Numerical validation of structural fire design for steel framed car park buildings

Abstract

The installed automatic sprinkler systems in car park buildings can control the fire spread between vehicles, leading to unique localized vehicle fire scenarios. An advanced structural fire design methodology specific to steel-framed car park buildings was proposed by Linus Lim [11] based on the overall performance of structures under localized fire. This paper aims to assess the accuracy and reliability of this design methodology through numerical modelling using ABAQUS. The validated approach of establishing finite element models for steel-framed structures is adopted to simulate an eight-bay car park frame under two different fire scenarios following the design procedure. The overall structural fire performance of simulated structures indicates that even though the structural beams generated plastic deformation in two fire scenarios, none reached failure in the simulation. The comparison of load between simulation and design shows that the structural fire design methodology overestimated the load on the structural components inducing a conservative design result, which can be used for the car park building structural fire design. It should be pointed out that the neighbouring beams at a lower temperature could sustain the additional load from the continuous bending beam right above the fire, resulting in better overall performance of steel beams in localized fire. The assumption of load redistribution between different beams was validated in simulation.