Presentation on theme: "PRESENTATION ON SEISMIC SAFETY CONSIDERATION IN SCHOOL BUILDINGS"— Presentation transcript:
1PRESENTATION ON SEISMIC SAFETY CONSIDERATION IN SCHOOL BUILDINGS By: Dr. Anand S. Arya, FNA, FNAEProfessor Emeritus, Deptt. of Earthquake Engg., I.I.T. RoorkeeNational Seismic Advisor, MHA, New DelhiPadmashree awarded by the President, 2002
2INTRODUCTION Children, vulnerable in earthquakes Schools in rural areas in vulnerable buildingsSchool buildings seldom designed for safetyBut very important assets for the community
3SEISMIC RISK TO SCHOOL Death & injury to students, teachers and staff Damage to or collapse of buildingsDamage and loss of furnishings, equipment and building contentsDisruption of educational programs and school operations.
5NATURAL HAZARDSEarthquakes: Richter M 5.5 to 8.7 in different Zone III, IV & VFloods: River plainsLocal choking of DrainsWind: – 55 m/s ( km/h)Fire : Any where due to various causesLandslides: In mountain areas
6EARTHQUAKE HAZARD ZONES 2002 Zone V MM IX or more“ IV MM VIII“ III MM VIIZone II MM VI or lessArea under the zonesV %IV %III ~30.8%Total damageable~ 59%IVVIVVVIIIIIIV
9LANDSLIDES ZONATION MAP OF INDIA Severe Risk AreaHigh Risk AreaModerate Risk AreaUnlikely Occurrence
10EARTHQUAKE OCCURRENCE MAGNITUDE M 5 – 8.7 Surface RuptureSeismic WavesNear Surface ShiftTsunami GenerationDamage to Buildings & StructuresSea WavesCoastal FloodsSoil Changes for M > 6.0Generation of VibrationDynamic Settlement, Soil LiquefactionSlope MovementsPrimary EffectsSecondary EffectsNatural River DammingCollapse of Structural Components/fire/flood (e.g. by dam break)FloodsNon- Structural DamageImpact on Man/SocietyPersonal injuryLoss of belongingsPsychological effectsSociological effectsEconomical effects
11DIFFERENT MATERIALS USED IN CONSTRUCTION OF SCHOOL BUILDINGS Mud wallStone wallBurned brick wallConcrete wall/columnWoodDifferent mortar usedMud mortarLime mortar (Lime surkhi)Cement mortar (1:8, 1:6)
12KACHCHH EARTHQUAKE IN GUJARAT Date of Occurrence : 26th January Time : 8.46 a.m. Epicenter : North Latitude and EastLongitude : 20km North East of Bhuj Magnitude : 6.9 Richter Scale Moment magnitude Surface Wave magnitude Intensity, maximum : IX-X MSK Scale
13A TERRIBLE HUMAN TRAGEDY Over 1.1 million homes affected; 4 Kachchh towns in ruins
14A TERRIBLE HUMAN TRAGEDY Over 5,000 Health units damaged / destroyedBhuj General HospitalHigh School of Dudhai VillageOver 42,000 School rooms damaged / destroyed
15A TERRIBLE HUMAN TRAGEDY Over 50,000 artisans lost their livelihood.Over 10,000 small and medium industrial units went out of production.
16A TERRIBLE HUMAN TRAGEDY Massive damage to telecom, power, water supply and transport infrastructure.
17School roof with precast R.C. panels collapsed (Ghandhidham)
18Connection failure in precast R.C. school building ( Kukma village)
19Summary of damage to physical assets of government & grant-in-aid academic institutions. SECTORNO. OF INSTITUTIONS AFFECTEDPrimary EducationSchool BuildingsTeacher Training Institutes959342Kitchens for Midday Meal Program1871Secondary/higher secondary educationGovernment SchoolsGrant-in-aid schools1271913Higher Education (Universities & Colleges)47Technical Education (polytechnics & engineering colleges)Grant-in-aids schools5851(Source: Department of Education, Government of Gujarat)
20DEATHS & INJURIES DEATHS INJURIES TEACHERS 31 95 STUDENTS 971 1051 910 in primary37 in secondary3 in colleges21 in teachers schoolsIncluding 300 children on streets in Anjar
21DAMAGES TO SOME OF THE SCHOOL BUILDINGS AROUND THE WORLD Earthquake of June 27, 1925, Helena, Montana, USA.The high school at Three Forks, Montana, with brick walls in lime mortar was badly damaged and the walls bulged on all sides.
22Earthquake of June 27, 1925, Helena, Montana, USA. Damage to school at Manhattan, Montana, 1925, partition walls of school house separated from the outside wall owing to lack of Ties.
23Earthquake of March 10, 1933, Long Beach, California, USA. Schools were among the buildings most severly damaged because they were not designed to resist shaking. In addition to the damage to the schools at Long Beach, the schools were badly damaged at Buena Park, Lomita and at Redondo Beach. Great loss of life would have occurred if the shock had taken place during school hours.
24The 1933 Long Beach, California Earthquake destroyed at least 70 schools and damaged 420 more, 120 of them seriously. As a direct response, California enacted the Field Act, which established strict design and constructions standards for new schools in California.
25In 1966 the Attorney General of California issued an opinion indicating that school boards were responsible for ensuring non-Field Act buildings were examined, and if schools were found to be unsafe and the board did not make the necessary corrections to make them safe, the individual school board members were personally liable.
26The Governor signed the Greene Act in 1967, which relieved the individual school board members of personal liability only once the board initiated the process of examining existing buildings and established an intent to carry through to completion all the steps necessary for their replacement or repair.
27Earthquake of October 31, 1935, Helena, Montana, USA. The photo shows the west wing of Helena High School that collapsed. The collapsed part of the school reinforced concrete frame, floors and roof and the tile floors were faced with brick.
28Collapsed school in Kern County, CA Earthquake, 1952
29School Split by Slumping Ground in Earthquake of March 27, 1964,Prince Willian Sound, Alaska, USA. Government Hill Elementary School split in two and was virtually destroyed when the ground beneath it slumped down. Fortunately, the earthquake occurred on Good Friday, a school holiday
30Earthquake of October 3, 1974, Lima, Peru Column failure caused the roof to sag on a one-storey classroom at Agricultural University. Note heavy roof structure on the concrete-frame building
31Earthquake of September 6, 1975, Lice, Turkey. All lateral resisting elements were shattered in the west wall of the high school building
32Earthquake of April 9, 1976, Esmeraldas, Ecuador Severe damage to exterior of Juan Montalvo School
33Earthquake of July 27, 1976, Tangshan, China. Collapse of a classroom and laboratory building at the College Mining Institute. The school was closed when the earthquake occurred, but more than 2000 students were killed in their dormitories.
34Earthquake of October 10, 1980, El Asnam, Algeria. This modern school collapsed at El Asnam. This school is one of 85 that collapsed during earthquake. The earthquake occurred after school hours, and so no loss of life was sustained at this school
35Earthquake of May 2, 1983, Coalinga, California, USA. Failure of pendent light fixtures in the Dawson Elementary School library would have caused many injuries if the library had been occupied.
36Earthquake of December 7, 1988, Spitak, Armenian SSR. Four Hundred children were killed at this elementary school in Dzhrashen Southeast of Spitak, Armenian SSR. The precast concrete floors in the building collapsed due to poor ties with the walls.
38PLANNING NORMS FOR SCHOOL BUILDINGS Room sizes to be in accordance with the State norms for school buildingsHeight of the rooms should not be less 3.6 m for all regions in urban areas.Safety consideration: - Every class room to have 2 doors opening outside in a verandah or courtyard for easy exit.For large two to three storey school buildings, there should be minimum two staircases with a width of 1.5 m opening into a large covered or open space.Toilets need to be provided as per the National Building Code specification given:
39PLANNING NORMS FOR SCHOOL BUILDINGS Toilet norms for urban areas:-Minimum floor area of water closet should be 1.1 Sq.m. with a minimum width of 0.9 m (NBC 2005, part – 3, pg.31).Minimum floor area of bath should be 1.8 Sq.m. with a minimum width of 1.2 m (NBC 2005, part – 3, pg.31).Every bath of water closet shall have window or ventilator, opening to a shaft or open space, of area not less than 0.3 Sq.m. with side not less than 0.3 m (NBC 2005, part – 3, pg.31).The height of a bathroom or water closet measured from the surface of the floor to the lowest point in the ceiling (bottom of slab) shall not be less than 2.1 m (NBC 2005, part – 3, pg.31).
40PLANNING NORMS FOR SCHOOL BUILDINGS Toilet norms for rural areas:-Minimum floor area of water closet should be 0.9 Sq.m. with a minimum width of 0.9 m (NBC 2005, part – 3, pg.58).Minimum floor area of bath should be 1.2 Sq.m. with a minimum width of 1.0 m (NBC 2005, part – 3, pg.58).
41PLANNING NORMS FOR SCHOOL BUILDINGS No. of toilet fixtures required in school buildingsFixtures Boys GirlsWater-closet 1 per 40 pupils 1 per 25 pupilsor part thereof or part thereofUrinals 1 per 20 pupils -or part thereofDrinking 1 per 50 pupils 1 per 50 pupilswater Fountain or part thereof or part thereofor taps
42PLANNING NORMS FOR SCHOOL BUILDINGS Preferably rain water harvesting may be included in large school buildings.The buildings to be designed for earthquake, cyclonic wind resistance applicable as per IS Codes.Plinth level of the school buildings to be kept atleast 15 cm above the known highest flood level, minimum 45 cm above the ground level.In storm surge prone coastal areas either the whole school or the roof of the school made accessible through stairs should be kept higher than the estimated maximum flood inundation due to cyclonic rains/storm surges.
50VERTICAL REINFORCEMENT IN THE BRICK WALLS For earthquake safety in reinforcing bars have to be embedded in brick masonry at the corners of all the rooms and the side of the door openings.These vertical bars have to be started from the foundation concrete, will pass through all seismic bands where they will be tied to the band R/F using binding wire & embedded to the ceiling band/roof slab as the case may be using a 300 mm 90° bend.
51RECOMMENDED JOINT DETAILS WITH VERTICAL R/F AT CORNORS
55VULNERABILITY ASSESSMENTS Building safety From Earthquake, Wind, Flood & FireAbsence of seismic bands, vertical reinforcement etc.Damageability of contents due to the above hazards (Sliding, Falling Over, Failure of Lift Houses, Power failure, Leakage of Chemicals, Breakage of Pipelines, Over turning of Control panels Etc.)
56RISK REDUCTION MEASURES Retrofitting of Buildings Against Seismic DamageRetrofitting of Roofs & Free Standing Walls Against High WindsProtection of the Building from the Flood WatersImproving Support Systems of EquipmentFire Safety MeasuresPreparedness Against Emergent Situations
58EXTRA COST OF EARTHQUAKE SAFETY ELEMENTS IN BUILDINGS Buildings constructed using the Indian Standard Codes & guidelines:Masonry Building:Seismic Zone III 2 – 3%Seismic Zone IV 3 – 4%Seismic Zone V 4 – 6%Reinforced Concrete Buildings of 8 – 10 storeys:Seismic Zone III 2.6 – 3.2%Seismic Zone IV 3.2 – 4%Seismic Zone V 5 – 6%(In each case, including about 0.7% only for ductile detailing)Retrofitting of buildings, not initially designed for earthquake will cost:2 – 3 times as much as the above mentioned costs.
59ROLE OF EDUCATIONAL AUTHORITIES Developing comprehensive policies: from Preparedness & Mitigation to Response.Increasing communication and interaction among Education and Emergency Management Agencies.Ensuring compliance with school safety planning regulationsAddressing the needs of special student population (e.g. disabled)
60STATE LEVEL ACTIONSField Act of California after 1933 Long Beach Earthquake.Japanese Ministry of Construction Resolution regarding strengthening of schools to act as post disaster shelters.South California State Board Regulation on Student & School Safety, USA requires State to develop a Model Safe School Check list to assess buildings & grounds.NBC & other Sate document specify safety planning norms for design schools.
61QUESTIONS TO PONDER Is there an earthquake hazard for your school? - Seismic zone in which the school is located.Are your school building safe?- Assessment of Damageability in the probable intensity.- Rapid Visual Screening.- More detailed Vulnerability Assessment.● Main points of deficiency requiring treatment.- Assessment of Risk● Death & Injuries – students, teachers, staff.
62● Disruption of school services. ● Destruction of school contents & equipments.● Disruption of school services.● Loss of sheltering services – post disaster.What can be done to reduce earthquake risk in existing vulnerable school buildings ?- Replace or Retrofit.- Single stage Retrofit – cost & disruption.- Incremental retrofit – reduce cost & disruption(sequential operation over a few years combinedwith annual maintenance).Preparedness measures.