Concept on positioning of Columns

1 ans)symmerty

it is observed that the distribution of mass,stiffness is across the plan has good symmetrical aspects.

the tends to ruduce the horizontal displacements in both of the two horizontal displacement in both of the orthogonal horizontal directions.

its also have a very good uniformity also.

redundancy:

there are missing structure elements in the periohery of the plan .this causes the uneven distribution of earthquake action effects in non linear range across the plan.

the energy dissipation across the structure is very low which results in non reliable structure .

ductility:

the building may not be able resist the elastic earthaquake forces in shorter direction .so it may result in inelastic response.

the reduction in design force in design force in the shorter dirction is to be compensated by ductility.

bi-direction stifness:

the building plan may not be able to resist the horizontal seismic actions in the shorter direction and also the resistance and stiffness in the short direction.

so it may result in inelastic response.

2 ans)the possible type of irregularities for the given structure are:

soft storey irregularity;

*stiff and strong upper floor due to mansonary fill

*the column in one storey is longer than the above

some provisions to avoid the irregulrities:

the buildings is torsionally irregular.so the building frame must be revised.

the mass irregulrity is avoided by providing light weight concrete / low weight masonary or by providing structure with more wood materials.

the structure should be built in well symmetric manner.

the weight of the building from ground floor should decrease towards top.

3 ans)*structure is not symmetric.

*larger strength is provided hence low ductility.

*in this building,there is no proper in the placement of masonry infill walls.

*in this building,redundancy in the vertical direction is not provided properly.