Analysis of the Progressive Collapse of Buildings underHigh Temperatures Using Successive ApproximationTechnique

This paper presents an investigation of the disproportionate collapse of multi-store steel buildings in a natural fire situation due to the progressive failure of their columns.For this purpose,it is intended to evaluate the effects of the redistribution of stress and vertical displacements of columns with the evolution of the temperature addressing,also,the impacts of the localized faults of these structural elements.In addition,another objective of this paper is the development of a practical analysis approach,which is called by successive approximations.As a methodology,advanced computational techniques were developed to predict the structural behavior of the building as the temperature reduces the strength and stiffness of its structural elements.For the parametric study,the overall response of the building was investigated through fire simulations in many columns.The results showed that the phenomenon of redistribution of stresses that occur during the heating period is essentially due to the reduction in the modulus of elasticity of the steel.In addition,the study pointed out that the use of advanced computational techniques through the use of successive approximations technique is an excellent alternative to study the progressive collapse of buildings subject to high temperatures.