Performance of Offshore Steel Jacket Platforms under Near-source Ground Motion Type Pulses

Authors

  • M. Zeinoddini Professor, Civil Engineering Department, K. N. Toosi University of Technology, Tehran, Iran Email id:zeinoddini[at]kntu[dot]ac[dot]ir
  • S.A.Hossini, H. Matin Nikoo

Abstract

Behaviour of jacket type offshore structures under ordinary ground excitations has already been addressed by a number of researchers. However, their performance under near-source ground excitations has not been particularly addressed in the literature. Records from recent earthquakes, such as the Kobe Japan (1995) and Chi-Chi Taiwan (1999), have revealed that the dynamic excitations in near-source are dominated by a large, narrow band and long period pulse caused by rupture directivity effects. Failure and sever damages were reported to occur in specific bridges, quay walls and multistory buildings near to the shaking fault. The dynamic characteristics of the damaged structures were close to the traits of the rupture directivity and fling pulses.This paper deals with the behaviour of jacket offshore structures under near-source strong ground excitations. A finite element approach has been chosen for this study. The numerical model has first been verified against available experimental data on tubular frames from other researchers. The verified model has then been used to examine the response of the jacket platform models, typical to those in the Persian Gulf, under harmonic, near-source and far-source excitations. To get an insight into both the pre and post failure zones of the structure response, an Incremental Dynamic Analysis (IDA) methodhas been employed.  In general, it has been found that with some jacket models the near-source excitations appear quite critical as compared with those from the corresponding far-sources. Conversely, with other some models, the far-source excitations have been found to be more unfavorable.

 

Keywords: Offshore Steel Platforms, Near-field Earthquakes, Incremental Dynamic Analysis (IDA)

Downloads

Published

2020-12-19

Issue

Vol. 1 No. 2 (2014)

Section

Research Article

License

Declaration and Copyright Transfer Form

(to be completed by authors)

I/ We, the undersigned author(s) of the submitted manuscript, hereby declare, that the above manuscript which is submitted for publication in the STM Journals(s), is not published already in part or whole (except in the form of abstract) in any journal or magazine for private or public circulation, and, is not under consideration of publication elsewhere.

  • I/We will not withdraw the manuscript after 1 week of submission as I have read the Author Guidelines and will adhere to the guidelines.
  • I/We Author(s ) have niether given nor will give this manuscript elsewhere for publishing after submitting in STM Journal(s).
  • I/ We have read the original version of the manuscript and am/ are responsible for the thought contents embodied in it. The work dealt in the manuscript is my/ our own, and my/ our individual contribution to this work is significant enough to qualify for authorship.
  •  I/We also agree to the authorship of the article in the following order:

Author’s name                                    

 

1. ________________

2. ________________

3. ________________

4. ________________

 

We  Author(s) tick this box and would request you to consider it as our signature as we agree to the terms of this Copyright Notice, which will apply to this submission if and when it is published by this journal.