Conceptual design of a building with columns and shear walls

1.

Answer:

a) Building: A

1. This structure is symmetric
2. The soil available below this building is strong and isolated foundation is used below the column
3. In this structure,shear walls are placed at 4 corners of building in same size
4. In this structure,their is heavy biaxial stresses acting on structure and due to this the floor will undergo heavy deformation
5. Due to shrinkage property of concrete the floor gets more shrinks
6. And the RC wall is more stiffer and it allows more shrinkage
7. The shear wall is more extensive because large amount of steel is used in this wall
8. The structure is not eccentric

b) Building: B

1. This structure is symmetric
2. In this structure,box type of foundation is used because it reduces weight of foundation and increase the frequency
3. Shear wall are placed on 4 edges in two orthogonal direction i.e, it is in horizontal direction
4. Due to shrinkage property of concrete the column get axially deflect and wants to shrink
5. The RC wall is stiff and it allows some shrinkage
6. The shear wall is on 4 edges,so it reduces the seismic forces which is acting on building
7. The structure is not eccentric

c) Building: C

1. This structure is not symmetric
2. Isolated footing is used because strong soil is available
3. In this structure stiffer support are in x-direction and there is no support on right hand side and due to this concrete gets expand and it shrinks more and same in y-direction
4. Lateral stiffness and torsional stiffness is more
5. There is eccentricity in left side of structure

2.

Answer:

1. First arrange the beam B5 and B6 is in straight line
2. Beam B5 and B6 is not continue or straight from span but its axis is offset at the column between them there is no smooth flow of internal forces through beam column joint neither continuity of beam longitudinal bars across the column from span to next and these bars have to terminate there and be separetely anchored at joint
3. Place column C5 to the right hand side of beam B3 and make the beam B3 and B4 straight because the load is transferred through beam and column easily and it is safe
4. Column C6 and C9 are placed in straight line i.e in the level of C3 column for easy distribution of load that means the beam B7 and B8 is in same line
5. And the structure is torsionally flexible because the mass of structure and centre of stiffness in not at same point both are different
6. There is a two way eccentricity in the frame along x direction and y direction also with stiffness the eccentricity in x direction is larger when compared to y direction
7. There is only two continous frames in the structure that is B1 and B2 in the x direction and B9,B10 and B11,B12 in the y direction and all other beams are broken at the midway in the frame
8. There will be torsional flexiblity in the structure to avoid torsional restraints it is better to make the room dimension even in both x and y direction and placing the columns at the junction of two if is feasible better to provide shear wall at appropriate location
9. The fundamental translation mode of vibration is large than the fundamental torsional mode of vibration
10. Beam with long span may have their top reinforcement at the supports governed by factored gravity load rather than by the sesmic design situation
11. Therefore this structure will alternate to better portal of better offset at symmetric in nature
12. The column beams connection should be in proper cross section area then it achieve lateral stiffness mass regularity moment resisting factor
13. As we consider beam sway mechanism in strong column/weak beam design frames is better because of its achieve a uniformly spread global inelastic displacement demand at roof level to all storeys

3.

Answer:

1. This plan totally unsuitable for heavy seismic zone area
2. In this plan the interior columns are in unsymmetric
3. The partition wall are provided through the base should support the lateral deformation due to the structure
4. The interios beams will supports the slab then the lateral load resisting the failure due to earthquakes
5. For this irregular columns in plan there we provided the flat slabs because its directly stay in a column centroidal axis
6. For here the beams at different locations is irregular in plan and are continuouss and is disallowed to resist the seismic load in the region
7. In this plan the flat slab 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
8. For the solution of this structure we provided the shear wall from the foundation of structure through vertical component it should minimize the loss of sudden failure occure due to lateral force acting on structure
9. The above plan that is given is totally unsuitable for normal areas and also in earthquakes prone area
10. In seismic region the lateral and verticals loads play important criteria because it helps in resisting the failure against the earthquake as the loads resultant will not co inside with the centre of the mass of the structure it becomes eccentric and not suitable for any type of area
11. In this plan a flat slab is more appropraiate than a regular beam columns junction as it provides support to the columns without any provision of the beam which reduces the weight of the building and also helps in the ductility which indirectly helps to maintain the structure in the the earthquake prone area
12. Apart from flab slab a wooden structure ia also appropriate which reduces the weight of the building and also helps to maintain the structure in the earthquakes prone area
13. The plan of the structure is non symmetric
14. The column is taggered not in proper position only bottom column is in straight line
15. We used box type of foundation to reduced the weight of foundation
16. And used shear wall at 4 edges of structure to resists the seismic forces and sudden failure of structure