scholarly journals Effective flexural stiffness for reinforced concrete shear walls having confined boundary elements

2021 ◽  
Vol 4 (2) ◽  
pp. 126-139
Author(s):  
Saeid Foroughi ◽  
S. Bahadir Yuksel
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Shear Walls ◽  
Effective Stiffness ◽  
Structural Safety ◽  
Design Parameters ◽  
Accurate Estimation ◽  
Reliable Estimate ◽  
Confining Effect ◽  
Rc Shear Wall

In the design of reinforced concrete (RC) shear walls strength, ductility and effective stiffness of the elements must be taken into account and are important parameters in terms of structural safety. Accurate estimation of the ductility and effective stiffnesses of RC members has always been an attractive subject of study as it provides a reliable estimate of the capacity of buildings under seismic loads. In this study, RC shear wall models with different concrete strength, longitudinal and transverse reinforcement ratios were designed to investigate effective section stiffness and coefficients. The effective stiffness of the cracked section in the RC shear walls designed in different parameters were analytically obtained. Analytically investigated parameters were calculated from TBEC (2018), ACI318 (2014), ASCE/SEI41 (2017) and Eurocode8 (2004, 2005) regulations and nonlinear behaviors. The results obtained according to different design parameters were compared and examined. In the relations suggested for the effective section stiffness coefficient, the confining effect is not taken into account as in the regulations. Therefore, it means neglecting the effects of parameters such as concrete strength, confining effect and axial load levels acting on the section. This situation can lead to unrealistic results in the design and evaluation of RC elements. For this reason, determining the moment-curvature relationship in the design and evaluation of RC elements and obtaining effective section stiffness values are of great importance in order to obtain more realistic results.

scholarly journals Assessment of ultimate drift capacity of RC shear walls by key design parameters

2017 ◽  
Vol 50 (4) ◽  
pp. 482-493 ◽  
Author(s):  
Chanipa Netrattana ◽  
Rafik Taleb ◽  
Hidekazu Watanabe ◽  
Susumu Kono ◽  
David Mukai ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Axial Load ◽  
Concrete Strength ◽  
Shear Walls ◽  
Load Ratio ◽  
Design Parameters ◽  
Seismic Behaviour ◽  
Drift Capacity ◽  
Axial Load Ratio

The latest version of the Standard for Structural Calculation of Reinforced Concrete Structures, published by the Architectural Institute of Japan in 2010 [1], allows the design of shear walls with rectangular cross sections in addition to shear walls with boundary columns at the end regions (referred to here as “barbell shape”). In recent earthquakes, several reinforced concrete (RC) shear walls were damaged by flexural failures through concrete compression crushing accompanied with buckling of longitudinal reinforcement in the boundary areas. Damage levels have clearly been shown to be related to drift in structures; this is why drift limits are in place for structural design criteria. A crucial step in designing a structure to accommodate these drift limits is to model the ultimate drift capacity. Thus, in order to reduce damage from this failure mode, the ultimate drift capacity of RC shear walls needs to be estimated accurately. In this paper, a parametric study of the seismic behaviour of RC shear walls was conducted using a fibre-based model to investigate the influence of basic design parameters including concrete strength, volumetric ratio of transverse reinforcement in the confined area, axial load ratio and boundary column dimensions. This study focused on ultimate drift capacity for both shear walls with rectangular sections and shear walls with boundary columns. The fibre-based model was calibrated with experimental results of twenty eight tests on shear walls with confinement in the boundary regions. It was found that ultimate drift capacity is most sensitive to axial load ratio; increase of axial load deteriorated ultimate drift capacity dramatically. Two other secondary factors were: increased concrete strength slightly reduced ultimate drift capacity while increased shear reinforcement ratio and boundary column width improved ultimate drift capacity.

Study on Seismic Behavior of the L-Shape Steel Reinforced Concrete Short-Pier Shear Wall with Different Concrete Strength

2013 ◽  
Vol 353-356 ◽  
pp. 1990-1999
Author(s):  
Yi Sheng Su ◽  
Er Cong Meng ◽  
Zu Lin Xiao ◽  
Yun Dong Pi ◽  
Yi Bin Yang
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Seismic Performance ◽  
Seismic Behavior ◽  
Concrete Strength ◽  
Shear Walls ◽  
Shear Wall ◽  
Simulation Software ◽  
Steel Reinforced Concrete ◽  
Shrinkage Effect

In order to discuss the effect of different concrete strength on the seismic behavior of the L-shape steel reinforced concrete (SRC) short-pier shear wall , this article analyze three L-shape steel reinforced concrete short-pier shear walls of different concrete strength with the numerical simulation software ABAQUS, revealing the effects of concrete strength on the walls seismic behavior. The results of the study show that the concrete strength obviously influence the seismic performance. With the concrete strength grade rise, the bearing capacity of the shear wall becomes large, the ductility becomes low, the pinch shrinkage effect of the hysteresis loop becomes more obvious.

Parametric Reliability Analysis of the Seismic Bearing Capacity of Bottom Columns in Reinforced Concrete Frame Structure

2012 ◽  
Vol 204-208 ◽  
pp. 2478-2482
Author(s):  
You Bao Jiang ◽  
Yu Lai Zhao ◽  
Wei Jun Yang ◽  
Zhi Ling Gong
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Seismic Design ◽  
Reliability Index ◽  
Concrete Strength ◽  
Design Parameters ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Parametric Reliability ◽  
Seismic Bearing Capacity

After the Wenchuan earthquake, Chinese Code for Seismic Design of Buildings (GB50011-2010) adjusts some seismic design parameters. Taking into account the randomness of gravity load and earthquake action and the uncertainty of steel strength and concrete strength, this paper analyzes the reliability of seismic bearing capacity of reinforced concrete frame bottom columns. Based on the structural analysis software PKPM, which is in accordance with code for seismic design of buildings, the reliability index of seismic bearing capacity of reinforced concrete frame bottom columns is calculated by the Monte Carlo method with different parameters, such as different seismic intensity, different building storey number, different seismic adjustment coefficient (increment coefficient of frame columns end moment and increment coefficient of design value of combination moment of underlying frame columns lower end section), different horizontal span number, different column location (side column and interior column) and so on. The results indicate that the reliability index can reach 2.0 or above, and can meet the target requirements for all cases which are designed with the current code for seismic design of buildings (GB50011-2010).

scholarly journals Structural Response to Blast Loading: The Effects of Corrosion on Reinforced Concrete Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hakan Yalciner
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Plastic Hinge ◽  
Structural Response ◽  
Blast Loading ◽  
Structural Safety ◽  
Terrorist Attacks ◽  
Important Place ◽  
The One ◽  
The Impact

Structural blast design has become a necessary part of the design with increasing terrorist attacks. Terrorist attacks are not the one to make the structures important against blast loading where other explosions such as high gas explosions also take an important place in structural safety. The main objective of this study was to verify the structural performance levels under the impact of different blast loading scenarios. The blast loads were represented by using triangular pulse for single degree of freedom system. The effect of blast load on both corroded and uncorroded reinforced concrete buildings was examined for different explosion distances. Modified plastic hinge properties were used to ensure the effects of corrosion. The results indicated that explosion distance and concrete strength were key parameters to define the performance of the structures against blast loading.

Damage Sensitivity Analysis for Main Design Parameters of Reinforced Concrete Shear Wall

2011 ◽  
Vol 374-377 ◽  
pp. 2574-2577
Author(s):  
Shan Suo Zheng ◽  
Qing Lin Tao ◽  
Yi Hu ◽  
Zhi Qiang Li
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Seismic Wave ◽  
Wave Energy ◽  
Shear Wall ◽  
Hybrid Structure ◽  
Design Parameters ◽  
Main Design ◽  
Energy Dissipation Capacity ◽  
Rc Shear Wall

As an indispensable force component to the hybrid structure, the seismic wave energy inputted into integral structure is dissipated by damping force working and plastic hysteresis of reinforced concrete shear wall which is taken as the first seismic fortification line of structure. Considering of the condition that the RC shear wall is mainly used to dissipate the seismic wave energy, this paper takes the ultimate energy dissipation capacity of reinforced concrete shear wall subjected to cyclic loading as the damage characterization. According to the related theoretical analysis and experimental research, the method for calculating ultimate energy dissipation capacity of RC shear wall is proposed and the damage sensitivity of various design parameters which contain the sectional thickness, the strength of concrete and reinforcement ratio are analyzed, then the influence laws of main design parameters impacted on damage evolution of RC shear wall are revealed in this paper. The research shows that sectional thickness is the most sensitive factor in the damage of reinforced concrete shear wall and the concrete strength degree takes the second place, and then the reinforcement ratio is the most insensitive design parameter. The research achievements will provide theoretical support for establishing the storey damage model of SRC frame-RC core wall hybrid structure under seismic excitation.

A concentric tube anchor system for fiber-reinforced polymer retrofit of reinforced concrete structural walls under extreme loads

2017 ◽  
Vol 9 (1) ◽  
pp. 77-98 ◽  
Author(s):  
David T Lau ◽  
Joshua E Woods
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Shear Walls ◽  
Fiber Reinforced Polymer ◽  
Experimental Program ◽  
Design Parameters ◽  
Fiber Reinforced ◽  
Anchor System ◽  
Reinforced Polymer ◽  
Polymer Sheets

In reinforced concrete elements strengthened with fiber-reinforced polymer sheets, premature debonding of the fiber-reinforced polymer from the concrete substrate occurs due to lack of anchorage, which reduces the efficiency of the retrofitting system. This article reviews several common anchor systems and describes the development, optimization, and testing of a steel tube anchor in retrofit of reinforced concrete structural elements using externally bonded fiber-reinforced polymer sheets suitable for application to improve resistance against extreme load conditions (e.g. blast, impact, or an earthquake). A detailed review of common anchor designs including the proposed tube anchor based on previous studies on flexure-dominated fiber-reinforced polymer-strengthened reinforced concrete shear walls is presented. In this study, finite element analysis is conducted to verify the observed behavior and better understand the deformation mechanisms of the tube anchor. Finite element modeling is then used to evaluate the influence of different design parameters on its performance and propose a design methodology that can be used to optimize the tube anchor design. To verify the performance of the optimized tube anchor, it is tested in an experimental program on the in-plane seismic strengthening of two shear-dominated squat walls strengthened using fiber-reinforced polymer sheets. Experimental results reveal that the optimized tube anchor performs well in preventing premature debonding and allows the fiber-reinforced polymer composite to achieve a higher level of strain when compared to an alternative anchor system. Finally, a set of design steps for the implementation of the tube anchor in fiber-reinforced polymer retrofit applications for reinforced concrete shear walls are presented.

Quasi-Static Test of Reinforced Concrete Shear Wall with Low Concrete Strength and Reinforcement Ratio

2012 ◽  
Vol 188 ◽  
pp. 106-111
Author(s):  
Kai Lai Deng ◽  
Peng Pan ◽  
Yuan Yuan Shi ◽  
Qi Song Miao ◽  
Wen Feng Li ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Shear Walls ◽  
Shear Wall ◽  
Fish Bone ◽  
Reinforcement Ratio ◽  
Technical Limitation ◽  
Static Tests ◽  
Static Test ◽  
Seismic Design Code

A large number of reinforced concrete (RC) buildings constructed in the 1970s, whose main structural form is fish-bone shear wall, are still used in Qiansanmen area of Beijing. Due to the economical and technical limitation at the time, both the concrete strength and reinforcement ratio are far from satisfying the requirements given in the current seismic design code for concrete structures. In order to investigate the seismic performances of the wall with the low concrete strength and reinforcement ratio, four RC shear wall specimens were constructed and tested. Quasi-static tests considering large axial compression ratio were carried out, and the stiffness, the strength and the energy dissipation capacity of the RC shear walls are investigated. Test results suggest that the wall with low concrete strength and reinforcement ratio has low strength and poor deformation capacity, indicating the necessity of strengthening.

Identifying Buckling Resistance of Reinforced Concrete Columns During Inelastic Deformation

2020 ◽  
Vol 20 (03) ◽  
pp. 2050029
Author(s):  
Jian Weng ◽  
Kang Hai Tan ◽  
Chi King Lee
Keyword(s):  
Reinforced Concrete ◽  
Parametric Study ◽  
Inelastic Deformation ◽  
Progressive Collapse ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Design Parameters ◽  
Rc Columns ◽  
Inelastic Material ◽  
Buckling Resistance

A simple solution method to identify buckling resistance of reinforced concrete (RC) columns during inelastic deformation is presented. Unlike conventional buckling solution methods, this proposed method predicts inelastic buckling loads of RC columns by directly solving the equilibrium differential equation under buckling. The method considers specific deflection configuration, end restraint conditions and inelastic material properties of the deformed column. In order to evaluate the reliability and accuracy of the proposed method, the results obtained from the purposed method are compared with the test results of eccentrically loaded RC columns. In addition, by using the proposed solution procedure, a parametric study is conducted to investigate the effects of critical RC column design parameters on column buckling behavior and resistance, including slenderness ratio, concrete strength, as well as longitudinal reinforcement and stirrup ratios. The results of the parametric study show that the proposed method is rational and can be adopted to effectively identify buckling resistance of RC columns subjected to inelastic damage, especially when load redistributions have occurred in the structure during progressive collapse.

scholarly journals Seismic Performance of Reinforced Concrete Coupled Walls with Segmental Coupling Beams

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiaobin Hu ◽  
Qinwang Lu ◽  
Zihao Xu ◽  
Shen Zhang
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Concrete Strength ◽  
Design Parameters ◽  
Engineering Practice ◽  
Main Role ◽  
Analysis Model ◽  
Element Analysis ◽  
Coupled Wall ◽  
Gravity Load

A novel reinforced concrete (RC) segmental coupling beam (SCB), which mainly comprises the energy dissipating (ED) segment and load bearing (LB) segment, is proposed in this paper. In order to examine its applicability in engineering practice, one scaled RC coupled wall specimen with the proposed SCBs was constructed and experimentally investigated under cyclic loading. The results show that both cracking and yielding occurred much earlier on the ED segments of the SCBs compared to the LB segments. In addition, a lot more cracks distributed densely on the ED segments were observed at the end of the test. It demonstrates that the ED segments play a main role in the energy dissipation, while the LB segments are always reliably capable of carrying the gravity load transferred from the floor beams. Finally, the finite element analysis model of the RC coupled wall is established and validated by comparing the analysis results with the experimental ones. Utilizing the proposed analysis model, parametric analyses are conducted to investigate the influence of a variety of design parameters, including the axial compressive ratio of the wall pier, concrete strength, and especially sectional height of the SCB, on seismic performance of the coupled wall. It shows that as the sectional height of the ED segment increases, the energy dissipating capacity of the coupled wall may improve while the ability of supporting the gravity load is lowered.

Seismic Behavior of RC Low-Rise Shear Wall with Vertical Mild Steel-Lead Energy Dissipation Strips

2011 ◽  
Vol 243-249 ◽  
pp. 1443-1449
Author(s):  
Jian Wei Zhang ◽  
Wan Lin Cao ◽  
Hong Ying Dong
Keyword(s):  
Energy Dissipation ◽  
Mild Steel ◽  
Seismic Behavior ◽  
Shear Failure ◽  
Shear Walls ◽  
Shear Wall ◽  
Design Parameters ◽  
Failure Behavior ◽  
The One ◽  
Rc Shear Wall

A RC shear wall with vertical mild steel-lead energy dissipation strips was proposed as an improvement in seismic behavior over existing shear wall designs. In order to test and ascertain the projected increase in performance, five low-rise shear wall specimens: one normal RC shear wall, one RC shear wall with slits, two shear walls with vertical X style mild steel energy dissipation strips under different design parameters, and one shear wall with vertical X style mild steel-lead energy dissipation strips were tested under cyclic loading. Based on the experiment, the damage characteristics, hysteresis characteristics, load-carrying capacity, stiffness, ductility, and energy dissipation of the specimens were comparatively analyzed. Results show that the ductility and energy dissipation of the RC low-rise shear wall with vertical X style mild steel energy dissipation strips and the one with X style mild steel-lead energy dissipation strips offer a significant improvement in seismic performance over accepted designs. In addition, the failure behavior of the low-rise shear wall tended towards bending failure rather than shear failure.

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