Shear Wall Configurations Research Articles

EFFECTIVE POSITION OF SHEAR WALL FOR HIGHER RISE FOR TIME HISTORY ANALYSIS

The abstract of the study that is titled "Effective Position of Shear Wall for Higher Rise for Time History Analysis" focuses on the investigation of the best placement of shear walls in tall buildings in order to improve the seismic performance of these buildings via the use of time history analysis. By doing this research, the researchers hope to find a solution to the essential problem of establishing the most effective location of shear walls in high-rise structures in order to reduce the effects of seismic forces. Evaluating the dynamic response of tall buildings under earthquake loading circumstances is the purpose of this work. This evaluation is accomplished through the utilisation of sophisticated numerical simulations and time history analytic methodologies. In order to conduct a full analysis of the structural behaviour, the investigation takes into account a number of parameters, including the height of the building, the configuration of the shear wall, and the seismic intensity. Additionally, the study analyses the influence of varied shear wall placements on key performance measures including base shear, story drift, and acceleration responses. The purpose of this research is to determine the ideal position and configuration of shear walls for higher buildings by means of systematic analysis and comparison of the results. This will help to reduce the structural vulnerability of the building and increase its seismic resilience. Those structural engineers and designers who are involved in the seismic design of high-rise structures will find the findings of this study to have significant implications. These findings provide valuable insights into effective strategies for improving the earthquake resistance of tall buildings through optimized shear wall placement. Keywords: Shear walls, High-rise buildings, Seismic analysis, Time history analysis, Structural optimization, Finite element analysis, Seismic performance, Building dynamics, Structural stability, Optimal placement.

EXPERIMENTAL STUDY OF THE LATERAL RESISTANCE OF CFS SHEAR WALLS

AbstractIn recent years, the attention grew toward sustainability issues. This led to the popularity of residential buildings made of cold formed steel profiles. In these systems the lateral bracing is provided by the shear walls. Their complex response calls for the design by testing approach. At the University of Trento an experimental study is in progress of the shear wall response under monotonic and cyclic loading. Five shear wall configurations differing in the steel skeleton and sheathings type are comprised in the programme. The paper presents the main features of the testing set‐up and the preliminary results related to two shear wall configurations. The key role of sheathing‐to‐steel framing connections is pointed out.

Evaluation of engineering demand parameters for seismic analyses of CLT-glulam hybrid structures

By bracing glulam frames with cross-laminated timber (CLT) shear walls, CLT-glulam hybrid structures offer a promising solution for multi-story timber construction. This paper presents an assessment of engineering demand parameters (EDPs) for seismic analyses of such hybrid structures. Five EDPs were considered, including the commonly used maximum inter-story drift ratios (MaxISDRs), peak floor accelerations (PFAs), and maximum roof drift ratios (MaxRDRs), as well as two newly developed EDPs named maximum connection damage index (MaxCDI) and maximum inter-story CLT shear wall damage index (MaxISWDI). The EDPs were assessed through nonlinear time-history analyses (NLTHAs) on 12 prototype CLT-glulam hybrid structures with different building heights, construction types of CLT shear wall subsystems (platform or balloon), and inter-story configurations of CLT shear walls. The MaxCDI was then employed as the benchmark EDP to evaluate the effectiveness of the other four EDPs in capturing structural damage. The results showed that the connection damage of glulam frame subsystems was limited during major earthquakes, and the construction type of CLT shear wall subsystems had a significant impact on the connection damage of CLT shear wall subsystems. The MaxISDR performed well in characterizing damage to glulam frame subsystems, while it could not reflect damage to CLT shear wall subsystems given that the Spearman’s rank correlation coefficient between the MaxISDR and the MaxCDI of CLT shear wall subsystems only reached −0.07. The MaxISWDI was capable of quantifying connection damage of CLT shear wall subsystems, with a Spearman’s rank correlation coefficient of 0.87.

Investigating the effect of the structural interactions due to floors and lintels on the lateral response of multi-storey Cross-Laminated Timber shear walls

The lateral behaviour of multi-storey Cross-Laminated Timber (CLT) structures is significantly influenced by the effects of the structural interactions between primary and secondary structural elements and their connections. In case of platform-type structures, in addition to the connections placed at the base of the walls, other structural components including the floor diaphragms and the lintels above the openings influence the lateral performances of the CLT shear walls. However, it is common practice in structural design to model multi-storey CLT shear walls by considering the wall base connections, while neglecting the effects of these structural interactions. This study investigates in detail the lateral behaviour of multi-storey CLT shear walls, comparing the results of simplified modelling strategy, typically adopted in practical design, and more advanced modelling strategies that take into account the effects of these structural interactions. Different shear wall configurations, including different geometries, number of storeys, and connection properties were analysed by means of linear elastic and nonlinear static analyses. The results of the numerical analyses highlighted significant differences between the lateral behaviour of multi-storey CLT shear walls modelled with these different modelling strategies and suggest that simplified modelling strategies may not always be reliable to describe the behaviour of multi-storey CLT shear walls.

Experimental-numerical assessment of laterally-loaded CFS frames with steel sheathing and K-shaped braces

In this study, the behavior of cold-form steel (CFS) frames equipped with various configurations of steel sheathing, and K-shaped braces are experimentally investigated. Low lateral resistance is a major problem with the CFS shear walls. Despite their advantages, such as being lightweight, ease of fabrication, and an environmentally friendly system, their lack of adequate lateral strength prevents engineers from widely using them, especially in areas with medium to high seismicity or mid-rise buildings. In this regard, a total of seven full-scale specimens with different configurations of steel sheathing and k-braced, with and without cladding, were tested to investigate their seismic behavior. The effect of gravity loading on the lateral resistance of the CFS frames was tested using three specimens. The gravity loadings of the CFS specimens were determined assuming an ordinary two-story CFS frame building. The effect of different CFS frame configurations on the energy dissipation, secant stiffness, and ductility factor of those frames was evaluated. The failure modes observed in this study can be classified into brace connection failure, brace element failure, sheathing, and chord stud failure. Moreover, using a calibrated simplified nonlinear model, the seismic behavior of different CFS configurations under earthquake excitation was examined. Based on the obtained experimental and numerical results, it can be concluded that the proposed dual CFS frame and shear wall configuration has a better performance both in the cyclic test and the numerical studies compared to the CFS walls with steel sheathing or bracing alone.

Experimental investigation on the lateral performance of CLT shear walls connected to perpendicular walls

Typically, the mechanical behavior of CLT shear walls for lateral loads is assumed to be governed by the wall base connections, such as hold-downs and angle brackets. However, many experimental and numerical studies available in literature have shown that in “box type” CLT buildings, the connections between perpendicular walls contribute to the lateral response of the CLT shear walls. This study presents the results of an experimental campaign aimed at investigating the lateral performance of CLT shear walls connected to perpendicular walls. Two CLT wall assembly configurations were tested: single Shear Wall configuration (SW), which considers a single CLT shear wall subjected to lateral load, and Shear Wall connected to Perpendicular Wall configuration (SW+PW), which considers a CLT Shear Wall connected to a Perpendicular Wall subjected to lateral load. Results showed that the SW+PW configuration reached higher structural performance in terms of lateral stiffness and lateral capacity than single SW configuration. This increase of lateral performances is governed by the properties of the wall-to-wall connections as well as the properties of the hold downs used in the perpendicular walls. Results of this experimental study show that the perpendicular walls and wall-to-wall connections may be included in the design models of CLT shear walls subjected to lateral loads.

Vulnerability of Multistory RCC Framed Building with Shear Wall During Fire

Fire in a building is a casual phenomenon but cannot be completely ruled out in spite of the facts that buildings are provided with mandatory fire safety measures. A symmetrical in plan with 5 bays with 20 stories regular RCC building has been considered with fire at three different level that is at the bottom, middle and top. The building has been designed for gravity loads and lateral loads having three different configuration of shear walls and columns. Fire temperature of 700 0C was considered. The minimum value of maximum fire temperature for failure of vertical members has been found out by iterations. The worst verticals members due to fire has been identified and their displacement calculated. Best location of shear walls using commercial software etabs is used for the analysis and design.

Damage assessment of stiffened steel plate shear walls with different configurations under far-fault and near-fault ground motions

Preventing damages and reducing the consequences of natural disasters such as earthquakes are nowadays considered as the most important considerations in improving the existing structures or designing new ones. A steel plate shear wall (SPSW) is one of the systems that resist lateral loads. Despite its significant benefits such as load capacity, plasticity, and high energy absorption capacity, the SPSW has a serious weakness: early buckling of infill plates under lateral loads. To solve this problem, some stiffeners with various distributions and geometries are used in the SPSWs. Adding these stiffeners brings about some changes in the seismic behavior (such as the seismic damages) of the structure. Therefore, in this study, we investigated the effects of various configurations of stiffeners in the shear walls on the damage level of the structures (5, 10, 15, and 20 floors) under earthquake excitations. The shear walls are either with openings (due to their implementation aspects and easy application) or without openings. Thirty-three earthquake excitations were applied (both far-field and near-field earthquakes) on the structures. Also, a non-linear dynamic analysis was performed to calculate the damages according to the three damage indexes of Park-Ang, Iemura-Mikami, and relative displacement. First, the structures were designed and modeled by the finite element software. Then, according to the definition of damage indices, the damage and performance level of the structures under earthquake records were studied and evaluated. The obtained results were presented in two separate parts. In the first part, due to the importance of model verification, the results of the study were compared with the results of the experimental models of the SPSWs with different stiffener configurations. In the second part, the effects of various configurations of stiffeners on damage indices of the SPSW with and without openings were evaluated. Based on the obtained results, the configurations of steel shear walls including the distribution of stiffeners and openings were found to have a significant effect on the amount of damage caused by seismic excitations. This effect depends on various factors for which the details are presented in this study.

Shear walls optimization in a reinforced concrete framed building for seismic risk reduction

Seismic hazards represent a permanent threat to buildings. The paper argues that risk-oriented approaches provide an interesting solution to account for the long-term resilience of buildings, both for the design of new structures and the rehabilitation of existing ones. The proposed research draws upon the standard definition of risk as a function of vulnerability, hazard and exposure to develop an optimization-based methodology for risk appraisal of buildings in seismic conditions. The proposed methodology allows to identify the optimum layout and thickness of shear walls in a reinforced concrete frame, based on a target risk performance. This is achieved through the coupling of an evolutionary computing environment with an object-oriented structural analysis tool, involving its native Application Programming Interface (API). The latter allows to automate the search for the optimum shear wall configuration solution. The research is validated on the Beichuan Hotel building in Old Beichuan (China), heavily affected by the 2008 Wenchuan Earthquake. The paper evidences that the adoption of the proposed methodology leads to a risk reduction of about 80% compared to the as-built scenario, with additional benefits from both a financial and building functionality perspective.

Response analysis of a multi-story building structure with a variety of horizontal irregularities and shear wall geometries

The growing growth of human activities has led to changes in housing patterns in urban areas. The land crisis in urban areas has made land prices uneconomical, so buildings are designed vertically. One solution to resist earthquakes in multi-story buildings is to add a shear wall structure with the proper profile and layout. Shear wall designs with variations influence the base shear, drift ratio, lateral deflection, and story drift patterns. This study presents the structural response comparison of buildings against variations in the profile and layout of shear walls subjected to earthquake loads. Force Based Design method utilizing the response spectrum approach was adopted in the analysis and carried out using SAP200. Six structural models comprise a frame without shear walls, three L-profile shear walls, two I-profile (straight) shear walls. The simulation results of the overall structural models show that the profile and layout configuration of shear walls in the frame structure of a multi-story building correlates directly to the performance of base shear, drift ratio, and story drift with relatively comparative conditions.

Analysis of Effective Location of Shear Wall for High Rise Building with U – Configuration

Indonesia is one of the countries that is prone to earthquakes. In addition to the dead loads, superimposed dead loads, and live loads, the design of buildings in Indonesia must be concerned with earthquake loads. Installing shear walls in the building structure as the Special Moment Frame Dual System is one of a solution to withstand earthquake loads. However, the location of shear walls must be considered, especially in buildings with horizontal irregularities. This study aims to determine the optimum location of the shear walls in a 10-storey building that has U-configuration with dynamic earthquake loads. This research is a numerical simulation ran by modelling the structure with software. To know the effect of the shear wall’s location on a building, several variations of the shear wall configuration with different positions have been conducted. It can be seen the lateral displacement of each floor and the shear force are the response structure to withstand the dynamic earthquake loads. Shear walls that are located close to the center of mass of the building are the optimum variation because the position of the shear wall is the closest to the core area of the building, which is the rotational axis of the building.

Seismic behavior of innovative hybrid CLT-steel shear wall for mid-rise buildings

This paper examines the seismic behavior of CLT-steel hybrid walls at 6- and 10-story heights to increase seismic force resistance compared to conventional wooden walls. The ultra-strong shear walls proposed in this paper are called Framing Panel Shear Walls (FPSW), which are based on a robust articulated steel frame braced with CLT board panels and steel tendons. Timber structures are well-known for their ecological benefits, as well as their excellent seismic performance, mainly due to the high strength-to-weight ratio compared to steel and concrete ones, flexibility, and redundancy. However, in order to meet the requirements regarding the maximum inter-story drifts prescribed in seismic design codes, a challenging engineering problem emerges, because sufficiently resistant, rigid and ductile connections and lateral assemblies are not available for timber to meet both the technical and economical restrictions. Therefore, it is necessary to develop strong and cost-effective timber-based lateral systems, in order to become a real alternative to mid- and high-rises, especially in seismic countries. In this investigation, the dynamic response of cross-laminated timber (CLT) combined with hollow steel profiles has been investigated in shear wall configuration. After experimental work, research was also carried out into numerical modelling for simulating the cyclic behavior of a hybrid FPSW wall and the spectral modal analysis of buildings of 6- and a 10-stories with FPSW. A FPSW shear wall can double the capacity and stiffness.

Effect of Location of Shear wall on Torsional Performance of Symmetric and Asymmetric High Rise Building

Torsion force is a load that is a applied to a building through torque. The torque applied creates a shear stress. If a torsion force is large enough, it can cause a building to undergo a twisting action. The main aim of the project is to study the effect of location of shear wall on torsional performance of symmetric and asymmetric high-rise building ,post tensioned slabs are being used in the construction of building hence the thesis also analyze these post tensioned slab structures by changing shear wall configuration. Post tensioned slab structures have weak resistance to lateral loads. so to provide stiffness to structures against lateral forces shear walls are used. A study of 30 storey building in zone III, is considered and determine various parameters like base shear, storey drift, and storey displacement.post-tensioning is a mature technology as it provide efficient, economic and elegant structural solutions for a wide range of applications. Post-tensioned flat slab could be a better option compared to RCC flat slab, in respect of the cost of project and time of construction. ETABS 2017 software is used for the analysis.

Experimental studies on screw connections between cold-formed steel framing and sandwich sheathing

Cold formed steel (CFS) framed wall panels with sheathing is one of the main lateral load resisting systems in light gauge structures. The nonlinear behavior of the CFS wall panel under in-plane shear loading is dictated by the nonlinear behavior of the screw connections between CFS framing and sheathing. Necessity for new and high performance CFS shear wall configurations is clearly felt by the engineering community in order to cater for the increased seismic demands in mid-rise CFS buildings. To this end the experimental studies on screw connections are essential to understand the behavior of full scale wall panels by phenomenological models. This paper presents the experimental studies on the screw connection between CFS framing and new sheathing configuration with screw subjected to shear parallel to the free edge of the sheathing. This setup mimics shear experienced by the screw as a component in full scale wall panel tests. The proposed new sheathing configuration consists of a brittle sheathing material (one of cement particle board, fiber cement board and gypsum wallboard) sandwiched between two thin steel sheets. The experiments are performed for both monotonic and cyclic loading protocols and the stiffness, ultimate strength and ductility showed a significant increase due to the sandwich steel sheets. Ultimately, the configuration with sheathing material which provides higher strength as well as ductility has been proposed for future study by full scale experiments.

High-strength cold-formed steel framed shear wall with steel sheet sheathing

The North American specifications for the design of cold-formed steel (CFS) framed shear walls (CFS-SSSW) with steel sheet sheathing provides tabulated values and equations for determining the shear strength when the thickness of frame is between 0.838 mm and 1.370 mm. At present, high-strength CFS framed shear walls with steel sheet sheathing can be needed in mid-rise construction, particularly in the seismic area. A research project was recently completed to improve the shear capacity for CFS framed shear walls with steel sheet sheathing by two methods: (1) thicker studs, tracks and blockings (thickness: 1.727 mm), (2) more sheathing screws (screws spacing: 50.8 mm). This paper presents the findings on the shear strength for high-strength CFS framed shear walls with steel sheet sheathing. Ten full-scale shear wall specimens with aspect ratios of 2:1 were tested, including four different shear wall configurations and two test methods. This paper details the test methods, specimen configurations, the test results, and provides the nominal shear strength values for the high-strength CFS framed shear walls with steel sheet sheathing. Additionally, the applicability of the effective strip method in the high-strength CFS framed shear walls with steel sheet sheathing is analyzed.

Predicting Behavior of Steel-Clad, Wood-Framed Shear Walls under Cyclic Lateral Loading

HighlightsA finite element analysis (FEA) model was developed to predict behavior of steel-clad, wood-framed (SCWF) shear walls under cyclic loading.This FEA model will be useful in determining post-frame building response to seismic forces.The model will save time and money in developing design coefficients and planning experiments for SCWF shear walls.Abstract. This article presents finite element (FEA) model results of steel-clad, wood-framed (SCWF) shear walls under cyclic lateral loading. The shear wall model consists of beam elements to model framing members, equivalent orthotropic plane stress elements to model corrugated steel cladding, linear spring elements to model nail connectors between framing members, and nonlinear hysteresis spring elements to model screw connectors. Screw connectors attaching steel panels to wood framing and steel panels to steel panels at lap joints were tested under cyclic loading to provide the constitutive relationships needed. A modified Bouc-Wen-Barber-Noori (BWBN) model was developed to capture slack, pinching, and strength and stiffness degradation of screw connectors under cyclic loading. The finite element models were validated by comparing them with experimental test results of six different SCWF shear wall configurations. Predicted peak shear strengths for most load cycles were slightly higher than those from the experimental tests, especially for stitched shear walls. Visual inspection of the FEA predicted hysteretic load curves demonstrated that pinching, and strength and stiffness degradation were well captured. The results of this study demonstrate the utility of the FEA model for comparative studies of different SCWF shear wall constructions under cyclic lateral loading. Keywords: Cyclic lateral loading, Diaphragm design, Post-frame building, Steel-clad wood-frame diaphragm.

Non-Linear Seismic Analysis of Steel Plate Shear Wall Subjected to Blast Loading

Compared to traditional lateral loading systems, such as steel braced frames, RCC walls and moment- frames, Steel plate shear walls (SPSWs) have affordable detailing pre-requisites, requires lower construction tolerances, allows faster construction and leads to less lateral load. Similar to concrete shear walls, SPSW structures are more versatile and due to their versatility, the designer also needs to have additional flexural rigidity when using SPSW in tall buildings. In spite of all advantages, SPSW are not universally accepted because of typical SPSW arrangements result in huge column sizes and forbid the usage of slender walls while reducing the efficiency of the structure. SPSW allow for less structural wall thickness in comparison to the thickness of concrete shear walls. So, it is necessary to design the thickness of a SPSW required for particular load. This paper would address the above issues with concrete examples and suggest approaches for the creation of the next generation of shear walls made of steel plate. Such approaches would allow SPSWs to be applied efficiently by offering new configuration, different modelling techniques and a more detailed understanding of model behaviour by comparing different SPSW thickness and different patterns in a particular structure. The analysis in this study is done by considering a steel structure. Earthquake data is considered for analysis and it is assigned using time history function in SAP 2000. The paper deals with lateral resistance of a steel structure for a seismic loading with different SPSW thickness and patterns. which showed SS2 type steel plate shear wall configuration performing well in resisting bending moment in both directions.

Experimental investigation of OSB sheathed timber frame shear walls with strong anchorage subjected to cyclic lateral loading

Sheathed timber frame shear walls (STFSW) with strong anchorage have recently been studied to be used as the main lateral force resisting system in timber buildings. The first part of this research project highlighted the enhancement of the shear stiffness and strength of the STFSWs with strong anchorage in comparison with the established configuration of light-frame timber shear walls under monotonic horizontal loading. In this paper, the in-plane seismic behavior of STFSWs with strong anchorage was further investigated by means of quasi-static monotonic and cyclic loading tests on large-scale timber shear walls. The boundary conditions of the specimens were considered more realistically by applying a combination of vertical force and bending moment on top of the walls. In addition to the ISO 21581, the walls were tested under a new horizontal cyclic loading protocol especially developed for the low-to-medium seismicity regions. The STFSWs with strong anchorage showed a marginally higher shear resistance under cyclic loading. Nevertheless, in terms of ultimate displacement, they did not evidently perform as well as under monotonic loading when subjected to cyclic loading. Withdrawing of staples was the main failure of the stapled connections resulting in the out-of-plane displacement of the sheathing panels, which was clearly observed by the 3D digital image correlation measurement system. The low-to- moderate seismicity loading protocol was not highly influential on their shear resistance and displacement capacity.

Effect of configuration of shear walls at story plan to seismic behavior of high-rise reinforced concrete buildings

In developing countries, the need for shelter, working area, shopping and entertainment centers is increasing due to the increasing population effect. In order to meet this need, it is necessary to turn to high-rise buildings. Significant damages have been observed as a result of insufficient horizontal displacement stiffness of high-rise buildings in major earthquakes in previous years. It is known that as the height of the structure increases, the displacement demand of the structure also increases. Since it is accepted that the structure will make inelastic deformation in the design of the structure, these displacements increase to very high levels as the number of stories increases. For this reason, damages can be much higher than expected. In order to limit the level of damage that may occur in high-rise buildings, the horizontal displacement of buildings is limited in many regulations in our age. This limitation is possible by increasing the rigidity of the structures against horizontal displacement. In recent years, the use of shear wall has increased due to the horizontal displacement limitation in the regulations. The use of shear walls in buildings limits the horizontal displacement. However, the choice of where the shear walls will be placed on the plan is very important. Failure to place the shear walls correctly may result in additional loads in the structure. It can also lead to torsional irregularity. In this study, a 10-storey reinforced concrete building model was created. Shear wall at the rate of 1% of the plan area of the building was used in the building. The shear walls are arranged in different geometric shapes and different layouts. The earthquake analysis of 5 different models were performed. Equivalent Earthquake Load, Mode Superposition and Time History Analysis methods were used for earthquake analysis. The results were compared and a proposal was made for the geometry and configuration of the shear wall.

Investigating the Effect of Seismic Loads on Multi-Story Buildings with Different Shear Wall Configurations and Building’s Ratios

One of the main and major drawbacks of conventional and rather high rise buildings is developing lateral displacements arising from lateral loads which finally make the whole structure uneconomical. In this research, a considerable effort has been made in order to investigate the effect of shear walls configurations on the lateral displacement in addition to maximum storey drift of the structure. Shear walls can be considered as one of the basic important structural elements. When a structure is subjected to external lateral loads, such as wind loads, earthquake loads etc. these walls play the main role in increasing both the strength and the safety of the structures. Therefore, this study presents the effect of configurations of shear walls, which significantly affect the behavior of the structure under loading. In order to investigate this hypothesis, four different shapes and locations of shear walls have been considered. Additionally, three different building heights (10, 20 and 30 stories), and three various ratios of the building’s length to its width (1:1, 1:1.5 and 1:2) have been taken in order to finish this research. Finite Element based software ETABS 2015 has been used for modeling and analyzing purposes. All the models have been analyzed, and the comparison of the results has been done for lateral displacement and storey drift ratio.