The document outlines the methods for seismic analysis of building structures, including static and dynamic analyses, and detailed calculations for seismic forces influenced by factors such as zone and importance. It discusses the significance of the design basis earthquake, maximum considered earthquake, and factors affecting response reduction and average response acceleration. Additionally, it highlights considerations for structural performance during earthquakes and the distribution of seismic forces across different elements.

1. Seismic analysis of the building structure
•Static analysis – Lumped mass analysis
• Approximate fundamental natural period of vibration
•In staad,
-reference load type definition
- seismic definition
-calling of seismic force
•Dynamic analysis – Time history analysis/ Response spectrum analysis
•In staad,
- seismic definition
- weight definition
-calling of weight for mass matrix calculation
-response spectrum definition

3. Inputs Parameters in STAAD

4. Seismic definition in STAAD

5. Mass matrix calculation in STAAD
Calling of
weights for
Mass matrix
calculation

6. Response spectrum analysis

7. Significant of the Dynamic Analysis
* Earthquake force

8. * Wind force

9. The design horizontal seismic coefficient
•Ah=(Z/2)*(I/R)*(Sa/g)
• Z-Zone factor
•I-Importance factor
•R-Response reduction factor
•Sa/g-Average response acceleration coefficient

10. • Expected intensity of shaking in different zones.
• Reasonable estimation of the Peak Groung Acceleration(PGA ) in respective zone.
• Maximum Considered Earthquake (MCE) is an upper bound of the expected
earthquake in a given area- 10% probability of exceedence in 100years.
• Design Basis Earthquake(DBE) - 10% probability of exceedence in 50years.
• Indian code assumed ½ of the MCE .
Zone factor

11. • Functional use of the structures after earthquake, historical value/ economic
importance.
• Increase the design force level for critical and important structures.
Response Reduction factor
• Seismic damage performance of the structure under shaking.
• Brittle/Ductile deformation of the structure
Importance factor

12. Factors Governing for Response Reduction
Factor

13. Average response acceleration coefficient
Depends on,
• Damping of the structure
• Fundamental natural time period
• Soil at site

14. • Vertical distribution of base shear to different floor levels.
• Distribution of Horizontal Design Lateral Force to Different Lateral Force Resisting
Elements
• Floor Diaphragm Action
Distribution of design lateral seismic force
Rigid diaphragm