Explain four general design principles of earthquake resistant building | Building construction

The building or structures which come under seismic or earthquake zones are required to resist the

earthquake or seismic forces. There are some design principles generally considered while constructing

the structures in earthquake zones.  

1. Continuity in the construction of a structure: The structures come in the seismic zone should be constructed in such a way that the total structure act as a single unit.  

2. Sufficient space between adjacent structures: To avoid collision during an earthquake it is advisable to keep some space between the adjacent structures. The recommended gap width varies from15 mm to 30 mm per storey.  

3. Foundation: Loose soil settles easily during an earthquake. So avoid constructing a structure on loose soil. And proper parameters of earthquake design should be adopted while designing foundation.  

4. Avoid unnecessary projections: The unnecessary projections such as balconies, canopies, etc should be avoided and if they are in the structure they should be firmly tied with the main part of structure.  

5. Shape of structure: 

a. Shape of structure plays very important role while resisting the earthquake forces. 

b. Simple rectangular structure is considered good in this case. 

c. Also some ratio of length to width is required to maintain. The length of the building should not exceed three times its width.  

d. Symmetrical designed structure with respect to mass and rigidity is also preferred. Because of this, centre mass of rigidity of building coincide with each other in which case no separate sections other than expansion joints are necessary. 

6. Structural design: Proper design considering the earthquake design parameters plays the important

role. The design should be such that there should not be sudden collapse of a structure. 

7. Weight of structure: The light weight structures are preferred to resist the seismic forces. The

building should be as light as possible. This practice is adopted in Japan since the earthquake is frequent

there. 

8. Avoid addition and alteration: Addition and alteration in the structure is not recommended if the

structure come in the seismic region. 

9. Strength in various directions: The structures should be designed to have adequate strength against

earthquake effect along both the horizontal axes. 

10. Ductility: Provide reinforcing steel in masonry to increase the strength and stability.  

11. Fire safety: Building should be constructed to make it fire resistant.