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GUIDED BY :-PROF. S. J. DAHIWELKARSUBMITTED BY :-PATIL JAYDEEP SANJAYSEISMIC RETROFITTINGTECHNIQUESA SEMINAR ONSeismic Retrofitting

Definition

It is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes.The retrofit techniques are also applicable for other natural hazards such as tropical cyclones, tornadoes, and severe winds from thunderstorms.IMPORTANCE

Earthquake creates great devastation in terms of life, money and failures of structures.Earthquake Mitigation is an important field of study from a long time now.It is of utmost importance for historic monuments, areas prone to severe earthquakes and tall or expensive structures.Why Seismic Retrofitting is needed ?

It is not possible to demolish all the buildings and build new with earthquake resistant features as demolition and rebuilding is not feasible due to economic, social, psychological and cultural reasons.When is Seismic Retrofitting Needed ?

The two circumstances are:-Earthquake damaged buildings, andEarthquake-vulnerable buildings

Retrofit Performance Objectives

Public safety only: Structure surviability: Need of Retrofitting in ExistingEarthquake Vulnerable BuildingsBuildings have been designed according to a seismic code, but the code has been upgraded in later years;Buildings designed to meet the modern seismic codes, but deficiencies exist in the design and/or construction;Essential buildings must be strengthened like hospitals, historical monuments and architectural buildings;Important buildings whose services are assumed to be essential just after an earthquake like hospitals;Problems faced by Structural Engineers are :-

Lack of standards for retrofitting methodsEffectiveness of each methods varies a lot depending upon parameters like type of structures, material condition, amount of damage , etc.

HERE ARE SOME EXAMPLES OF RETROFITTING

BASE ISOLATIONOakland City Hall

San Francisco City Hall

CONCLUSIONAs it is not good to destruct and again reconstruct every structurefor small reasons in social, economic and every point of view it isbetter to adopt retrofitting technique to increase the performanceof structure.THANK YOU