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Strength Analysis and Repair Strategy of Aged Steel Jetty Pile Riyanto, Raditya Danu; Syahroni, Nur; Mulyadi, Yeyes
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 18, No 1 (2021): February
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v18i1.34899

Abstract

Indonesia has 95.161 km coastal lines with a total of 17.504 islands. With this nature, Indonesia has 1.226 ports, with a total accumulated length of up to 92 km. However, not all these ports are in proper condition. For ports that have steel jetty piles, corrosion is one of the problems. This paper provides technical experience and methodology for analyzing the pier's corrosion conditions and evaluating existing corrosion's effect on its strength. The survey methodology and required data, including a survey of cathodic protection, visual conditions, and pile thickness, are discussed in this paper. The static strength analysis of the existing state structure was carried out. This article provides repair strategies, including repair methods and a study of the number of piles repaired. This methodology results in the recommendations for pile repair strategies and guidance on effective analytical methods in determining the number of repaired piles for aged steel jetty pile repair.
SOLUSI ANALITIK RESPON GERAKAN SURGE OCEAN THERMAL ENERGY CONVERSION BERBENTUK TENSIONED LEG PLATFORM (OTEC-TLP Wibowo, Yuni Ari; Riyanto, Raditya Danu; Alfaris, Lulut; Baswantara, Arif
MARLIN Vol 3, No 2 (2022): (Agustus 2022)
Publisher : Politeknik Kelautan dan Perikanan Pangandaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15578/marlin.V3.I2.2022.103-112

Abstract

Peningkatan kebutuhan energi dunia relatif mengalami peningkatan yang cukup signifikan dari tahun ke tahun. Kebutuhan akan Energi Baru Terbarukan (EBT) juga meningkat seiring dengan menurunnya cadangan energi fosil. Ocean Thermal Energy Conversion (OTEC) menajdi salah satu alternatif sumber EBT yang pengembangan teknologinya berkembang dalam beberapa dekade terakhir. Umumnya OTEC menggunakan barge sebagai struktur apung penyangganya, namun dengan bertambahnya kedalaman perairan barge menjadi tidak lagi ekonomis. Tipe struktur apung Tensioned Leg Platform (TLP) menjadi solusi pada daerah perairan dalam (>1000m). Struktur OTEC-TLP terdiri dari ponton dan kolom yang ditambatkan secara taut dengan memanfaatkan daya apung. Daya apung dari struktur ini dipengaruhi oleh perbedaan sarat air saat kondisi free floating dengan sarat air tertambat (DT). Perubahan DT akan mempengaruhi parameter hidrodinamika yang terdiri dari massa tambah, kekakuan, periode alami, gaya dan respon struktur. Studi ini dilakukan untuk mengidentifikasi pengaruh DT terhadap sensitivitas parameter hidrodinamika dengan pendekatan analitik. Persamaan Morison digunakan dalam studi analitik ini untuk menyelesaikan respon gerakan surge. Berdasakan studi yang dilakukan, semakin besar DT, menyebabkan kenaikan pada massa tambah, kekakuan, gaya dan respon struktur pada gerakan surge. Periode alami OTEC-TLP pada saat DT rendah memiliki nilai yang lebih besar dibandingkan dengan DT yang lebih besar, namun keduanya memiliki periode alami yang relatif lebih besar jika dibandingkan dengan periode gelombang dominan (2 – 30s). Kondisi ini menjadikan OTEC-TLP memiliki kondisi stationkeeping yang baik karena tidak berada pada area periode gelombang dominan.Increasing demand of energy worlwide is increasing significantly year on year. The need for New and Renewable Energy (NRE) also increases along with the decline in fossil energy reserves. Ocean Thermal Energy Conversion (OTEC) is a viable alternative sources of NRE which has been in the development process in the last few decades. In general, OTEC uses barge as its floater, however in accordance with increasing water depth, the barge becomes no longer economical. Tensioned Leg Platform (TLP) is a solution in deep water areas (>1000m). OTEC-TLP structure consists of pontoons and columns which are tethered by means of buoyancy. The buoyancy of floater is formed by the difference of drafts (DT) between tethered and free floating condition. Changes in DT will induce the hydrodynamic parameters consisting of added mass, stiffness, natural period, force and structural response. This study was conducted to identify the effect of DT on the sensitivity of hydrodynamic parameters with an analytical approach. Morison's equation is used in this study to solve the surge motion response. Based on this study, the greater DT induce the higher added mass, stiffness, force and response of the structure in surge motion. The natural period of OTEC-TLP at low DT has a larger natural period than the higher DT. However both of them have relatively larger natural periods when compared to the wave period (2 – 30s), this condition creates OTEC-TLP having a good stationkeeping responses.