Concept on positioning of Columns

Symmertry:

In the figure there is good symmetric in x as well as in y axis.

The distribution of mass and stiffness is symmetric in x & y axis.

It has a good uniformity.

Redundancy:

The structure has good redundancy in X direction but weak in Y direction according to X direction beacuse the no of beams is more in X direction and less in Y direction.

Bi-directional Stifness:

The structure bearing any kind of lateral forces in X direction.

The Major force diversion takes place in Y direction because there is no straight to straight beam, so shear force transfer to the beam has no straight path.

Ductility:

Stifness is inversoly proportional to Ductility.

So, Ductility in X is lesser than Y direction.

2.

The possible type of irregularities for the given structure are:

Soft story mechanism :

The building has soft story mechanism. In 6th floor there is no partition wall so formation of plastic hinge is occur at column.

Verical Irregularities:

The building is torsionally irregular. So the building framing must be revised.

The mass irregulrity is avoided.

The structure should be built in a well symmmetric manner.

Stifness :

The building has more stiffnes in longer side hince reducing ductility but in shorter side there is more ductility.

The major force diversion takes place in shorter side of the building.

3.

Open base structure (1st Floor) will form soft story mechanism.

Structure is not symmetric.

The structure has reduces stiffness in Y direction hence more Ductility.

The major force diversion takes place in Y direction of the building.

There should be framing (Beam) in Y direction.

In this building, there is no proper placement of masonry infill walls.

In this building, Redundancy in the vertical direction is not provided properly.

The staircase is sperated from building so it must be provided with required reiforcement whiich resist the sesmic loads.

Two short sides are coverd with infill wall which will cause cracks.