Case studies of tall buildings have been conducted to provide direction for performance-based seismic design

Case studies of tall buildings have been conducted to provide direction for performance-based seismic design. The analytical building models were derived from actual building projects, and were assembled using software familiar to practicing engineers. The analytical building models were subjected to large numbers of earthquake ground motions from certain magnitude-distance bins to identify response statistics for various engineering demand parameters. Parameters of interest include roof drift, interstory drift, floor accelerations, wall and column shears, inelastic rotations, axial loads in outriggers, and collector and drag forces at critical floors. Various ground motion selection and scaling techniques are studied as well to identify which techniques produce reliable estimates of the median values and their dispersions.

The findings are useful from two perspectives. For ground motion selection and scaling procedures that are found to provide good estimates of median results but poor estimates of native dispersion in those results, the computed response statistics can be used to estimate statistics based on computed median values. For other ground motion selection and scaling methods, direct measures of these statistics can be derived directly from nonlinear dynamic analysis. These results are useful in estimating design values for ductile and nonductile response modes.