Evaluation of Lateral Load Patterns for Pushover Analysis

Abstract

Performance based seismic engineering is the modern approach to earthquake resistant design, which attempts to predict buildings with predictable seismic performance rather than based on prescriptive empirical code formulations. The performance of a building depends on various parameters out of which lateral load pattern is most critical. FEMA 273 & ATC-40 adopts specific pattern of lateral loading for nonlinear static analysis, widely known as pushover analysis. For a performance evaluation the load pattern selection is likely to be more critical than the accurate determination of the target displacement. The load patterns are intended to represent and bound the distribution of inertia forces in a design earthquake. This paper includes the evaluation of different loading patterns for pushover analysis applied on R.C.C. building. The capacity curve (V/W) to displacement for different levels was obtained for three different types of lateral loading namely, Triangular (k=1), Parabolic (k=2) and Rectangular.