What are the methods of seismic analysis of buildings and what is the criteria for choosing one?

The way I know it, there are 3 methods to perform seismic analysis of buildings depending on basic factors like building height and shape.

The 3 methods are:

Equivalent Static Load method - also known as Simplified Modal Response Spectrum

This is the simplest method and happens to be the most commonly used. Its concept is to represent the seismic forces by horizontal static forces acting on the building.

However, there are some criteria that must be satisfied in order to use this method; the building must not be higher than 60 meters, the ratio of length to breadth should not exceed 4 and the building should be fairly uniform in shape and in its static system.

2. Multi-Modal Response Spectrum method

This method takes into consideration the displacement of the structure due to the impact of the seismic forces. The reference, in this case, is a commonly used graph known as ‘the response spectrum curve’.

3. Time History Analysis

This method relies on calculating the internal elements’ response to the dynamic seismic forces. The dynamic properties of the building must also be known and accounted for. It is a complex method requiring laboratory-grade investigation and analysis.

Post by: Sherif Issa