Electronic Theses and Dissertation

Struktur baja Moveable Bridge Pelabuhan Ulee Lheue berperan penting dalam mendukung operasi kapal feri RO-RO, namun berada pada lingkungan laut yang agresif sehingga rentan mengalami degradasi akibat korosi. Penelitian ini bertujuan menentukan laju korosi serta menghitung sisa umur pakai (Remaining Life) struktur baja H-beam pada Moveable Bridge Pelabuhan Ulee Lheue. Metode penelitian meliputi survei lapangan, inspeksi visual, dan pengujian tak merusak (Non-Destructive Test) menggunakan Ultrasonic Thickness Gauge untuk memperoleh ketebalan aktual pada komponen top flange, bottom flange, dan web. Pengukuran dilakukan pada sejumlah titik yang menunjukkan indikasi korosi; pada setiap titik diambil tiga kali pengukuran dan digunakan nilai ketebalan minimum sebagai kondisi paling kritis. Data ketebalan dianalisis menggunakan pendekatan API 570 untuk menghitung laju korosi, kemudian digunakan dalam perhitungan Remaining Life Assessment. Hasil menunjukkan laju korosi dan sisa umur tidak merata dan terkonsentrasi pada zona tertentu. Laju korosi tertinggi ditemukan pada top flange zona Main Beam Kanan sebesar 0,42 mm/tahun dengan Remaining Life −14 tahun, yang mengindikasikan elemen telah melewati batas aman dan memerlukan tindakan segera. Sebaliknya, laju korosi terendah sebesar 0,01 mm/tahun dengan Remaining Life hingga 478 tahun terdapat pada web flange zona Cross Beam 1, menunjukkan kondisi relatif aman. Secara umum, bottom flange merupakan bagian paling rentan akibat paparan lingkungan laut dan siklus basah–kering (wet–dry cycle) selama operasi jembatan. Studi ini menegaskan bahwa RLA berbasis API 570 efektif untuk mengidentifikasi elemen kritis dan menetapkan prioritas pemeliharaan.

The steel structure of the Moveable Bridge at Ulee Lheue Port plays a critical role in supporting RO-RO ferry operations; however, its location in a highly aggressive marine environment makes it susceptible to corrosion-induced degradation. This study aims to determine the corrosion rate and evaluate the remaining service life of H-beam steel members of the Moveable Bridge at Ulee Lheue Port. The research methodology includes field surveys, visual inspections, and non-destructive testing using an ultrasonic thickness gauge to measure the actual thickness of the top flange, bottom flange, and web components. Thickness measurements were conducted at several locations exhibiting corrosion indications; at each location, three measurements were taken, and the minimum thickness was adopted to represent the most critical condition. The thickness data were analyzed using the API 570 approach to calculate corrosion rates, which were subsequently used in the remaining life assessment. The results indicate that corrosion rates and remaining life are non-uniform and concentrated in specific zones. The highest corrosion rate was observed at the top flange of the right main beam, reaching 0.42 mm/year with a remaining life of −14 years, indicating that this component has exceeded the acceptable safety limit and requires immediate intervention. In contrast, the lowest corrosion rate of 0.01 mm/year, with a remaining life of up to 478 years, was found at the web of Cross Beam 1, indicating a relatively safe condition. Overall, the bottom flange is identified as the most vulnerable component due to continuous exposure to the marine environment and wet–dry cycles during bridge operation. This study confirms that an API 570-based remaining life assessment is effective for identifying critical structural elements and establishing maintenance priorities