Incremental wave analysis method: An alternative to load factor method in SACS pushover analysis

摘要

Many offshore jacket platforms in Malaysia are operating beyond their design life. In reassessment for life extension, Pushover Analysis is used to acquire the reliability of the platforms. Pushover Analysis imposes loadings onto platform model by incrementally increasing the Load Factor (LF) until the platform exceeds specified displacement or collapse limit. Recent study has established a new approach to perform Pushover Analysis. It is called the Incremental Wave Analysis (IWA) method. IWA increases wave height which coherently increases lateral load acting on the platform. Hence, to quantify the differences, this study compares both the methods; including analyzing Reserve Strength Ratio (RSR) and failure mechanism. In IWA apart from wave height other prospective significant parameters such wind speed and wave period are studied. The study concludes that IWA results in a lower RSR than LF, even when the wave period is included. But LF has more member failures compared to IWA.