A More Rational Approach to Capacity Design of Seismic Moment Frame Columns

1996 ◽  
Vol 12 (3) ◽  
pp. 395-406 ◽  
Author(s):  
K. Dirk Bondy
Keyword(s):  
Seismic Moment ◽  
Response Spectrum ◽  
Time History ◽  
Rational Approach ◽  
Elastic Analysis ◽  
Moment Frames ◽  
Capacity Design ◽  
Moment Frame ◽  
Maximum Credible Earthquake ◽  
Existing Structures

Inelastic time history analyses typically indicate that the traditional sub-assembly “capacity” approach used in the design of ductile moment frames grossly underestimates the maximum moments experienced by the columns during a maximum credible earthquake. In addition, these analyses predict that the maximum column demand moments often occur near the mid-height of concrete structures, whereas a conventional elastic analysis predicts maxima at the lowest levels of these structures. Incremental displacement analyses using modal properties and displacements predicted by a maximum credible response spectrum should be used to more accurately predict the maximum anticipated column demand moments in the analysis of existing structures or the design of new structures.

Investigation of Damages in RC Frames Under Near Field Earthquakes Using a Damage Index

2016 ◽  
Vol 16 (02) ◽  
pp. 1450094 ◽  
Author(s):  
Seyed Morteza Zinati Yazdi ◽  
Mohammad Taghi Kazemi
Keyword(s):  
Near Field ◽  
Damage Index ◽  
Time History ◽  
General Rule ◽  
Nonlinear Time History Analysis ◽  
Far Field ◽  
Moment Frames ◽  
Moment Frame ◽  
Rc Frames ◽  
Nonlinear Time History

Heavy damages on structures caused by near field earthquakes in recent years has brought serious attention to this problem. An examination of previous records has shown significant differences for near field earthquakes, including a large energy pulse, unlike far field earthquakes. But as a general rule, the effects of near field earthquakes have been ignored in most building codes. The purpose of this paper is to investigate the effect of near field earthquakes on reinforced concrete (RC) moment frames. To achieve this goal, the Erduran damage index, an efficient way to calculate damage, was employed to analyze two 4- and 8-story RC moment frame buildings. The buildings with moderate and high ductility were designed by the strength criteria. Seven pairs of near field and far field earthquakes were scaled and used for dynamic nonlinear time history analysis. Using Erduran’s beam and column damage index, respectively, based on rotation and drift, the results from both near and far field earthquakes were compared. Moreover, for better assessment, 4-story buildings were evaluated from the performance based viewpoint of design. We observe from the results that most of the components of the structures under near field earthquakes sustained severe damages and in some cases even component failure. Components of the structures under near field earthquakes suffered from 30% more of damage, on average, than that under far field earthquakes.

scholarly journals Seismic Performance and Evaluation of Controlled Spine Frames Applied in High-rise Buildings

2018 ◽  
Vol 34 (3) ◽  
pp. 1431-1458 ◽  
Author(s):  
Xingchen Chen ◽  
Toru Takeuchi ◽  
Ryota Matsui
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Evaluation Procedure ◽  
Equivalent Linearization ◽  
Stiffness Ratio ◽  
Moment Frames ◽  
Moment Frame ◽  
High Rise ◽  
Frame System ◽  
Frame Stiffness

A controlled spine frame system consists of moment frames and spine frames with concentrated energy-dissipating members. This system guarantees the continuous usability of buildings against Japanese Level-2 earthquake events (similar to DBE events in California), and the authors have confirmed its excellent performance in preventing damage concentration in low-rise buildings. This study further investigates the effect of diverse structural properties on the seismic performance of controlled spine frames applied in high-rise buildings. The effect of building height, yield drift of dampers, spine-to-moment frame stiffness ratio, and damper-to-moment frame stiffness ratio are illustrated in detail, and optimal values are discussed. Also, a segmented spine frame system is proposed for high-rise buildings. The simple evaluation procedure proposed by the authors for low-rise buildings, based on equivalent linearization techniques and response spectrum analyses, was modified to include higher-mode effects for high-rise buildings based on modal analysis. The modified evaluation method was verified by modal pushover and time-history analyses.

Seismic response of two-storey buildings with concentrically braced steel frames

1999 ◽  
Vol 26 (4) ◽  
pp. 497-509 ◽  
Author(s):  
M S Medhekar ◽  
DJL Kennedy
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Time History ◽  
Steel Buildings ◽  
Capacity Design ◽  
Concentrically Braced Frames ◽  
Braced Frame ◽  
Seismic Zones ◽  
Concentrically Braced Frame ◽  
Concentrically Braced

The seismic performance of two-storey steel buildings with concentrically braced frames as the lateral load resisting system is evaluated. The buildings are designed in accordance with the National Building Code of Canada (1995) and CSA Standard S16.1-94 for five seismic zones in western Canada. Only frames designed with a force modification factor of 1.5 are considered. Analytical models of the buildings are developed, which consider the nonlinear seismic behaviour of the concentrically braced frame, the shear strength of the roof diaphragm, and the stiffness and strength contributions of the nonstructural partitions. The seismic response is estimated with nonlinear static and dynamic time history analyses. Roof diaphragm flexibility does not influence the dynamic behaviour significantly. The distribution of lateral forces from response spectrum analysis agrees well with that specified. Current design procedures provide reasonable estimates of the lateral drift in low and moderate seismic zones. Brace ductility demands are reasonable and may be limited due to the contributions of nonstructural partitions. However, in moderate and high seismic zones, the connections, beams, columns, and roof diaphragm are overloaded. The capacity design procedure is recommended to provide adequate resistance to the overloaded components.Key words: analyses, capacity design, concentrically braced frame, diaphragm, dynamic, earthquake, low-rise, nonlinear, seismic design, steel.

scholarly journals Modified Partial Capacity Design (M-PCD): achieving partial sidesway mechanism by using two steps design approach

2021 ◽  
Vol 907 (1) ◽  
pp. 012003
Author(s):  
L S Tanaya ◽  
H Herryanto ◽  
P Pudjisuryadi
Keyword(s):  
Response Spectrum ◽  
Pushover Analysis ◽  
Structural Models ◽  
Time History ◽  
Soil Classification ◽  
Seismic Load ◽  
Capacity Design ◽  
History Analysis ◽  
Design Response Spectrum ◽  
Non Linear

Abstract Partial Capacity Design (PCD) has been developed by using magnification factor to keep some columns undamaged during major earthquake. By doing so, the structures will experience the partial side sway mechanism which is also stable, instead of the beam sidesway mechanism. However, in some cases, structures designed by PCD method failed to show the partial side sway mechanism since unexpected damages were still occurred at some columns. In this research, modification of PCD method is proposed by using two structural models in the design process. The first model is used to design beams and columns which are allowed to experience plastic damages, while the second model is used to design columns which are intended to remain elastic when the structure is subjected to a target earthquake. Two nominal earthquakes corresponding to Elastic Design Response Spectrum (EDRS) level with seismic modification factors (R) of 8.0 and 1.6 are used in the first and second structural models, respectively. It should be noted that the second model is identical to the first model except that the stiffnesses are reduced for elements to simulate potential plastic damages. This proposed method is applied to symmetrical 6 and 10 storey buildings with seismic load according SNI 1726:2012 and with soil classification of SE in Surabaya city. A Non-linear Static Procedure (NSP) or pushover analysis and Non-linear Dynamic Procedure (NDP) or time history analysis are employed to evaluate the performance of the structure. The evaluation is conducted at three earthquake levels which are nominal earthquake that is used in second model, earthquake corresponding to EDRS level, and maximum considered earthquake (MCER) specified by the code (50% higher than EDRS level). The building performances satisfy the drift criteria in accordance with FEMA 273. However, the partial side sway mechanism was not achieved at NDP analysis at maximum seismic load, MCER.

Modeling of Hysteretic Damper in Three-Story Steel Frame Subjected to Earthquake Load

2010 ◽  
Vol 163-167 ◽  
pp. 3981-3986
Author(s):  
Mohammad Saeed Masoomi ◽  
Siti Aminah Osman ◽  
Shahed Shojaeipour
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Base Shear ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Braced Frame ◽  
Vector Method ◽  
Hysteretic Damper ◽  
Earthquake Load ◽  
Nonlinear Time History

This paper presents the nonlinear time-history and response spectrum analysis for a three-story steel moment frame and a braced frame by hysteretic damper against earthquake load which analyzed by SAP2000 software. The mentioned frames were analyzed by Eigenvalue method for linear analysis and Ritz-vector method for nonlinear analysis. Simulation results were presented as a time-displacement graph based on dynamic analysis, the dynamic base shear force is also calculated.

Seismic Behavior of Steel Moment Frames with Mechanical Hinge Beam-to-Column Connections

2020 ◽  
Vol 20 (06) ◽  
pp. 2040005
Author(s):  
Han Peng ◽  
Jinping Ou ◽  
Andreas Schellenberg ◽  
Frank Mckenna ◽  
Stephen Mahin
Keyword(s):  
Seismic Behavior ◽  
Shaking Table Test ◽  
Plastic Hinge ◽  
Time History ◽  
Shaking Table ◽  
Base Shear ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Moment Frame ◽  
Steel Moment Frame

This paper presents an investigation on the seismic behavior of steel moment frames with mechanical hinge beam-to-column connections. The connection uses a mechanical hinge to carry shear force and a pair of buckling-restrained steel plates bolted to the beam flange to transfer bending moment. The moment-rotation behavior of the connection was theoretically studied. A nonlinear numerical model for steel moment frames under strong earthquakes was developed and validated using a shaking table test of an 18-story steel moment frame at the E-Defense facility. Then, nonlinear static and time-history analyses were conducted to compare the seismic behavior of a conventional steel moment frame and three innovative steel frames equipped mechanical hinge connections in terms of roof displacement, base shear, inter-story drift ratio, and plastic hinge rotation.

Multi-story truss moment frames equipped with friction dampers and self-centering system for enhanced seismic performance

2019 ◽  
Author(s):  
Keyhan Faraji ◽  
Robert Tremblay
Keyword(s):  
Seismic Performance ◽  
Structural Damage ◽  
Linear Time ◽  
Time History ◽  
Moment Frames ◽  
Moment Frame ◽  
Friction Energy ◽  
Hazard Level ◽  
Residual Deformations ◽  
Dynamic Time

<p>In this article, two new truss moment frame (TMF) systems exhibiting enhanced seismic performance are examined: truss moment frames with friction energy dissipation dampers between the truss bottom chord and the columns (F-TMFs) and F-TMFs with tendons added to achieve self-centering response (FT-TMFs). In both cases, all steel components of the systems are expected to behave essentially elastically to eliminate structural damage. The second system is also expected to have negligible residual lateral deformations. To compare and investigate the seismic performance of the proposed TMF systems, a 5-story commercial steel building located in Vancouver, BC, is designed in accordance with the National Building Code of Canada 2015 (NBCC) and it is subjected to a series of nonlinear static and dynamic time history analyses. The earthquake records, employed in non-linear time history analyses, are scaled for a hazard level corresponding to a probability of 2% in 50 years. The analytical results show that structural damage does not occur in neither of the two proposed systems . Meanwhile, FT-TMF system showed notably better seismic response and negligible residual deformations due to its self-centering capacity provided by the tendons.</p>

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