PERANCANGAN DESAIN TENSION LEG PLATFORM 4 KOLOM DI SELAT MAKASSAR
The development of the offshore industry so far is highly dependent on the development of the oil and gas industry. The tension leg platform is similar to the conventional fixed platform construction. The alternative design principles that are designed need to know the basis for making offshore structures by following applicable codes such as the Standard Specification for Steel Forgings code, General requirements (ASTM), Offshore standard DNV-OS-C201 (Structural Design of Offshore Unit WSD Method), and DNV-RP-C205 (Environmental Conditions and Environmental Loads). In general, the environmental forces acting on the tension leg platform are in the form of a wave, current, and wind forces. The overall environmental load that occurs is 5,301 kN. Tension Leg Platform 4 Column is designed with a total overall size of 50 m x 50 m x 52.5 m. Then the hull system, consists of four circular steel columns, with a diameter of 28.28 m and an overall height the hull of 52.5 m. In the results of the TLP 4 column alternative design, it can be seen that the largest displacement result is on the dead load on the dz axis with a value of 0.05 m and the environmental load on the dz axis with a value of 0.42 m. The results of the Principle stress on the dead load and those that occur in the top, middle, and bottom P1 sections are 0.92 ksi, 145.03 ksi, 145.03 ksi, and the results of the Principle stress on the environmental load that occurs in the top, middle, and bottom P1 are 1.45 ksi, 23.2 ksi, 23.2 ksi then compared with the allowable stress on the ASTM A 788 steel used is 60 ksi. It can be seen from the results of the dead load modeling that the stress at the top is smaller than the allowable stress of the material so that the material selection is better. Then in the middle and bottom, the stress value is greater than the allowable stress so the material selection is not right for use in this modeling. So it is necessary to change the material for a material specification that is higher than ASTM A788 steel. In the environmental load value compared to the allowable stress on the same steel, it can be seen from the results of the SESAM modeling that the stress on the entire surface is smaller than the allowable stress of the material so that the material selection is better. Then, the calculation of Archimedes' law with the applicable conditions. After doing the calculations, the object's buoyant force is smaller than the weight of the structure with a value of 206,937 kN > 122,468.5 kN. So based on the requirements of Archimedes' law, it is said that the designed TLP structure experiences a floating state with a draft calculation of 7.8 m.
Keywords: Design Code, Tension Leg Platform, Structure Analysis
URI
https://repo.itera.ac.id/depan/submission/SB2208220034
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