Discussion of “Comparison of Base Shears Estimated from Floor Accelerations and Column Shears”

The author agrees with Dr. Pinho about difficulties associated with the use of different damping models in nonlinear dynamic analysis. However, the focus of the original manuscript was to illustrate the difference between base shear estimated from floor accelerations, denoted as inertial base shear, and base shear estimated from column shears, denoted as the structural base shear. The difference between the two base shears exists regardless of the damping model used in the nonlinear analysis. In order to illustrate this conclusion, the Los Angeles building of the original manuscript (Goel 2011) was re-analyzed for Earthquake No. 15 using two different Rayleigh damping models: C 1⁄4 α0mþ α1kinitial, in which the stiffness-proportional component is proportional to the initial elastic stiffness, kinitial, and C 1⁄4 α0mþ α1kcurrent, in which the stiffness-proportional component is proportional to the current stiffness, kcurrent.