SAFE CONSTRUCTION PRACTICE

1. SAFE CONSTRUCTION PRACTICE

2. CONTENTS • DISASTER • TYPES OF DISASTER • EARTHQUAKES • LANDSLIDES • FLOODS • CYCLONES • REFERENCES

3. DISASTER • The term ‘Disaster’ owes its origin to the French word ‘Desastre’ which is the combination of two terms ‘des’ meaning bad or evil and ‘astre’ meaning star . The combination expression is ‘Bad or Evil Star’. • A catastrophe, sudden, calamitous event bringing great damage, loss, destruction and devastation to life and property by natural or man-made causes.

4. TYPES OF DISASTER Two Types – Natural and Manmade Natural disasters: • Flood • Cyclone • Earthquake • Landslides

5. Manmade Disaster • Setting of fires • Epidemic • Deforestation • Chemical pollution. • Wars • Road / train accidents, riots • Food poisoning • Environmental pollution

6. EARTHQUAKES • Ground shaking – back-&-forth motion , caused by the passing vibratory waves. • Soil failures – caused by shaking e.g. landslides . • Surface fault ruptures, such as cracks , vertical shifts. • Tidal waves ,i.e. large waves on the surface of bodies of water that can cause major damage to shoreline areas.

7. EFFECTS ON BUILDINGS • As vibrations & waves continue to move through the earth –buildings ,set in motion. • Each building response differently ,acc.to its construction. • When waves strike ,earth moves backward & forward . • The lower part of building moves with the earth. • The upper portion –initially remains at rest.

8. The upper portion tries to catch up with the bottom but as it does so, the earth moves in the other direction – ‘whiplash effect’. • Taller buildings also tend to shake longer than short buildings.

9. PROTECTION MEASURES • The building should have a simple rectangular plan. • Long walls should be supported by reinforced concrete columns. • Large buildings having plans with shapes like T,U,L and X. • It should preferably be separated into rectangular blocks by providing gaps in between.

10. Doors and window openings in walls , preferably be small & more centrally located. • The location of openings should not be too close to the edge of the wall.

12. LANDSLIDES • Landslides occur because of the interplay of several factors. • Natural factors :- Intensity of rainfall, Steep slopes, Poor drainage, Stiffness of slopes etc. • Manmade factors:- Deforestation leading to soil erosion etc.

14. MOST VULNERABLE HOMES • Existing landslides area. • Steep natural slopes. • Area in or at the mouths of drainages. • Houses constructed near foothills.

15. PROTECTION MEASURES FROM DAMAGE TO BUILDINGS (a) Site selection: • Safe area – that have not moved in the past . • Houses built at the toe of steep slopes. (b) Signs and warnings: • Doors or windows stick for the first time. • New cracks appear on plaster,tile,brick. • Underground utility lines break. • Fences, retaining walls, utility poles or trees tilt or move.

16. (c) Preventive action: • Proper development. • Sound construction techniques. • Seasonal inspections. • Regular maintenance of drainage facilities. (d) Protect vulnerable area: Keep surface drainage water away from vulnerable areas (steep slopes, loose soils & non-vegetated surfaces.)

17. (e) Intercept surface water. (f) Stabilize slopes: • Improve soil’s ability . • Straw, woodchips applied to a depth of at least one inch.

18. FLOODS Water is a source for all life forms . Without water no life is sustainable. ‘How tragic it is’ , when water in the form of floods takes away thousand of human and cattle lives. More than one million huts and poor houses are lost every year in floods in India. CAN WE PREVENT THIS LOSS ????????????

19. MOST VULNERABLE HOMES • Building – constructed with earth –based materials or using stone & brick in mud mortar . • The huts made from biomass materials. • The occupation of areas within the flood plain of rivers has increased vulnerability.

20. EFFECT ON BUILDINGS • The houses are commonly destroyed so severely that their reconstruction is not feasible. • It is constructed out of light weight material . • Damage caused by inundation of house . • Undercutting of houses. • Damage caused by debris.

21. PROTECTION MEASURES FROM DAMAGE TO BUILDINGS • To avoid residing on river banks & slopes on river sides. • To build at least 250 mts away from the sea coast . • To build proper drainage system in all flood prone areas. • To construct the building with a plinth level higher than the known high flood level.

22. To construct the whole village on a raised plat form higher than the high flood level. • To construct buildings on stilts or columns with wall – free space at ground level permitting free flow of water.

23. CYCLONES • Cyclones pose a major threat to life and property in many parts of the world. Every year these sudden, violent cyclones bring widespread devastation to coastlines and islands lying in their erratic paths. A windstorm's destructive work is done by the high wind; flood producing rains and associated storm surges.

25. MOST VULNERABLE HOMES • Location • Light weight • Older buildings • Poorly constructed concrete blocks • Urban and rural communities on low islands • Effected by the velocity of cyclone wind at ground level

26. EFFECTS ON BUILDINGS • Uprooting of trees • Damage to signposts , electric poles, etc • Damage to improperly attached windows • Damage to roof/lintel projections • Failure of improperly attached parapets • Overturning failures of compound walls of various types

27. PROTECTION MEASURES FROM DAMAGE TO BUILDINGS • Site selection • Platforms and orientation • Foundations:- (a) effect of surge or flooding, (b) Building on stilts • Wall openings • Glass panelling • Roof architecture

28. REFERENCES • www.google.com • www.bte.gov.au • http :// gujarat-earthquake .gov.in/ • Text book of disaster management • www.wikipedia.com

29. THANKS