Concept on positioning of Columns

1.
SYMMETRY:
⦁ It is observed that the distribution of mass, stiffness across the plan has good symmetrical aspects.
⦁ this tends to reduce the horizontal displacements in both of the two horizontal displacements orthogonal horizontal directions.
⦁ it also has a very good uniformity.

REDUNDANCY:
⦁ There are missing structual elements in the periphery of the plan.
⦁ This causes the uneven distribution of earthquake action effects in non linear range across the plan.
⦁ The energy dissipation across the structure is very low which results in non-reliable structure.

BI-DIRECTIONAL STIFFNESS:
⦁ The building force may not be able to resist the horizontal seismic actions in the shorter direction (Y-axis) and also the resistance and stiffness in the shorter direction (Y-axis) is less when compared to longer direction (X-axis).

DUCTILITY:
⦁ The building may not be able to resist the elastic earthquake forces in shorter direction (Y-axis).
⦁ So, it may result in inelastic response.
⦁ The reduction in design force in the shorter direction (Y-axis) is to be compensated by ductility.

2.
⦁ The possible type of irregularities for the given structure are:
⦁ Soft storey irregularity.
⦁ Stiff and strong upper floor due to masonry fill.
⦁ The column in one storey is longer than the above.
⦁ some provision to avoid the irregularities are,
⦁ The building is torsionally irregular. so the building framing must be revised.
⦁ The mass irregularity is avoided by providing light weight concrete\low weight masonry or by providing structure with more wood materials.
⦁ The structure should be built in well symmetric manner.
⦁ The columns which are provided on the structure should be of the same size and height through out the building.
⦁ The weight of the building from the ground floor should decrease towards top.

3.
⦁ Structure is not symmetric.
⦁ Larger strength is provided hence low ductility.
⦁ In this building, there is no proper placement of masonry infill walls.
⦁ In this building, Redundancy in the vertical direction in not provided properly.