PROPOSING DRIFT PUSHOVER ANALYSIS AS AN ALTERNATIVE FOR CURRENT NONLINEAR STATIC SEISMIC EVALUATION PROCEDURES

There have been a few alternatives available for pushover analysis of buildings to estimate earthquake demands and predict seismic behavior in a real event. On the other hand, it is now well known that relative displacement along height of building is a major parameter controlling the level of damage throughout structure. Therefore, a more accurate pushover procedure can be one comprising of applying the drift pattern, instead of the lateral load distribution, to a building model. This is the idea that is pursued in this paper. The procedure of this new method is called drift pushover analysis, DPA. In this method, the displacement profile along the height of structure is determined using the generalized interstory drift spectrum and the structure is pushed with displacements (not forces) until a predefined displacement for each story is attained. In order to evaluate the proposed method, demand parameters including lateral displacement and story shear forces computed from conventional pushover analysis (CPA), modal pushover analysis (MPA) and drift pushover analysis (DPA) are compared with those of the nonlinear time history analysis (NTA), in Opensees analysis environment. It is shown that the new method DPA is successful in estimating demand parameters more accurately with less computational effort.

Keywords:

Drift Spectrum , Conventional Pushover , Modal Pushover , Drift Pushover , Nonlinear Time History Analysis