Professional paper

https://doi.org/10.17559/TV-20150806093823

Bearing capacity and stability of elastically fixed CFT slender columns

Marija Lazovic orcid.org/0000-0001-9931-5093 ; Faculty of Civil Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11000 Belgrade, Serbia
Janko Radovanovic ; Technical Director V.d.o.o. "Morava", Ljubićska 8, 32102 Čačak, Serbia
Biljana Deretic Stojanovic ; Faculty of Civil Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11000 Belgrade, Serbia

Abstract

CFT columns are one of the basic structural elements in "top-down" construction method. Because of the large depth of excavation the question of stability of these columns raises. This paper presents a procedure for calculation of critical buckling force of CFT columns which are on the upper side elastically fixed in the concrete ceiling and on the bottom side elastically fixed in the drilled pile. Using computer programs ABAQUS 6.12 and LPILE, as well as appropriate constitutive models the boundary conditions on the upper and lower end of the CFT columns are determined. For a building called "Cvijetni prolaz" in Zagreb, using program created in Excel the critical buckling force of elastically fixed CFT columns is determined. The dependence of the critical buckling force decreasing with increasing depth of excavation is presented. The impact of concrete class, diameter and wall thickness of the steel section, length and diameter of the pile, the thickness of the ceiling on the critical buckling force of CFT columns is analysed. The results are shown in diagrams and tables.

Keywords

CFT column; FEM; p-y curve; stability of bifurcation

Hrčak ID:

183062

URI

https://hrcak.srce.hr/183062

Publication date:

15.6.2017.

Article data in other languages: croatian

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