Rotational restraint of a simple column base connection

1987 ◽  
Vol 14 (1) ◽  
pp. 49-57 ◽  
Author(s):  
A. Picard ◽  
D. Beaulieu ◽  
B. Pérusse
Keyword(s):  
Base Plate ◽  
Relative Displacement ◽  
Effective Length ◽  
Test Results ◽  
Effective Length Factor ◽  
Steel Base ◽  
Steel Column ◽  
Simple Column ◽  
Base Connections ◽  
Column Base

This paper presents the results of an experimental investigation on the behaviour of steel column base connections. The purpose of the study was to determine the value of the rigidity ratio at the column base (GL). The connection is made of a steel base plate welded to the lower end of the column and attached to the footing by means of two or four anchor bolts. It is generally admitted that this type of connection behaves like a hinge and it is recommended to use GL = 10.0 to evaluate the effective length factor of the column.The test results indicate that for weak-axis buckling a conservative value of the rigidity ratio is GLY = 0.50 and for strong-axis buckling GLX = 1.50, if there is no relative displacement of column ends. The effective length of the column is therefore reduced. A design example shows that the column strength is increased by approximately 30% for slenderness ratios currently met in practice. Key words: steel column, column base connection, moment–rotation curve, buckling.

Behaviour of a simple column base connection

1985 ◽  
Vol 12 (1) ◽  
pp. 126-136 ◽  
Author(s):  
A. Picard ◽  
D. Beaulieu
Keyword(s):  
Base Plate ◽  
Moment Capacity ◽  
Steel Base ◽  
Steel Column ◽  
Ultimate Moment ◽  
Fixity Factor ◽  
Simple Column ◽  
Concrete Footing ◽  
Base Connections ◽  
Column Base

This paper presents the results of an experimental investigation on the behaviour of steel column base connections. The connection is effected by means of a steel base plate welded to the lower end of the column and attached to the concrete footing with two or four anchor bolts. The testing program comprised 15 specimens. The measured moment–rotation curves were used to determine the fixity factors of the base connections, taking into account the presence of an axial compression load.The results indicate that the compression force in the column significantly increases the flexural stiffness of the base connection and that the rotational restraint offered by the column base is sufficient to be considered in design. The results also show that the method of analysis used to determine the ultimate moment capacity of the base connection is conservative. Key words: steel column, column base connection, moment–rotation curve, anchor bolt, flexibility factor, fixity factor.

Strain distribution in steel base plates under eccentric loads

1989 ◽  
Vol 24 (3) ◽  
pp. 173-183
Author(s):  
P Paramasivam ◽  
D P Thambiratnam
Keyword(s):  
Base Plate ◽  
Lateral Strain ◽  
Test Results ◽  
Element Analysis ◽  
Bending Strain ◽  
Steel Base ◽  
Steel Column ◽  
Flexible Base ◽  
Base Plates ◽  
Column Base

Experiments have been conducted on steel column base plates subjected to eccentric loads and the strain distributions in the base plates at various stages of loading have been determined. The thickness of the base plate and the eccentricity of load have been treated as parameters. Test results for the maximum bending strains, which always occurred at the column–base plate junction on the side of the load, compare reasonably well with those from a finite element analysis. However, the present results for the bending strains in the cantilever portions of the base plates which failed by yielding are greater than those obtained from classical theory, which is, therefore, seen to be conservative for these cases. Longitudinal and lateral strain distributions, strain contour plans, maximum bending strain variation with load, and interaction diagrams are presented and the results discussed. From these results it is evident that flexible base plates, especially when loaded at higher eccentricities, behave somewhat differently from what is assumed in classical methods.

Using composite yield mechanism to mitigate seismic damage to exposed steel column base connections

2021 ◽  
Vol 232 ◽  
pp. 111877
Author(s):  
Yao Cui ◽  
Fengzhi Wang ◽  
Cancan Yang ◽  
Hao Li ◽  
Yangzi He
Keyword(s):  
Seismic Damage ◽  
Steel Column ◽  
Base Connections ◽  
Column Base

scholarly journals Seismic Demands in Column Base Connections of Steel Moment Frames

2018 ◽  
Vol 34 (3) ◽  
pp. 1383-1403 ◽  
Author(s):  
Pablo Torres-Rodas ◽  
Farzin Zareian ◽  
Amit Kanvinde
Keyword(s):  
Time History ◽  
Base Plate ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Seismic Demands ◽  
Axial Forces ◽  
Plate Connections ◽  
Nonlinear Time History ◽  
Base Connections ◽  
Column Base

Methods for the seismic design of base connections in steel moment frames are well-developed and routinely utilized by practicing engineers. However, design loads for these connections are not verified by rigorous analysis. This knowledge gap is addressed through nonlinear time history simulations using design-level seismic excitation that interrogate demands in column base connections in 2-, 4-, 8-, and 12-story steel moment frames, featuring base connections that reflect current U.S. practice. The results indicate that: (1) for exposed base plate connections, lower bound (rather than peak) estimates of axial compression are suitable for design because higher axial forces increase connection strength by delaying base plate uplift; (2) even when designed as pinned (as in low-rise frames), base connections carry significant moment, which can be estimated only through accurate representation of base flexibility; and (3) the failure of embedded base connections is controlled by moment, which may be estimated either through overstrength or capacity-based calculations.

Analysis and design of demountable embedded steel column base connections

2017 ◽  
Vol 23 (3) ◽  
pp. 303-315 ◽  
Author(s):  
Dongxu Li ◽  
Brian Uy ◽  
Vipul Patel ◽  
Farhad Aslani
Keyword(s):  
Analysis And Design ◽  
Steel Column ◽  
Base Connections ◽  
Column Base

Force Analysis of Steel Column Base Plate Base on the Interaction Principle

2013 ◽  
Vol 800 ◽  
pp. 345-350
Author(s):  
De Bin Zhu ◽  
Sun Hao
Keyword(s):  
Comparative Analysis ◽  
Stress Distribution ◽  
Working Condition ◽  
Interaction Model ◽  
Base Plate ◽  
Traditional Model ◽  
Force Analysis ◽  
Axial Pressure ◽  
Steel Column ◽  
Column Base

This paper analyse the force of the column base plate which suffering the axial pressure. First, the comparative analysis between the traditional model and interaction model is made. Second, for the steel frame, sole plate and concreat base as a entirety, analyse the factor which affect the stress distribution of sole plate and base top at the different working condition. Result shows that, there is a big gap on the result between the traditional model and interaction model, difference of length-wide ratio of box column section have a small affect on the stress of base top. The change of concreat strength have a big affect on the sole plate and concreat stress distribution.

Characterization equations for steel column base connections

2006 ◽  
Vol 33 (4) ◽  
pp. 409-420 ◽  
Author(s):  
Martin Dumas ◽  
Denis Beaulieu ◽  
André Picard
Keyword(s):  
Steel Structure ◽  
Experimental Results ◽  
Finite Element Models ◽  
Analysis Software ◽  
Analytical Characterization ◽  
Steel Connections ◽  
Steel Column ◽  
Base Connections ◽  
Column Bases ◽  
Column Base

This paper presents partial results of a research program under way at Laval University for which the main goal is to introduce the behaviour of steel connections into commercial structural analysis software. The objective of this paper is to derive analytical characterization equations for three commonly used steel column base connections. The procedure to derive these equations is based on a curve standardization theory that requires a number of experimental results in the form of moment–rotation curves that characterize the behaviour of column base connections. Because of a lack of available experimental results, data were obtained from finite element models. The design of a simple steel structure introducing the semi-rigid behaviour of column bases is presented as an example. It shows that consideration of the semi-rigidity of column base connections increases the accuracy of the analysis results and leads to a decrease in structure weight and deformation.Key words: analysis, base, behaviour, column, connection, frame, partial, rigidity, steel, structure.

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