Earthquake or seismic analysis is a subset of structural analysis which involves the calculation of the response of a structure subjected to earthquake excitation. This is required for carrying out the structural design, structural assessment and retrofitting of the structures in the regions where earthquakes are prevalent. Various seismic data are necessary to carry out the seismic analysis of the structures. These data are accessible into two ways viz. in deterministic form or in probabilistic form. Data in deterministic form are used for design of structures etc whereas data in probabilistic form are used for seismic risk analysis, study of structure subjected to random vibration and damage assessment of structures under particular earthquake ground motion. Major seismic input includes ground acceleration/velocity/displacement data, magnitude of earthquake, peak ground parameters, duration etc.
In this chapter, the seismic response of the structures is investigated under earthquake excitation expressed in the form of time history of acceleration. The response is investigated for the structures modeled as Single Degree of Freedom (SDOF) and discrete Multi Degree of Freedom (MDOF) System.