SEISMIC BEHAVIOR OF FRP-CONCRETE-STEEL DOUBLE SKIN TUBULAR COLUMNS

This paper reports on the first experimental study on the seismic behavior of FRP-concrete-steel composite double-skin tubular columns (DSTCs). Six DSTCs that were made of high-strength concrete (HSC) were tested under constant axial compression and reversed-cyclic lateral loading. The main parameters of the experimental study included the axial load level, level of confinement, concrete strength and thickness of inner steel tube. Test results indicate that DSTCs are capable of developing very high inelastic deformation capacities under simulated seismic loading, which makes them an attractive alternative for construction of new earthquake-resistant columns. Examination of the test results have lead to a number of significant conclusions in regards to the influence of the important column parameters on the performance of DSTCs. These results are presented together with a discussion on the influence of the main parameters on the seismic behavior of DSTCs.