Equivalent Static Analysis

COMPARITIVE STUDY OF RESPONSE OF MULTI STOREY BUILDINGS SUBJECTED TO EARTHQUAKE FORCES WITH AND WITHOUT DAMPERS

D.V.BANGARA RAJU1, CHANDAN KUMAR.PATNAIKUNI2 1 D.V.Bangara Raju, M.tech student, Department of Civil Engineering, Gitam University, Andhra Pradesh, India

2 Chandan Kumar Patnaikuni , Assistant Professor, Department of Civil Engineering, Gitam University, Andhra Pradesh, India

Abstract

Dampers helps in reducing the vibrations caused by wind and earthquake. By using dampers we can improve the resistance of building towards the forces which are caused by earthquakes .In this study an attempt has been made to compare the results of equivalent static method and response spectrum method of seismic analysis for various models with

Generally Equivalent static analysis is not adopted for high rise buildings. Practically it does not take into account all the factors that are importance of foundation condition. The equivalent static analysis is used to design small structures. In this method only one mode is considered for each direction. Earthquake resistant designing for low rise structures the equivalent static method is enough. Tall structures are needed more than two modes and mass weight of each story to design earthquake resistant loads. Equivalent static method is not suitable to design high rise structures and dynamic analysis method to be used for high rise

displacement, velocity and acceleration as a function of natural vibration period or frequency and damping ratio of single degree of freedom system (SDOF).As the seismic forces strikes the foundation of structure it will move with the ground motion. It shows that movement of structure is generally more than the ground motion. The movement of structure depends on the natural frequency of vibration,. The revised IS 1893-2002 uses the dynamic analysis by response spectrum. In this method the most five important engineering properties of the structures i.e, the fundamental natural period of vibration of the building ( T in seconds), damping properties of the structure ,Type of foundation provided for the building , Importance factor of the building ,the ductility of the structure represented by response reduction factor are considered .

Many new techniques are found out for resisting earthquakes. One of the technique is Dampers. Dampers are used for vibration control of structure which are caused due to earthquakes and winds. Depending on type of material dampers are classified into different types and they are classified as Tuned Mass Dampers, Friction Dampers, Viscous Dampers, Metallic damper, Visco elastic dampers , Elasto plastic damper .Other techniques like base isolation are used for decrease of damage caused due to earthquake.

2. MODEL GEOMETRY The details