Earthquake Resistant Designs: By M. Mayur IVth CIVIL - SIETK, PUTTUR. Earthquake Resistant Designs 1 Structure of Earth: Structure of Earth Earth - three layers - Crust, Mantle, Core. Crust - surface of Earth, Mantle – second inner part of the Earth, Core - most inner part of the Earth. 2 What are Earthquakes? : What are Earthquakes? sudden movement - surface of the earth - may be tiny or several feet. enormous amounts - of energy released – greater - Nuclear Bomb. sudden shift of rock - fracture of Earth. 3 PowerPoint Presentation: 4 Origin of Earthquakes: Earthquakes - Plate Tectonic Forces. Theory of Plate tectonic forces - He stated that continents moved from their original position - Continental Drift . Origin of Earthquakes 5 Alfred Wegener. : Different boundaries - tectonic forces induces Earth: Divergent boundary, Convergent, Transform boundaries. 6 Seismology: Seismology When earthquakes occur, waves travel in Earth in form of vibrations, such waves are called Seismic Waves. Study of such waves - Seismology. Instrument measuring seismic waves - Seismometer. Graphs given by that seismometer - Seismic Graph. 7 PowerPoint Presentation: 8 Terms of EQ’s:: Terms of EQ’s: Seismic Loading : Main cause of Earthquakes Seismic Performance : Structure’s ability - functions - safety and serviceability - exposure - earthquake. Seismic Analysis : Major intellectual tool – understand seismic performance of structures. 9 : Earthquakes affect RCC structures too… Slabs forces the beam to bend with it when horizontal forces act. 10 Earthquake resistant designs: Earthquake resistant designs Design - but it is analysis of forces - buildings due to loads acting on it. If a building is enough to resist the earthquake, then such building is called Earthquake resistant structure. Such design is called Earthquake resistant designs 11 Popular Earthquake resistant Techniques: Popular Earthquake resistant Techniques 12 Earthquake may not be able to damage entire building but it damages members of it. So special techniques are adopted: Base Isolation Devices and Seismic Dampers. Introduction of Resistant techniques: Introduction of Resistant techniques Thought - Base Isolation Devices - separate building from ground by some rubber devices. Seismic dampers - special devices - introduced in building - absorb the energy - produced by seismic waves. 13 Base Isolation Devices: Base Isolation Devices 14 Base Isolation Devices: Base Isolation Devices Base isolation Devices - Active Control System which contains: Sensors - measure external excitation - structural response. Computer hardware and software - compute control forces – observed excitation. Actuators – provide – necessary control forces. 15 PowerPoint Presentation: Control Force Devices Active Tuned Mass Dampers - natural extension – experiments indicate 25% less damage. Tendon Control – used even for active devices – works when active devices are off – act by resisting tension in structure. 16 PowerPoint Presentation: 17 PowerPoint Presentation: 18 PowerPoint Presentation: 19 PowerPoint Presentation: 20 Seismic Dampers: Seismic Dampers 22 SD’s in structures:: SD’s in structures: 23 PowerPoint Presentation: 24 PowerPoint Presentation: Dampers are of: Viscous Damper Friction Damper Yielding Damper Note points:: Note points: BID SD’S separating structures from ground by means of devices. Can be done when structure is already constructed, but it is costly. Cheaper compared to Seismic Dampers. additional systems introduced in structures. even when structure is completed, systems can be introduced. Very costly, since linked with hardware programmes. 28 Frames Resisting EQ’: Frames Resisting EQ’ 29 PowerPoint Presentation: 30 PowerPoint Presentation: 31 Increase in Seismic Performance: Increase in Seismic Performance Quality Control in Construction. 32 : 33 PowerPoint Presentation: 34 CONCLUSION: CONCLUSION We are only hope of tomorrow’s constructions. WE ARE HERE ONLY TO PROVIDE SAFETY TO PUBLIC TO LEAD THEIR LIFE HAPPILY. 35 PowerPoint Presentation: THANK YOU… 36 PowerPoint Presentation: 37 Any clarifications ?