Effect of Column Base Behavior on Seismic Performance of Multi-Story Steel Moment Resisting Frames

2018 ◽  
Vol 19 (01) ◽  
pp. 1940007 ◽  
Author(s):  
Yao Cui ◽  
Fengzhi Wang ◽  
Satoshi Yamada
Keyword(s):  
Plastic Deformation ◽  
Local Buckling ◽  
Time History ◽  
Thickness Ratio ◽  
Nonlinear Time History Analysis ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting ◽  
The Moment ◽  
Column Base

Column base is one of the most important elements of steel structures. Exposed column base is commonly used in low-to-medium-rise steel moment resisting frames because of better constructability and low cost. To study the effect of exposed column base behavior on the seismic behavior of low-to-medium-rise steel moment resisting frames, a four-story, four-bay steel moment frame is studied by the nonlinear time history analysis. In the numerical analysis, two types of column base connections (rigid and semi-rigid) are considered. The width–thickness ratio of column and stiffness ratio of column base to column are chosen as the analysis parameters. The characteristics of structural responses, hysteresis loops, and the distribution of plastic energy dissipation are compared. It indicates that the collapse margin ratio is significantly increased when the exposed column base behavior is considered for the moment resisting frames with large width–thickness ratio. Moreover, if the column base connection is allowed to rotate and transfer a portion of the moment, the demand of plastic deformation capacity of steel columns is reduced, then subsequently strength deterioration caused by the local buckling at the bottom of column could be avoided. Also, the whole structure has a better ductility, the ability of plastic deformation and energy absorbance of the moment resisting frame under earthquake are therefore enhanced. The structure with the semi-rigid column base connection has larger potential to avoid the structural collapse caused by the local buckling of first-story columns.

Performance-based assessment of seismic-resilient steel moment resisting frames equipped with innovative column base connections

Structures ◽  
2021 ◽  
Vol 32 ◽  
pp. 1646-1664
Author(s):  
Elena Elettore ◽  
Annarosa Lettieri ◽  
Fabio Freddi ◽  
Massimo Latour ◽  
Gianvittorio Rizzano
Keyword(s):  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Performance Based Assessment ◽  
Moment Resisting ◽  
Base Connections ◽  
Column Base

Performance‐based assessment of seismic‐resilient steel moment resisting frames equipped with innovative column base connections

ce/papers ◽  
2021 ◽  
Vol 4 (2-4) ◽  
pp. 1736-1746
Author(s):  
Annarosa Lettieri ◽  
Elena Elettore ◽  
Fabio Freddi ◽  
Massimo Latour ◽  
Gianvittorio Rizzano
Keyword(s):  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Performance Based Assessment ◽  
Moment Resisting ◽  
Base Connections ◽  
Column Base

Effect of Column Base Flexibility on Earthquake-Induced Residual Deformations of Steel Columns

2018 ◽  
Vol 763 ◽  
pp. 149-156 ◽  
Author(s):  
Hiroyuki Inamasu ◽  
Dimitrios G. Lignos ◽  
Amit M. Kanvinde
Keyword(s):  
Finite Element ◽  
Local Buckling ◽  
Steel Columns ◽  
Steel Moment Resisting Frames ◽  
High Rise ◽  
Moment Resisting ◽  
Residual Deformations ◽  
Steel Mrfs ◽  
Column Base ◽  
Axial Shortening

Post-earthquake residual deformations often control decisions regarding potential demolition of earthquake-damaged buildings. While residual deformations are typically assumed to be lateral, the column residual axial shortening has similar implications for such decisions. This paper investigates the effect of column base flexibility on residual axial shortening of columns in steel moment resisting frames (MRFs). The mechanistic reason for this dependency is that higher base flexibility reduces plastic rotation demands in the column, in turn mitigating local buckling-induced shortening. To investigate this issue, parametric finite element (FE) simulations interrogate various column sizes used in conventional mid-to high-rise steel MRFs. The simulations suggest at 1-2% story drifts, the base flexibility virtually eliminates the column axial shortening.

Seismic fragility of steel moment-resisting frames in Vancouver and Montreal designed in the 1960s, 1980s, and 2010

2015 ◽  
Vol 42 (11) ◽  
pp. 919-929 ◽  
Author(s):  
Lucía Valentina Díaz Gómez ◽  
Oh-Sung Kwon ◽  
Mohammad Reza Dabirvaziri
Keyword(s):  
Numerical Models ◽  
Fragility Curves ◽  
Time History ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Nonlinear Time History Analyses ◽  
Moment Resisting ◽  
The 1960S ◽  
Steel Mrfs ◽  
Nonlinear Time History

Typical steel moment-resisting frames (MRF) of six-storey buildings in Vancouver and Montreal were designed for three different provisions of the National Building Code of Canada (1960s, 1980s, and 2010). Numerical models were developed in OpenSees to understand the seismic performance of the structures. These models accounted for strength and stiffness degradation through appropriate representations of the beam–column connection behaviours, which were calibrated against experimental results available in the literature. The behaviour of the buildings was evaluated through pushover and nonlinear time history analyses. The pushover analysis results showed that the 1960s and 2010 steel MRFs of both cities exhibited strong-column-weak-beam failure mode. The 1980s steel MRFs of both cities showed soft-storey mechanism. Fragility curves were developed for the steel MRFs based on the seismic demands evaluated using nonlinear time history analyses, which can be used for regional seismic impact assessment studies in the future.

Amplified Seismic Loads in Steel Moment Frames

2016 ◽  
Vol 847 ◽  
pp. 222-232
Author(s):  
Bora Aksar ◽  
Selcuk Dogru ◽  
Bulent Akbas ◽  
Jay Shen ◽  
Onur Seker ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Ground Motions ◽  
Time History ◽  
Load Level ◽  
Steel Buildings ◽  
Moment Frames ◽  
Axial Loads ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting

This study focuses on exploring the seismic axial loads for columns in steel moment resisting frames (SMRFs) under strong ground motions. For this purpose, the increases in axial loads are investigated at the maximum lateral load level and the corresponding lateral displacement. The results are presented in terms of maximum amplification factors (Ω0) of all frame columns under the selected ground motions and axial load-moment levels in columns. four typical steel moment resisting frames representing typical low, medium and high rise steel buildings are designed based on the seismic design requirement in ASCE 7-10 and AISC 341-10 . An ensemble of ground motions range from moderate to severe are selected to identify the seismic response of each frames. Two sets of ground motions corresponding to 10% and 2% probability of exceedance are used in nonlinear dynamic time history analyses.

Seismic assessment and upgrade of Type 2 construction steel moment-resisting frames built in Canada between the 1960s and 1980s using passive supplemental damping

2013 ◽  
Vol 40 (7) ◽  
pp. 644-654 ◽  
Author(s):  
Nikolas Kyriakopoulos ◽  
Constantin Christopoulos
Keyword(s):  
Time History ◽  
Nonlinear Time History Analysis ◽  
Experimental Program ◽  
Steel Moment Resisting Frames ◽  
Construction Steel ◽  
Moment Resisting ◽  
Interstorey Drift ◽  
Supplemental Damping ◽  
Nonlinear Time History

The seismic performance of a typical 1960s Type 2 construction steel moment-resisting frame hospital structure designed only for lateral wind loads was investigated. The structure was found to have a soft first storey and displayed large P–Δ sensitivities. An experimental program determined that the connections had considerable inherent ductility and were stable up to 2.0% interstorey drift, despite not having been designed for a ductile cyclic response. The structure was numerically modelled using advanced strength degradation considerations. A nonlinear time-history analysis was conducted using Montreal and Vancouver ground motions and the structure’s performance was found to be inadequate under the considered design hazard levels. Retrofits were proposed for the two orthogonal frames using a performance-based approach and supplemental damping, rather than local interventions to increase the ductility of these connections, and the performance of the final retrofit designs were investigated numerically to confirm that the desired performance levels were achieved.

scholarly journals Seismic Upgrading of Steel Moment-Resisting Frames by Means of Friction Devices

2014 ◽  
Vol 8 (1) ◽  
pp. 289-299 ◽  
Author(s):  
Esra Mete Güneyisi ◽  
Mario D'Aniello ◽  
Raffaele Landolfo
Keyword(s):  
Structural Response ◽  
Time History ◽  
Seismic Behaviour ◽  
Steel Moment Resisting Frames ◽  
Residual Drift ◽  
Moment Resisting Frames ◽  
Drift Ratio ◽  
Nonlinear Time History Analyses ◽  
Moment Resisting ◽  
Nonlinear Time History

In recent decades, several passive energy dissipation systems have been conceived in order to minimize the damage in structural and non-structural components of either new or existing buildings. In this study, the use of friction damped tension-compression diagonal braces for seismic upgrading of a steel moment resisting frames is investigated. To this aim, nonlinear time history analyses have been carried out on a set of representative frames with and without friction damped braces. In the nonlinear time history analyses, two sets of natural accelerograms compatible with seismic hazard levels of 10% and 2% probability of exceedance in 50 years have been considered. Under these records, the structural response has been comparatively investigated in terms of the maximum inter-storey drift ratio, maximum storey acceleration, residual drift ratio and displacement demand for the friction device. The results clearly highlighted that the application of friction damped braces allows reducing the damages to the main structural elements, thus significantly improving the seismic behaviour of the frame.

Direct Displacement-Based Design of a Novel Hybrid Structure: Steel Moment-Resisting Frames with Cross-Laminated Timber Infill Walls

2016 ◽  
Vol 32 (3) ◽  
pp. 1565-1585 ◽  
Author(s):  
Matiyas A. Bezabeh ◽  
Solomon Tesfamariam ◽  
Siegfried F. Stiemer ◽  
Marjan Popovski ◽  
Erol Karacabeyli
Keyword(s):  
Design Method ◽  
Hybrid Structure ◽  
Nonlinear Time History Analysis ◽  
Earthquake Ground Motion ◽  
Cross Laminated Timber ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Direct Displacement Based Design ◽  
Moment Resisting ◽  
Displacement Based

This study proposes an iterative direct displacement based design method for a novel steel-timber hybrid structure. The hybrid structure incorporates cross-laminated timber (CLT) shear panels as an infill in steel moment-resisting frames. The proposed design method is applied to design three-, six-, and nine-story hybrid buildings, each with three bays and a CLT-infilled middle bay. Nonlinear time history analysis, using 20 earthquake ground motion records, is carried out to validate the performance of the design method. The results indicate that the proposed method effectively controls the displacements due to seismic excitation of the hybrid structure.

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