Intensity Measures for Probabilistic Structural Fire Engineering

A framework for probabilistic structural fire engineering has recently been proposed. It is based on the Pacific Earthquake Engineering Research Center Performance-Based Earthquake Engineering approach which performs a hazard analysis, structural analysis and loss analysis to assess a building's performance as a result of ground motions. Similar to earthquake engineering, the assessment in fire requires the calculation of intensity measures, engineering demand parameters, damage measures and decision variables for a full assessment of the fire effects, the structural response, the extent of damage and the resulting loss. A number of fire intensity measures have been proposed by a few authors. However, these have been found to only partially reflect the severity of the fire, thereby not uniquely capturing the consequent structural response. For realistic assessments of damage and costs of reinstatement, more appropriate intensity measures are required. Using a two-span reinforced concrete beam as an example, the present research identifies ideal intensity measures by investigating several alternatives and selecting the one with the least dispersion of results with engineering demand parameters.