelombang reguler dengan variasi tinggi gelombang sebesar 11 cm, 13 cm, dan 15 cm. Posisi pipa terhadap seabed divariasikan meletak (e/D=0) dan in-trench (e/D = -0.05, e/D = -0.075, dan e/D = -0.1). Kedalaman air 50 cm dan 40 cm. Kedalaman dan lebar scouring terbesar terjadi pada kondisi pipa meletak (e/D=0) dengan kedalaman air 40 cm dan tinggi gelombang 15 cm. Kedalaman scouring 0.989 cm dan lebar scouring 8.314 cm. Waktu yang dibutuhkan untuk terjadinya kedalaman scouring maksimum yaitu 25 menit. ================================================================== Submarine pipeline is one of the media for the distribution of oil and gas from offshore platform to on shore which is considered more efficient. However, the use of pipe still has any problem about its positioning that can affect the environment around. The pattern of water flow will change when there is a structure that blocks flow. That can cause scouring at the bottom of the pipe resulting in a freespan pipe condition. If not correctly calculated when designing the pipe, then there will be structural failure with a short time. In this final project will be conducted experiments on the effect of scouring on the pipeline in the flume tank of Energy and Ocean Environment Laboratory of Ocean Engineering Department FTK ITS. The test model used is a PVC pipe with 1.5 inch in diameter. Soil diameter size is d50 by 0.55 mm with specific gravity of 2.8. Wave used is regular waves with variations of wave height, on seabed and in-trench pipe and water depth. Pipe position toward seabed was variated by on-seabed (e/D=0) and in-trench (e/D = -0.05, e/D = -0.075, and e/D = -0.1). Water depth are 50 cm and 40 cm.The largest depth and width of scouring occurs in pipe conditions (e / D = 0) with a water depth of 40 cm and a wave height of 15 cm. Scouring depth 0.989 cm and scouring width 8.314 cm. Time spended on a maximum height of scouring is 25 minutes.

Item Type: Thesis (Undergraduate)
Uncontrolled Keywords: eksperimen, gelombang reguler, pipa bawah laut, scouring
Subjects: Q Science > QE Geology > QE571 Sedimentation and deposition. Sediment transport.
T Technology > TC Hydraulic engineering. Ocean engineering
Divisions: Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User: Novia Dwi Rahayu
Date Deposited: 18 Jan 2018 03:09
Last Modified: 06 Mar 2019 07:53
URI: http://repository.its.ac.id/id/eprint/45363

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