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Keywords: embedded column base, tensile pullout strength, mode of failure, ultimate strength, steel-concrete interface..

Summary

Post-Kobe studies revealed that embedded column bases respond better to earthquake uplift forces than the exposed column bases. This paper presents the results of numerical and experimental studies for the static pullout strength and modes of failure of the steel column bases ('roots') embedded in unreinforced cuboid concrete blocks. The embedded roots have an end plate (headed roots) or are tapered in a single plane. The studies include the effect of the change in the size of the concrete block (its depth and plan dimensions), the boundary conditions of the concrete block, and the effect of the tapering angle. The numerical results are supported with experimental results. The embedded steel sections are proportioned to remain well under the yield point, hence, the pullout failure occurs only in the concrete block. The presence of the end plate dominates the overall pullout capacity and 'masks' the resistance provided by the 'body' of the embedded section. This effect leads to the conclusion that, for a specified embedding depth and size of the end plate, the shape of the embedded section will not seriously affect its pullout strength. The headed roots, normally, have a cone like (a `compound cone') failure mechanism. The most common type of pullout failure of the tapered roots is splitting. For the embedded roots tapered in a single plane, however, the confining boundary conditions change the splitting failure of the concrete block into a 'butterfly' or 'biconical' type of failure. The biconical failure could double the pullout strength. Also, the tapered roots under similar conditions, sustain much larger displacements prior to the development of the peak pullout strength as compared with that of the headed roots. The headed and tapered embedded roots both can provide the design strength, stiffness and ductility with more freedom in detailing.

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Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 108 PROCEEDINGS OF THE FIFTEENTH INTERNATIONAL CONFERENCE ON CIVIL, STRUCTURAL AND ENVIRONMENTAL ENGINEERING COMPUTING Edited by: J. Kruis, Y. Tsompanakis and B.H.V. Topping Paper 46 Embedded Column Bases: Tensile Strength and Modes of Failure M. Heristchian and P. Pourakbar Islamic Azad University, South Tehran Branch, Iran doi:10.4203/ccp.108.46 purchase the full-text of this paper Full Bibliographic Reference for this paper M. Heristchian, P. Pourakbar, "Embedded Column Bases: Tensile Strength and Modes of Failure", in J. Kruis, Y. Tsompanakis, B.H.V. Topping, (Editors), "Proceedings of the Fifteenth International Conference on Civil, Structural and Environmental Engineering Computing", Civil-Comp Press, Stirlingshire, UK, Paper 46, 2015. doi:10.4203/ccp.108.46 Keywords: embedded column base, tensile pullout strength, mode of failure, ultimate strength, steel-concrete interface.. Summary Post-Kobe studies revealed that embedded column bases respond better to earthquake uplift forces than the exposed column bases. This paper presents the results of numerical and experimental studies for the static pullout strength and modes of failure of the steel column bases ('roots') embedded in unreinforced cuboid concrete blocks. The embedded roots have an end plate (headed roots) or are tapered in a single plane. The studies include the effect of the change in the size of the concrete block (its depth and plan dimensions), the boundary conditions of the concrete block, and the effect of the tapering angle. The numerical results are supported with experimental results. The embedded steel sections are proportioned to remain well under the yield point, hence, the pullout failure occurs only in the concrete block. The presence of the end plate dominates the overall pullout capacity and 'masks' the resistance provided by the 'body' of the embedded section. This effect leads to the conclusion that, for a specified embedding depth and size of the end plate, the shape of the embedded section will not seriously affect its pullout strength. The headed roots, normally, have a cone like (a `compound cone') failure mechanism. The most common type of pullout failure of the tapered roots is splitting. For the embedded roots tapered in a single plane, however, the confining boundary conditions change the splitting failure of the concrete block into a 'butterfly' or 'biconical' type of failure. The biconical failure could double the pullout strength. Also, the tapered roots under similar conditions, sustain much larger displacements prior to the development of the peak pullout strength as compared with that of the headed roots. The headed and tapered embedded roots both can provide the design strength, stiffness and ductility with more freedom in detailing. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £75 +P&P)
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