Concept on positioning of Columns

1.

Respect to symmetry in X direction

If we split the plan vertically half, it will look mirrored. So we conclude the given plan is symmetric in X direction

Respect to symmetry in Y direction

If we split the plan horizpntally half, it will look mirrored. So we conclude the given plan is symmetric in Y direction

Respect to redundancy in X direction

The column in X direction are comparatively more and evenly spaced. So the structure is more redundant in X direction. Expect the top and bottom column rows are having quite longer spans

Respect to redundancy in Y direction

The column in Y direction are comparatively lesser but evenly spaced. So the structure is redundant but lesser than that of in X direction

Respect to Bi-directional stiffness

The columns in horizontal direction are connected with straight to straight beams. This means any lateral load passing from left end of the building will have its path straight till it reaches right end of the building. So no or less possibility of force diversion takes place

The columns in vertical direction are not connected with straight to straight beams. So a lateral load passing from south side of building will get diverted to east & west direction to reach next bay. There will be major force diversion take place with seismic force in Y direction. The framing plan is weak with respect to bi-directional stiffness in Y direction

Framing plan with respect to ductility

Prima facie, the aspect ratio of the plan clearly hints more column in X direction compared to Y direction. It will result in higher stiffness of the  building in X direction which would reduce ductility in X axis

2.

Vertical irregularity

The building plan area is large in bottom stories. The floor plan areas are getting reduced with increase in height. These building offsets has to be crosschecked with reference to IS 1893-2016 

Soft Storey

The building has uncovered opening space in 6th floor. As there is no occupancy or a partition wall , this will lead to plastic hinge  formation at the column. This has to be checked and suffiently designed

Slopy base

 The building is constructed on a sloping ground at one side. This will lead to significant variations in the stiffness. Few levels may be subjected  to soft storey mechanism

 3.

Open ground floor

This denotes soft storey mechanism acting in the building

Rooms along 2 bays separated by an open corridor

The bays filled with rooms will have hihger mass compared to the middle bay left open for corridor. This induces mass irregularity along height unifomly

Two short sides covered with infill walls

This means the buildings left and right sides periphery is more stiffer during seismic forces

Staircase portion at left top corner

Usually staircase and lift portions are stifffer than other parts because of concentrated concrete elemnets . So the staircase portion contains more stiffness in the provided building plan