Comparison between Spectral Modal Dynamic Analysis and Equivalent Static Seismic Analysis

Resumo

The study consists of analyzing and comparing the equivalent static behavior and the dynamic behavior,
under seismic excitation, of a structure located in the city of Portoviejo (Republic of Ecuador). The building was
designed for office occupancy, having five floors and being irregular in plan. The equivalent static analysis uses
the Ecuadorian seismic code that defines the maximum acceleration of the soil on the construction site, the soil
amplification coefficients, the type of importance of the building, the types of construction irregularity and the
factor of reduction of the seismic resistance. In the dynamic analysis of the structure was used the modal analysis
and to represent the seismic force, the response spectrum for accelerations. Additionally, a nonlinear static analysis
(Pushover) was used to determine the behavior of the structure after overcoming the elastic regime going until the
collapse. The results show the values of the basal shear forces, both for the equivalent static analysis and in the
spectral modal analysis, demand/capacity curves and transverse displacements in the structure.