STIFFNESS AND STRENGTH REQUIRED FOR CONTINUOUS COLUMNS TO MITIGATE DRIFT CONCENTRATIONS IN PARTICULAR STORIES (PART 1) : ESTIMATION ON FLEXURAL STIFFNESS AND YIELD STRENGTH REQUIRED FOR CONTINUOUS COLUMNS USING COUPLED SHEAR-FLEXURAL-BEAM MODELS

The 3-, 5- and 10-story coupled shear-flexural-beam (SFB) models with various flexural stiffness of the continuous columns (C.C.) are analyzed for the 20 SAC near-fault ground motions. It is found that drift response is sometimes significantly influenced by the inelastic behavior and drift concentrations in particular stories due to insufficient flexural stiffness of the C.C. The coupled SFB models with large flexural stiffness of the C.C. exhibit almost identical response to the equivalent SDOF model. The stiffness and strength required for the C.C. to mitigate large drift concentration in particular stories and to maintain the elastic state are quantitatively estimated.