Concept on positioning of Columns

1) Talking about the layout given , It is been investigated on factors such as symmetry , redundancy, ductility and bi-directional stiffness along both X-axis and Y-axis.
Symmetry - Symmetry is defined as all directions following a specific pattern . Along X-axis , if layout is folded into half horizontally, we will see a mirror image both sides. This concludes that layout is symmetrical along x-axis.
Along Y-axis, if layout is folded into half vertically , we will see a mirror image both sides, therefore, layout is symmetrical along y-axis also.
Ductility - The layout shows more columns in X-axis, than y-axis. More columns will lead to high stiffness in that direction thus resulting in reducing ductility in that direction. Taking Y-axis in consideration, It will have more ductility. More columns, means more beams connected to them, but they are n zigzag pattern giving a discontinous bracing in x direction.
Redundant - In X direction there are more no. of columns in the middle portion and equally spaced. Considering top and bottom in X direction, columns are given more space. In Y direction , there are less columns but all of them are equally spaced. Concluding, structure is more redundant in X axis.
Bi- directional Stiffness - Taking X direction in consideration, all the beams are alinged and connected from extreme right to extreme left without any gaps. So the load will get transferred easily in that direction. Along Y direction , there are certain spaces where beam is not provided between the columns so the load travelling from top or bottom will move to X direction. Concluding this X- axis framing is good with bi-directional stiffness but not with Y- axis as we get some points of diversions.

2) In the building shown, we see some irregularities which needs to be identified and corrected
Soft storey in the middle- The building has an open area in 6th floor with no structural member, which will lead to plastic hinge formation at the columns. We may categorize it as stiffness irregularity which needs to be rectified.
Vertical structure - With elevation at every floor , we see a decrease in the floor area as compared to the bottom portions. This may be categorized as vertical irregularity.
Slopy base - Half portion of the building is constructed on a slpong elevation which can lead to stiffness irregularity in the upper storey. This needs to be designed as per IS provisions.

3) Given is 4 storey building with open ground floor.
Open storey - This leads to a soft storey mechanism in the bottom of the building.
Further it tells that it has rooms separated by open corridor.
Open corridor - Rooms on the side and open corridor will leave mass irregularity in the structure.
The two short sides are covered with infill walls but there are certain openings.
Infill walls- This concludes the perimeter with those walls will be more stiff.
A staircase is given in the upperhand left corner
Staircase - Stair portion are much more stiff due to midlanding beams provided.
If we study the column beam layout , we can see that there are no beams provided between columns in the vertical directions. This denotes that in Y-axis building is weak.
Also columns in X axis are also not properly oriented with the beams, the beam is connected with smaller side of the column which can not help in transferring forces to the right directions.
There is a major difference in the size of the column provided which can lead to structural deformity and hence , the structure collapsed.