Stochastic Evaluation of Offshore Carbon Fibre Reinforced Concrete Decks

A stochastic evaluation of the performance of Carbon Fibre Reinforced Plastics (CFRP) offshore platforms considering submerged and partially submerged environmental conditions was analyzed using Swedish code, Boverket (2004). A Probability-based analysis using First Order Reliability Method (FORM) was used to determine the safety index of the deck considering varied load ratios, effective depths of the deck, and ultimate strength of Fibre Reinforced Plastics (FRP) tendons. The results generated from FORM indicates that the theoretical framework for risk assessment based on the Joint Committee for Structural Safety JCSS (2003) gave maximum safety index of the CFRP deck to be 3.49 which is higher than the limit set by the JCSS (2003) code. Hence, the deck can adequately transmit the given loading conditions when designed in accordance with the Boverket (2004). The flexural as well as shearing resistance is also within safety limits; and is 500% greater than that of a corresponding steel reinforced concrete platform. The imposed load that can be sustained on a 150mm thick CFRP deck is 20kN/m2; while that of 200mm thick CFRP deck is 30kN/m2.