04-03-2010, 11:52 AM
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SMART BASE ISOLATION SYSTEMS
BASE ISOLATION
MOST WIDELY USED IN SEVERE SEISMIC ZONE
ISOLATE THE STRUCTURE FROM GROUND
LOCATED UNDER THE STRUCTURE
REDUCED INTERACTION BETWEEN GROUND
AND STRUCTURE
Guided By:
Presented By
RAJESH RAMAKRISHNAN
DEEPAK.G S7MA Roll No: 23
NEED
Minimize interstorey drift ^ Minimize floor acceleration
CONCEPT OF BASE ISOLATION
CONSIDER ENERGY CONSERVATION OF A STRUCURE DURING AN EARTHQUAKE
E = Ek + Es + En + Ed
E- Absolute energy input from earthquake motion
Ek -Absolute kinetic energy
Es -recoverable elastic strain energy
En-irrecoverable energy dissipated by structural
system through inelastic or other forms of
action.
Ed-Energy dissipated by supplemental damping
CONVENTIONAL SYSTEMS
BASE ISOLATED SYSTEMS
DESIGN FACTORS
¦ SEISMIC DEMAND AND PERFORMANCE LEVEL
+ PERMISSIBLE DISPLACEMENT + ISOLATOR DESIGN
* SEISMIC MOAT OR SEISMIC GAP
* INTERACTION BETWEEN STRUCTURE AND GROUND SHOULD BE DETAILED
BASIC ELEMENTS
¦ FLEXIBILITY
¦ ENERGY DISSIPATION
RIGIDITY UNDER SERVICE LOADS
APPLICATIONS
¦ AN ALTERNATIVE FOR BUILDINGS TO REMAIN FUNCTIONAL AFFTER AN EARTHQUAKE-IMMEDIATE OCCUPANCY
ATTRACTIVE RETROFIT APPROACH TO
CONSERVE HISTORIC MONUMENTS
MAINLY USED FOR HOSPITALS, AIRPORT TERMINALS, COMMUNICATION CENTERS etc.
ISOLATION DEVICES
'SHOULD SUPPORT THE STRUCTURE
PROVIDE HORIZONTAL FLEXIBILITY
SHOULD DISSIPATE THE ENERGY
SUCCESSFUL ISOLATION-APPROPRIATE
CHOICE OF SYSTEM
ISOLATION SYSTEMS
^ Laminated Rubber Bearings
^ Lead Rubber Bearing
^ Magneto Rheological Damper (MRD)
LAMINATED RUBBER BEARINGS
MADE OF VULCANISATION BONDING OF RUBBER TO THIN STEEL PLATES
VERY STIFF IN VERTICAL DIRECTION
FLEXIBLE IN HORIZONTAL DIRECTION
DAMPING ACHIEVED VERY LOW-SOME EXTRA DAMPING DEVICES PROVIDED
MOST SUITABLE-NATURAL RUBBER
LEAD PLUG BEARING
CYLINDER OF LEAD ENCLOSED IN LRB ¦ LEAD PLUG-DISSIPATE ENERGY
ECOMOMICAL AND EFFECTIVE SOLUTION
Internal steel plates +
rubber
Multilayer natural rubber
The durability of natural rubber has been proven by various kinds of testing for tensile strength, rigidity, creep, aging and fatigue.
Lead plug
The excellent damping characteristics and durability of the high purity lead used has been proven by many and aried testing methods.
MAGNETO RHEOLOGICAL DAMPER
CONSTITUENTS - Zirconia(ZrO2) and Iron Powder
Operating Temp : -40 to 150°c
Low Voltage requirement
Not affected by the presence of impurities
LIMITATIONS
¦ ONLY SUITABLE FOR LOW AND MEDIUM
RISE BUILDINGS
¦ COST INVOLVED-COMPARATIVELY HIGH
¦ NO STANDARD TESTING METHODS
CONCLUSION
RELIABLE TECHNOLOGY
¦ LOW COST BEARINGS SHOULD BE DEVELOPED TO EXTEND STRATEGY
ADAPTABILITY TO DIFFERENT
EARTHQUAKES SHOULD BE ACHIEVED
SMART BASE ISOLATION SYSTEMS
BASE ISOLATION
MOST WIDELY USED IN SEVERE SEISMIC ZONE
ISOLATE THE STRUCTURE FROM GROUND
LOCATED UNDER THE STRUCTURE
REDUCED INTERACTION BETWEEN GROUND
AND STRUCTURE
Guided By:
Presented By
RAJESH RAMAKRISHNAN
DEEPAK.G S7MA Roll No: 23
NEED
Minimize interstorey drift ^ Minimize floor acceleration
CONCEPT OF BASE ISOLATION
CONSIDER ENERGY CONSERVATION OF A STRUCURE DURING AN EARTHQUAKE
E = Ek + Es + En + Ed
E- Absolute energy input from earthquake motion
Ek -Absolute kinetic energy
Es -recoverable elastic strain energy
En-irrecoverable energy dissipated by structural
system through inelastic or other forms of
action.
Ed-Energy dissipated by supplemental damping
CONVENTIONAL SYSTEMS
BASE ISOLATED SYSTEMS
DESIGN FACTORS
¦ SEISMIC DEMAND AND PERFORMANCE LEVEL
+ PERMISSIBLE DISPLACEMENT + ISOLATOR DESIGN
* SEISMIC MOAT OR SEISMIC GAP
* INTERACTION BETWEEN STRUCTURE AND GROUND SHOULD BE DETAILED
BASIC ELEMENTS
¦ FLEXIBILITY
¦ ENERGY DISSIPATION
RIGIDITY UNDER SERVICE LOADS
APPLICATIONS
¦ AN ALTERNATIVE FOR BUILDINGS TO REMAIN FUNCTIONAL AFFTER AN EARTHQUAKE-IMMEDIATE OCCUPANCY
ATTRACTIVE RETROFIT APPROACH TO
CONSERVE HISTORIC MONUMENTS
MAINLY USED FOR HOSPITALS, AIRPORT TERMINALS, COMMUNICATION CENTERS etc.
ISOLATION DEVICES
'SHOULD SUPPORT THE STRUCTURE
PROVIDE HORIZONTAL FLEXIBILITY
SHOULD DISSIPATE THE ENERGY
SUCCESSFUL ISOLATION-APPROPRIATE
CHOICE OF SYSTEM
ISOLATION SYSTEMS
^ Laminated Rubber Bearings
^ Lead Rubber Bearing
^ Magneto Rheological Damper (MRD)
LAMINATED RUBBER BEARINGS
MADE OF VULCANISATION BONDING OF RUBBER TO THIN STEEL PLATES
VERY STIFF IN VERTICAL DIRECTION
FLEXIBLE IN HORIZONTAL DIRECTION
DAMPING ACHIEVED VERY LOW-SOME EXTRA DAMPING DEVICES PROVIDED
MOST SUITABLE-NATURAL RUBBER
LEAD PLUG BEARING
CYLINDER OF LEAD ENCLOSED IN LRB ¦ LEAD PLUG-DISSIPATE ENERGY
ECOMOMICAL AND EFFECTIVE SOLUTION
Internal steel plates +
rubber
Multilayer natural rubber
The durability of natural rubber has been proven by various kinds of testing for tensile strength, rigidity, creep, aging and fatigue.
Lead plug
The excellent damping characteristics and durability of the high purity lead used has been proven by many and aried testing methods.
MAGNETO RHEOLOGICAL DAMPER
CONSTITUENTS - Zirconia(ZrO2) and Iron Powder
Operating Temp : -40 to 150°c
Low Voltage requirement
Not affected by the presence of impurities
LIMITATIONS
¦ ONLY SUITABLE FOR LOW AND MEDIUM
RISE BUILDINGS
¦ COST INVOLVED-COMPARATIVELY HIGH
¦ NO STANDARD TESTING METHODS
CONCLUSION
RELIABLE TECHNOLOGY
¦ LOW COST BEARINGS SHOULD BE DEVELOPED TO EXTEND STRATEGY
ADAPTABILITY TO DIFFERENT
EARTHQUAKES SHOULD BE ACHIEVED
