EXTREME ENVIRONMENTAL LOAD MODELS FOR WAVE AND CURRENT RESPONSE SURFACE METHOD

Abstract

The three most uncertain environmental design loads acting on offshore structures are wave height, current and wind velocity. If the reliability of structure is to be determined, then we need to have limit state function for load which requires that we should transform the environmental loads into load model. Load model, which predicts the load, will ultimately affect the design resistance and thus its final impact on cost could be large. Since, there are many offshore structures located in different offshore regions in Malaysia, the calibration of the environmental load model, should be evaluated to determine which model fits best. To obtain the environmental load model, response surface technique is generally applied. Load models suggested by DNV and ISO code are analysed to determine the best model fit for local conditions of Malaysia. Base shear, wave height and current velocity are used in a linear fit to determine polynomial response surface. The results showed that due to the geography of Malaysia different regions might have to use specific load models instead of a general load model for all regions.