STRENGTH ANALYSIS OF FIXED STEEL JACKET STRUCTURE UNDER DYNAMIC EFFECTS OF WAVE LOADS IN VIETNAM SEA CONDITIONS

Abstract

This paper presents an algorithm to evaluate the dynamic effects of wave loads on fixed steel Jacket structures (Jacket structures) through the ratio between the dynamic response and the static response of the structure under the action of sea waves. The algorithm proposed in this paper can be applied to evaluate the dynamic effects of wave loads in the strength analysis for Jacket structures, to provide a limit to the selection of a method for analyzing the structure, and the structure period. The research to find out the limit on the distance between the wave period and the natural period of the structure to choose the appropriate structural analysis method for each sea area is necessary. Because the current Design standards give the “3.0 s or 2.5 s rule”, (use the quasi-static method when T_max ≤ 3.0 s or T_max ≤ 2.5 s) and also only it is clear that the scope of this rule is for the North Sea and the Gulf of Mexico. The research results of this paper will answer the question: Is the use of standards for the North Sea and Gulf of Mexico to analyze Jacket structures in marine conditions outside the study area of ​​the standards suitable? Hoped that this paper will be a reference for engineers when choosing a method of strength analysis of Jacket structures in specific marine conditions at the construction site.