| Steel and Composite Structures Volume 1, Number 2, June 2001, pages 187-200 DOI: https://doi.org/10.12989/scs.2001.1.2.187 | |
Investigation of rotational characteristics of column\'PINNED\' bases of steel portal frames | |
Timothy Chi-ho Liu(U.K.)
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| Abstract [Buy Article] | |
| Most of the portal frames are designed these days by the application of plastic analysis, withrnthe normal assumption being made that the column bases are pinned. However, the couple produced by therncompression action of the inner column flange and the tension in the holding down bolts will inevitablyrngenerate some moment resistance and rotational stiffness. Full-scale portal frame tests conducted during arnprevious research program had suggested that this moment can be as much as 20% of the moment ofrnresistance of the column. The size of this moment of resistance is particularly important for the design ofrnthe tensile capacity of the holding down bolts and also the bearing resistance of the foundation. The presentrnresearch program is aiming at defining this moment of resistance in simple design terms so that it could bernincluded in the design of the frame. The investigation also included the study of the semi-rigid behaviour ofrnthe column base/foundation, which, to a certain extent, affects the overall loading capacity and stiffness ofrnthe portal frames. A series of column bases with various details were tested and were used to calibrate arnfinite element model which is able to simulate the action of the holding down bolts, the effect of thernconcrete foundation and the deformation of the base plate. | |
| Key Words | |
| column base; holding down bolts; flexibility; portal frame. | |
| Address | |
| Manchester School of Engineering, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom | |
