scholarly journals Earthquake Analysis of a High-Rise Building Retrofitted with Support Braced Systems

2021 ◽  
Vol 10 (12) ◽  
pp. 180-186
Author(s):  
Özlem Çavdar
Keyword(s):  
Reinforced Concrete ◽  
Time History ◽  
Tall Buildings ◽  
Shear Walls ◽  
Earthquake Hazard ◽  
Developed Countries ◽  
Superposition Method ◽  
Mode Superposition Method ◽  
Plastic Rotations ◽  
Nonlinear Time History

The use of support braced systems represents one of the best solutions for retrofitting or upgrading the tall reinforced concrete buildings in areas with a high earthquake hazard. In this study, the behavior of a reinforced concrete tall structure under seismic loads is examined based on the Turkish Building Earthquake Code 2019 (TBEC-2019). Support braced systems were added to the 25-story structure on 0.4H and 0.8H levels (H is height of structure). For two different models, firstly, the Mode-Superposition Method for linear computational methods used within the scope of strength-based design is performed. In order to determinate more accurately the behavior of tall buildings, as in the earthquake regulations of other developed countries, the TBEC-2019 advises a nonlinear deformation-based design approach. In addition, the nonlinear time history analyses of these buildings were performed. As a result of these analyzes, it was determined whether the two models examined were within the targeted performance effects or not. In the model having support braced system, stiffness and shear forces in shear walls were increased. Thus, displacements, relative story drift, plastic rotations and bending moments of shear walls were decreased.

Seven Mega Floor MSCSS Modal Analysis

2013 ◽  
Vol 353-356 ◽  
pp. 2210-2215
Author(s):  
Jun Jun Wang ◽  
Lu Lu Yi
Keyword(s):  
Modal Analysis ◽  
Response Spectrum ◽  
Time History ◽  
Response Analysis ◽  
Superposition Method ◽  
Response Spectrum Analysis ◽  
Mode Superposition Method ◽  
History Analysis ◽  
Basic Performance ◽  
Dynamic Time

Modal analysis is also known as dynamic analysis for mode-superposition method. In the seismic response analysis of linear structural systems, it is one of the most commonly used and the most effective ways. Through the modal analysis of building structure, we can get some basic performance parameters of the structure. These parameters can help us make qualitative judgments for the respond of a structure first, and can help us judge whether they meet demands for conceptual design. Modal analysis is also the basis of other dynamic response analysis, including dynamic time history analysis and response spectrum analysis.

scholarly journals Global Retrofitting Strategies for an Existing Three-storied RC School Building in Mandalay, Myanmar

2020 ◽  
Vol 37 (2) ◽  
Author(s):  
Thiri Thwe ◽  
Nang Su Le′ Mya Thwin ◽  
Ne Min Hein
Keyword(s):  
Reinforced Concrete ◽  
Steel Plate ◽  
Pushover Analysis ◽  
Shear Walls ◽  
Earthquake Hazard ◽  
Vulnerability Index ◽  
Seismic Zone ◽  
Index Method ◽  
Steel Plate Shear Walls ◽  
Existing Building

Low to severe earthquakes occur around the world every year, damaging and causing structural failure in buildings. Consequently, seismic improvements are required for existing buildings that are vulnerable to damage by seismic forces. The objective of this study was to investigate retrofitting strategies in terms of their sustainability. Mandalay, Myanmar, was selected as the study area as it is located near the Sagaing fault, which itself is in a strong earthquake zone (seismic zone 4). A three-storied RC building with a non-seismic design was selected as a case study building. An investigation was carried out into the performance and vulnerability of the building under three earthquake hazard levels. The vulnerability index value was calculated using the Priority Index method. Meanwhile, non-linear static pushover analysis was performed to investigate the performance of the existing building using SAP2000 V14 software. Four different types of retrofitting strategies were considered, namely reinforced concrete shear walls with openings, reinforced concrete shear walls without openings, steel plate shear walls, and finally steel bracing. Among these, it was found that the use of steel plate shear walls was the best retrofitting technique, owing to it having the best performance along with the lowest displacement. Its performance level reached up to the Immediate Occupancy (IO) level even under the conditions of a Maximum Consider Earthquake (MCE).

Seismic force demand on ductile reinforced concrete shear walls subjected to western North American ground motions: Part 1 — parametric study

2012 ◽  
Vol 39 (7) ◽  
pp. 723-737 ◽  
Author(s):  
Yannick Boivin ◽  
Patrick Paultre
Keyword(s):  
Reinforced Concrete ◽  
Parametric Study ◽  
Plastic Hinge ◽  
Time History ◽  
Shear Walls ◽  
Beam Model ◽  
Site Class ◽  
Seismic Force ◽  
Inelastic Shear ◽  
Axial Interaction

A parametric study of regular ductile reinforced concrete (RC) cantilever walls designed with the 2010 National building code of Canada and the 2004 Canadian Standards Association (CSA) standard A23.3 for Vancouver is performed to investigate the influence of the following parameters on the higher mode amplification effects, and hence on the seismic force demand: number of storeys, fundamental lateral period (T), site class, wall aspect ratio, wall cross-section, and wall base flexural overstrength (γw). The study is based on inelastic time-history analyses performed with a multilayer beam model and a smeared membrane model accounting for inelastic shear–flexure–axial interaction. The main conclusions are that (i) T and γware the studied parameters affecting the most dynamic shear amplification and seismic force demand, (ii) the 2004 CSA standard A23.3 capacity design methods are inadequate, and (iii) a single plastic hinge design may be inadequate and unsafe for regular ductile RC walls with γw < 2.0.

Inelastic analysis of a reinforced concrete shear wall building according to the National Building Code of Canada 2005

2006 ◽  
Vol 33 (7) ◽  
pp. 854-871 ◽  
Author(s):  
M Panneton ◽  
P Léger ◽  
R Tremblay
Keyword(s):  
Reinforced Concrete ◽  
Three Dimensional ◽  
Time History ◽  
Shear Walls ◽  
Shear Wall ◽  
Fundamental Period ◽  
Building Code ◽  
Base Shear ◽  
Inelastic Analysis ◽  
The Impact

An eight-storey reinforced concrete shear wall building located in Montréal and designed according to the 1995 National Building Code of Canada (NBCC) and the Canadian Standards Association standard CSA-A23.3-94 is studied to evaluate the impact of new requirements for inclusion in new editions of the NBCC and CSA-A23.3. Static and modal analyses were conducted according to the 2005 NBCC (draft 2003) and CSA-A23.3-04 (draft 4) procedures, and three-dimensional dynamic inelastic time history analysis was performed using three earthquake records. The building is braced by four flat shear walls and three cores. Various estimates of the fundamental period of vibration based on empirical expressions presented in the literature or structural models with different stiffness assumptions were examined. The analysis also permitted the study of the displacement and force demand on the lateral load resisting system. It was found that the base shear from the 2005 NBCC is 29% higher than the 1995 NBCC value when code empirical formulae are used for the fundamental period of vibration.Key words: building, shear wall, inelastic seismic response, NBCC, CSA-A23.3 design of concrete structures.

scholarly journals EFFECTS OF SHEAR WALLS ON A TYPICAL FOUR-STORY REINFORCED CONCRETE STRUCTURE SUBJECTED TO SEVERE EARTHQUAKE EVENTS

2021 ◽  
Vol 30 (4) ◽  
pp. 779-795
Author(s):  
Nader Zad ◽  
Hani Melhem
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Analysis ◽  
Concrete Structure ◽  
Time History ◽  
Shear Walls ◽  
Shear Stresses ◽  
Reinforced Concrete Structure ◽  
Beneficial Effects ◽  
Structural Resistance ◽  
Study Results

Various seismic-resistant design methods are used to ensure the stability of multi-story buildings against lateral forces caused by earthquakes. Utilization of reinforced concrete shear walls is one of the most reliable methods of design and construction of earthquake-resistant buildings because it increases structural resistance to lateral loads and stiffens and strengthens the structure, thereby minimizing earthquake-induced damages. This paper investigates the beneficial effects of using shear walls in the structural design of a typical low-rise building to improve its resistance to earthquake events. To this end, a four-story reinforced concrete structure is modeled first without shear walls, then with the addition to shear walls. The 2002 Denali Alaska earthquake is used as an example of a severe seismic excitation because it is considered the most massive strike-slip earthquake in North America in almost 150 year. SAP2000 is used to perform the dynamic analysis. In order to obtain an accurate representation of the structure’s behavior, response modal nonlinear time-history dynamic analysis is utilized to analyze and compare the response of the building with and without shear walls. Study results showed that shear walls are very effective in achieving compliance with seismic design codes. In addition, the use of shear walls significantly reduces the shear stresses, bending moments, and displacements of the various members of the structure.

scholarly journals Simplified nonlinear analysis of reinforced concrete coupling beams subjected to cyclic loading

2020 ◽  
Vol 19 (3) ◽  
pp. 224-232
Author(s):  
Rafael Alves de Souza ◽  
◽  
Sergio F. Brena ◽  
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Nonlinear Analysis ◽  
Failure Modes ◽  
Tall Buildings ◽  
Shear Walls ◽  
Monotonic Loading ◽  
Good Precision ◽  
Coupling Beams ◽  
Failure Loads

Reinforced concrete shear walls connected by coupling beams form an efficient structural system to resist earthquake and wind loads in tall buildings. However, the analysis of the effects caused by cyclic loading in this kind of system are not so straightforward. In the present paper, simplified nonlinear analysis using monotonic loading are used in order to obtain the behavior of tested coupling beams subjected to cyclic loading. Numerical results have shown that numerical monotonic loading is able to predict with good precision the yielding and the failure loads of the tested coupling beams subjected to cyclic loading. Both the cracking patterns and the predicted failure modes also followed the experimental behavior, ensuring that monotonic loading may be applied to have a first insight concerning cyclic loading.

Evaluation of the level of seismic protection afforded to reinforced concrete shear wall systems

1999 ◽  
Vol 26 (5) ◽  
pp. 572-589 ◽  
Author(s):  
Brian Stonehouse ◽  
Arthur C Heidebrecht ◽  
M Reza Kianoush
Keyword(s):  
Reinforced Concrete ◽  
Pushover Analysis ◽  
Time History ◽  
Shear Walls ◽  
Shell Element ◽  
Shear Wall ◽  
Lateral Force ◽  
Damage Potential ◽  
Existing Building ◽  
Torsion Element

This paper presents the results of an investigation into the seismic level of protection afforded to reinforced concrete shear wall systems. The vulnerability and damage potential of a 30-storey building consisting of a coupled shear wall as well as noncoupled shear walls as lateral force resisting systems is evaluated. The structure, which is similar to an existing building designed and constructed in Vancouver, is designed in accordance with the 1995 National Building Code of Canada and detailed using the provisions of CAN3-A23.3-M94 (1994). Elastic analysis is performed using both two-dimensional and three-dimensional shell element models for lateral loading with and without the effects of torsion. Element design specifications are used to create moment curvature envelopes to describe the members (beam and wall) deformation characteristics. These characteristics are incorporated into the nonlinear pushover analysis and dynamic inelastic time history analysis. The level of protection investigation illustrates that the coupled and noncoupled shear wall systems exhibit excellent performance following excitations of two and three times the design level earthquake. Maximum interstorey drift and element damage levels are within the acceptable limits for life-safe performance.Key words: seismic, reinforced concrete, shear walls, coupling beams, performance, inelastic, dynamic, design.

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