Conceptual design of a building with columns and shear walls

    PROPERTIES

                  CASE 1

                     CASE 2

                           CASE 3

Restraint of floor shrinkage

Shear walls are positioned at corners. It offers strong resistance to floor shrinkage. The floor will be tightly held in place by these shear walls at the corners, and shrinkage will be controlled.

Shear walls are positioned along the wall's margins on all sidewalls. So better stability to floors near the walls. Shrinkage can occur at corners  due to absence of shear walls

Shear walls are placed in an order less manner and are incomplete, so high chances to shrinkage exposure.

The lateral stiffness

As the Shear walls are positioned only at corners, in the case of an earthquake the forces tends to act along the edges of the floor and will have low lateral stiffness and stability

The structure will have better stability and lateral stiffness along both principal planes because the shear walls are located along the edges, which is the same direction as the earthquake excitation.

As there are two shear walls in the x axis that increase stiffness in that direction. But in the y axis, there is only one shear wall, which concentrates seismic force in that wall, causing instability and decreasing lateral stiffness in that direction.

Torsional stiffness with respect to the vertical axis

 There is no eccentricity between the centre of mass and the centre of stiffness; they both coincide, making the model less prone to torsion and allowing it to be classified as torsional stiffened model.

There is no eccentricity between the centre of mass and the centre of stiffness as the shear walls are positioned symmetrically and   As a result, this configuration is less vulnerable to torsion.

The shear wall is placed asymmetrical in the y direction, so as a result, the centre of stiffness shifts to the left edge, resulting in an eccentricity between the centre of mass and the centre of stiffness, causing torsional instability in this configuration.

Vertical reinforcement at base

Since the shear reinforcements are positioned at the corners, they play a little role in the lateral force resistance to the remainder of the wall As a result, less reinforcement will be required for these walls.

Here the shear walls are arranged along the main directions, they absorb a substantial amount of lateral forces.  As a result, considerably more reinforcing should be added to these walls in order to withstand these forces.

The shear walls are asymmetrically arranged here, the shear walls will take up a significant amount of lateral forces.  Especially the wall on the left side of the room. As a result, these walls must be heavily reinforced.

Static eccentricity

There is no eccentricity because the shear walls they are symmetrically located at the corners, the centre of mass and stiffness coincides in this layout

There is no eccentricity because the shear walls are symmetrically arranged around the edges, the centre of mass and stiffness coincide in this arrangement

There will be eccentricity in the arrangement because there is only one shear wall along the left edge with a larger mass than the other two shear walls in the y direction. As a result, the centre of stiffness shifts to the left, resulting

System’s redundancy

The structure will have less redundancy, because this design contains shear walls at its corners which does not actively participate in resisting the lateral force, so the other parts of the structure must take care of a large portion of the lateral force.

The structure will have moderate to good redundancy, here as the forces are evenly distributed due to the symmetric placement of shear walls along the mid portion of each edge.

The structure has the lowest redundancy as the shear walls is placed asymmetric and there is a concentration of load at the left edge.

Foundation systems

As the shear walls are at the structure's corners, an isolated footing with a tie beam can be used as a foundation.

A raft foundation or a box foundation can be used.

a combined footing can be provided along the y direction and isolated footing in X direction

Architectural constraints

From an architectural standpoint, this shear wall configuration is pleasing. since it does not interfere with other elements such as doors, windows, and so on

While this design is stable, there is a potential that these shear walls will interfere with the wall openings, which is not ideal.

In this configuration, the two walls on the right side along the X direction are architecturally sound, but the shear wall on the left edge along the y direction takes up over half of the wall, obstructing open spaces.