Comparative Response of Earthquake Resistant CBF Buildings Designed According to Canadian and European Code Provisions

2018 ◽  
Vol 763 ◽  
pp. 1155-1163 ◽  
Author(s):  
Yu Dong Wang ◽  
Elide Nastri ◽  
Lucia Tirca ◽  
Rosario Montuori ◽  
Vincenzo Piluso
Keyword(s):  
Cross Sections ◽  
Eurocode 8 ◽  
Braced Frames ◽  
Base Shear ◽  
Concentrically Braced Frames ◽  
European Code ◽  
Interstorey Drift ◽  
Comparative Response ◽  
Code Provisions ◽  
Floor Acceleration

In this study, both Canadian and European code provisions for steel concentrically braced frames (CBF) are discussed and issues addressing ductility classes for brace cross-sections, q factor value and brace configurations as covered in Eurocode 8 are presented. From comparison with the Canadian provisions it is concluded that beams and columns of CBFs designed according to Eurocode 8 could be under-design when braces perform in the inelastic range. A prototype 8-storey CBF building with multi-storey X-braces is designed and analysed in agreement with both code provisions. The nonlinear seismic responses are presented in terms of interstorey drift, residual interstorey drift and floor acceleration. It was concluded that both buildings are able to yield similar base shear, show similar floor acceleration while the European building undergoes larger residual interstorey drift.

Code provisions for seismic design for concentrically braced steel frames

1992 ◽  
Vol 19 (6) ◽  
pp. 1025-1031 ◽  
Author(s):  
R. G. Redwood ◽  
A. K. Jain
Keyword(s):  
Seismic Design ◽  
Structural Engineering ◽  
Steel Frames ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Braced Frame ◽  
Concentrically Braced ◽  
Interstorey Drift ◽  
Available Information ◽  
Steel Braced Frame

Extensive research into the inelastic seismic response of concentrically braced frames and their components has been carried out in the last two decades. This knowledge has now been incorporated into seismic design practice in several countries, notably the U.S.A., Canada, and New Zealand. In this paper, design specifications from these three countries, which derive largely from the same body of research, are compared. The basic design philosophy for concentrically braced steel frames, loading, and member detailing are examined. It is concluded that, in general, the Canadian specifications are in conformity with the available information and have many similar features to codes of the other countries. Significant differences exist in the classification of braced frames, between interstorey drift requirements, in the treatment of dual structural systems, and to a lesser extent in member detailing requirements. Some features of Canadian codes meriting review are identified. Key words: structural engineering, earthquakes, standards, steel, braced frame, ductility, concentric bracing, dual system.

Ductility Enhancement in Reinforced Concrete Structure with Buckling Restrained Braced Frames

2016 ◽  
Vol 847 ◽  
pp. 281-289
Author(s):  
Erkan Senol ◽  
Ismail Kose ◽  
Bilge Doran ◽  
Pelin Elif Mezrea ◽  
Bulent Akbas
Keyword(s):  
Reinforced Concrete ◽  
Pushover Analysis ◽  
Design Procedure ◽  
Braced Frames ◽  
Base Shear ◽  
Moment Frames ◽  
Concentrically Braced Frames ◽  
Capacity Curve ◽  
Concentrically Braced ◽  
Buckling Restrained Braced Frames

Adding braces to moment frames is considered to be quite an efficient technique for increasing the global stiffness and strength of the structure. It has not only been used in steel moment frames, but also in reinforced concrete (RC) moment frames in recent years. It certainly can increase the energy absorption capacity of structures and also decrease the demand imposed by seismic ground motions. Steel braces are anchored firmly to boundary beams and columns. They are modeled as truss elements and increase earthquake resistance of the building. Buckling restrained braced frames (BRBFs) in which members yield under both tension and compression without significant buckling have been used in recent years in order to ensure the desired seismic performance of special concentrically braced frames. BRBFs are similar to the special concentrically braced frames in that seismic accelerations are resisted by a building-frame members and diagonal braces whereas the design procedure is different. BRBs should be designed to permit ductile yielding both in compression and tension. In this paper, flat-slab RC building with two different configurations of buckling restraint braces (BRBs) is studied. The buildings have 4-storey with 5 bays in both X-and Y-directions and have been designed according to Turkish Specification of Reinforced Concrete Design (TS 500). In order to explore overall behavior up to failure and lateral load resisting capacities for these buildings, nonlinear static analyses have then been performed using SAP 2000-V14.1. Pushover analysis under constant gravity loads and monotonically increasing lateral forces during an earthquake until a target displacement is reached is generally carried out as an effective tool for performance based design. The major outcome of a pushover analysis is the capacity curve which shows the base shear vs. the roof displacement relationship and represents the overall performance of the building. The results of the analyses are presented in terms of capacity curve and energy dissipation.

scholarly journals Evolution of EC8 Seismic Design Rules for X Concentric Bracings

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1807
Author(s):  
Alessia Campiche ◽  
Silvia Costanzo
Keyword(s):  
Seismic Design ◽  
Structural Engineering ◽  
Design Procedure ◽  
Eurocode 8 ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Design Rules ◽  
Factor Ii ◽  
And Behavior ◽  
Seismic Area

Eurocodes are currently under revision within a six-year program by CEN/TC 250. In this framework, concentric bracings, particularly in cross configuration, have been largely debated; indeed, several criticisms affect the seismic design procedure currently codified within Eurocode 8, entailing significant design efforts and leading to massive and non-economical structural systems, even characterized by poor seismic behavior. The efforts of SC8 have been aimed at improving the codified seismic design criteria for concentrically braced frames, by providing requirements and detailing rules conceived to simplify the design process and to improve the seismic performance. The current paper provides recent advances in the field of computational and structural engineering focusing on symmetric X concentrically bracings in seismic area, outlining the evolution of Eurocode 8 (EC8) seismic design rules, by examining the following aspects: (i) ductility class and behavior factor, (ii) analysis and modelling aspects, (iii) design of dissipative members; (iv) design of non-dissipative zones; (v) brace-to-frame connections.

scholarly journals Seismic Behaviour of EC8-Compliant Moment Resisting and Concentrically Braced Frames

Buildings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 196 ◽  
Author(s):  
Silvia Costanzo ◽  
Roberto Tartaglia ◽  
Gianmaria Di Lorenzo ◽  
Attilio De Martino
Keyword(s):  
Design Procedure ◽  
Eurocode 8 ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Research Activity ◽  
Seismic Behaviour ◽  
Concentrically Braced ◽  
Dynamic Analyses ◽  
Moment Resisting ◽  
Energy Dissipation Capacity

The design procedure codified within current Eurocode 8 for dissipative moment resisting and concentrically braced frames have led to the design of massive systems characterized in the most of cases by poor energy dissipation capacity. The research activity presented in the current paper addresses the identification of the main criticisms and fallacies in the current EN 1998-1 for those seismic-resistant typologies. In this regard, the design provisions and codified rules for both moment resisting frames (MRFs) and chevron concentrically braced frames (CCBFs) are critically discussed and numerically investigated. Static and incremental dynamic analyses were performed on a set of 3 and 6-story frames designed compliant to EN 1998-1. The results from the numerical analyses are reported and discussed.

High strength steel in chevron concentrically braced frames designed according to Eurocode 8

2016 ◽  
Vol 124 ◽  
pp. 167-185 ◽  
Author(s):  
Andre Tenchini ◽  
Mario D’Aniello ◽  
Carlos Rebelo ◽  
Raffaele Landolfo ◽  
Luis Simões da Silva ◽  
...  
Keyword(s):  
High Strength Steel ◽  
High Strength ◽  
Eurocode 8 ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Concentrically Braced

Remarks on Seismic Design Rules of EC8 for Inverted-V CBFs

2018 ◽  
Vol 763 ◽  
pp. 1147-1154 ◽  
Author(s):  
Silvia Costanzo ◽  
Mario D'Aniello ◽  
Raffaele Landolfo ◽  
Attilio de Martino
Keyword(s):  
Design Procedure ◽  
Eurocode 8 ◽  
Structural System ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Design Rules ◽  
Concentrically Braced ◽  
Dynamic Analyses ◽  
Study Case ◽  
Nonlinear Dynamic Analyses

Chevron concentrically braced frames (C-CBFs) are expected to provide limited ductility in the framework of Eurocode 8: differently from North American codes, lower values of behavior factors are recommended by EN 1998 for C-CBFs than for other concentric bracing configurations (namely diagonal and cross bracings). The research presented in this paper is aimed at revising the design rules and requirements provided for by EN 1998-1 for C-CBFs in order to improve the ductility and the dissipative capacity of this structural system. The proposed design criteria are validated by means of nonlinear dynamic analyses performed on a study case. The results confirm the effectiveness of developed design procedure.

scholarly journals Dual-concentrically Braced Frames Using High Strength Steel – Seismic Response

2017 ◽  
Vol 11 (1) ◽  
pp. 496-512 ◽  
Author(s):  
André Tenchini ◽  
Carlos Rebelo ◽  
Luis Simões da Silva ◽  
Luciano Lima
Keyword(s):  
Seismic Performance ◽  
High Strength Steel ◽  
Steel Production ◽  
High Strength ◽  
High Yield ◽  
Eurocode 8 ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Concentrically Braced ◽  
Steel Grades

The recent technological advances on steel production process allowed introducing in construction market steel grades with significantly high yield strength. These new materials are known as High Strength Steel (HSS). The use of these steel grades offers economical and mechanical benefits compared with mild carbon steel (MCS). Consequently, their use is constantly increasing especially for seismic applications that are the rational field to exploit the high performance of HSS, by means of the “dual-steel” concept, which combines the HSS with MCS in order to provide overstrength to non-dissipative element and ductility to dissipative ones, thus controlling the global frame behaviour into a ductile overall failure mode. In this paper, a comprehensive parametric study devoted to investigate the seismic performance of Eurocode 8 compliant dual-steel chevron Dual-Concentrically Braced Frames (D-CBF) is presented and discussed. This structural typology is composed of two dissipative sub-systems acting in parallel, namely Moment Resisting Frames (MRFs) and Concentrically Braced Frames (CBFs). Static nonlinear pushover analyses were carried out in order to assess the seismic performance of the D-CBFs. The examined parameters cover both geometric and mechanical variables, as the type columns, span length, number of storeys and spectral shape. The analyses showed that the use of HSS in Eurocode 8 compliant D-CBFs is effective to avoid the damage in non-dissipative members. On the other hand, the use of HSS leads to design flexible members, especially for the braced-intercepted beams, resulting in poor performance of bracing members due to significant damage concentration. The economic evaluation shows that the use of HSS allows reducing the material consumptions and dropping the total constructional costs.

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