Concept on positioning of Columns

Answer 1

(a) Symmetry : From the above figure if the structure divide along the centre of direction say X-X

, then the arrangement of columns and beams looks similar on both the sides on Y direction.

Similarly if the structure divides along the centre of direction say Y-Y it looks the arrangement of structural elements were looks similar

Therefore it is more reliable and resistance to earthquake motion

Due to symmetry the mass and stiffness will show uniformity and torsional response will also be less due to minimum eccentricity.

(b) Redundancy

Generally for earthquake resisting structure the major criteria on layout system is continunity, regularity and redundant.

In this figure the at the periphery region corner columns were missing therefore uneven distribution of earthquake action appears across the plan

(c) Bi-lateral Stiffness

The arrangement of beam column are connected straightly therefore by means of seismic force acts on x direction passing straightly and less possibility of force diversion happens. where as in the column arrangement on y direction were not connected straighly which forms more amount of force diversion occurs

(d) Ductility

Ductility which means an ability of material to undergo large deformation without significant rupture before failure.

In the structural the more number of columns are aranged in x - direction while compare with y direction. Therefore higher stiffness with less ductility on x- direction, while on the other direction their is a discontinuity of beam column connection which produce more ductility.

Answer 2

(i) Vertical Irregularity: The building area is large at bottom stories and the floor plan area get reduced with increased in floor height.

(ii) Soft storey Mechanism: The building looks opening in between the floor which leads to plastic hinge formation at the columns.

(iii) Slope Terrain Base: The Structure is rest on Slope terrain therefore variation in stiffness happens

Answer 3

(i) The Structure is designed as open ground floor therefore it deals with soft storey mechanism

(ii) The beams were missing along the y - direction therefore the structure may collapse during seismic action.

(iii) The orientation of columns are in Y - direction and the beam connected along with column minor axes which may leads to high deflection to beams and less in stiffer.

(iv) As in the figure the middle portion of corridor doesn't have any mass as compared to other sides having rooms which result greater mass, due to this mass irregularity structure may collapse.