Reinforced Concrete Beam under Support Removal-Parametric Analysis.

Seweryn Kokot

doi:10.3390/ma14205917

Abstract

This paper investigates the behaviour of a reinforced concrete beam under a support removal. A detailed parametric analysis is carried out, covering the effect of support removal rate on dynamic response. The linear elastic and nonlinear inelastic responses are computed and studied in detail. Critical parameters during the structural response are identified. In order to determine the ultimate load, the vertical pushover analysis is performed. The key parameters driving the beam response are assumed as random variables, and respective reliability study makes it possible to check the overall uncertainty of the dynamic response. In particular, the response spectrum measuring the effect of support removal rate has been computed. It has been demonstrated that the critical vertical response occurs when the time of support removal is up to to 17% of the first natural period. The vertical pushover analysis results in obtaining capacity curves and showed the order in which two plastic hinges occur for various load patterns. Finally, the reliability-based sensitivity analysis indicates the geometric cross-section cover and height are the most sensitive parameters of the beam response.

Highlights

The recent (24 June 2021) partial collapse of the Champlain Towers South condominium located at the Miami suburbs of Surfside gave rise to increasing attention of better understanding of progressive collapse of buildings
The three objectives of this paper are: (1) the examination of the impact of support removal rate on the dynamic response, (2) the observation of the nonlinear behaviour of reinforced concrete beams under increasing deformation up to collapse, and (3) reliability-based sensitivity studies leading to the identification of the most important geometric and material parameters under vertical pushover loading conditions
Since this study focuses on beams, it is of interest to perform similar investigations pertaining to various configurations of frame structures by applying realistic distributed load patterns

Summary

Introduction

The recent (24 June 2021) partial collapse of the Champlain Towers South condominium located at the Miami suburbs of Surfside gave rise to increasing attention of better understanding of progressive collapse of buildings. The research of this problem has a long tradition starting from the Ronan Point apartment building partial collapse in London 1968 [1]. The progressive collapse phenomenon happens when a local failure causes successive structural damages leading to the partial or total collapse of a building. The problem of progressive collapse of buildings often leads to human life losses enhancing fear in the society and generating substantial economic costs. An extensive literature review on research and practice in the field of progressive collapse can be found in Mohamed [5], Nair [6], Kokot [7], Kokot and Solomos [8] and Adam et al [9]

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Conclusion