Deformation and ductility considerations of ductile coupled shear walls located in Canadian seismic regions

2001 ◽  
Vol 28 (4) ◽  
pp. 738-746
Author(s):  
O Chaallal ◽  
D Gauthier
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Shear Walls ◽  
Coupling Beams ◽  
Maximum Displacement ◽  
Ductility Demand ◽  
Displacement Ductility ◽  
Demand Factor ◽  
Interstorey Drift ◽  
Degree Of Coupling

This paper presents the results of an analytical study on the nonlinear deformation and ductility response of reinforced concrete ductile coupled shear walls (CSWs) under seismic loadings. The CSWs were designed, calculated, and detailed in compliance with the National Building Code of Canada (NBCC) 1995 and the Canadian Concrete Standard CAN3-A23.3-94. The parameters and assumptions of the study as well as the description of the models and the procedure were fully described elsewhere. Results indicated that the maximum interstorey drift from dynamic analyses was well below that obtained from static analyses with NBCC specified lateral forces. It was also found to be substantially lower for tall CSWs compared to short or medium-height walls, and decreased only slightly as the degree of coupling increased within the range considered in this study. It was also highest for seismic records with low PGA/PGV ratios. Plastic hinge rotations as well as accumulated plastic hinge rotations generally decreased as the number of storeys increased. The maximum displacement ductility demand factor remained below the NBCC value of 4.0 specified for ductile CSWs. The influence of degree of coupling on the maximum displacement ductility demand factor was found negligible. Also, the maximum displacement ductility demand factor generally decreased as the number of storeys increased. The maximum rotational ductility demand factor in coupling beams decreased as the number of storeys increased and was generally less than the practical accepted limit of 10, except for a few short CSWs.Key words: coupled shear walls, reinforced concrete, seismic, degree of coupling, frequency content, interstorey drift, plastic hinge deformation, ductility.

The Research of the Relative Rigid Effect in the Numerical Simulation of the Steel Plate Reinforced Concrete Coupling Beams

2014 ◽  
Vol 638-640 ◽  
pp. 283-286
Author(s):  
Li Song ◽  
Dong Chen ◽  
Bao Lei Li
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Steel Plate ◽  
Simulation Analysis ◽  
Great Influence ◽  
Shear Walls ◽  
Internal Force ◽  
Coupling Beams ◽  
Loading Mode ◽  
Deformation Properties

The coupling beam work as an important component in coupled shear walls, the strength,stiffness and deformation properties of which have great influence on the seismic performance of shear walls, the steel plate reinforced concrete coupling beams have the advantages as follows: simplify the constructional details, make the construction convenient and reliable performance [1][2]. The numerical simulation model in this paper is a coupled shear wall connected by steel plate reinforced concrete coupling beams in reference [3], and the loading mode is the same as the reference [4] . The relative stiffness effect was explored by study the internal force and displacement of the model with changing the stiffness of the coupling beams and the shear walls while the span-depth ratio is stable .The study will provide a reference for the numerical simulation of the finite element simulation analysis of the coupling beams and the steel reinforced concrete structures.

The Use of ARMA Models in Earthquake Response Spectra

2006 ◽  
Author(s):  
Malek Brahimi ◽  
Sidi Berri
Keyword(s):  
Linear Response ◽  
Energy Demand ◽  
Arma Model ◽  
Response Spectra ◽  
Response Analysis ◽  
Arma Models ◽  
Maximum Displacement ◽  
Ductility Demand ◽  
Displacement Ductility ◽  
Hysteretic Energy

Structural design spectra are based on smoothed linear response spectra obtained from different events scaled by their peak values. Such an approach does not incorporate other characteristics of the excitation represented by measured data. This study investigate the use of non-stationary models which can be considered characteristic and representative of specific historical earthquakes. An earthquake record is regarded as a sample realization from a population of such samples, which could have been generated by the stochastic process characterized by an Autoregressive Moving Average (ARMA) model. ARMA models are developed for four major earthquakes after processing by a variance stabilizing transformation. Samples of acceleration records are generated for each event. In this earthquake modeling procedure, parameters describing the modulating function of the record and the stabilized series are estimated. Maximum displacement ductility demand and normalized hysteretic energy demand for linear and stiffness softening single degree of freedom system systems are computed for the samples generated for each event. The sensitivity and dependence of demand spectra on earthquake model characteristics are examined to develop a response prediction model. Non linear response analysis of the four events indicates that ARMA (2,1) process using samples of twenty simulated earthquakes provide a reliable description of the information contained within acceleration records. Empirical relationships for displacement ductility and Normalized hysteretic energy demand spectra are developed.

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.

scholarly journals Evaluation of elastic stiffness factor of 2D reinforced concrete frame system with different parameters

2021 ◽  
Vol 2 (2) ◽  
pp. 26-31
Author(s):  
Omar Ahmad
Keyword(s):  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Shear Walls ◽  
Elastic Stiffness ◽  
Span Length ◽  
Base Shear ◽  
Reinforced Concrete Frame ◽  
Plastic Hinges

In general, the buildings are designed based on the applied loads on them, and these buildings generally have elastic structural behaviour. However, these structures may be subjected to unexpectedly strong seismic forces that exceed their elastic limits. In order to find the rigidity and load-bearing trend of the building without the formation of plastic hinges and failure, pushover analysis should be performed. Pushover analysis is a non-linear static analysis in which the structure is subjected to lateral loads, so some parameters are recorded, such as failure, formation of plastic hinges, and yield. The elastic stiffness factor is the ability of a building to bear the loads on it before the failure and existent of the plastic hinges. In this study, pushover analysis had been done on 12 two-dimensional reinforced concrete frames with a different number of stories, different span lengths and with or without shear walls to find the effect of the span length, shear wall and the number of stories on the elastic stiffness factor. After performing the pushover analysis, the elastic stiffness factor had been evaluated from the pushover curve by dividing the base shear over the lateral displacement at the first point of the occurrence of the plastic hinge. The results obtained from the study showed that the elastic stiffness factor increases with the increase of the span length, while it decreases with the increase of the number of stories. As well, the frames with shear walls are stiffer than the frames without shear walls.

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.

Comportement sismique d'un système formé de murs couplés tronqués et d'un cadre

2001 ◽  
Vol 28 (4) ◽  
pp. 752-758
Author(s):  
O Chaallal ◽  
P Malenfant ◽  
M -J Nollet
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Shear Walls ◽  
Ductility Demand ◽  
Soft Story ◽  
Plastic Mechanism ◽  
Wide Range ◽  
Frame System ◽  
Seismic Records ◽  
Frame Systems

This paper presents results of a numerical investigation on the nonlinear seismic behavior of a reinforced concrete system made of truncated coupled shear walls (CSWs) and a frame. The objective of the study is twofold: (a) examine the seismic behavior of CSW–frame systems with setbacks and (b) verify the adequacy of the National Building Code (NBC) as far as the design of such systems. The study considers two types of CSWs, coupled and partially coupled, two Canadian seismic zones, 4 and 6, six different levels of setbacks, and 10 historic seismic records encompassing a wide range of frequency content. Results of the study show that the CSW–frame system with no setback offers a satisfactory seismic behavior with regards to the sequence of plastification and the ductility demand. For the truncated systems, the NBC recommendations that the static method is not adequate is justified. Also, in the presence of setbacks, the columns show a higher degree of plastification with a possibility of formation of plastic mechanism (soft story). The ductility demand is also higher and can exceed the accepted practical limit in certain cases.Key words: coupled shear walls, frame, reinforced concrete, setback, seismic behavior, code.

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