Investigation on the Effect of Pile Scouring on the Structural Behavior of a Recently-Built Fixed Jacket Platform

In offshore field, several past studies reveal that most of collapse failures are caused by lack of sufficient piles strength because loads are distributed and transmitted through piles body. Therefore, scour phenomena affects load transition and eventually pile strength. The necessity of the scouring phenomena investigation emerges when the scour depth becomes remarkable which can endanger jacket stability. In this paper, the simple stepping up method of soil curves is used for the sake of regarding scour by push over analysis of software SACS. A recently-built existing jacket platform namely SPD 19C is opted as a case study. Results shows that recently-built jacket platform RSR decreases with scour depth increasing. RSR decreasing becomes more sensible as scour depth increases. According to API RP2A collapse will be occurred in the range of RSR 1.6, results show that at RSR=1.6, collapse will be occurred in the scouring depth of 13.5m for recently-built platform, which approximately 27% lower RSR than their original state. So scour protection methods should be addressed in vulnerable areas as preventive alternatives.