What is the shear wall?

In structural engineering, a shear wall is a vertical element of a seismic force-resisting system that is designed to resist in-plane lateral forces, typically wind and seismic loads. In many jurisdictions, the International Building Code and International Residential Code govern the design of shear walls. A shear wall resists loads parallel to the plane of the wall. Collectors, also known as drag members, transfer the diaphragm shear to shear walls and other vertical elements of the seismic force-resisting system. Shear walls are typically constructed from materials such as concrete or masonry.

Shear forces can also be resisted by steel braced frames which can be very effective at resolving lateral forces but may be more expensive. When a structural member experiences failure by shear, two parts of it are pushed in different directions, for example, when a piece of paper is cut by scissors. Shear walls are particularly important in large, or high-rise buildings, or buildings in areas of high wind and seismic activity. Shear walls can be positioned at the perimeter of buildings or they may form a shear core – a structure of shear walls in the center of a building, typically encasing a lift shaft or stairwell. Lateral pressures tend to create a rotational force on the shear wall which, due to the shear wall acting as one member, produces a compression force at one corner and a tension force at another. When the lateral force is applied from the opposite direction, this ‘couple’ is reversed, meaning that both sides of the shear wall need to be capable of resolving both types of forces.

Functions of Shear Wall

1- Providing Lateral Strength to the building: Shear Wall must provide lateral shear strength to the building to resist the horizontal earthquake forces, wind forces and transfer these forces to the foundation.

2-Providing Lateral Stiffness to the building: Shear Walls provide large stiffness to building in the direction of their orientation, which reduces lateral sway of the building and thus reduces damage to the structure.

What are Columns and functions?

The column is a vertical member in a building whose primary function is to support the structural load and transfer it through beams. Upper columns transfer the load to the lower columns and finally to the ground through footings.

Difference between them Visually

Just by visual inspection, you could say that columns are a bit less wide than shear walls; and you could already answer the reason that why the shear wall is absent in low-rise structures as compared to the must-to-have presence in high-rise sky-scrappers and buildings.

Difference between them in purpose

The reason to provide a shear wall is to strengthen the building against seismic forces due to the fact that shear wall resists lateral load by initiating the shear deformation, hence named shear wall; instead of flexural and buckling deformation in case of columns, which is very dangerous and the primary reason for column failure in buildings.

The difference from a Strength point of view

Now let’s examine the strength characteristics of both the members; Columns in a building are provided to transfer the imposed loads either through-beam or without beam into the foundation directly underneath. Columns transfer these loads by using the crushing or compressive strength of the concrete. However, the column is very weak in the case of lateral load, buckling load, or shear load. Shear wall, on the other hand, is designed to resist lateral load by shear strength or shear action.

Difference Concrete column and Shear wall

##### Shear wall
• Ratio of breadth/width < 0.4
• Ratio of breadth/width > 0.4
• The concrete column’s minimum width should be 200 mm. However many codes prefer it be of 300 mm for seismic resistance.
• The shear wall minimum width should be 150 mm.
• Concrete columns are less resistant to earthquakes as compared to shear walls.
• Shear wall is hugely resistant to earthquakes as compared to Column.
• Normally concrete columns are provided at the ends of the room as per the structural plan.
• Shear walls run along the full length of walls.
• Concrete columns cross-section can be square, rectangle, circular, I shape, L shape.
• Shear wall cross-section is like a vertically oriented wide beam.
• The lateral load is resisted by flexural deformation.
• The lateral load is resisted by shear deformation.
 The clear surface is not possible as column offset is seen at corners. A clear surface without any offset is possible. Normally consumption of concrete is less when compared to the shear wall system. Normally consumption of concrete is more when compared to the beam-column system. Normally more consumption of bricks/blocks. Normally less consumption of bricks/blocks. From an aesthetic point of view, the column is not as good as the shearwall. From an aesthetic point of view, a shear wall is better than a column. Beam-Column System is more efficient and preferred for low-rise structures. The shear wall system is more efficient for high-rise structures. Finished corners are not possible. Finished corners are possible. Provision of openings for door/window in column system is easy. Provision of openings in the shear wall systems is tedious and needs special design skills. Less carpet area is available as compared to the shear wall. More carpet area is available as compared to the column beam system. Needs skills for the placement of concrete columns. Needs advanced skills for its placement because if not kept at the proper location it may lead to adverse effects.
 Minimum steel in RCC Column as per different codes: (a) American Standard – 1.0 % (b) British Standard – 0.4 % Minimum steel in RCC Shear as per different codes: (a) American Standard – 0.25% (b) British Standard – 0.4 %

Click Here To See What Is A Difference Between A Tie Beam And A Plinth Beam?

Share this