Presentation on theme: "PRESENTATION ON SEISMIC SAFETY CONSIDERATION IN SCHOOL BUILDINGS By: Dr. Anand S. Arya, FNA, FNAE Professor Emeritus, Deptt. of Earthquake Engg., I.I.T."— Presentation transcript:
PRESENTATION ON SEISMIC SAFETY CONSIDERATION IN SCHOOL BUILDINGS By: Dr. Anand S. Arya, FNA, FNAE Professor Emeritus, Deptt. of Earthquake Engg., I.I.T. Roorkee National Seismic Advisor, MHA, New Delhi Padmashree awarded by the President, 2002
INTRODUCTION 1.Children, vulnerable in earthquakes 2.Schools in rural areas in vulnerable buildings 3.School buildings seldom designed for safety 4.But very important assets for the community
SEISMIC RISK TO SCHOOL Death & injury to students, teachers and staff Damage to or collapse of buildings Damage and loss of furnishings, equipment and building contents Disruption of educational programs and school operations.
NATURAL HAZARDS Earthquakes: Richter M 5.5 to 8.7 in different Zone III, IV & V Floods: River plains Local choking of Drains Wind: 33 – 55 m/s ( km/h) Fire : Any where due to various causes Landslides: In mountain areas
EARTHQUAKE HAZARD ZONES 2002 Zone V MM IX or more “ IV MM VIII “ III MM VII Zone II MM VI or less Area under the zones V 10.8% IV 17.5% III~30.8% Total damageable ~ 59% V V III V IV V
WIND & CYCLONE HAZARD ZONES IN INDIA
FLOOD HAZARD PRONE AREAS OF INDIA
LANDSLIDES ZONATION MAP OF INDIA Severe Risk Area High Risk Area Moderate Risk Area Unlikely Occurrence
EARTHQUAKE OCCURRENCE MAGNITUDE M 5 – 8.7 Surface RuptureSeismic Waves Near Surface Shift Tsunami Generation Damage to Buildings & Structures Sea Waves Coastal Floods Soil Changes for M > 6.0 Generation of Vibration Dynamic Settlement, Soil Liquefaction Slope Movements Primary Effects Secondary Effects Damage to Buildings & Structures Natural River Damming Damage to Buildings & Structures Collapse of Structural Component s/fire/flood (e.g. by dam break) FloodsNon- Structural Damage Impact on Man/Society Personal injury Loss of belongings Psychological effects Sociological effects Economical effects
DIFFERENT MATERIALS USED IN CONSTRUCTION OF SCHOOL BUILDINGS Mud wall Stone wall Burned brick wall Concrete wall/column Wood Different mortar used Mud mortar Lime mortar (Lime surkhi) Cement mortar (1:8, 1:6)
KACHCHH EARTHQUAKE IN GUJARAT Date of Occurrence:26th January 2001 Time :8.46 a.m. Epicenter : North Latitude and East Longitude:20km North East of Bhuj Magnitude:6.9 Richter Scale 7.7 Moment magnitude 7..9 Surface Wave magnitude Intensity, maximum:IX-X MSK Scale
A TERRIBLE HUMAN TRAGEDY Over 1.1 million homes affected; 4 Kachchh towns in ruins
A TERRIBLE HUMAN TRAGEDY Over 5,000 Health units damaged / destroyed Bhuj General HospitalHigh School of Dudhai Village Over 42,000 School rooms damaged / destroyed
A TERRIBLE HUMAN TRAGEDY Over 50,000 artisans lost their livelihood. Over 10,000 small and medium industrial units went out of production.
A TERRIBLE HUMAN TRAGEDY Massive damage to telecom, power, water supply and transport infrastructure.
School roof with precast R.C. panels collapsed (Ghandhidham)
Connection failure in precast R.C. school building ( Kukma village)
SECTORNO. OF INSTITUTIONS AFFECTED Primary Education School Buildings Teacher Training Institutes Kitchens for Midday Meal Program1871 Secondary/higher secondary education Government Schools Grant-in-aid schools Higher Education (Universities & Colleges)47 Technical Education (polytechnics & engineering colleges) Government Schools Grant-in-aids schools (Source: Department of Education, Government of Gujarat) Summary of damage to physical assets of government & grant-in-aid academic institutions.
DEATHSINJURIES TEACHERS3195 STUDENTS in primary 37 in secondary 3 in colleges 21 in teachers schools Including 300 children on streets in Anjar DEATHS & INJURIES
DAMAGES 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.
Earthquake 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.
Earthquake 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.
The 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.
In 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.
The 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.
Earthquake 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.
Collapsed school in Kern County, CA Earthquake, 1952
School 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
Earthquake 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
Earthquake of September 6, 1975, Lice, Turkey. All lateral resisting elements were shattered in the west wall of the high school building
Earthquake of April 9, 1976, Esmeraldas, Ecuador Severe damage to exterior of Juan Montalvo School
Earthquake 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.
Earthquake 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
Earthquake 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.
Earthquake 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.
DESIGN OF NEW SCHOOL BUILDINGS
PLANNING NORMS FOR SCHOOL BUILDINGS Room sizes to be in accordance with the State norms for school buildings Height 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:
PLANNING 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).
PLANNING 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).
PLANNING NORMS FOR SCHOOL BUILDINGS No. of toilet fixtures required in school buildings Fixtures Boys Girls Water-closet1 per 40 pupils 1 per 25 pupils or part thereof or part thereof Urinals1 per 20 pupils - or part thereof Drinking 1 per 50 pupils 1 per 50 pupils water Fountainor part thereofor part thereof or taps
PLANNING 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.
ONE ROOM SCHOOL BUILDING
TWO ROOM SCHOOL BUILDING
FOUR ROOM SCHOOL BUILDING
SEISMIC BANDS Overall arrangement of reinforcing in masonry double storey building
SEISMIC SAFETY DETAILS
VIEW SHOWING THE FOUNDATION DETAIL
VIEW SHOWING THE SECTION OF SEISMIC BANDS
VERTICAL 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.
RECOMMENDED JOINT DETAILS WITH VERTICAL R/F AT CORNORS
VERTICAL R/F AT JAMBS OF OPENINGS
ASSESSMENT OF RISK TO SCHOOLS
VULNERABILITY ASSESSMENTS Building safety From Earthquake, Wind, Flood & Fire Absence 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.)
RISK REDUCTION MEASURES Retrofitting of Buildings Against Seismic Damage Retrofitting of Roofs & Free Standing Walls Against High Winds Protection of the Building from the Flood Waters Improving Support Systems of Equipment Fire Safety Measures Preparedness Against Emergent Situations
SEISMIC RETROFITTING OF MASONRY BUILDINGS
EXTRA COST OF EARTHQUAKE SAFETY ELEMENTS IN BUILDINGS Buildings constructed using the Indian Standard Codes & guidelines: Masonry Building: Seismic Zone III2 – 3% Seismic Zone IV3 – 4% Seismic Zone V4 – 6% Reinforced Concrete Buildings of 8 – 10 storeys: Seismic Zone III2.6 – 3.2% Seismic Zone IV3.2 – 4% Seismic Zone V5 – 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.
ROLE OF EDUCATIONAL AUTHORITIES 1.Developing comprehensive policies: from Preparedness & Mitigation to Response. 2.Increasing communication and interaction among Education and Emergency Management Agencies. 3.Ensuring compliance with school safety planning regulations 4.Addressing the needs of special student population (e.g. disabled)
STATE LEVEL ACTIONS 1.Field Act of California after 1933 Long Beach Earthquake. 2.Japanese Ministry of Construction Resolution regarding strengthening of schools to act as post disaster shelters. 3.South California State Board Regulation on Student & School Safety, USA requires State to develop a Model Safe School Check list to assess buildings & grounds. 4.NBC & other Sate document specify safety planning norms for design schools.
QUESTIONS TO PONDER 1.Is there an earthquake hazard for your school? - Seismic zone in which the school is located. 2.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.
● 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 combined with annual maintenance). Preparedness measures.
Thank You and wish you the best in your efforts