Pile Length Optimization in Fixed Template Offshore Platform Using Risk Reduction Approach

Document Type : Original Article

Authors

1 Ph.D. student of university of Qom

2 Assistant professor, University of Qom

3 3Assistant Professor, University of Qom

Abstract

The purpose of risk management is managing the uncertainties by considering activities for identifying, assessing, monitoring, and reducing the impact of risks. Three strategies may be used to deal with the kind of risks that exist in projects: risk acceptance, risk transfer, and risk reduction. Events that can affect the economical goals of a project must be identified and evaluated so that they can be appropriately managed. Fixed jacket-type offshore platform (JTOP) as an expensive and necessary structure in energy facilities. in this research, the effect of knowledge increasing on the risk reduction and cost optimization for  JTOP is studying. This paper focuses on optimizing the pile length of the fixed jacket-type offshore platforms and reducing the conservative design by using the risk reduction approach. Fixed offshore platform in South Pars Gas Fields of Iran as a case study.Increasing the Geotechnical knowledge and reducing the pile lengths is performed as considering similar geotechnical study at this regions and pile dynamic driving test (PDA), updating the pile bearing capacity base on increased knowledge for geotechnical data, and finally assessing the result based on inplace analyzing Pile driving result shows increasing the longterm soil bearing capacity, So first of all the required strength and parameters extracted from the existing data with analyzing and comparing where to adjust and matches with the lower limit of the theoretical equations. Finally, this new assumption is used for optimizing the pile length design.  This research shows that that the numerical analysis and assumptions that have been used in the design procedure are conservative and a proper risk management program with the knowledge increasing could have resulted in risk reduction. The analysis process that has been used in the present research leads to the pile cost reduction by 11% that is considerable for stakeholders in such an expensive structure. The most important innovation in this paper is the use of the results of pile driving operation for optimal pile design because, in pile driving operation, piles with design diameter are used.

Keywords