Concept on positioning of Columns

1. Ans:

Symmetry :

• Along X direction
• That structure is cutting horizontally and the structure undergoes mirrored the structure willl be sane henct its is symmetry

• Along Y direction
• The structure is cutting vertically and the stucture undergoes mirrored the structure will be samm hence it is symmetry

• Investigation 0f redundancy along X direction
• The columns in X direction is comparatively high compared to Y direction so the redudancy is high at X direction and the column are evenly spaced.
• Expect the column in Top and bottom lines

• Investigation 0f redundancy along Y direction
• The column along Y direction has low number of column 6 nos but the column are evely spaced.
• Hence it has less Redundancy.

• Investigation of Bi-directional stiffness
• The load travel along the X- diredction straight path from left to right due to the column are connected with series of beams and the load transfers easily from left to right.
• Hence it have higher Bi-directional stiffness.
• There is no force deviations take place.

• The load travel along Y-direction the load from bottom to top the column are not in series and the two column are connected with beam.
• Hence the load transfer from bottom to top will not transfer.
• The load from seismic force the load travel from one column to another column through beam and the load get deviated along the right and left side of the beam.
• So it is weak at the Bi - directional stiffness.

• Ductility
• The Ductility is inversely prospers to Stiffness.
• The direction X has higher Stiffness and less Ductility.
• Where as Y direction has lower stiffness and higher ductility.

2. Ans:

• The possible sources of irregularity in the building,
• Vertical irregularity ;
• The building lower floor area is higher than the top
• The floor area is reduce with increase in height
• Which was explained in CODE IS 1893 -2016 Table 6 Serial number 3.

• Soft Storey
• In the Floor 6 there is no columns are supported to the building.
• There is no shear wall or any other wall with stand the load of the builidng which lead to load in column form plastic hinges.
• This is referenced as the IS code 1893 - 2016 Table 4A.

• Slopy Base
• The structure side surface which is slopy area which lead to the builidng as the soft storey.
• This lead to change is stiffiness.
• This referance are shown in IS Code 1893 - 2016 Table . 5E.

3. Ans:

The above Building have a details explation for failures they are,

• The open ground floor ( Soft storey ) the lower portion of the builidng has no wall to resist the force.

• Uneven Mass transfers
• The building along grid 2 and 4 having evenly distrubiton of mass due to rooms in the grids
• Where as inthe grid 3 it is corridor here the mass distrubtion is less, which is major issue in all storey.

• The staircase along left hand side top
• The staicase area has more stiffer compare to other because it is concrete member.
• So due to the high stiffness the staircase is safe

• Two storey covered with infill walls
• The right and left side of the building is more periphery which is more stiffness in seismic load ( along North and South).

• No framing connection along Y - Direction
• Form the above plan there is no inter connection beam along Y- axis which leads to failure if the seismic load accrue along Y - Direction which leads to failure.

• The Building beam and column connection
• The column are along Y - Direction where as Beams are along X - Direction which leads to less transfer of load to the column which leads to failure.

• The column sizes,
• The outer column are small in size compared to inner column it is normal because the load transfers maximum inside the builidng.

Hence there are cause for the failure and with stand of the builidng under seismic load.