Concept on positioning of Columns

1

Investigation of the framing the plan with 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

Investigation of the framing plan with respect to symmetry in Y-direction

If we split the plan horizontally half, it will look mirrored .so we have to conclude the given plan is symmetric in Y-direction

Investigation of the framing the plan with respect to symmetry in X-direction

The coloumn in x-direction are comparatively more and evenly spaced so the structure is more redundant in x-direction , except the top and bottom coloumn rows are having quite longer spans

Investigation of the framing plan with respect to symmetry in Y-direction

The coloumns in y-direction are comparatively lesser but evenly spaced. so the structure is redundant but lesser than that of in x-direction

Investigation with respect to Bi-directional stiffness

The coloumns in horizontal direction are connected with straight to straight beams. this means, any lateral load (Sesimic force in X-direction ) passing from left end of the building will have its path staright till it reaches rigth end of the building. so no/less possibility of force diversion takes place

The coloumns in vertical direction are not connected with straight to straight beams. so a lateral load passing from south side of the 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

Investigation of the framing plan with respect to ductility

Prima facie the aspect ratio of the plan clearly hints morec coloumn in x-direction compared to y-direction. it will result in higher stiffness of the building in x-direction which would reduce the ductility in x-axis

Moreover the x-force will easily pass from one bay to its next due to beam alignment whereas the y-force will struggle to pass through the north-south beams are arranged in zig-zag which leads to a discontinuous bracing

We can conclude that the given framing plan is more ductile in y-direction than that of in x-direction

2

Vertical irregularity - The building plan area is large in bottom stories. the floor plan areas are getting reduced with increase in heigth these building offsets has to be crosschecked with reference to IS-1893-2016 Table-6 serial number 3

Soft storey - The building has uncovered opening space in 6th floor. as there is no occupancy/a partition wall this will lead to plastic hinge formation at the coloumns(with reference to IS - 1893 -2016 Fig.4A ) this has to be checked and sufficiently designed

Slopy base - The building is constructed on a sloping ground at one side this will lead to significant variations in the stiffness (with reference to IS -1893 -2016 -Fig.5E) few levels may be subjected to soft storey mecahnism

Vertical irregularity - IS-1893-2016 Table-6 serial number 3

Soft storey - IS - 1893 -2016 Fig.4A

Slopy base - IS -1893 -2016 -Fig.5E

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 higher mass compared to the middle bay left open for corridor. this induces mass irregularity along the heigth uniformity

Two short sides covered with infill walls - This means the buildings left and rigth sides periphery is more stiffer during the seismic forces ( especially along the North - South )

Staircase portion at left top corner - Usually staircase and lift portions are stiffer than other parts because of concentrated concrete elements. so the staircase portion contains more stiffness in the provided building plan

No framing connection along the Y-direction - We could see no structural beams provided along the vertical direction between coloumns. this makes the building more vulnerable during the North-South seismic force

Beams connected along the coloumn minor axes - The coloumns are having longer dimension in Y-direction. this means they are more stiffer along the y-direction . but the beams are running only along x - direction which would attract much lesser lateral forces and hardly transfers it

Variation in coloumn sizes - The internal coloumns are having higher sizes compared to exterior coloumn (This is common because of higher load demands ) but this will lead to significant difference in lateral drift of coloumns. so the concrete floor might have suffered heavy out - of - plane shear which would led to collapse