Concept on positioning of Columns

1.Examining the framing plan with respect to symmetry in the X direction:

If we split the plan in half vertically, it will look like a mirror. So we
assume that the given plan is symmetric in the X direction.

Examining the framing plan with respect to symmetry in the Y direction:

If we split the plan in half horizontally, it will look like a mirror. We therefore conclude that the given plan is symmetric in the Y direction.


Examining the frame plan with respect to redundancy in the X direction

The columns in the x direction are relatively more and evenly spaced. The structure is therefore more redundant in the x direction. Except that the rows of the upper and lower columns have a relatively longer span.

Examining the framework plan with respect to redundancy in the Y direction.

The columns in the y direction are relatively smaller but evenly spaced. Thus, the structure is redundant but smaller than the structure in the x direction.

BI-DIRECTIONAL STIFFNESS INVESTIGATION:

1. The column in the horizontal direction is connected by straight to straight beams. this means that any lateral load (seismic force in the x direction) passing from the left end of the building will have a straight path until it reaches the right end of the building, so there will be no or less possibility of force divers.

2. The column in the vertical direction is not connected by straight and straight beams, so the lateral load passing from the south side of the building will be diverted to the east and west to reach the next field. there will be a large force deflection by the seismic force in the y direction. the framing plan is weak with respect to bidirectional stiffness in the y direction

EXAMINATION OF THE FRAMING PLAN FOR DUCTILITY:

1.prima face aspect ratio of the floor plan clearly suggests more columns in the x direction compared to the y direction. The result will be a higher stiffness of the building in the x-direction, which would reduce ductility in the x-axis

2. in addition, x-force will easily pass from one field to another due to the alignment of the beams, while y-forces will have difficulty passing through the north-south beams are arranged in zigzags, resulting in discontinuous stiffening.

3. we can conclude that the given framing plan is more ductile in the y direction than in the x direction



2. ANS

VERTICAL IRREGULARITY:

the floor plan of the building is large on the lower floors. floor plan areas decrease with increasing height. these building displacements shall be compared with reference IS-1893-2016 table -6 serial number 3

SOFT STORES:

the building has an uncovered open space on the 6th floor. since there is no habitation or partition walls, plastic curtains are formed at the columns (with reference to IS -1893-2016 figure 4A). this needs to be checked and designed sufficiently.

dirty base:

the building is built on sloping terrain on one side, which will lead to significant changes in stiffness (referring to IS-1893-2016 figure 5E), several levels may be exposed to the soft floor mechanism

3. ANS

OPEN GROUND FLOOR - this refers to the soft floor mechanism operating in the building

ROOMS ALONG 2 BAY SEPARATED BY OPEN HALLWAY - bays filled with rooms will have more weight compared to the middle bay left open for the hallway. this uniformly induces mass irregularity along the height

TWO SHORT SIDES COVERED BY FILLER WALL - this means that the perimeter of the right and lowest side of the building is stiffer under seismic forces (especially along the north and south)

UPPER LEFT CORNER STAIR SECTION - The stair and elevator sections are usually stiffer than other sections due to the concentrated concrete elements. so the stair section includes more stiffness in the provided building plan

NO FRAMING CONNECTIONS ALONG THE Y DIRECTION - we saw no structural beams in the vertical direction between the columns, making the building more vulnerable during north-south seismic force

BEAMS CONNECTED ALONG THE MINOR AXIS OF THE COLUMNS- the column has longer dimensions in the y direction- this means that they are stiffer in the y direction, but the beams only run in the x direction, which would attract much less lateral forces and hardly transmit them

VARIATION IN COLUMN SIZES - internal columns are larger in size compared to external columns (this is common due to higher load demands) but this will result in a significant difference in lateral displacement of the columns so the concrete floor could suffer heavy runoff - a shear plan that would led to collapse