In structural engineering, the sliding wall is a structural system consisting of reinforced panels (also known as shear panels) to counter the effects of lateral loads acting on the structure. Wind and seismic loads are the most common building codes, including the International Building Code (where are called embedded wall lines) and Uniform Buildings Code, all exterior wall lines in the wood or steel frame construction must be prepared. Depending on the size of the building, some interior walls should be retained as well.
Sliding wall structures in the middle of large buildings - often wrapping elevator or stair shafts - forming shear cores .
The shear wall holds the load inside the plane that is applied along its height. The applied load is generally transferred to the wall by the diaphragm or collector or member of the drag. They are built in wood, concrete, and CMU (masonry).
Plywood is a conventional material used in wood shear walls (wood), but with advances in technology and modern building methods, other prefabricated options have made it possible to inject sliding assemblies into narrow walls that fall on both sides of the opening. Steel sheets and steel-backed shearers in place of structural plywood on shear walls have been shown to provide stronger seismic resistance.
Video Shear wall
Structural design considerations
Loading and Failure Mechanism
The shear wall is more rigid on its main axis than on any other axis. It is considered to be the main structure that provides relatively stiff resistance to the vertical and horizontal forces acting in its field. Under these combined loading conditions, the shear wall develops appropriate axial, shear, torsional and bending styles, resulting in a complex internal stress distribution. In this way, the load is transferred vertically to the foundation of the building. Therefore, there are four critical failure mechanisms; as shown in Figure 1. Factors that determine the mechanism of failure include geometry, loading, material properties, restraint, and construction.
Slenderness Ratio
The slimness ratio of the wall is defined as a function of the effective height divided by the effective thickness or radius of the circle of the wall. This is closely related to the limit of slimness which is the boundary between elements that are classified as "lean" or "sturdy". The sleek walls are susceptible to fashion congestion, including Euler being buckled due to axial compression, Euler out-of-plane bend due to axial compression and lateral torsional bending due to bending moments. In the design process, structural engineers need to consider all these failure modes to ensure that the wall design is safe under any kind of possible loading conditions.
Wall shear coupling effect
In the actual structure system, the sliding wall can serve as a combined system rather than an isolated wall depending on its settings and connections. Two adjacent wall panels can be considered combined when the interface is transferring longitudinal shear to withstand deformation mode. This stress arises whenever a part is subjected to a bending or controlled flexural stress and the magnitude depends on the stiffness of the clutch element. Depending on this rigidity, the performance of the combined portion will fall between the ideal uniform element of the same gross plan cross-section and the combined performance of the independent component parts. Another advantage of coupling is that it increases the overall bending stiffness in proportion to the shear stiffness, resulting in smaller shear deformations.
Maps Shear wall
Settings in buildings with different functions
The location of the sliding wall significantly affects the function of the building, such as natural ventilation and natural lighting performance. Performance requirements vary for buildings with different functions.
Hotel and dormitory building
Hotel or dormitory building requires many partitions, which allows insertion of sliding walls. In this structure, the traditional cellular construction (Fig. 2) is preferred and the regular wall arrangement with transverse cross between space and spine wall extending flanking the central corridor is used.
Commercial buildings
In multilevel commercial buildings, shear walls form at least one nucleus (Figure 3). From a building service perspective, sliding core homes provide communal services including stairs, elevators, toilets, and maid service. The requirements of building serviceability require proper setting of the sliding core. From a structural point of view, the shear core can strengthen the building's resistance to lateral loads, ie wind loads and seismic loads, and significantly improve building security.
Construction Methods - Concrete
Concrete shear walls are reinforced with horizontal and vertical reinforcement (Figure 4). The reinforcement ratio is defined as the ratio of the area of ​​coarse concrete to the portion taken orthogonally to the reinforcement. The construction codes of practice determine the maximum and minimum quantities of reinforcement and detail the steel bars. Common construction methods for in-situ reinforced concrete walls include traditional closed elevators, slip form, jump form and tunnel shape.
Method of removal disconnected
The traditional closed lift method should be used when the number of small walls or irregular arrangements. In this method, a wall is formed one story at a time along with a column. Although slow, this technique can produce premium quality or premium texture.
Slip form method
Slip forming is a method of concrete placement where a moving shape is used to create continuous wall extrusion. This method is very efficient for suitable structures, such as flanged wall systems and cores. Very accurate wall thickness can be achieved but a rough surface due to the abrasion of the wall.
Method jump form
Jump forming, also known as climbing forming, is a construction method in which a wall is cast in a discrete lift. This is a stop-start process with the day joints that are formed at each lift level. Similar to slip forming, jump forming is only efficient for structures with repetition of wall arrangements. In addition, it will be easier to add connections and extrusion on the floor due to its separate features. Nevertheless, inclusion of the joints of the day leaves a higher chance for defects and imperfections.
Tunnel shape method
The construction of the tunnel forms using a formwork system to cast sheets and walls as a single casting operation. It is suitable for cellular structures with regular repetitions of horizontal and vertical members. The advantage of this method is that construction can develop vertically and horizontally at the same time, thereby increasing the integrity and stability of the structure.
Nonplanar sliding wall
Due to functional requirements, the designer can select non planar parts such as C, L as opposed to planar parts such as rectangular bell/bar parts. The nonplanar section requires 3D analysis and is a research area.
Modeling techniques
The modeling technique has been updated progressively over the past two decades, moving from static to linear nonlinear linear, enabling a more realistic representation of global behavior, and different modes of failure. Different modeling techniques include wall ranges of macro models such as modified beam-column elements, to micro models such as 3D to 3D models. Appropriate modeling techniques should:
- Be able to predict an inelastic response
- Combine important material characteristics
- Simulate behavioral features: Connection and Slip Bar
- Is a migration of the neutral axis
- Tension stiffening
- Interaction between bending and shear motion
Different models have been developed over time, including macro models, vertical line element models, finite element models, and multi-layer models. Recently, fiber-section beam-column elements have become popular, as they can model most of the global response and failure modes correctly, while avoiding the sophistication associated with finite element models.
Analytical methods
- Restricted element method
- Stringer panel model
See also
- Hold
References
Source of the article : Wikipedia
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