Inelastic Response of Tubular Steel Offshore Towers

Abstract

Three alternative experimental methods for subjecting structural models of steel offshore towers to severe inelastic lateral loadings simulating siesmic effects are described. These pertain to either pseudo‐static or pseudodynamic methods of loading, or to experiments performed using a shaking table. These methods are evaluated with respect to their advantages and disadvantages. Test results are highlighted to provide insight into the inelastic cyclic behavior of this type of structure. Since the seismic problem is by its very nature nondeterministic, seismic experiments primarily provide a data base for verifying the capabilities of available computer programs. Methods for predicting the inelastic seismic response of braced tubular steel platforms are briefly reviewed. Comparisons of experimental with analytical results are then presented to indicate the confidence that can be placed in such analytical predictions.