Concept on positioning of Columns

1.

Answer:

    Symmetry:

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

          This tends to reduce the horizontal displacements in both of the two horizontal displacements in both            of the two orthogonal horizontal directions

          It also has a very good uniformity also

    Redundancy:

          There are missing structural elements in the periphery of the plan this causes the uneven distribution            of earthquake action effect in non linear range across the plan

          The energy dissipation across the structure is very low which result in non-reliable structure

    Bi-directional stifness:

          The building plan may not be able to resist the horizontal seismic actions in the shorter direction(Y-              axis)and also the resistance and stiffness in the shorter direction(Y-axis) is less when compared to                longer direction(X-axis)

    Ductility:

          The building may not be able resist the elastic earthquake forces in shorter direction(Y-axis) so it may            result in inelastic response 

          The reduction in design force in the shorter direction(Y-axis) is to be compensated by ductility

2.

Answer:

     The possible type of irregularities for the given structure are:

     soft storey irregularity:

          1.Stiff and strong upper floor due to masonary fill

          2.The column in one storey is longer than the above

     some provisions to avoid the irregulrities:

             The building is torsionally irregular so the building framing must br revised

             The mass irregulrity ia avoided by providing light weight concrete/low weight masoary or by                         providing structure with more wood materials

             The structure should be built in a well symmetric manner

             The columns which are provided on the structure should be of same size and height through out                   the building

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

3.

Answer:

       Structure is not symmetric

       Larger strength is provided hence low ductility

       In this building there is no proper placement of masonry infill walls

       In this building redundancy in the vertical direction is not provided properly