Probabilistic Evaluation o-Story Steel MRF Subject to Post Earthquake Fires

Abstract

This paper investigates the structural performance of a steel moment resisting frame (MRF) subject to fire and fire following earthquake, using a methodology that is based on system level reliability analysis. The study includes probabilistic models for the quantities with uncertainty including fire load, and mechanical and thermal properties of steel at elevated temperatures. Performance of the structure is evaluated based on several different limit states, and at different fire locations. Results show that the location of fire in the frame (e.g., lower vs. upper floors and interior vs. exterior bays) affects the beam response. Compartments in the interior bays reach limit states faster than those on the perimeter, and upper floors reach limit sates sooner than lower floors. The post-earthquake damage does not affect the structural response under a fire for the considered limit states; however, fire following earthquake increases the drift demand on columns located on the perimeter of the structure.