Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484766
Title: Progressive collapse assessment of tall buildings
Author: Vlassis, Anastasios G.
ISNI:       0000 0001 3548 8075
Awarding Body: Imperial College London (University of London)
Current Institution: Imperial College London
Date of Award: 2007
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Abstract:
The events of 11 September 2001 have instigated a comprehensive debate among the structural engineering community regarding the performance of tall buildings under extreme loading conditions such as blast, impact or fire. The main issues that have been identified include the dynamic robustness of such buildings, the parameters that could possibly initiate progressive collapse following the extreme event, and the design guidance that needs to be introduced in order for buildings to survive such events and assure life safety of their occupants. Since the structural components of buildings subject to extreme loading events are likely to undergo large inelastic deformations, which can induce excessive ductility demands in the joint regions of the members involved, the behaviour and modelling of joints is discussed in detail. With respect to design recommendations, this thesis proposes a multi-level framework for progressive collapse assessment of building structures subject to sudden column loss, which is the design scenario adopted by most recent guidelines to assess the potential of multi-storey buildings for progressive collapse. The proposed framework offers a rational and practical means for assessing structural robustness at various levels of structural idealisation, it accommodates both simplified and detailed models of the nonlinear structural response, and importantly it moves the debate on structural robustness towards the quantifiable. Application of the new approach is demonstrated with reference to steel-framed composite buildings with partial-strength joints. Furthermore, a methodology is developed, based on the proposed assessment framework for sudden column loss, to consider the impact of floor failure on a lower floor, in order to establish whether this would in fact trigger progressive collapse. Application of this methodology is also illustrated by means of a case study, where consideration is given to a floor grillage system subject to impact of the floor above, and the ability of the impacted floor members to sustain the dynamically induced loads associated with various impact scenarios is thoroughly examined. From the presented application studies, important conclusions are drawn relating to the inherent robustness of steel-framed structures, the factors influencing this robustness, and the adequacy of current regulations for the avoidance of progressive collapse.
Supervisor: Izzuddin, Bassam A. ; Elghazouli, Ahmed Y. ; Nethercot, David A. Sponsor: ARUP ; EPSRC
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.484766  DOI: Not available
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