PowerPoint Presentation

EARTHQUAKE RISK MANAGEMENT AND EARTHQUAKE RESISTANT DESIGN1Dr. Ajay Sharma, Associate ProfessorB.E. (Hons.), M.E. (Structural Engg.), Ph.D. IIT Bombay(Earthquake Engg.)Department of Structural Engineering,MBM Engineering College JodhpurSeminar on Earthquake Risk Management PWD Dungarpur Rajasthan2

World Earthquake Fault Lines

www.forceborne.com/FBW/Tech/fault_line_chart.htm3

45

Earthquakes6

7

8

What do Structural Engineers do?Structural engineering's combine their knowledgeof science and design making as they constructbetter framework for buildings and other structuresto safely resist natural and made-made forces. They are involved in physicaltesting, mathematical modeling, computer simulation all of which support decisions that Aid in the creation and maintenance of safe and economical structures.http://www.seaint.org /http://cee-ux49.cee.uiuc.edu/strweb/home.htmlwww.earthscience.org/.../geopro/seismic/seismic.html

9What is Earthquake Engineering?Earthquake engineers are concerned with creating earthquakes resistant designs and construction techniques to build of all kinds of bridges, roads and buildings. Earthquake engineers are faced with many uncertainties and must be smart in their decisions in developing safe solutions to challenging problems. They rely on state-of-the-art technology, materials science, laboratory testing and field monitoring.

www.sciencedaily.com 10

http://www.berkeley.edu/news/berkeleyan/2006/01/18_resumption.shtmlNorthridge Earthquake Southern California 199411Kobe Earthquake Japan 19956.9 MagnitudeHomes and building construction was older built with heavy tile roofs that collapsed

http://www.seismo.unr.edu/ftp/pub/louie/class/100/effects-kobe.html12Another anomaly was the large number of about 20-year-old high rise buildings that collapsed at the fifth floor. The older version of the code they were built under allowed a weaker superstructure beginning at the fifth floor.

http://www.seismo.unr.edu/ftp/pub/louie/class/100/effects-kobe.html13Behind this completely collapsed wood-frame house is a house of reinforced concrete that suffered no structural damage. The number of wood versus masonry buildings that collapsed in Kobe astonished most observers, as wood-frame structures are usually thought to be much better at resisting shear forces. Possibly the concrete house was better-designed and stronger even for its greater weight. The proportionally heavier tile roofs on wooden houses also might have been a factor.

http://www.seismo.unr.edu/ftp/pub/louie/class/100/effects-kobe.html14

http://www.niksula.hut.fi/~haa/kobe.html15

http://www.city.kobe.jp/cityoffice/15/020/quake/disaster/d-index_e.html16Mexico City Earthquake, 19858.1 MagnitudePoorly constructed buildings caused thousands of deaths

http://www.johnmartin.com/earthquakes/eqshow/647003_06.htm17

Damage to the Intercontinental Hotel during Mexico City's 1985 earthquake was severe even though the building was relatively new http://www.calstatela.edu/dept/geology/G351.htm18Northridge Earthquake, 1994 Southern California, USA6.7 Magnitude most houses were wooden and did not collapse

www.survival1.com/ 19Problems for Building Structures when Seismic Waves pass For tall buildings the top may sway in the opposite direction as the base

Buildings in close proximity with one another may collide do to differing phase motions.

Changing types of wave motion cause damage.

Buildings with different resonant frequencies will be affected differently by passing seismic waves depending on the wave frequency.

http://www.mines.utah.edu/~schuster/gg103/res/resonance.html20

http://www.scarborough.k12.me.us/wis/teachers/dtewhey/webquest/nature/earthquake_images.htm21Loma Prieta Earthquake, 1989San Francisco Bay, California7.1 magnitudeMany homes were damaged because of old construction- unreinforced bricks and mortarMany building and homes were built on were unconsolidated flood plain sedimentary land (In contrast, nearby sections of the city experienced only minor damage. These areas contain sturdy wood frame houses built on relatively stable marine terraces.)22

As the second story of this building collapsed, its facade fell into the street, knocking down the tree which in turn damaged the car. This building in downtown was one of the heavily damaged buildings situated on the unconsolidated flood plain sediments of the San Lorenzo River. http://www.es.ucsc.edu/~es10/fieldtripEarthQ/Damage2.html23

An automobile lies crushed under the third story of this apartment building in the Marina District. The ground levels are no longer visible because of structural failure and sinking due to liquefaction http://pubs.usgs.gov/dds/dds-29/24

Collapsed brickwork from a corner apartment building, Marina District. http://pubs.usgs.gov/dds/dds-29/25Oakland Support failure

http://pubs.usgs.gov/dds/dds-29/26

http://pubs.usgs.gov/dds/dds-29/27

Oakland Bridge failurehttp://pubs.usgs.gov/dds/dds-29/28

http://pubs.usgs.gov/dds/dds-29/29

http://pubs.usgs.gov/dds/dds-29/3031Bhuj Earthquake, 2001Gujrat, India7.7 magnitude

32

33

34

35

36

37

38WHAT A EARTHQUAKE CAN DO TO OUR ASSETS

Damage of buildings(Photos from Hokkaido Journal) Earthquake is sudden shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity a disturbance that is extremely disruptive. 39

40

Damage of Oil Tank(Photos from Hokkaido Journal)41

Damage of roads(Photos from Hokkaido Journal)42

43

Damage of Lifeline structuresFirst way to design Traditionally Seismic Resistant (e.g., adding structural components to resist horizontal Load like shear wall, braced frames etc., shape of plan etc.) Sufficiently strong, stiff to withstand inelastic deformations, Motif is to have inherent strength to Dissipate seismic energy up to certain level of Acceptable deformation and damage.DisadvantagesLarge interstory driftLocalized damages to structural components and secondary systemsStrengthening further attracts more earthquake forces

44SEISMIC RESISTANT DESIGN45

46

47

48

49

50

51

Indias Vulnerability to Disasters57% land is vulnerable to earthquakes. Of these, 12% is vulnerable to severe earthquakes.68% land is vulnerable to drought.12% land is vulnerable to floods.8% land is vulnerable to cyclones.Apart from natural disasters, some cities in India are also vulnerable to chemical and industrial disasters and man-made disasters.

Seismic Activity in India 180 AD - 2004

Distribution of epicenters of earthquakes greater than magnitude 5.0 for the period 1976-2000, South East Asia and Indian Ocean

Areas of ConcernActivating an Early Warning System network and its close monitoringMechanisms for integrating the scientific, technological and administrative agencies for effective disaster managementTerrestrial communication links which collapse in the event of a rapid onset disasterVulnerability of critical infrastructures (power supply, communication, water supply, transport, etc.) to disaster eventsAreas of ConcernFunding : Primacy of relief as disaster response.Preparedness and Mitigation very often ignored.Lack of integrated efforts to collect and compile data, information and local knowledge on disaster history and traditional response patterns.Need for standardised efforts in compiling and interpreting geo-spatial data, satellite imagery and early warning signals.Weak areas continue to be forecasting, modelling, risk prediction, simulation and scenario analysis, etc.

Areas of ConcernAbsence of a national level, state level, and district level directory of experts and inventory of resources.Absence of a National Disaster Management Plan, and State level and district level disaster management plans.Sustainability of effortsEffective Inter Agency Co-ordination and Standard Operating Procedures for stakeholder groups, especially critical first responder agencies.Emergency medicine, critical care medicine, triage, first aidNodal Agencies for Disaster ManagementFloods : Ministry of Water Resources, CWCCyclones : Indian Meteorological DepartmentEarthquakes : Indian Meteorological DepartmentEpidemics : Ministry of Health and Family WelfareAvian Flu: Ministry of Health, Ministry of Environment, Ministry of Agriculture and Animal HusbandryChemical Disasters : Ministry of Environment and ForestsIndustrial Disasters : Ministry of LabourRail Accidents : Ministry of RailwaysAir Accidents : Ministry of Civil AviationFire : Ministry of Home AffairsNuclear Incidents : Department of Atomic EnergyMine Disasters : Department of MinesDynamics of DisastersThere is a high probability of a low probability event happening somewhere sometime soonThe unpredictability of disaster events and the high risk and vulnerability profiles make it imperative to strengthen disaster preparedness, mitigation and enforcement of guidelines, building codes and restrictions on construction of buildings in flood-prone areas and storm surge prone coastal areas.New Directions for Disaster Management in IndiaThe National Disaster Management Authority (NDMA) has been set up as the apex body for Disaster Management in India, with the Prime Minister as its Chairman.Disaster Management Authorities will be set up at the State and District Levels to be headed by the Chief Ministers and Collectors/Zilla Parishad Chairmen respectively. New Directions for Disaster Management in IndiaA National Disaster Mitigation Fund will be administerd by NDMA. States and districts will administer mitigation funds.A National Disaster Response Fund will be administerd by NDMA through the National Executive Committee. States and Districts will administer state Disaster Response Fund and Disaster Response Fund respectively.8 Battalions of National Disaster Response Force (NDRF) are being trained and deployed with CSSR and MFR equipments and tools in eight strategic locations.A National Disaster Management Policy and National Disaster Response Plan will also be drawn up.Lessons Learnt Be Prepared : Preparedness and Mitigation is bound to yield more effective returns than distributing relief after a disaster.Create a Culture of Preparedness and Prevention.Evolve a code of conduct for all stake-holdersFuture DirectionsEncourage and consolidate knowledge networksMobilise and train disaster volunteers for more effective preparedness, mitigation and response (NSS, NCC, Scouts and Guides, NYK, Civil Defence, Homeguards)Increased capacity building leads to faster vulnerability reduction.Learn from best practices in disaster preparedness, mitigation and disaster responseFuture DirectionsMobilising stakeholder participation of Self Help Groups, Womens Groups, Youth Groups, Panchayati Raj InstitutionsAnticipatory Governance: Simulation exercises, Mock drills and Scenario AnalysisIndigenous knowledge systems and coping practicesLiving with Risk: Community Based Disaster Risk ManagementInclusive, participatory, gender sensitive, child friendly, eco-friendly and disabled friendly disaster managementTechnology driven but people ownedKnowledge Management: Documentation and dissemination of good practicesPublic Private PartnershipInvest in PreparednessInvestments in Preparedness and Prevention (Mitigation) will yield sustainable results, rather than spending money on relief after a disaster.Most disasters are predictable, especially in their seasonality and the disaster-prone areas which are vulnerable.Communities must be involved in disaster preparedness.Best Practices

On 12 November, 1970 a major cyclone hit the coastal belt of Bangladesh at 223 km/hr. with a storm surge of six to nine meters height, killing an estimated 500,000 people.Due to the Cyclone Preparedness Program, the April 1991 cyclone with wind speed of 225 km/hr. killed only 138,000 people even though the coastal population had doubled by that time.In May 1994, in a similar cyclone with a wind speed of 250 km/hr. only 127 people lost their lives.In May 1997, in a cyclone with wind speed of 200 km/hr. only 111 people lost their lives.

New possibilitiesNational Urban Renewal Mission for 70 cities: recent experience of unprecedented extreme weather conditions in a few major metros and megacities100,000 Rural Knowledge Centres ( IT Kiosks): Need for Spatial e-Governance for informed decision making in disaster-prone areas: before, during and after disasters

71Second way is applying additional structural control-passive, active or semi-active, objective is to control structural response by either reduce the amount of energy transfer into the structure from the ground motion or to absorb some of the earthquake energy after it has been transmitted to the structure.SEISMIC RESISTANT DESIGNStructural ControlPassive ControlActive controlSemiactive ControlHybrid Control72Earthquake-Resistant StructureBuilding designed to prevent total collapse, preserve life, and minimize damage

http://nisee.berkeley.edu/elibrary/getpkg?id=GoddenD50-69http://www.infinityfoundation.com/mandala/t_es/t_es_agraw_quake.htm73

74Structural ControlPASSIVE CONTROLNo Power requirement, Very reliable, dissipate energy either by structures own relative motion within control devices or converting kinetic energy into heat. Low maintenance, do not destabilize structureTypesBase IsolationTMDs, TLDsMetallic Yield DampersViscous Fluid and Friction Dampers

Base-IsolationDecouple the Superstructure from Ground with or without Flexible Mounting Period of the total System is ElongatedA Damper- Energy Dissipating Device provided at the Base MountingsRigid under Wind or Minor EarthquakeAdvantages of Base Isolation-Reduced floor Acceleration and Inter-storey Drift-Less (or no) Damage to Structural Members-Better Protection of Secondary Systems -Prediction of Response is more Reliable and Economical LRB, NZ, FPS, R-FBI, VFPS, VFPI, VCFPS etc. are some common type of isolators7576Isolation BearingsElastomeric Bearings

77

78

Lead-Rubber Bearings

79

Friction Pendulum System

Friction Pendulum Bearing80 Base Isolation System DampersLead damper

Oil damperFriction damper with Coned disc springsSteel damperThe Concept of Base Isolation81

Fixed BaseBase IsolatedPeriodResponseSignificantly Increase the Period of the Structure and the Damping so that the Response is Significantly ReducedDuring a Richter 8.0 Earthquake a Seismically Isolated Building Will Behave as if it Were Experiencing a 5.5 Earthquake

82

Location: Rancho Cucamonga California.Isolator :HDREngineers: Taylor & Gaines; Reid & Tarics.Year :1985The Washington State Emergency Operations Center at Camp Murray is an essential facility used for the central coordination of emergency responses for the State of Washington. The building houses critical communications and computer equipment. The Friction Pendulum TM seismic isolation bearings were designed to enable the building to withstand the maximum credible earthquake for the Seattle region. The building is located 8 miles from the epicenter of the Magnitude 6.8 earthquake that shook the Seattle region on February 28, 2001. The building and all its equipment and contents remained fully operational after the earthquake.

8384

Location: Los Angeles, California.Isolator : LRBEngineers: KPFFYear :199185

Location: Sendai, Miyako ProvienceIsolator :HDRYear :199086

The U.S. Court of Appeals is a 350,000 sq. ft. building listed in the National Register of Historic Places. The building has an elaborate granite exterior and interiors of marble, decorative plaster and hardwoods. Installation of 256 Friction Pendulum TM bearings completed in June 1994, it became the largest building in the world to have been retrofitted with seismic isolators. .

8788

Location: 1 k.m. SW of PelabuhanBuilding : 4-Story MR RCC.Isolator : 16 HDRManufacturer: MRPRA, UK

212 Friction Pendulum TM bearings.

89LNG storage tanksRevithoussa, AthensCapacity: 38 million gallons (226 ft dia. x 106 ft. high)The largest and heaviest tanks in the world to use seismic isolation90

The American River Bridge & installed friction pendulum bearing 91I-40 Mississippi River Bridge Memphis, Tennessee

92

ACTIVE CONTROL93Requires External power to operate Actuators that supply control. Directly add the force to system, Usually require large external power source to operate.Use responses of the structure such as displacement, velocity and acceleration to calculated needed forcesRequire sensors and real-time data processing systemMore complicate than passive control force to structures.Active mass Dampers

Hydraulic actuatorActive mass damper- Provides force by moving the mass with suitable acceleration May activate the higher modes of structures and make more damageSemi-active control94Required small external power sourceUse structures movement to generate control forceStiffness and damping can be easily changedRequired sensors and data processor to calculate control forceDefaults to a passive device when no power is availableExample of a semi-active device (MR-Damper)

MR Dampers95

96

Hybrid control97Combine controls system togetherPassive + ActivePassive + Semi-ActiveSmart base-isolationReduce external power requirementImprove reliabilityWhen loss of electric during earthquake, hybrid control can act as a passive controlReduce construction and maintenance costs due to active or semi-active

98

99

Thank you

Figure 7.2 Foothill Communities Law and Justice Center,

Rancho Cucamonga,California (photo by I.D. Aiken).

168

_1022329474.doc

Figure 7.3 University of Southern California, University Hospital

(Photo by P.W. Clark).

PAGE 69

Figure 7.9 Tohoku Electric Power Company, Japan (Kelly, 1997).

PAGE 74

San Francisco city hall

Figure 7.1 Demonstration building in Indonesia (1994)

Current Status

United States

22 New Buildings on Base-Isolation - Foot Hill Communities Law and Justice Centre,

California 1985

Hayward City Hall, December 1997

18 Buildings Retrofitted Salt Lake City and Country Building, Utah, 1989

Asian Art Museum, SF, October 2000

City Halls at San Francisco, Los Angeles

Isolation Systems

LRB, HDR, HDR+PTFE Slider, FPS, FPS+Dampers

Japan - More than 100 Buildings

Europe - 2 Buildings/Several Bridges

New Zealand - 10 Buildings (Lead Rubber Bearing)