1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

The modal pushover analysis (MPA) is an improvement of the standard nonlinear performance-based seismic evaluation of structures, based on the first mode constant force distribution over the height. The MPA is based on the theory of dynamics of structures, it retains conceptual simplicity and the computational attractiveness of a standard pushover analysis (SPA). MPA considers higher vibration modes using modal expansion procedure. It can evaluate displacements, inter-storey drift ratios (IDR), and plastic hinge rotations with high accuracy. The total seismic demand is presented as the sum of the effective inertia forces which are in accordance with the invariant force distribution of each significant mode considered. The structure is incrementally pushed to the target displacement, whereby the relationship between force and roof-displacement is successively established, the yield point of the structure estimated, and the capacity curve derived for each mode separately. Target displacement is estimated by solving the governing differential equation of motion or from response spectra.
Application of the method is shown on the example of the 10-storey parking garage located at the airport Zürich with dimensions in the plan view of 85 x 105 m approximately.