Earthquake resistant buildings (1)

In this PDF you will get some techniques that are used in modern world to protect the buildings

1. Earthquake Resistant Buildings
A PROJECTREPORT
Submitted in partial fulfilment for the award of degree
Of
BACHELOR OF ENGINEERING
IN
CIVIL ENGINEERING
Submittedby:
Kartik Yadav
(1908400000026)
Underthe Guidance of:
Mr. PunitYadav
AssistantProfessor
DEPARTMENT OF CIVILENGINEERING
RAJKIYA ENGINEERING COLLEGE MAINPURI
Affiliated to Dr. A.P.J. Abdul Kalam Technical University, Lucknow

2. ACKNOWLEDGEMEN T
WesincerelyacknowledgeandexpressmydeepsenseofgratitudetoMr.
PunitYadav(AssistantProfessor)theguideofthisproject.Asaguidehe
gavemaximumhelpandcoordinationinfinishingtheprojectwork.With
hispastyearsofexperienceandteachingsteeredmetocomeoutwith
successthroughthedifficultproblemsfacedbyme.Wewouldliketo
placeonrecordourdeepsenseofgratitudetoourguidesfortheir
cooperation and unfailing courtesy to me at every stage.

3. LIST OF CONTENT
●ABSTRACT
●Introduction
●What is Earthquake
●CLASSIFICATION OF EARTHQUAKE
●How Earthquake affects Buildings
●Zone of Earthquake
●Seismology
●PRINCIPLE OF EARTHQUAKE RESISTANT DESIGN
●RULES FOR BUILDING DESIGN
●SEISMIC RISK TO BUILDING IN INDIA
●INDIAN SEISMIC CODES
●SEISMIC DESIGNING:
●CAUSES OF EARTHQUAKE DAMAGE
●Popular Earthquake resistant Techniques
1) Shear walls
2) Seismic Dampers
3) Base Isolation
4) Bands

4. ABSTRACT
ThefieldofEarthquakeEngineeringhasexistedinourcountryfor
over35yearsnow.Indianearthquakeengineershavemade
significant contributionstotheseismicsafetyofseveralimportant
structuresinthecountry.However,astherecentearthquakeshave
shown,theperformanceofnormalstructuresduringpastIndian
earthquakeshasbeenlesssatisfactory.Thisismainlyduetothe
lackofawarenessamongstmostpractisingengineersofthe
specialprovisionsthatneedtobefollowedinearthquakeresistant
design and thereafter in construction.
Earthquakesconstituteoneofthegreatesthazardsoflifeand
propertyontheearth.Duetothesuddennessoftheiroccurrence,
theyareleastunderstoodandmostdreaded.Theearthquake
resistantconstructionisconsideredtobeveryimportantto
mitigatetheireffects.Thispaperpresentsthebriefessentialsof
earthquakeresistantconstructionandafewtechniquestoimprove
theresistanceofbuildingandbuildingmaterialstoearthquake
forces, economically.

5. Introduction
What is Earthquake
AnearthquakeisthesuddenmovementortremblingoftheEarth's
tectonicplates,resultinginshakingoftheground.Therecanbemany
earthquakesoverashorttimeframeinasmallarea.Thesudden
releaseoftensioninthetectonicplatessendswavesofenergythat
travelthroughtheEarth.Thesecausestructurestovibrateandinduce
inertia forces on them.
CLASSIFICATION OF EARTHQUAKE
Slight: Magnitude up to 4.9 on the Richter Scale
Moderate: Magnitude 5.0 to 6.9
Great: Magnitude 7.0 to 7.9
Very Great: Magnitude 8.0 and above
How Earthquake affects Buildings
Whilecolumnscanbend,theswayingmotion,whenintensified,snaps
thebuildinglikematchsticksandcollapses.Asuperstructurecanbe
damaged,notonlyonaccountoftheshakingwhichresultsfromquakes
butalsoduetochaineffectslikefire,landslideetccausedby
earthquake.
Someofthecommonimpactsofearthquakesincludestructuraldamage
tobuildings,fires,damagetobridgesandhighways,initiationofslope
failures, liquefaction, and tsunami.

6. Zone of Earthquake
Seismology
Whenearthquakesoccur,wavestravelonEarthintheformofvibrations,
suchwavesarecalledSeismicWaves.Studyofsuchwavesisknownas
Seismology.Instrumentmeasuringseismicwavesisknownasa
Seismometer.Graphsgivenbythatseismometerarecalled
Seismographs.

7. PRINCIPLE OF EARTHQUAKE RESISTANT DESIGN
Thebuildingshallwithstandalmostnodamagetomoderateearthquakes
which have probability of occurring several times during life of a building.
Thebuildingshallnotcollapseorharmhumanlivesduringsevere
earthquakemotions,whichhaveaprobabilityofoccurringlessthanonce
during the life of the building.
RULES FOR BUILDING DESIGN
Theconfigurationofthebuilding(Planandelevation)shouldbeas
simple as possible.
The formation should generally be based on hard and uniform ground.
Themembersresistinghorizontalforcesshouldbearrangedsothat
torsional deformation is not produced.
The structure of the building should be dynamically simple and definite.
Theframeofthebuildingstructureshouldhaveadequateductilityin
addition to required strength.
SEISMIC RISK TO BUILDING IN INDIA
The construction may generally be classified into two types:
Non-EngineeredConstruction:Exunreinforcedbrickmasonry,stone
masonry
Semi -Engineered Construction:Ex Reinforced brickmasonry .
EngineeredConstruction:ExReinforcedConcreteframedstructures
or steel structures.
Non-Engineeredbuildingsarethosewhicharespontaneouslyand
informallyconstructedinvariouscountriesinthetraditionalmanner

8. withoutanyorlittleinterventionbyqualifiedarchitectsandengineersin
theirdesign.Suchbuildingsinvolvefieldstone,firedbrick,concrete
blocks,adobeorrammedearth,acombinationofwoodwiththese
traditionallocallyavailablematerialsintheirconstructionthedesign
frequentlyadoptedinanon-engineeredmanneris,withouttakinginto
considerationthestabilityofthesystemunderhorizontalseismicforces.
Masonrybuildingsofalltypes,exceptthoseconstructedwithearthquake
resistingelements,areatthegreatestriskofheavydamageinseismic
zoneIII and of destruction to collapse in zones IV and V.
INDIAN SEISMIC CODES
IS1893-2002,IndianStandardCriteriaforEarthquakeResistantDesign
of Structures (5 th Revision).
IS4326-1993,IndianStandardCodeofPracticeforEarthquake
Resistant Design and Construction of Buildings (2 nd Revision).
IS13827-1993,IndianStandardGuidelinesforImprovingEarthquake
Resistance of Low Strength Masonry Buildings.
IS13920-1993,IndianStandardCodeofPracticeforDuctileDetailingof
Reinforced Concrete Structures Subjected to Seismic Forces.
IS13935-1993,IndianStandardGuidelinesforRepairandSeismic
Strengthening of Buildings.
SEISMIC EFFECTS ON STRUCTURES
INERTIA FORCES IN STRUCTURES
HORIZONTAL AND VERTICAL SHAKING

9. SEISMIC DESIGNING:
• Planning stage
• Plan building in symmetrical way (both axis)
• Avoid weak storey and provide strong diaphragm
•Don’taddappendageswhichwillcreatedifferenceinCentreofmass
and centre of rigidity
• Conduct soil test to avoid soil liquefaction
•Steeltobeusedofhavingelongationof14%andyieldstrengthof415
N/mm2
•Design stage
• Avoid weak columns and strong beam design.
• Provide a thick slab which will help as a rigid diaphragm. Avoid thin
slab and flat slab construction.
• Provide cross walls which will stiffen the structures in a symmetric
manner.
• Provide shear walls in a symmetrical fashion. It should be in outer
boundary to have a large lever arm to resist the EQ forces.
• Construction stage
• Compact the concrete by means of needle vibrator.
• Cure the concrete for at least a minimum period.
• Experienced supervisor should be employed to have
• good quality control at site
CAUSES OF EARTHQUAKE DAMAGE

10. Heavydeadweightandverystiffbuildings,attractinglargeseismic
inertia forces.
Verylowtensileandshearstrength,particularlywithpoormortars.
Brittle behaviour in tension as well as compression.
Weak connection between wall and wall & roof and wall.
Stress concentration at corners of doors and windows.
Overall un symmetry in plan and elevation of the building.
Unsymmetryduetoimbalanceinthesizesandpositionsofopeningsin
the wall.
Defectsinconstruction,suchasuseofsubstandardmaterials,unfilled
joints between bricks.
BEHAVIOUROFBRICK
MASONRY WALL
Ground vibrations during
earthquakescauseinertiaforcesto
travelthroughtheroofandwallsto
thefoundation.Themainemphasis
isonensuringthattheseforces
reachthegroundwithoutcausing
majordamageorcollapse.Ofthe
threecomponentsofmasonry
buildings,wallsaremostvulnerable
todamagecausedbyhorizontal
forces due to earthquakes.

11. IMPROVING BEHAVIOUR OF
MASONRY WALL
Ensuring good interlocking of the
masonry courses at the junction.
Employing horizontal bands at
various levels, particularly at the lintel
level. The size of the doors and
window opening need to be kept
small. The smaller the opening, the
larger is the resistance offered by the
wall.
Thetendencyofwalltotopple
whenpushedintheweak
directioncanbereducedby
limitingitslength-to-thickness
andheight-to-thicknessratios
Thelengthofthewallshouldbe
limitedto6morelsecrosswalls
should be provided
Popular Earthquake resistant Techniques
1) Shear walls
2) Seismic Dampers
3) Isolation
4) Bands

12. 5) Rollers
6) Light weight material
7) Others
1) Shearwall
1) Vertically oriented wide beams.
2) It carries seismic loads down to the bottom of the foundation.
3) Provides large strength and stiffness to buildings.
4)Thicknessgenerallyvariesfrom150mmto450mminhighrise
buildings.
5) Should be symmetrical in plan along both axes.
6) The opening provided in the shear wall should be symmetrical.
7) Effective when located along the Exterior parameter of the building.

13. 2) Seismic Dampers

14. SeismicDampersareusedindampingtheoscillationsofabuilding
during anearthquake.
ADamperisanymaterialordevicethatabsorbsvibrations.Seismic
dampersdissipatetheenergyofseismicwavesmovingthrougha
buildingstructure.Dampersworkbyconvertingthekineticenergyof
bouncingorswayingintoheatenergy,whichthen(typically)dissipates
into hydraulic fluid.
These are used in place of structural elements such as diagonal braces.
Acts like a hydraulic shock absorber in a car.
Whenseismicenergyistransmittedthroughthem,dumpersabsorbpart
of it and thus dump the motion of the building.
Types of dumpers
Viscous dampers:
Reducethevibrationsbyfluid
action
Friction dampers:
Reducethevibrationsby
rubbing action b/w surfaces
Tuned mass dampers:
TunedmassdampersReduce
thevibrationsbyharmonic
action

15. 3) BASE ISOLATION
Baseisolationisoneofthemostpowerfultoolsofearthquake
engineeringpertainingtothepassivestructuralvibrationcontrol
technologies.Itismeanttoenableabuildingornon-buildingstructureto
surviveapotentiallydevastatingseismicimpactthroughaproperinitial
design or subsequent modifications.
ADamperisanymaterialordevicethatabsorbsvibrations.Seismic
dampersdissipatetheenergyofseismicwavesmovingthrougha
buildingstructure.Dampersworkbyconvertingthekineticenergyof
bouncingorswayingintoheatenergy,whichthen(typically)dissipates
into hydraulic fluid.
Lead rubber bearing is sandwiched between two steel plates.
Baseisolatedbyaseriesofbearingpadswhichareplacedbetween
building and building foundation.
Reducethebuildingaccelerationby¼theaccelerationoffixedbase
building.
Accelerationdecreasedbecausethebaseisolationsystemlengthens
the building's period of vibration.
RubberishighlyelasticsoreducethedamageConvertsthekinetic
energy as heat.

16. Some Largest Base-Isolated Buildings in the World
●Apple Park, Cupertino, California, 445,005 squaremetres.
●Adana Integrated Health Campus, Adana, Turkey, 430,000
square metres.
●Tokyo Skytree East Tower, Tokyo, 229,237 square metres.
●IspartaCity Hospital, Isparta, Turkey, 221,000 squaremetres.
●Logistics Park Hino, Tokyo, 212,853 square metres.
Base Isolation in India
In India base isolation was
first demonstrated after 1993
Killari EQ.
Two single story buildings
was built with rubber base
isolators resting on hard
ground.
The four story bhuj hospital
building was built with base
isolation technique after 2001
Bhuj EQ
4) Horizontal bands
Horizontal bandsare the most important earthquake-resistantfeature in
masonry buildings. Thebandsare provided to holda masonry building
as a single unit by tying all the walls together, and are similar to a closed
belt provided around cardboard boxes.

17. Plinth band: This should be provided in those cases where the soil is soft
or uneven in their properties, as it usually happens in hilly areas. This
band is not too critical. Lintel band: This is the most important band and
covers all door and window lintel. Roof band: In buildings with flat
reinforced concrete or reinforced brick roofs, the roof band is not
required because the roof slab itself plays the role of a band. However,
in buildings with flat timber or CGI sheet roof, a roof band needs to be
provided. In buildings with pitched or sloped roofs, the roof band is very
important. Gable band: It is employed only in buildings with pitched or
sloped roofs