Question

how we can strengthen the existing buildings against earthquake effects?

existing old buildings

Answer 1

1.Determine the construction characteristics and earthquake resistive capacity of existing building.

2. Determine seismic hazard level or seismic zone.

3.Reduction of the mass particularly at high level. Example by removal of heavy roof covering materials.

4.Adding new bracing walls.

5. Improvement of the quality of the masonary like by grouting.

6. Repair of cracked walls.

7.Removal of existing irregularities and discontinuities

For example a) High values within one Storey at one    Side of the building.

b) Large opening in walls without proper peripheral   reinforcement. Such features are sources of   weakness that should be eliminated.

8) Base isolation this technique is effective for low rise buildings with heavy mass but this technique is Costly.

9) Modify the components like beams, Column, beam column connections, Shear wall, diaphragm. In existing building that may not have adequate strength or deformation capacity.

a) Post tensioning existing beam, column or joints using external post-tensioned reinforcement.

b) Improvement of existing deficient reinforcement. detail.

c) Strengthening of individual diaphragm components by addition of additional reinforcement.

d) Increasing the diaphragm thickness.

e) Retrofitting of column, Beam, beam-column joints.

10. Repair or strengthing of foundations.

a) Providing additional piles or piers.

b) Improving soil adjacent to existing foundations.