2. INTRODUCTION
WHAT IS EARTHQUAKE ?
AN EARTHQUAKE IS THE SHAKING OF THE SURFACE OF THE
EARTH. EARTHQUAKES CAN BE EXTREMELY VIOLENT. THEY
ARE CAUSED BY MOVEMENTS OF THE EARTH'S TECTONIC
PLATES THE STUDY OF EARTHQUAKES IS CALLED
SEISMOLOGY. THE SUDDEN RELEASE OF TENSION IN THE
TECTONIC PLATES SENDS WAVES OF ENERGY THAT TRAVEL
THROUGH THE EARTH.
3. EARTHQUAKE AND TECTONICS
PLATES
TECTONIC PLATE IS A PIECE OF EARTH’S CURST.
THE SURFACE OF EARTH CONSIST OF SEVEN MAJOR
TECTONIC PLATES AND MANY MORE MINORS ONES
THE TECTONIC PLATES ARE IN SLOW BUT
CONSTANT MOTION. PLATE BOUNDRIES GLIDE PAST
EACH OTHER, CREATING FRICTIONAL STRESS.
THE BOUNDARY OF TECTONIC PLATES ALONG
WHICH FAILURE OCCURS IS CALLED THE FAULT PLANE. THUS
CAUSING
EARTHQUAKE
ACCORDING TO UNITED STATES GEOLOGICAL
SURVEY 1999 PLATE SIZE CAN VARYGREATLY
FROM A FEW HUNDRED TO THOUSANDS OF
KILOMETERS AND PLATE THICKNESS ALSO
VARIES GREATLY, RANGING FROM LESS THAN
15 KM
4. FAULT AND DIFFERENT TYPES OF
FAULTS
THE CRUST ALONG CRACKS CALLED FAULT
NORMAL FAULT : TENSION, A PULLING FORCE THAT
CAUSES THE PLATE TO MOVE APART,CAN CREATE A
NORMAL FAULT
THRUST FAULT : WHEN THE EARTH’S PLATES COME
TOGETHER, THEY PRODUCE COMPRESSION FORCES.
SOMETIMES THE ROCKS BEND. OTHER TIMES THEY BREAK
AND ONE ROCKSLIDES UP OVER THE OTHER.
STRIKE-SLIP FAULT : AT A STRIKE-SLIP FALT, THE
ROCKS ON EITHER SIDE OF THE FAULT SLIDE PAST EACH
OTHER.
5. EARTHQUAKE HAZARD MAP OF
INDIA
THE WAVES
GENERATED DUE TO
EARTHQUAKE
SPREAD OUT.
THESE WAVES
STRIKES THE
FOUNDATION OF THE
BUILDINGS AND
PRODUCE
VIBRATION IN THEM.
6. DAMAGE DEPENDS ON BUILDING TYPE
RESISTANT CONSTRUCTION REDUCES
EARTHQUAKE RISKS
7. SEISMIC-SAFE DESIGN
PRINCIPLES
THE THREE MOST IMPORTANT PROPERTIES FOR SEISMIC
RESISTANCE BUILDINGS ARE ADEQUATE STRENGTH,
STIFFNESS, DUCTILITY AND APPROPRIATE BUILDING
CONFIGURATION.
o STRENGTH: IT IS A PROPERTY OF MATERIAL TO RESIST AND
BEAR APPLIED FORCES WITHIN A SAFE LIMIT.
o STIFFNESS: STIFFNESS OF MATERIAL IS THE DEGREE OF
RESISTANCE TO DEFLECTION OR DRIFT.
o DUCTILITY: IT IS THE CARACTER OF A MATERIAL (SUCH AS
STEEL) TO BEND, FLEX, OR MOVE, BUT FAILS ONLY AFTER
CONSIDERABLE DEFORMATION HAS OCCURRED.
o BUILDING CONFIGURATION: THIS TERM DEFINES A
BUILDING’S SIZE AND SHAPE, AND STRUCTURAL AND NON
STRUCTURAL ELEMENTS
9. SHEAR WALLS
VETICALLY ORIENTED
WIDE BEAMS
IT CARRIES SESMIC
LOADS DOWN TO THE
BOTTOM OF FOUNDATION
PROVIDES LARGE
STRENGTH AND
STIFFNESS TO BUILDINGS.
THICKNESS
GENERALLY VARIES FROM
150 MM TO 450 MM IN
HIGH RISE BUILDINGS.
10. SHEAR WALLS
SHOULD BE SYMETRICAL IN
PLAN AMONG BOTH THE AXES
THE OPENING PROVIDED IN
SHEAR WALL SHOULD BE
SYMMETRICAL
EFFECTIVE WHEN LOCATED
ALONG THE EXTERIOR
PERIMETER OF BUILDING
12. BRACINGS
CROSS-BRACING,
WHICH USES TWO
DIAGONAL MEMBERS IN
AN X-SHAPE, IS A
POPULAR WAY TO
BUILD WALL TRUSSES.
INSTEAD OF BRACED
FRAMES OR IN
ADDITION TO THEM,
ENGINEERS MAY USE
SHEAR WALLS -
VERTICAL WALLS THAT
STIFFEN THE
STRUCTURAL FRAME
OF A BUILDING AND
14. SEISMIC DAMPERS
SEISMIC DAMPERS ARE
USED IN BUILDINGS,
BRIDGES OR ANY OTHER
CONSTRUCTIONS TO
CONTROL EARTHQUAKE
INDUCED VIBRATIONS ON
BUILDINGS.
WHEN SEISMIC WAVES
START TO PENETRATE A
BASE OF BUILDING
STRUCTURE, SEISMIC
DAMPERS CAN DECREASE
THEIR DAMAGING EFFECT
AND IMPROVE THE
BUILDINGS SEISMIC
PERFORMANCE.
WHEN SEISMIC ENERGY IS TRANSIMETED
THROUNG THEM. DAMPERS ABSORB SOME PART OF IT
AND THUS DAMPS THE MOTION OF IT
15. BASE ISOLATION
BASE ISOLATION IS A STATE-OF-THE-
ART METHOD IN WHICH THE
STRUCTURE (SUPERSTRUCTURE) IS
SEPARATED FROM
THE BASE (FOUNDATION OR
SUBSTRUCTURE) BY INTRODUCING A
SUSPENSION SYSTEM BETWEEN
THE BASE AND THE MAIN STRUCTURE.
BASE ISOLATION IS
A TECHNIQUE DEVELOPED TO
PREVENT OR MINIMISE DAMAGE TO
BUILDINGS DURING AN EARTHQUAKE.
... WHEN A BUILDING IS BUILT AWAY
(ISOLATED) FROM THE GROUND,
RESTING ON FLEXIBLE BEARINGS OR
PADS KNOWN AS BASE ISOLATORS, IT
17. HORIZONTAL BANDS
THE HORIZONTAL
BAND CAN BE DEFINED AS
A METHOD OF
REINFORCING THE
MASONRY BUILDINGS BY
PROVIDING BANDS WITH
HIGHER TENSION
STRENGTH.
THIS IS ENABLED IN
AREAS WHERE TWO
STRUCTURAL ELEMENTS
OF A
BUILDING MEET, SO THAT A
CONNECTION IS FORMED
18. BUILDING CONFIGURATION
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, L, U
AND X SHOULD PREFERABLY BE SEPARATED INTO
RECTANGULAR BLOCKS BY PROVIDING GAPS IN BETWEEN.
19. EXPANSION JOINT
AN EXPANSION JOINT OR MOVEMENT JOINT IS AN ASSEMBLY
DESIGNED TO SAFELY ABSORB THE HEAT-
INDUCED EXPANSION AND CONTRACTION
OF CONSTRUCTION MATERIALS, TO ABSORB VIBRATION, TO
HOLD PARTS TOGETHER, OR TO ALLOW MOVEMENT DUE TO
GROUND SETTLEMENT OR EARTHQUAKES
20. CASE STUDY 1
1934 BIHAR EARTHQUAKE
THE 1934 BIHAR EARTHQUAKE WAS ONE OF THE
WORST EARTHQUAKE IN INDIA'S
HISTORY. MUNGER AND MUZAFFARPUR WERE COMPLETELY
DESTROYED. THIS 8.0 MAGNITUDE EARTHQUAKE OCCURRED ON 15
JANUARY AT AROUND 2:13 PM AND CAUSED WIDESPREAD DAMAGE
IN NORTHERN BIHAR AND IN NEPAL.
IMPACTS
IN MUZAFFARPUR, SAND FISSURES ERUPTED AT SEVERAL PLACES IN
TOWN. THE WELLS WERE CHOKED WITH SAND, WHILE WATER
LEVELS IN TANKS BECAME SHALLOWER DUE TO SAND DEPOSITED
IN THE TANK BEDS. MOST OF THE BUILDINGS IN MUZZAFARPUR
WERE DAMAGED. ALL THE WEEK BUILDINGS COLLAPSED, WHILE
OTHER PUKKA (SOLIDLY BUILT) BUILDINGS SUFFERED DAMAGE
DUE TO SINKING AND CRACKING OF THE GROUND
22. LACK OF AWARENESS BEFORE
1934
THE CRITICAL AREAS OF CONCERN FOR THE
MANAGEMENT OF EARTHQUAKES IN INDIA INCLUDE
THE:
o LACK OF AWARENESS AMONG PEOPLE ABOUT THE
SEISMIC RISK
o INADEQUATE ATTENTION TO STRUCTURAL MITIGATION
MEASURES IN THE ENGINEERING EDUCATION
SYLLABUS
o INADEQUATE MONITORING AND ENFORCEMENT OF
EARTHQUAKE-RESISTANT BUILDING CODES AND TOWN
PLANNING BYE-LAWS
o ABSENCE OF SYSTEMS OF LICENSING OF ENGINEERS
AND MASONS
o ABSENCE OF EARTHQUAKE-RESISTANT FEATURES IN
NON-ENGINEERED CONSTRUCTION IN SUBURBAN AND
RURAL AREAS
o LACK OF FORMAL TRAINING AMONG PROFESSIONALS
23. HERITAGE BUILDING
HERITAGE BUILDING MEANS A BUILDING POSSESSING
ARCHITECTURAL, AESTHETIC, HISTORIC OR CULTURAL
VALUES WHICH IS DECLARED AS HERITAGE BUILDING BY
THE PLANNING AUTHORITY/HERITAGE CONSERVATION
COMMITTEE OR ANY OTHER COMPETENT AUTHORITY IN
WHOSE JURISDICTION SUCH BUILDING IS SITUATED.
WHY ARE HERITAGE BUILDINGS IMPORTANT?
CONSERVATION OF HERITAGE BUILDINGS IS
VERY IMPORTANT BECAUSE IT PROVIDES A SENSE OF
IDENTITY AND CONTINUITY IN A FAST CHANGING WORLD
FOR FUTURE GENERATIONS. HERITAGE
BUILDINGS BASICALLY REPRESENT THE PAST HISTORY AND
CULTURE OF A NATION. THEY CONSTITUTE TOGETHER THE
ARCHITECTURAL HERITAGE OF AN AREA
24. SEISMIC STRENGTHENING AND
RETROFITTING
RETROFITTING MEANS TO ADD OR ALTER SOMETHING IN A
BUILDING OR STRUCTURE WHICH WAS NOT AN ORIGINAL PART
OF IT. STRENGTHENING TAKES PLACE WHEN A STRUCTURE OR A
PART OF IT MAY HAVE SOME DAMAGE OR THERE IS A NEED FOR
MORE STRENGTH SUCH AS A CHANGE IN OCCUPANCY WHICH
CALLS FOR THE MEMBER TO BE STRONGER.
JAMA MASJID IN PORT BLAIR
(A) TIE RODS USED FOR RETORTING
(B)TIE-RODS PLACED IN BOTH DIRECTION
(C)NOTICE THE IRON ANGLE FOR ANCHORING THE TIE RODS USED FOR