Coupled Shear Wall Structures Research Articles

Analysis of reinforced concrete shear walls with single band of octagonal openings

The applications of cast-in-situ reinforced concrete shear walls for tall buildings are prevalent in many countries. Shear walls with openings are called coupled shear walls which act as cantilevered walls joined by coupling beams. Openings for windows and doors affect the behaviour of the structure and cause to decrease the strength of shear wall. Some methods were suggested in the past to increase the strength of shear wall but they are not easy to apply and need labour attentiveness. This study proposes adding haunches to the corners of rectangular openings as a simple method to increase the strength of coupled shear wall structures. Analytical analysis employing Total Moment Concept and Continuous Connection Method (CCM) and Nonlinear Finite Element Analysis (NLFEA) were carried out on symmetrical shear walls with single band of octagonal openings. The results are compared with outputs of previous study on shear wall with rectangular openings. The analysis results demonstrated that it is confidently worth to use the octagonal openings due to very small percentage increase in the total weight of the structure compared with the amount increase in ultimate load of the shear walls.

Stiffness optimisation of coupled shear wall structure by modified genetic algorithm

A novel method by modified genetic algorithm (GA) for stiffness optimisation of coupled shear wall structure has been proposed. The method is established mainly for lateral stiffness and torsional stiffness optimisation simultaneously, which aims to search optimum shear wall distribution using modified GA. A new concept of torsional moment has been defined to depict the torsional performance. Other than traditional crossover and mutation, a modified coding system is proposed to describe the shear wall properties. Moreover, partial derivations of inertia moment and torsional moment are defined as selective probability in modified GA. A chart-based optimum procedure has been given to reveal the operational progresses based on the modified GA method. Finally, a case study of coupled shear wall structure is used to demonstrate the feasibility and efficiency of the proposed method.

Large-Scale Testing of Coupled Shear Wall Structures with Damping Devices

When coupled shear wall (CSW) systems are built in a high seismic region, excessive shear forces are induced in the coupling beams. As a result of these shear forces, brittle failure of coupling beams and wall-coupling beam joints may occur or shear walls may yield first. The ductility demands on coupling beams can also be of critical concern. To solve these problems, new damping systems are proposed to improve the seismic performance of high-rise coupling shear wall structures. The proposed systems, which are CSW systems with a metallic damper or a friction damper, offer important advantages over the conventional reinforced concrete CSW systems: increasing energy dissipation capacity and reducing damage to the structures. This paper presents the results of large-cale cyclic tests of damped CSW systems. Test results show that the proposed systems exhibit a stable hysteretic response. In addition, the energy dissipation in these systems is concentrated in the energy dissipation devices, while the inelastic behavior of the beams and walls is prevented through appropriate capacity design.

Optimization Design for Coupling Beam Dampers of Shear Walls

The couple shear wall structures are well known for their anti-lateral stability, they have a promising future in macro complex high-level structures. Coupling beam dampers are the key components of coupled shear wall structures. In this manuscript, metallic in plane yield coupling beam damper with four types of poration and different pore areas are analyzed by Finite Element Method. It is found that the hourglass-shaped poring coupling beam damper has superior hysteretic behavior and higher carrying capacity comparing to other types of poring damper. In addition, the optimized poration parameters are further obtained by using Kriging surrogate model, which maximize the carrying capacity and enhance hysteretic behavior of the hourglass-shaped coupling beam damper.

Experiment Study and Nonlinear Analysis of a New Skip-Floor Staggered Shear Wall Structure for High-Rise Buildings

A new tall building structure is presented -- skip-floor staggered shear wall structure. According to the result of nonlinear analysis and experiment study, this new structural system has good economic benefits and better structural behavior. In order to study its spatial nonlinear properties, based on a 3D nonlinear FEM analysis model, the 3D seismic nonlinear analysis is provided by considering both spatial effect and influence of slab and connecting beam. It shows, compared with traditional coupled shear wall structure, the skip-floor staggered shear wall structure has superiority in many respects, such as providing bigger space and lateral stiffness, reducing seismic force, etc. Therefore, this new structural system has wide applications.

Nonlinear Analysis of a New 3D Skip-Floor Staggered Shear Wall Structure

The elastoplastic nonlinear analysis is provided by considering both spatial effect and influence of slab and connecting beam. The seismic internal force distribution is also studied. It shows that compared with the 2D model and traditional 3D coupled shear wall structure, 3D skip-floor staggered shear wall structure has superiority in many respects, such as initial rigidity, uniformity of force, energy dissipation, etc. Therefore, this new structural system has good economic benefits and wide applications.

Free vibration analysis of coupled shear walls with axial force effects

In this article, an approximate method of determining the vibrational frequencies of coupled shear walls with inclusion of axial force effects is presented. For this purpose, first the continuum approach is adopted for modelling linked beams. Then by applying force equilibrium conditions to each of the walls, and enforcement of displacement compatibility relations for the inflection point of linked beams subjected to bending, the governing differential equation of a statically loaded structure is formed. Using D'Alembert's principle, this equation is converted to a structural dynamics equation. The obtained model is a partial differential equation in space and time. Using separation of variables, two independent differential equations are further obtained, one of which, depends on time and the other on position. Finally, a new method of determining natural frequencies of coupled shear wall structures with axial force effect is presented. Also comparisons between the proposed method, finite element analysi...

A New Type of Coupled Shear Wall Structure System with Buckling-Restrained Brace Steel Coupling Beam

This paper introduces the status quo and development trend of coupling beam structure system at home and abroad, proposes a new type of buckling-restrained brace steel coupling beam structure system and puts forward main problems to be studied regarding the structure systems of buckling-restrained brace steel coupling beam and coupled shear wall with buckling-restrained brace steel coupling beam.

전단벽 구조물의 풍응답 저감을 위한 LRB의 적용

In general, shear walls are employed as lateral resistance system. Most of shear wall structures require openings in shear walls and thus shear walls are linked by floor slabs or coupling beams resulting in the coupled shear wall structures. In this study, an LRB (lead rubber bearing) was introduced in the middle of the coupling beam of the coupled shear wall structures and the wind-induced response reduction effect of this system was investigated. In order to evaluate the control performance of the proposed method, 20- and 30-story building structures were used as example structures and boundary nonlinear time history analyses have been performed using artificial wind excitation. Japanese vibration evaluation criteria was employed to evaluate whether the proposed system could improve the serviceability of the tall coupled shear wall structures under wind excitation. Based on analytical results, it has been shown that the proposed method that connects shear walls with LRBs can improve the wind-induced response control effect.

LRB를 이용한 병렬전단벽 구조물의 지진응답제어

Most of shear wall structures require openings in shear walls and thus shear walls are linked by floor slabs or coupling beams resulting in the coupled shear wall structures. When these structures are subjected to seismic excitations, excessive shear forces are induced in coupling beams. Accordingly, brittle failure of coupling beams may occur or shear walls may yield first. To avoid this problem, damping devices can be installed in coupling beams. It can increase the vibration control effect and improve the seismic resistance performance of the coupled shear wall structure by avoiding stress concentration and the brittle failure of coupling beams. Based on this background research, an LRB (lead rubber bearing) was introduced in the middle of the coupling beam in this study and the authors investigated the seismic response control effect and stress distribution of the proposed system. To this end, a modeling technique that can effectively predict the structural behavior of coupled shear wall structures has been proposed. With this proposed technique, time history analyses of the example coupled shear wall structure subjected to seismic excitation were performed and the vibration control effects of the seismic responses were investigated.

Earthquake Response of RC Coupled Shear Walls Strengthened with Thin Composite Plates

This paper deal with the seismic analysis of reinforced concrete (RC) coupled shear wall structures strengthened by bonded composite plates. In the analytical formulation of the present study, the adherent and the adhesive layers are modeled as shear wall elements, using the mixed finite element method. In the validation process of the proposal model, static and free vibration analyses of coupled shear walls are firstly studied. Comparisons with theoretical results reported in the literature are made and good agreement is observed. After this stage, numerical results are presented that relate to the performance of RC coupled shear walls bonded with composite plates under several different earthquake scenarios, in which an RC coupled shear wall strengthened by steel plates is treated as a limiting case.

Lateral stiffness and vibration characteristics of damaged RC coupled shear walls strengthened with thin composite plates

This paper deals with the bending and vibration analysis of moderately damaged coupled shear wall structures with externally bonded carbon fiber-reinforced polymer (CFRP) sheets. In the analytical formulation, the adherent and the adhesive layers are all modelled as shear walls, using the mixed finite-element method (FEM). The anisotropic damage model is adopted to describe the damage extent of the RC coupled shear walls. A free vibration analysis is carried out to determine the frequencies of multi-storey strengthened shear wall structures with openings. Test problems are conducted to demonstrate the accuracy and effectiveness of the proposed method. Numerical results are presented to show the performance of reinforced concrete coupled shear wall structures bonded with composite plates in which a damaged RC shear wall with openings strengthened by a thin steel sheets is treated as a comparator. The effects of damage extent and of the bonded sheets on the bending and vibration characteristics of damaged RC coupled shear wall structures are also studied.

Non-Linear Performance of Slabs in Coupled Shear Wall Structures

The non-linear coupling action of reinforced concrete slabs in shear wall structures is investigated by the finite element method and the results are validated by small scale model tests using micro-concrete. Flexural stiffness and effective width of the coupling slabs are found to be influenced by the geometric and non-linear material parameters of the structures. Design curves for the determination of flexural stiffness and effective width are presented as functions of geometric parameters in the pre-cracking, cracking and post-yielding stages of non-linear material response. Comparative study of numerical and experimental results suggested that the design curves are reliable and can be used in the analysis and design of shear wall structure in practical situations.

Cyclic behaviour of deep reinforced concrete coupling beams

Six half-scale models of reinforced concrete coupling beams with span/depth ratios ≤ 2·0 were tested under reversed cyclic load by a newly developed test method that can accurately simulate the boundary conditions of coupling beams in coupled shear wall structures. Five of them were conventionally reinforced and one was diagonally reinforced. Span/depth ratio and reinforcement layout were the main structural variables studied. Test results revealed that the deep conventionally reinforced coupling beams behaved quite differently from the ordinary beams in frame structures. Generally, shear failure was more likely to occur. Moreover, the additional longitudinal reinforcement bars (those placed near the centroidal axis) could contribute significantly to bending strength and therefore lead to an increase in shear demand. Nevertheless, the measured drift ratios of the conventionally reinforced coupling beams still reached 3·6–5·7%, which are not small for deep coupling beams. On the other hand, it was found that the provision of diagonal reinforcement radically changed the load resisting mechanism and significantly improved the energy dissipation capacity of the coupling beam. However, it had not improved the deformability of the coupling beam.

Cyclic behaviour of deep reinforced concrete coupling beams

Six half-scale models of reinforced concrete coupling beams with span/depth ratios ≤ 2·0 were tested under reversed cyclic load by a newly developed test method that can accurately simulate the boundary conditions of coupling beams in coupled shear wall structures. Five of them were conventionally reinforced and one was diagonally reinforced. Span/depth ratio and reinforcement layout were the main structural variables studied. Test results revealed that the deep conventionally reinforced coupling beams behaved quite differently from the ordinary beams in frame structures. Generally, shear failure was more likely to occur. Moreover, the additional longitudinal reinforcement bars (those placed near the centroidal axis) could contribute significantly to bending strength and therefore lead to an increase in shear demand. Nevertheless, the measured drift ratios of the conventionally reinforced coupling beams still reached 3·6–5·7%, which are not small for deep coupling beams. On the other hand, it was found that the provision of diagonal reinforcement radically changed the load resisting mechanism and significantly improved the energy dissipation capacity of the coupling beam. However, it had not improved the deformability of the coupling beam.

Seismic Analysis and design of 2D coupled shear wall structures using expert systems technology

Seismic Analysis and design of 2D coupled shear wall structures using expert systems technology

Analysis of reinforced concrete coupled shear wall structures

The ultimate strength analysis of reinforced concrete coupled shear walls with one or two bands of openings requires a two-stage approach. In the first stage, the analysis of the coupling beams is carried out. This is followed by the analysis of the complete wall in the second stage. A simple approach based on the ‘total moment concept’ for the analysis of coupled shear walls with one or two bands of openings is presented. Experimental results supporting the predictions of the mode of failure and ultimate strength is also presented. This study updates previous research and enhances further understanding of the behaviour of reinforced concrete shear wall structures at ultimate limit states of loading. Copyright © 1999 John Wiley & Sons, Ltd.

On The Methodics Providing Software Quality InCivil Engineering Applications

The paper presents some experiences in a software development for civil engineering applications. It is oriented towards software quality maintenance. It relates to the computerbased analysis of three-dimensional coupled shear wall structures in multistorey buildings. The implemented method provides the calculation of internal forces, stresses and displacements due to lateral and vertical loads and to the vertical settlement, as well as it enables a dynamic analysis by means of response spectrum method. An integrated system for analysis of coupled torsional-flexural vibrations due to seismic actions and for static analysis is presented.

Response of Large Panel Precast Wall Systems: Analysis and Design

A general design procedure proposed by Clough is applied to a precast coupled shear wall structure located in UBC Seismic Zones 2, 3 and 4. Both slender and deep coupling beams are considered. Inelastic static analyses using the finite element method are carried out to compare the results with Clough's method. This study showed that large panel structures with deep coupling beams behave in a satisfactory manner in all seismic zones. In comparison, coupled walls with slender beams showed a less satisfactory response. The application of Clough's method is illustrated with the aid of a fully worked design example.

A continuous-discrete approach to the free vibration analysis of stiffened pierced walls on flexible foundations

A hybrid approach, based on the analysis of an equivalent continuous medium and a discrete lumped mass system, is presented in this paper for conducting dynamic analysis of stiffened coupled shear walls supported on foundations which are flexible rotationally, and in both the vertical and horizontal directions. The effect of shear deformation on the free vibration behaviour of coupled shear walls reinforced by stiffening beams located at the top and the base level, and at an arbitrary level along the structural height is considered. The stiffened coupled shear wall system is represented by either a continuous system or a discrete system at various stages of the analysis. The advantage of using these two ways of representing the shear wall system is that the stiffness and mass matrices required for structural dynamic analysis are easily obtained. Numerical studies on a typical example structure, carried out by this continuous-discrete approach, to investigate the effects of shear deformation and the incorporation of stiffening beams on the free vibration characteristics of stiffened coupled shear wall structures, are also presented.