Showing papers on "Shear wall published in 2006"

Experimental In-Plane Shear Strength Investigation of Reinforced Concrete Masonry Walls

Abstract: This paper presents test results of ten single-story reinforced concrete masonry shear walls. Test results are summarized and compared with design formulae specified by the New Zealand masonry design standard NZS 4230:1990 and by the National Earthquake Hazards Reduction Program. It was determined that the test walls exhibited shear strength significantly exceeding the NZS 4230:1990 maximum permissible shear stress, confirming that NZS 4230:1990 was overly conservative in accounting for masonry shear strength. It was also confirmed from the test results that masonry shear strength increases with the magnitude of applied axial compressive stress and the amount of shear reinforcement, but that the shear strength decreases inversely in relation to an increase in wall aspect ratio. In addition, it was shown that the postcracking performance of shear dominated walls was substantially improved when uniformly distributing the shear reinforcement up the height of the walls.

Cyclic behavior of low yield point steel shear walls

Abstract: This paper presents the research works on the cyclic behavior of low yield point (LYP) steel shear wall. In the LYP steel shear wall system, the LYP steel plate is used for steel panel and conventional structural steel is used for boundary frame. A series of experimental studies were carried out to examine the stiffness, strength, deformation capacity, and energy dissipation capacity of the LYP steel shear wall under cyclic load. The effect of width-to-thickness ratio of steel plate, continuity of shear wall, and the design of beam-to-column connections on the boundary frame was examined. Good energy dissipation capacities were obtained for all specimens studied. Excellent deformation capacities were obtained from both rigid frame–shear wall system and simple frame–shear wall system. The LYP steel shear wall is able to maintain stable up to 3–6% of story drift angle. A two-force strip model was also proposed to simulate the elastic and inelastic behavior of shear wall system. Good correlations were found between experimental and analytical studies. Based on these research findings, suggestions are made for the design of LYP steel shear wall systems.

Seismic Behavior of Sheathed Cold-Formed Structures: Physical Tests

Abstract: The paper presents the results of an experimental study on the seismic behavior of cold-formed steel stud shear walls, sheathed with wood-based [oriented strand board (OSB)], and gypsum-based (wallboard) panels. Tests were carried out on two, nominally identical, prototypes, which were designed in such a way to contain all the structural elements and components used for this type of structure. The first specimen was tested under monotonic loading conditions. The second one was instead tested under cyclic loading conditions, with a loading history previously derived from an ad hoc numerical study of the deformation histories likely to be imposed by typical Italian earthquakes. The results obtained allow consideration of typical seismic behavior issues (capacity design, connections between horizontal diaphragms and vertical walls, performance criteria) to be drawn. In particular, all the components of this structural system can be designed according to capacity design criteria, imposing collapse in the sheathing connections of the vertical shear wall. In addition, no appreciable deformation of the OSB sheathing-to-floor framing connections was observed in both monotonic and cyclic tests.

Design Criteria for Seam and Sheeting-to-Framing Connections of Cold-Formed Steel Shear Panels

Abstract: In recent years important research activity has been undertaken in order to determine the earthquake performance of light gauge steel house structures. Usually, studies approach the problem of earthquake performance through experiments on wall panels conducted either under monotonic or cyclic loads. All studies underline the overwhelming importance that the behavior of the connections has in determining the overall performance of wall panels. However, although these studies focused on the global behavior of the panel, they did not try to characterize the behavior of and provide design criteria for connections, as components of the structural system, and to provide relevant design criteria. The present paper attempts to fill this gap.

Inelastic analysis of a reinforced concrete shear wall building according to the National Building Code of Canada 2005

Abstract: An eight-storey reinforced concrete shear wall building located in Montreal and designed according to the 1995 National Building Code of Canada (NBCC) and the Canadian Standards Association standard CSA-A23.3-94 is studied to evaluate the impact of new requirements for inclusion in new editions of the NBCC and CSA-A23.3. Static and modal analyses were conducted according to the 2005 NBCC (draft 2003) and CSA-A23.3-04 (draft 4) procedures, and three-dimensional dynamic inelastic time history analysis was performed using three earthquake records. The building is braced by four flat shear walls and three cores. Various estimates of the fundamental period of vibration based on empirical expressions presented in the literature or structural models with different stiffness assumptions were examined. The analysis also permitted the study of the displacement and force demand on the lateral load resisting system. It was found that the base shear from the 2005 NBCC is 29% higher than the 1995 NBCC value when code e...

Behaviour of light-gauge steel-frame – wood structural panel shear walls

Abstract: At present, no Canadian document is available with which engineers can design light-gauge steel-frame – wood structural panel shear walls that are relied upon to resist lateral in-plane loading (ea...

Non-combustible reinforced cementitious lightweight panels and metal frame system for shear walls

Abstract: A vertical shear wall system including vertical metal framing members, for example, C-joists, U-joists, open web joists, or other metal frame systems that support a reinforced, lightweight, dimensionally stable SCP panel. The shear wall system is non-combustible, water durable, mold and rot resistant, termite resistant and is capable of resisting shear loads equal to or exceeding shear loads provided by plywood or oriented strand board panels. The panels employ one or more layers of a continuous phase resulting from the curing of an aqueous mixture of inorganic binder, for example, calcium sulfate alpha hemihydrate, hydraulic cement, an active pozzolan and lime. The continuous phase is reinforced with glass fibers and contains lightweight filler particles, for example, ceramic microspheres.

Behaviour of cold-formed steel shear walls under horizontal and vertical loads

Abstract: Shear walls made of cold-formed steel with sheathing on one or both sides are composite structures. They can carry horizontal and vertical loads. Based on the results of a large series of tests a design procedure was developed that allows for the design of walls carrying horizontal and vertical loads. In addition to this a model is introduced by which the stabilising effect of the sheeting for the cold-formed sections can be assessed.

Seismic Behavior of Sheathed Cold-Formed Structures: Numerical Study

Abstract: This paper presents and discusses the results of a numerical study on seismic deformation demand to sheathed cold-formed steel structures. It is part of a wider research, involving also physical tests on oriented strand board-sheathed stud walls. Numerical results have been obtained using an ad hoc mathematical model of the hysteresis response of sheathed stud walls, also taking into account the strong nonlinearity of the response for small lateral displacements and the strong pinching of hysteresis loops. This model has been calibrated against data coming from physical tests, using both old available experimental results and newly obtained ones. Numerical results have been elaborated on in order to both judge the seismic performance of the structure under increasing seismic intensity levels and develop an ad hoc cyclic loading protocol for physical tests.

Structural wall panel assemblies

Abstract: Novel wall panel assemblies and shear wall assemblies are disclosed herein. Preferred embodiments include novel corner posts, studs, and sill plates for formed of composite materials and suitable for fabricating wall panels and shear wall assemblies for use in the construction of residential and commercial buildings.

Shaking table tests on a high‐rise RC building model having torsional eccentricity in soft lower storeys

Abstract: A series of shaking table tests on a 1:12-scale model using scaled TaftN21E earthquake records were conducted to investigate the seismic performance of a 17-storey high-rise reinforced concrete structure with a high degree of torsional eccentricity and soft-storey irregularities in the bottom two storeys. Based on the analysis of test results, the following conclusions were drawn: (1) the model responded mainly in the coupled mode of translation and torsion or in the torsional mode. Under severe table shaking, the flexible side underwent large inelastic deformation, and the predominant mode of the model changed from the coupled mode to the torsional mode, resulting in greatly increased torsional stiffness, thereby limiting damage in the flexible frame; (2) the shear force and deformation of the flexible side were governed by the torsional behaviour, whereas those of the stiff side were affected mainly by the overturning deformation. The lateral stiffness of the shear wall in the torsional mode was about four times that in the coupled mode because the warping deformation due to torsion counteracted the flexural deformation due to overturning moment in the torsional mode; and (3) the reversed cyclic overturning moments predicted by linear elastic dynamic analysis in the direction transverse to the table excitations contradicted unilateral overturning moments of the serviceability-level test results, which showed a bias towards tension or compression in the columns.

Experimental testing of joints for seismic design of lightweight structures. Part 1. Screwed joints in straps

Abstract: An experimental testing campaign on tensile bolted joints between straps is reported. Two dominant failure modes are identified: (1) tilting, bearing and tearing of the sheets (TS) and (2) tilting, bearing and net-section failure (NSF). The analysis in terms of ductility and strength shows that bolted connections are less adequate than screwed connections (reported in Part 1 of this paper) for the seismic design of X-braced shear walls in lightweight structures. NSF joints are more ductile than TS joints in the sense that they undergo larger displacements before failure. However, if washers are not used, both types of connections fail before energy dissipation through yielding of the diagonal straps can occur. Some design recommendations to improve the seismic performance of bolted joints, including the use of washers, are given. The accuracy of Eurocode 3 formulas to predict the ultimate load is also analyzed.

Strength and stiffness determination of shear wall panels in cold-formed steel framing

Abstract: Shear wall panels, as the one of the primary lateral load resisting elements, have been extensively used in lightweight framing of low- and mid-rise residential construction, particularly in seismic applications In current practice, lateral strengths of shear wall panels with cold-formed steel framing are primarily determined by tests, owing to the lack of applicable analytical methods Meanwhile, the use of numerical methods such as the finite element method has rarely been employed in the design practice to determine the lateral strength of shear wall panels due to the extensive amount of computational effort associated with the modelling Presented in this paper is an analytical method to determine the ultimate lateral strength of the shear wall panel and its associated displacement The method takes into account the factors that primarily affect the behaviour and the strength of the shear wall panel, such as material properties, geometrical dimensions and construction details Lateral strengths obtained from the proposed method for shear wall panels with different sheathing materials and steel stud thicknesses, sizes and spacing of sheathing-to-stud fasteners were compared with those of recent experimental investigations The comparison demonstrates that the predicted results are in good agreement with those of the tests Therefore, it is recommended that the proposed method be used in engineering practice

Blast Assessment of Load-Bearing Reinforced Concrete Shear Walls

Abstract: In this paper a methodology for assessing the performance of structural elements subject to explosive loading is presented. The method combines basic section analyses, equivalent single degree of freedom (SDOF) modeling, and a static finite element pushover analysis to calculate the blast resistance of an existing shear wall subject to an external explosion. The method optimizes the breadth of results while minimizing the calculation complexity required. A static pushover analysis is conducted to identify regions of vulnerability. The second floor wall is identified as the location of failure and is modeled as a system, which includes the stiffness contributions of adjoining wall sections, and also as a component with fixed ends. Pressure–impulse curves are developed to quantify the blast resistance of the wall relative to various levels of damage. The component model is found to underpredict the blast resistance by 7% when compared to the system model for impulsive demands. Simplified energy methods are ...

Midply wood shear wall system : Concept and performance in static and cyclic testing

Abstract: This paper introduces a new concept in shear wall design. One ply of sheathing material is placed at the center of the wall between a series of pairs of studs and plates oriented in 90° rotated position relative to those in standard shear walls. The new wall design is called “midply” in reference to the location of the sheathing panel. Test results for midply walls under static and cyclic loading conditions are presented and compared with those presented for standard shear walls under similar loading conditions. In midply walls, nails connecting framing members to sheathing work in double shear in contrast to connections in standard shear walls, which work in single shear. This results in substantial improvements in the shear performance of midply walls. As verified by the test results presented herein, load-carrying capacity of midply walls is over three times that of comparable standard shear walls.

Nonlinear FE Model for RC Shear Walls Based on Multi-Layer Shell Element and Micro-Plane Constitutive Model

Abstract: Nonlinear simulations for structures under disasters have been widely focused in recent years. However, precise modeling for the nonlinear behavior of reinforced concrete (RC) shear walls, which are the major lateral-force-resistant structural member in high-rise buildings, still has not been successfully solved. In this paper, based on the principles of composite material mechanics, a multi-layer shell element model is proposed to simulate the coupled in-plane/out-plane bending or the coupled bending/shear nonlinear behaviors of RC shear wall. The multi-layer shell element is made up of many layers with different thickness. And different material models (concrete or steel) are assigned to various layers so that the structural performance of the shear wall can be directly connected with the material constitutive law. And besides the traditional elasto-plastic-fracture constitutive model for concrete, which is efficient but does not give satisfying performance for concrete under complicated stress condition, a novel concrete constitutive model, referred as micro-plane model, which is originally proposed by Bazant et al., is developed to provide a better simulation for concrete in shear wall under complicated stress conditions and stress histories. Three 10-story buildings under static push-over load and dynamic seismic load, with various shear wall arrangements, were analyzed with the shear wall model proposed in this study. The simulation results show that the multi-layer shell elements can correctly simulate the coupled in-plane/out-plane bending failure for tall walls and the coupled in-plane bending-shear failure for short walls. And with micro-plane concrete constitutive law, the cycle behavior and the damage accumulation of shear wall can be precisely modeled, which is very important for the performance-based design of structures under disaster loads.

Light-gauge steel-frame wood structural panel shear wall design method

Abstract: Design guidelines for laterally loaded (wind and seismic) light-gauge steel-frame – wood structural panel shear walls are currently unavailable in Canadian standards and codes. A research project w...

Reinforced cementitious shear panels

Abstract: This invention relates to a structural cementitious panel (SCP) panel able to resist lateral forces imposed by high wind and earthquake loads in regions where they are required by building codes. These panels may be used for shear walls, flooring or roofing or other locations where shear panels are used in residential or commercial construction. The panels employ one or more layers of a continuous phase resulting from the curing of an aqueous mixture of inorganic binder reinforced with glass fibers and containing lightweight filler particles. One or more reinforcement members, such as mesh or plate sheets, are bonded to at least one surface of the panel to provide a completed panel that can breathe and has weather resistant characteristics to be capable of sustaining exposure to the elements during construction, without damage.

A simple model for assessing periods of vibration and modal response quantities in symmetrical buildings

Abstract: A simple mathematical model is proposed for assessing periods of vibration and mode shapes of common cantilever bents used in concrete structures, such as shear walls, coupled walls, rigid frames and wall-frame assemblies. The bent is treated as a continuum and the proposed model is based on the technique of decomposing a cantilever bent into two complementary subsystems (a flexural and a wall-frame bent) and on the finding that the use of Dunkerley's formula for calculating natural frequencies yields reasonable results for the first three modes of vibration. The objective in proposing this model is to consider the effect of column axial shortenings in the analysis of structural bents. With this model any cantilever bent may be approximated by a simple incompressible shear–flexure system of equal flexural rigidity, but of equivalent modal shear rigidity. This approach has the advantage that the response of different structural bents may be combined in buildings composed of these bents in any arrangement. All bents are approximated by equivalent shear–flexure models and therefore the complete structure may be analysed by a simple methodology, which has been extensively used in the past. Particularly in symmetrical buildings, frequencies may be determined by a simple formula and modal response quantities by available design charts. A quick estimate of these quantities is of particular importance at the early stages of structural design, prior to a full dynamic analysis. In order to illustrate the application of the proposed model a symmetrical building of varying height, composed of different structural bents, is analysed and comparisons are made with more accurate results obtained by 3D computer dynamic analyses. Copyright © 2006 John Wiley & Sons, Ltd.

Connectors and Methods of Construction for a Precast Special Concrete Moment Resisting Shear Wall and Precast Special Concrete Moment Resisting Frame Building Panel System

Abstract: A precast concrete wall panel molding system for fabricating a wall shell and a plurality of ribs and beams. A precast concrete wall panel molding system with facilities for incorporating door and window frames. A ductile panel end connector for attaching panels one to another whether in parallel or angled as in inside or outside corners. A ductile panel end connector for attaching panels to columns. A wall anchor/shear plate with post-tensioning brace plate. A hybrid precast/cast-in-place special moment resisting shear wall/special moment resisting frame reinforced concrete building system for regions of potential seismic activity. A prescriptive method building system for composite structural building assemblies with conventional wood and light-gauge steel framing, structural steel, and other building code approved and tested building systems, building components, building panel systems, building roofing systems, modular and manufactured buildings, and building electrical, mechanical, and plumbing systems. A precast concrete wall panel system conforming to industry practices and standards as published by the Precast/Prestressed Concrete Institute, (PCI) in it's “PCI Design Handbook” (fifth edition, 1999), the American Concrete Institute “Building Code Requirements for Structural Concrete” (ACI 318-05), The “International Building Code 2006” and the “Uniform Building Code”.

Lateral Stiffness of Shear Walls with Openings

Abstract: This technical note investigates the accuracy of a simplified hand method recommended in several design guidelines for practicing structural engineers for calculating the lateral stiffness of shear walls with openings. Parametric studies are performed in which the location and size of the opening as well as the aspect ratio of the wall are varied. Toward this goal, a special-purpose finite-element algorithm is developed and implemented in the computing package MATLAB. Results from finite-element analysis are compared to those of the hand method. It is found that the hand method, despite its complexity, is highly approximate and often enormously overestimates the stiffness of shear walls with openings.

Slot opening building blocks or bricks as well as light shear wall and related building, and construction method

Abstract: The present invention relates to a kind of light concrete block with reinforcement slot, microporous brick, general brick and its masonry light shear wall and building system, and its concrete construction method It is basically characterized by utilizing clever and reasonable reinforcement arrangement to build up two-way combined wall