This approximate calculation method is developed and designed for replacement of the arbitrary Non-Linear Push-Over (NLPO) method. The proposed rational methodology is an intermediate engineering approach between the Linear-Elastic Dynamic Modal Response Spectrum method and Non-Linear Dynamic Time Domain (History) method and comprises six steps, i.e.
Perform a numerical 3-D Linear-Elastic Dynamic Modal Response Spectrum calculation based on the relevant Horizontal Elastic Ground Acceleration Response Earthquake (Seismic) Spectrum (input). Utilize the Complete Quadratic Combination (CQC) method instead of the Square-Root-of-Sum-of-Squares (SRSS) method. Because it is well-known for a long era that application of the Square-Root-of-Sum-of-Squares (SRSS) method in seismic analysis for combining modal maxima can yield significant errors.
Resolve the numerical calculated mass of the structure mstructure. It is tacitly assumed that the sum of the effective (participating) modal masses for the vibration modes taken into
account amounts to 100% of the total mass of the structure, i.e. meffective (participating) modal mass = mstructure.