Earthquake Risk Analysis of Reinforced Concrete Frame Structures

Abstract

Reinforced concrete (RC) frame structures in high seismic regions generally experience many earthquakes, developing inelastic deformations under strong ground motions which requires nonlinear dynamic analysis procedures for complete assessment of the seismic resistant design of RC frame structures. On the other hand, estimating seismic loss and assessing seismic performance of buildings is essential for decision making and risk management. Performance newlinebased earthquake engineering (PBEE) has provided a useful tool to incorporate the seismic hazard, structural analysis, building information, and relevant uncertainties into performance assessment and loss estimation. This study deals with a methodology based on Incremental Dynamic Analysis (IDA) to assess probabilistic seismic performance and to determine the structural performance, damage levels, fragility and hazard-survival probability of various low newlinerise, midrise and high rise (3, 5, 10, 15, 20 and 25 storied) RC frames which are seismically designed and detailed for Zone-V as per Indian standard code of practice (IS 1893 Part I, 2002 and IS 13920, 1993) and then designed by adopting capacity design concept of columns in flexure and contribution of floor reinforcement to beams from American Concrete Institute standard (ACI 318-08). A group of 20 ground motion records used by Vamvatsikos and Cornell newline(2002) are selected with appropriate scaling in terms of intensity measuresfor performing IDA of RC frames on IDARC platform. Further, seismic risk assessment and loss estimation of low rise, midrise and high rise RC frames is performed to quantify the seismic hazard probabilities. The newlineresults provide complete information of low to high rise multi-storey RC frames at various damage states for earthquake events of different annual probabilities. During this study it is observed that by adopting capacity design principles, buildings perform well at higher intensity ground motions.