Seismic Performance Of Shear Walls Research Articles

Shear Wall and Frame Dual Systems Featuring Discontinuous Load Paths in Frame Elements in Low-to-Moderate Seismic Regions

ABSTRACT Reinforced concrete buildings constitute a significant portion of construction in Australia. Many existing buildings in Australia and other low to moderate seismic regions have been designed with little to no consideration for ductile detailing. The majority of these buildings also possess vertical irregularities, which can exacerbate their vulnerability in an earthquake event. The seismic performance of shear wall and frame dual systems possessing discontinuities in frame elements in the form of ductility and failure mechanism has been assessed. And design recommendations in terms of response modification factors and designation of appropriate methods of analysis have been provided.

A mechanical bond model for reinforcing bar in concrete subjected to monotonic and reversed cyclic loading

The reinforcing bar with diameters of 10 mm and 12 mm are widely used in shear walls, whose bond-slip performance has great influence on the seismic performance of the shear walls. Besides, the bond stress-slip model plays an important role in the theoretical analysis of the seismic performance of shear walls. Therefore, an analytical solution for the maximum bond stress was carried out and modified based on the thick-walled cylinder model and the tensile stress-strain model of concrete. The bond-slip tests of reinforcing bars in concrete were conducted on 48 specimens under monotonic and reversed cyclic loading. The effects of concrete strength, diameter of bar and bonding length on the bond-slip performance were examined and analyzed. The test results showed both the maximum bond stress and residual bond stress increased with increasing concrete strength, but decreased with increasing diameter of bar or bonding length. The reversed cyclic loading can cause the degeneration of the maximum bond stress and the bond stiffness. According to the bond-slip performance, the bond stress-slip model was established based on the analytical solution for the maximum bond stress, which is suitable for calculating both monotonic and reversed cyclic loading. A good agreement was observed by comparing the proposed models with the test curves in the study.

Experimental study on seismic performance of recycled aggregate concrete shear wall with high-strength steel bars

In order to investigate the seismic behavior of recycled aggregate concrete (RAC) shear wall using high-strength steel bars (HSS), five concrete walls with an aspect ratio of 2.2 were tested under the horizontal cyclic load. The influence of various parameters which include replacement percentage of recycled coarse aggregate (RCA), concrete strength, and the grade of longitudinal bars at boundary elements on the seismic performance of shear walls were analyzed. The failure mode, hysteresis behavior, skeleton curve, stiffness and energy consumption of RAC shear walls were analyzed. The results showed that as the replacement rate of RCA increased, the seismic performance of the wall hardly changed. The use of higher concrete strength could significantly improve the bearing capacity, initial stiffness and energy dissipation of the shear walls, while the ductility was similar. Almost all seismic indexes of the shear wall reinforced with HRB400 bars decreased. Reasonable matching of HSS and RAC could help the shear wall to achieve better seismic performance. The flexural strength and secondary stiffness of the RAC wall with ultra-high-strength steel bars (UHSS) were significantly improved and the concrete damage was reduced. In addition, the restoring force model based on experimental data was established and the hysteretic behavior of RAC shear walls was well predicted.

Experimental study on seismic performance of shear wall with precast concrete hollow molds

AbstractA new type of connection between shear walls is proposed for the shear wall with precast concrete hollow molds (PCHM). The overlapping reinforcements are inserted into the PCHM before pouring concrete into the hollow in this method. Full‐scale test specimens are tested under low cyclic loading test to analyze their seismic performance, such as failure modes, hysteretic characters, stiffness degradation, energy dissipation, and ductility. For the precast specimen, although the penetrating crack appears at the horizontal connection, there is no large slippage leading to anchorage failure and disengagement of interfaces. Generally, compared with cast‐in‐situ shear walls, shear walls with PCHM have no large difference in bearing capacity, failure mode, stiffness degradation, energy dissipation and ductility. Therefore, the proposed shear wall with the new type of connection method is worth popularizing and utilizing in practical engineering projects with similar design procedure to cast‐in‐situ structures.

Numerical Analysis on the Effect of Vital Design Parameters on the Seismic Performance of Shear Walls with Horizontal Ring Connection

Prefabricated shear walls are currently widely applied in mid-to-high-rise structures. As a new type of structural form of assembled shear walls, the ring connection assembled concrete shear wall has clear mechanical mechanism, easy construction and better performance and other significant advantages, which are gradually being applied in actual engineering. However, few systematic studies are carried on this new type of shear wall structure, and a complete theoretical system for guiding the design could not be given, especially in terms of mechanical mechanism and seismic performance, more detailed research work is needed. This paper uses numerical simulation as the main method to study the influence of different design variables such as shear span ratio, buckle size, axial compression ratio on the mechanical properties of the connection area in shear wall and the overall seismic performance of the structure. In this way, the theoretical basis for further optimizing the structural performance of the shear wall connection with ring connection.

Hysteretic model of shear walls built with high‐strength reinforcement

AbstractThe seismic performance of shear walls reinforced with high‐strength bars has been experimentally studied in depth; however, limited analytical research exists on such walls. As part of this study, two shear walls reinforced with Grade HRB 600 bars and subjected to different axial load ratios (0.1 and 0.2) were tested under cyclic loading to study their hysteretic performance. As part of the analytical investigation, a method to model the hysteretic response of shear walls built with high‐strength bars is proposed, consisting of a skeleton curve and a set of empirical hysteretic rules. The skeleton curve consists of a simplified quadrilinear model, represented by points at cracking, yield, peak, and ultimate. The empirical hysteretic rules are based on the Park hysteretic model. The experimental test data in this paper were used to validate the accuracy of the proposed analytical method. The results show that the analytical lateral force‐displacement hysteretic curves are in reasonable agreement with the experimental curves, especially in terms of the loading and unloading stiffnesses and pinching behavior.

Cyclic testing of moment-shear force interaction in reinforced concrete shear wall substructures

Previous quasi-static cyclic tests of shear walls, which routinely used an incremental lateral displacement test protocol with a constant axial load, failed to reflect the character of moment-shear force interaction of prototype buildings. To study the effect of the moment-shear force interaction on the seismic performance of shear walls, three identical 2-story shear wall specimens with different loading patterns were constructed at 1/2 scale, to represent the lower portion of an 11-story high-rise building, and were tested under reversed cyclic loads. The axial force, shear force and bending moment were simultaneously applied to simulate the effects of gravity loads and earthquake excitations on the prototype. The axial force and bending moment delivered from the upper structure were applied to the top of the specimens by two vertical actuators, and the shear force was applied to the specimens by two horizontal actuators. A mixed force-displacement control test program was adopted to ensure that the bending moment and the lateral shear were increased proportionally. The experimental results show that the moment-shear force interaction had a significant effect on the failure pattern, hysteretic characteristics, ductility and energy dissipation of the specimens. It is recommended that moment-shear force interaction should be considered in the loading condition of RC shear wall substructures cyclic tests.

Experimental study on seismic performance of shear walls with steel fiber recycled concrete

The paper studies the seismic performance of shear walls with steel fiber recycled concrete. Four shear wall specimens were designed and manufactured in this paper and tested under low cyclic loading. The effects of waste fiber and recycled aggregate on the seismic behavior of shear wall were studied. The results show that the incorporation of waste fiber can delay the generation of cracks in concrete. The incorporation of waste fiber can improve the bearing capacity and ductility of shear wall to some extent, while the recycled aggregate has little influence on the bearing capacity and ductility of shear wall.

Research Progress on Internal Shear Connection of Double Steel Plate-concrete Composite Shear Wall

A comprehensive analysis of three types internal shear connection of double steel plate-concrete composite shear walls is carried out. There are internally welded shear connectors, tension restraints shear connectors, and cavity-type. The analysis shows that these three types of shear connection forms have significant effects on the improvement of the seismic performance of shear walls, and can give full use of the properties of steel and concrete. Compared with the traditional shear wall, the steel plate concrete shear wall has been greatly improved and has a high level of industrialization. Aiming at these three types of shear connection forms, their deficiencies and future development directions were clarified.

Structural behavior of seawater sea-sand concrete shear wall reinforced with GFRP bars

This paper investigates the seismic performance of seawater sea-sand concrete (SSC) shear wall reinforced with glass fiber reinforced plastic (GFRP) bars. Three shear wall specimens were designed for the seismic performance evaluation, including natural aggregate concrete (NAC) reinforced with steel bars (SNW), NAC reinforced with GFRP bars (GNW) and SSC reinforced with GFRP bars (GSW). The results show that the application of SSC seems to have a negligible effect on the seismic performance of shear wall in the short term. The GNW and GSW have similar failure patterns and shapes of hysteresis curves. Also, with the same reinforcement ratio, the bearing capacity of GFRP reinforced specimens can be over 85% that of SNW while the deformability can reach the lateral drift up to 1/50. The ductility of GFRP reinforced specimen is lower than that of steel reinforced specimen but its residual deformation is relatively smaller. Furthermore, the applicability of existing design methods on the SSC shear wall is also evaluated.

Effect of Replacing Steel with Shape Memory Alloy in Shear Wall Systems

Shape memory alloys are materials which has the ability to undergo reversible phase transition processes. This result in two major features: superelasticity and shape memory effect. Hence, it can be used to improve dynamic response of structures. In this respect, the present work focuses on seismic performance of shear walls equipped with SMA rebars, in order to evaluate the possibility of adopting an innovative reinforcement material in place of traditional steel. For this purpose, pushover and time history analysis were performed and the results showed that the use of SMA as reinforcement caused improvement in seismic response of shear walls.

Seismic behavior and cross-scale refinement model of damage evolution for RC shear walls

The influence on the seismic behavior of RC shear walls by axial loads is evaluated and the observed damage in the earthquake damage investigation of RC shear walls is reproduced in this paper. Six RC shear walls with aspect ratio of 2 were analyzed by the method of nonlinear finite element under different axial load ratios, and the suggested modeling techniques and the accuracy of the numerical method were verified. The seismic performance of shear walls including load–displacement responses, ductility performance, stiffness degradation and energy dissipation capacity were discussed. The analysis results indicate that axial load has a significant effect on the seismic performance of RC shear walls. On the basis of this, the qualitative and quantitative relationships between the development of material damage and the deterioration of component performance were analyzed. It realizes the cross-scale conversion of damage information about structural components of RC shear wall from the local material scale to the component scale. Then the cross-scale refinement model of damage evolution of RC shear walls in the whole process was established, simplified and verified. The results show that, the refinement model can explain the development and distribution of damage evolution of RC shear walls in the whole process quickly and easily. The research results can provide a reference for the refinement of seismic design, damage assessment and reinforcement of RC shear walls.

Seismic Performance of Shear Wall Using Seismic Resistant Steel Deformed Bar with High-Ductility

Seismic Performance of Shear Wall Using Seismic Resistant Steel Deformed Bar with High-Ductility

Seismic Performance of Shear Wall with CFST Columns and Encased Steel Truss

A shear wall with concrete filled steel tube (CFST) columns and encased steel truss is a new type of shear wall. To determine the seismic performance of the new shear wall, an experiment was carried on a 1/5-scale model. Based on the experimental study, the load-carrying capacity, stiffness, ductility, hysteretic property, energy dissipation and failure phenomena of the model were analyzed. It shows that the seismic performance of a shear wall with CFST columns and encased steel truss has high bearing capacity, stiffness, energy dissipation capacity and good ductility. In addition, a numerical elastic-plastic finite element (FE) analysis of a shear wall with CFST columns and encased steel truss were carried out. The computation results were in good agreement with the test results. FE software, ABAQUS, was used to change the ratio of steel truss to steel tubes and normalized axial force. The influences of different parameters of shear walls were carried out.

The Statement of Research Progress in Embedded Steel Plate Shear Wall

Shear wall is the main component that resists the lateral force for high-rise buildings. With the rapid development of high-rise buildings, especially the super high-rise buildings, requirements for seismic performance of shear walls have become more sophisticated. This introduction summarizes the commonly used in embedded development and existing problems of steel plate shear wall, which are stiffened steel plate shear wall, non-stiffened steel plate shear wall, composite steel plate shear wall, preventing buckling of steel plate shear wall and low yield point steel plate shear wall.

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

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.

Research on Deformation Index Limits of RC Shear Walls Based on Material Damage

This paper divides the seismic performance of shear wall into five levels: integrity, slight damage, slight ~ moderate damage and serious damage which are defined based on material damage. And physical and mechanical description of shear walls in each performance level is given. The displacement angle is selected as the seismic performance index limit. The numerical analysis of 524 pieces of shear walls has been made to discuss the influence on seismic deformation index limits of component according to axial compression ratio, flexure shear ratio, the nominal shear stress level, the hoop characteristic value and the reinforcement ratio of longitudinal bars. With mathematical statistic method, the calculation formula for deformation index limits of components is obtained, which can be used as the basis in the performance-based seismic evaluation of shear wall structures.

Load Carrying Capacity Calculation of Shear Wall with Concrete Filled Steel Tube Columns and Concealed Trusses

Shear wall with concrete filled steel tube columns and concealed trusses is a new kind of shear wall. In order to further the seismic performance of the new shear wall, experiment was carried on three 1/5 scale models, which included one traditional RC shear wall, one shear wall with concrete filled steel tube columns, one shear wall with concrete filled steel tube columns and concealed trusses. Based on the experimental study, load-carrying capacity and hysteretic property of each model were analyzed. The study show that the seismic performance of shear wall with concrete filled round steel tube columns and concealed steel trusses has high bearing capacity and good hysteretic property. Load carrying capacity calculation of shear wall with concrete filled steel tube columns and concealed steel trusses were carried out, the calculate results were in good agreement with the measured results.

A numerical model for the analysis of masonry walls in-plane loaded and strengthened with steel bars

A novel macro-model for the analysis of masonry shear walls reinforced with steel bar grids is presented. The model is based on the so-called disturbed state concept (DSC), with a modified hierarchical single yield surface (HISS-CT) plasticity model accounting for a distinct behavior in tension and compression. The effect induced by the introduction of different reinforcement ratios is discussed, in terms of increase of both failure load and ductility. With reference to a quasi-square shear wall, an optimal reinforcement ratio is evaluated by means of the numerical model proposed and subsequently compared with recommendations provided by the Canadian masonry design standard. The comparison shows how minimum values proposed by Canadian standard are suboptimal and hence not totally suitable to obtain a proper increase of the seismic performance of shear walls in high seismicity region. A second example, relying into a shear panel with eccentric openings and subjected to horizontal loads, is analyzed in detail. It is assumed to strengthen the structure by means of a light and a heavy reinforcement, to deeply investigate the role played by steel bars in masonry seismic upgrading. A new explicit formula is finally presented, useful to provide a quick estimation of the load carrying capacity of reinforced masonry, to be eventually used in common design.

Finite Element Analysis of the Precast Shear Walls

To reduce the construction cost of the domestic promotion of the new prefabricated concrete shear wall structure system which is promoted in our country. To analyze the factors which can affect the load-carrying capacity and seismic performance of shear wall, including the axial compression ratio, the concrete strength, the reinforcement ratio and some other factors. Among all these factors, the axial compression ratio is the main factor influencing the seismic performance and the section ductility [1]. This paper adopts the ANSYS finite element analysis program, operating a nonlinear analysis on the performance of the precast shear wall when it is with one-way loading, studying the axial compression ratio's effect on the bearing capacity and deformability of the precast shear wall. According to the finite element analysis, when the axial compression ratio is between 0.2 to 0.4 and as it rises, the specimen's bearing capacity and stiffness will increases while deformability and ductility will decrease. Through the finite element analysis, we can provide reliable theory basis for the performance of the precast shear wall when it is with one-way loading.