Conceptual design of a building with columns and shear walls

Question 1

(a)

• In the first structure, the L Shaped shear walls are placed along with the corners,thus it completely restraints at corners. but, it leads to crakcs in the floor.
• Comparitively lower lateral stiffness along with X and Y directions.
• In terms of torsional resistance, corner wall produce more resistance to twist.
• Its a symmetric Structure.

(b)

• In the second structure, the shear walls are placed in the centre of the walls,thus it restraints along with the edges. The crack will be minimal.
• The walls of a wall system of this frame could be arranged in two horizontal directions with as much two-way symmetric as possible.
• In terms of torsional resistance,middle wall produce average resistance to twist.
• Its a symmetric Structure.so it can be considered at every storey to fairly uniform resistant in seismic forces and deformation demands, minimizing the uncertainty about the seismic response.

(c)

• In the third structure, the shear walls are placed in both corners and the centre of the walls,thus it have non uniform restraints along with the edges.
• The center of mass and center of gravity of such structure will not lie far away from each other enabling transitional modes in the first two principles modes.
• The foundation , shear wall and columns are arranged different arrangements, so here take up huge amount moments in case of during earthquakes,
• This type of shear wall system will not carry the load equally in either directions. So this structure have lack of redundancy.
• On left hand side the wall provide more eccentricity, lateral stiffness is more. Therefore it occurs then the damage or failure will be less.

Question 2

• In this structural frame , there is a two-way eccentricity of the center of mass in accordance with the center of stiffness , which is eccentricity of x-direction is larger than y-direction.
• In this structure beams are provided at stronger than column, so it can consider as Weak column strong beam design in nature.
• Therefore this structure need some shear wall to resist the column failure, when the lateral forces acting about the structure.
• Combination of shear wall and column tends to prevent the failure about the structure during the seismic forces occur.
• As the frame plan, we can see about the alignment of beam is uniformly continuous of B1 and B2 at X- direction, and B11 & B12, B9 & B10 at Y-direction.
• But another all beams are provided at discontinuous of structural frame, so here cause to difficult of transmission of load evenly at entire structure due to action of lateral forces.
• Beams with long span may have their top reinforcement at the supports governed by factored gravity load, rather than by the seismic design situations.
• Therefore,this structure will alternate to better portal of better offset at symmetric in nature.
• The column beams connections should be in proper cross section area, then it achieve lateral stiffness, mass regularity, moment resisting factor.

Question 3

• This plan totally unsuitable for heavy seismic zone areas.
• In this plan, the interior columns are in unsymmetric.
• The partition wall are provided through the base of beam, should support the lateral deformation due to the structure.
• The interiors beams will supports the slab, then the lateral load resisting the failure due to earthquakes.
• For this irregular columns in plan, there we provided the flat slabs, because its directly stay in a column centroidal axis.
• For here, the beams at different locations is irregular in plan and are continuous and is disallowed to resist the seismic load in the region.
• In this plan, the flat sab is more appropriate than a regular beam column junctions, because of as its provide support to the columns without any provision of the beam, which reduces the weight of the building and also helps in the ductility of the structure by indirectly.
• for the solution of this structure, we provide the shear wall from the foundation of structure through vertical components, it should minimize the loss of sudden failure occur due to lateral force acting on structure.