Earthquake Resistant Designs

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Earthquake Resistant Designs

  1. 1. EARTHQUAKE RESISTANT DESIGNS By, M. Mayur, Siddharth Institute of Engineering and Technology, Puttur. Abstract: Earthquakes are very serious problems since they affect human life in various ways.The Earthquakes are mainly prevented by two methods namely Base Isolation Methods andSeismic Dampers. The present paper deals with Base Isolation and Seismic Damper Methods inbrief manner. This paper explains the main theme of the above methods and their preventivemethods about Earthquakes. The present paper deals with structures which resist Earthquakes. Itexplains the frames which help in resisting Earthquakes. In total, this present paper deals withMethods of resisting Earthquakes and Frames resisting them and also the prominent techniquesfollowed to resist Earthquakes. Email id: mittal.mayur91@gmail.com Contact number: +91 9985967108
  2. 2. Abstract: layers namely Crust, Mantle and Core. Earthquakes are very seriousproblems since they affect human life invarious ways. The Earthquakes are mainlyprevented by two methods namely BaseIsolation Methods and Seismic Dampers.The present paper deals with Base Isolationand Seismic Damper Methods in briefmanner. This paper explains the main themeof the above methods and there preventivemethods about Earthquakes. The presentpaper deals with structures which resistEarthquakes. It explains the frames which The above diagram mainly shows thehelp in resisting Earthquakes. In total, this structure of Earth in a diagrammatic manner.present paper deals with Methods ofresisting Earthquakes and Frames resisting What are Earthquakes?them.  Earthquakes are sudden movementsIntroduction: over the surface of Earth.The two common methods which are used in  It may also be defined as suddenconstructing Earthquake Resistant Designs shift of rock over the Fracture ofare Base Isolation Devices and Seismic Earth.Dampers. This present scenario deals withthe above two methods in a brief manner.  When such quakes happen,This present paper also deals with enormous amounts of energy ispreventive measures taken by them in released, which is far greater thanresisting Earthquakes. big nuclear bomb.Structure of Earth: Earthquakes are not only related to surface of earth, they are interrelated to Tsunami inLet us know about the structure of Earth. oceans also.The Mother Earth mainly consists of three Earthquakes and Tsunami: Earthquakes and Tsunami are interrelated in deep way as they show in below diagram.
  3. 3.  The damaging behavior of RCC buildings is explained in diagrammatic manner.The above diagram shows the interrelationbetween Earthquakes and Tsunami.Hypocenter is the point where Earthquakesgenerate and Epicenter is point whereenergy of Earthquakes reach surface ofEarth. When an Earthquake occurs under The above diagram shows the behavior ofsea, it causes Tsunami. RCC structures when an EQ happens.Origin of Earthquakes: The Tension and Compression in members’  An earthquake mainly occurs in reverses due to EQ loads, and the buildings Mantle part of Earth. fails to resist and it collapses.  Most of earthquakes mainly occur by How Earthquakes are measured? sudden slippage of fault. The EQ’s are measured by process called  Alfred Wegener is the person who Seismology. developed theory of Plate Tectonic During an EQ, waves travel in surface of Forces which clearly explains Earth, which carry the load of EQ to surface Earthquakes. and then from surface to Structure toWhy study of Earthquakes is necessary? damage it.  When an earthquake happens, not The waves which travel in surface of Earth only surface of earth, or masonry and transfer to load of EQ are called buildings collapse, but also Earthquake waves or Seismic Waves. Reinforced Concrete Structures also Study of such waves is called Seismology. damages. Based on Seismology, Seismometer is designed which gives the effect of EQ in graph manner.
  4. 4.  The above methods are widely used and commonly used in different constructions to resist EQ loads. Evolution of Techniques:  Earthquakes mainly happen in surface of Earth, so if we separate the structure from surface, then we can build EQ resistant Designs.  The main thought behind Base Isolation Devices is to separate buildings from surface of Earth.The above diagram shows the Seismometerand graph given by such meter during EQ’s.Seismic Performance is structure’s ability toperform its due functions such as safety andserviceability during exposure to anearthquake.Process of finding out seismic performanceof a particular structure is called SeismicAnalysis. The above diagram shows the Base Isolation Devices in a diagrammatic manner.Earthquake Resistant Designs: In the above diagram, we can see how the structure is separated with help of rubber  Design is nothing but calculation of bearings from surface of Earth, and it loads on to structure and to make became an EQ resistant Buildings. structure to resist them.  If such design is to make such that it resists EQ, then such design is called Earthquake Resistant Designs.Popular Earthquake Resistant Designs:  The most popular EQ resistant Designs are :  Base Isolation Devices  Seismic Dampers.
  5. 5. The above diagram shows the movement ofbuildings separated by BID, during an EQ.If the ground motion is in left horizontaldirection, the buildings separated by In the above diagram, it not only resistsbearings moves in backward direction, Earthquakes by means of BID, but also itwhich resists earthquakes. resists by Cross Bracings, Shear Walls and Shear Cores which resists EQ’s.In above cases, the foundation is in Earth,but the structure is separated by Bearings. The cross bracings resist the movement of columns due to EQ, and it resists damage of structure in Vertical Direction. Shear Walls and Shear cores are used to resist structure during Earthquake in Horizontal Direction. This is most efficient technique and it is advancement in Base Isolation Devices. Even Earthquake happens in this case, the Base Isolation Devices help in resisting the Earthquake, Cross Bracings are provided forIn this case, the foundation pier of entire is each and every floor and on both sides ofstructure is separated by means of Spherical Structure to not only resist columns, beams,Sliding Isolation Bearing and there is no slabs, but also to resist structural membersmedium by which waves of EQ reaches the against Earthquake.Structure. So, it becomes purely EQ resistantDesigns. Shear walls are mainly provided to resist any shear motion in structure duringIf EQ happens even inside Surface of Earth, Earthquake and Shear Cores are provided tothen even the structure is remained resist Shear walls and structure.undamaged by EQ.
  6. 6. In the above diagram, it explains three cases. • If the structure is stiffened, • If the structure is Bolted, • If the structure is unbolted.If the structure is stiffened, the shock bywaves reaches and buildings damage.If the structure is bolted, stresses travelthrough cabinet frames.If the structure is unbolted, then the reactionof structure is shown in dotted line mannerin diagram.The main thought behind Base IsolationDevices, is to separate building from surfaceof Earth by means of some devices namelyBase Isolation Devices.If the structure is bolted, the members ofstructure may be damaged.If it is unbolted, the structure can becollapsed. The above diagram shows all the affects by EQ when buildings are fixed base, when buildings are Base Isolated and when they are Hypothetical in condition. • When buildings are fixed bases, then building will shake violently. • When buildings are Base Isolated, then building will shake less. • When buildings are rested on rollers on friction bearings, then they will absorb EQ, and resist Buildings.
  7. 7. Seismic Dampers:Seismic Dampers are the devices introducedin buildings, which absorb the EQ loads, andresist the buildings.The above diagram shows the typicaldiagram of Seismic Damper in a structure. The above diagram shows the movement of building during an Earthquake with andThe world’s variety construction Taipei 101 without Seismic Dampers.consists of Seismic Dampers. With SD’s, the buildings have less sway that it less shaking is seen. Without Seismic Dampers, heavy sway is observed. Frames Resisting Earthquakes: A shaped Frame:The above diagram shows the SD’s inTaipei 101.
  8. 8. T shaped Frames:Bay shaped Frames:Hipend “ t ” Frames: L shaped Frames:Hip end 1 unit Frames: H shaped Frames:Hip end 2 unit FramesU shaped Frames: Hip end “U” shaped Frames:
  9. 9. Popular EQ Resistant Designs:
  10. 10. Conclusion:As we are Civil Engineers, we are onlyhopes of TOMORROW’S WONDERFULCONSTRUCTIONS.BID are best and also SD’s are most costlyprocedures in preventing Earthquakes.

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