Analisis Free Span pada Jalur Pipa Bawah Laut Menggunakan Multibeam Echosounder dan Side Scan Sonar Studi Kasus: Pipa Gas Transmisi Sswj (South Sumatera West Java) Jalur Pipa Gas Labuhan Maringgai-muara Bekasi PT. Perusahaan Gas Negara Persero (Tbk)

摘要

Indonesia is a country with the condition which is prone to trigger a natural disasters and it is called a hazard. The trigger of hazard could be a human activity. The human activity which triggers hazards is the construction of pipe bridge under the sea. This research area has an unevenness topography and pipe bridge under the sea. The impact of these conditions can lead to a free span.Free span analysis carried out after post-installation inspection process. The detection of free span on the underwater pipeline uses Multibeam Echosounder and Side Scan Sonar. The data which is used for this research are raw data Multibeam Echosounder, Side Scan Sonar data after real-time processing, sound velocity profile data and tide data. Multibeam Echosounder (MBES) is used for the the bathymetric survey to obtain the depth data and the seafloor topography. Meanwhile, Side Scan Sonar (SSS) is used for the interpretation of topography qualitative and quantitative objects.This research resulted in the condition of the sea floor that is a relative steep. Areas of the research that has a relative steep topography contained in KP 111.62- KP 111.83. Conditions of the free span identified in four locations in the study area. Location FS_1 has a span length of 94.4 meters and a span height of 3.31 meters. Location FS_2 has a span length of 93.94 meters and a span height of 10.66 meters. Location FS_3 has a span length of 58.12 meters and a span height of 1.87 meters. Location FS_4 has a span length of 98.4 meters and a span height of 4.93 meters. The free span indication which is resulted of multibeam echosounder and side scan sonar data processing can not identify the hazard on the study area.Key words : Pipe, Free Span, Multibeam echosounder, Side Scan Sonar, Hazard*) Penulis, Penanggungjawab