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Title: The Seismic Reliability of Offshore Structures Based on Nonlinear Time History Analyses

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.2963938· OSTI ID:21149077
 [1];  [2];  [3];  [4]
  1. Associate Professor, Civil Engineering Department, Graduate School, Tehran South Branch of the Islamic Azad University (IAU), Jamalzadeh St., Keshsavarz Blvd, Tehran 14187 (Iran, Islamic Republic of)
  2. Graduate Student, Civil Engineering Department, Graduate School, Tehran South Branch of the Islamic Azad University (IAU), Jamalzadeh St., Keshsavarz Blvd, Tehran 14187 (Iran, Islamic Republic of)
  3. Assistant Professor, Civil Engineering Department, Tehran Central Branch of the Islamic Azad University (IAU), Tehran (Iran, Islamic Republic of)
  4. PhD Student, Graduate Program, International Institute of Earthquake Engineering and Seismology (IIEES), P.O. Box 19395/3913, Tehran (Iran, Islamic Republic of)

Regarding the past earthquakes damages to offshore structures, as vital structures in the oil and gas industries, it is important that their seismic design is performed by very high reliability. Accepting the Nonlinear Time History Analyses (NLTHA) as the most reliable seismic analysis method, in this paper an offshore platform of jacket type with the height of 304 feet, having a deck of 96 feet by 94 feet, and weighing 290 million pounds has been studied. At first, some Push-Over Analyses (POA) have been preformed to recognize the more critical members of the jacket, based on the range of their plastic deformations. Then NLTHA have been performed by using the 3-components accelerograms of 100 earthquakes, covering a wide range of frequency content, and normalized to three Peak Ground Acceleration (PGA) levels of 0.3 g, 0.65 g, and 1.0 g. By using the results of NLTHA the damage and rupture probabilities of critical member have been studied to assess the reliability of the jacket structure. Regarding that different structural members of the jacket have different effects on the stability of the platform, an 'importance factor' has been considered for each critical member based on its location and orientation in the structure, and then the reliability of the whole structure has been obtained by combining the reliability of the critical members, each having its specific importance factor.

OSTI ID:
21149077
Journal Information:
AIP Conference Proceedings, Vol. 1020, Issue 1; Conference: 2008 seismic engineering conference: Commemorating the 1908 Messina and Reggio Calabria earthquake, Reggio Calabria (Italy), 8-11 Jul 2008; Other Information: DOI: 10.1063/1.2963938; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English