b_belev_fds_eng
TRANSCRIPT
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 1/44
Dr.Dr. BorislavBorislav BelevBelev
Dept. of Steel and Timber StructuresDept. of Steel and Timber StructuresUACEG, Sofia, BulgariaUACEG, Sofia, Bulgaria
Balkan Seminar on Earthquake Engineering Balkan Seminar on Earthquake Engineering KIIP KIIP - - Sofia Sofia
Sofia, 6 Sofia, 6 - - 7 October 20117 October 2011
Seismic protection of buildingsSeismic protection of buildingswith friction damper systemswith friction damper systems
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 2/44
22Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Lecture overviewLecture overview
1.1. IntroductionIntroduction
2.2. Capacity design philosophy and its evolutionCapacity design philosophy and its evolution
3.3. Essential definitions and classificationEssential definitions and classification
4.4. Basic concept of passive energy dissipationBasic concept of passive energy dissipation
5.5. Advantages and drawbacks of FDSAdvantages and drawbacks of FDS
6.6. Seismic response of structures with FDSSeismic response of structures with FDS
7.7. Damper configurations and applicationsDamper configurations and applications8.8. Concluding remarksConcluding remarks
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 3/44
33Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
IntroductionIntroduction
Capacity Design Philosophy in SeismicCapacity Design Philosophy in Seismic EngineeringEngineering::
Originates from New Zealand (Originates from New Zealand (~ 1970)~ 1970);;
Is also termed “Failure mode control”Is also termed “Failure mode control”
Applicable to all major structural materials and systems;Applicable to all major structural materials and systems;
Is a design approach, not an analysis technique;Is a design approach, not an analysis technique;
Serves as a tool for providing more reliable andServes as a tool for providing more reliable andpredictable seismic response of the structures;predictable seismic response of the structures;
Already embedded in most modern design codes;Already embedded in most modern design codes;Assumes that adequate ductility can be achievedAssumes that adequate ductility can be achievedthrough proper detailing of the potential plastic zonesthrough proper detailing of the potential plastic zones
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 4/44
44Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
History of developmentHistory of development
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 5/44
55Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Capacity design principlesCapacity design principles
The structures shall be madeThe structures shall be made insensitiveinsensitive to the uncertainto the uncertain
parameters of ground shakingparameters of ground shakingThe locations of dissipative zones that will experienceThe locations of dissipative zones that will experiencelarge plastic strains should belarge plastic strains should be prepre--selectedselected so that theyso that theydo not endanger the overall stabilitydo not endanger the overall stability
These plastic regions require special detailing in order toThese plastic regions require special detailing in order tomaintain the desired ductile failure mode during amaintain the desired ductile failure mode during aseismic eventseismic event
For maximizing the global ductility, the other (nonFor maximizing the global ductility, the other (non--
dissipative) parts of structuredissipative) parts of structure must be securedmust be secured againstagainstpremature (brittle) failure via adding extra strengthpremature (brittle) failure via adding extra strength
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 6/44
66Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Capacity design principles (contCapacity design principles (cont’’d)d)
Explanation via Prof. Tom Paulay’s chain
Option 1: Brittlelinks weaker
Option 2: Brittlelinks stronger
(Capacity Design)
Brittle links Ductile link Brittle links
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 7/44
77Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
The overstrength issueActual resistances at the plastic regions Actual resistances at the plastic regions
well above their nominal/design values well above their nominal/design values
may endanger the global ductility and resistance may endanger the global ductility and resistance
Typical sources ofTypical sources of overstrengthoverstrength::
MaterialMaterial overstrengthoverstrengthStrain hardeningStrain hardening
Strain rate effectsStrain rate effects
Design of members governed by nonDesign of members governed by non--seismicseismiccombinations of loads or noncombinations of loads or non--ULSULS(serviceability) criteria(serviceability) criteria
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 8/44
88Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Approach of the design codesApproach of the design codes
EurocodeEurocode 8, for steel structures:8, for steel structures:
materialmaterial overstrengthoverstrength factorfactor γγovov = [1.25]= [1.25]crosscross--sectionsection overstrengthoverstrength factorfactor ii
systemsystem overstrengthoverstrength factorfactor =min{=min{ii}}
system redundancy insystem redundancy in ee--pp stagestage ααuu / / αα11
typical combination for design actions on nontypical combination for design actions on non--dissipativedissipativemembers: Emembers: Edd == EEd,Gd,G ++ 1.11.1γγovov EEd,Ed,E
strength limit for the dissipative zones:strength limit for the dissipative zones: ffy,maxy,max ≤≤ 1.11.1γγovovffyy
Major drawback: the actual ultimate strength of the Major drawback: the actual ultimate strength of the structure is not known if only linear elastic analysis is structure is not known if only linear elastic analysis is performed performed
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 9/44
99Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Evolution of capacity designEvolution of capacity design
philosophyphilosophy
Structural fuse conceptStructural fuse concept
DamageDamage--tolerant structures (Prof. A. Wada)tolerant structures (Prof. A. Wada)PerformancePerformance--based design with:based design with:
-- Explicit performance objectives for at least twoExplicit performance objectives for at least two
seismic intensity levelsseismic intensity levels-- Direct comparison of seismic demands vs.Direct comparison of seismic demands vs.
capacities via nonlinear analysescapacities via nonlinear analyses
-- Damage limitation not only to structure, butDamage limitation not only to structure, butalso to nonstructural components andalso to nonstructural components andequipmentequipment
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 10/44
1010Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Structural fuse concept (SFC)Structural fuse concept (SFC)SFC uses the idea of protecting the electric circuits bySFC uses the idea of protecting the electric circuits byinserting fusesinserting fuses -- sacrificeablesacrificeable and replaceable (relativeand replaceable (relative
cheap) components that limit the damage in extremecheap) components that limit the damage in extremesituations.Thesituations.The fuses are thefuses are the weakestweakest links of the system;links of the system;
Structural fuses have the following functions:Structural fuses have the following functions:
-- dissipate a major part of seismic input energydissipate a major part of seismic input energy
-- keep primary structure deformations in elastic rangekeep primary structure deformations in elastic range-- provide a predictable response of the systemprovide a predictable response of the system
First implementation: the EBFFirst implementation: the EBF--systemsystem
Further developments:Further developments:
BucklingBuckling--restrained braces (BRB)restrained braces (BRB)Rocking systemsRocking systems
Passive energy dissipation systemsPassive energy dissipation systems
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 11/44
1111Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
EBF link elementsEBF link elements
Plastic link rotation angle (demand) : γp = (L/e) θp
The eccentric brace configuration “amplifies” theThe eccentric brace configuration “amplifies” the interstoreyinterstorey drift:drift:
e.g. for e = 0.2Le.g. for e = 0.2L
γp = 5 θp
“Short” links (e ≤1.6M pl / V pl ) preferred: θp,c = 0.08 Rad (capacity)
Closely spaced web stiffeners to suppress the web shear buckling
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 12/44
1212Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
BucklingBuckling--restrained braces (BRB)restrained braces (BRB)Also known as “Also known as “UnbondedUnbonded brace”brace”
Symmetrical response in tension and compressionSymmetrical response in tension and compressiondue to avoided bucklingdue to avoided buckling
Enhanced energy dissipating capacityEnhanced energy dissipating capacity
Capacity design approach compulsory due to braceCapacity design approach compulsory due to brace
overstrengthoverstrength (strain hardening)(strain hardening)
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 13/44
1313Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Rocking systems (fuses at base)Rocking systems (fuses at base)
(Image from Matt Eatherton et. al paper)
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 14/44
1414Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Passive energy dissipation systemsPassive energy dissipation systems
Source:Source: Soong Soong , T.T. and G.F., T.T. and G.F. Dargush Dargush . Passive Energy Dissipation . Passive Energy Dissipation Systems in Structural Engineering. J. Wiley & Sons, 1997.Systems in Structural Engineering. J. Wiley & Sons, 1997.
STRUCTURAL
PROTECTIVE
SYSTEMS
PASSIVE ENERGY
DISSIPATION
SYSTEMS
SEMI-ACTIVE
AND ACTIVE
CONTROL
SEISMIC
(BASE)
ISOLATION
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 15/44
1515Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Energy balanceand seismic energy dissipation
Seismic input energy E i = E k + E s + E ξ + E h
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 16/44
1616Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Comparison in terms of energyComparison in terms of energy
dissipationdissipationThe structures differ in the way they “manage” andThe structures differ in the way they “manage” and”distribute” the total seismic input energy”distribute” the total seismic input energy E E
i i
Conventional structuresConventional structures::
energy dissipation through cyclic plastic deformationenergy dissipation through cyclic plastic deformation
ductile response means damage and lossesductile response means damage and lossescodecode--based design does not explicitly evaluatebased design does not explicitly evaluate E E h h / / E E
i i
the structure may remain vulnerable to aftershocksthe structure may remain vulnerable to aftershocks
Structures with damping systems:Structures with damping systems:energy dissipation performed byenergy dissipation performed by ““specialized partsspecialized parts””
primary structure/frame has mainly gravity loadprimary structure/frame has mainly gravity loadsupporting function and resupporting function and re--centering functioncentering function
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 17/44
1717Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Passive energy dissipation systemsPassive energy dissipation systems
Classification of FEMA 450(Chapter 15: Structures with damping systems)
The damping system (DS) may be external or internal to the structure and may have no shared elements, some shared elements, or all elements in common with the seismic-force-resisting system (SFRS).
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 18/44
1818Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Basic types of damper devicesBasic types of damper devices
1. Displacement-dependent
devices (metallic dampers,friction dampers)
2. Velocity-dependent devices(fluid viscous dampers, solid
visco-elastic dampers, etc.)
3. Other types (shape-memoryalloys, self-centering
devices, etc.)
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 19/44
1919Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Example: TADAS steel damperExample: TADAS steel damper
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 20/44
2020Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Arrangement of TADAS deviceArrangement of TADAS device
Arrangement is identical to that of a vertical link elementin the EBF-system
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 21/44
2121Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Expected benefitsExpected benefitsAdded damping (viscous dampers)Added damping (viscous dampers)
Added stiffness and damping (Added stiffness and damping (viscovisco--elastic, metallic, frictionelastic, metallic, frictiondampers)dampers)
As a result, enhanced control of theAs a result, enhanced control of the interstoreyinterstorey driftsdriftsThe capacity design is not abandoned, but the sources ofThe capacity design is not abandoned, but the sources ofoverstrengthoverstrength in the dissipative zones (dampers) are essentiallyin the dissipative zones (dampers) are essentiallyreducedreduced
Seismic response is much more predictable than in conventionalSeismic response is much more predictable than in conventional
structuresstructures------------------------------------------------------------------------------------
In new structures:In new structures:
Enhanced performance (reduced damage)Enhanced performance (reduced damage)
Less stringent detailing for ductilityLess stringent detailing for ductility
In existing structures:In existing structures:
Alternative solution to new shear walls (speedAlternative solution to new shear walls (speed--up retrofit works)up retrofit works)
Correction of irregularitiesCorrection of irregularities
SupressionSupression ofof torsionaltorsional responseresponse
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 22/44
2222Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Friction dampersFriction dampers
Images provided by Damptech A/S., Denmark(www.damptech.com)
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 23/44
2323Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Advantages of metallic and frictionAdvantages of metallic and friction
damper devicesdamper devices
Relatively cheapRelatively cheap
Easy maintenanceEasy maintenance
DurabilityDurability
WellWell--defined and predictable response, sodefined and predictable response, so
that the supporting members can be safelythat the supporting members can be safely
designed according to the capacity designdesigned according to the capacity design
rulesrules
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 24/44
2424Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Drawbacks of metallic and frictionDrawbacks of metallic and friction
damper devicesdamper devices
Nonlinear response which complicates the analysis
Relatively stiff and thus not very efficient in weakquakes
Relatively small number of working cycles and potentiallow-cycle fatigue problems (metallic dampers)
Possible variation of the coefficient of friction with time
and degradation of contact surfaces (friction dampers)
Reaction to static displacements due to temperatureeffects and long-term deformations (shrinkage, creep)
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 25/44
2525Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Parameters governing the seismicParameters governing the seismic
responseresponse
U s U
F s
F
O
K t 1
1
K t
K p
1K f
1K bd
t ss K U F strengthYield =bd f t K K K += f p K K =
f bd K K SR =lock d M F F strengthdamper Normalized ==η
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 26/44
2626Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Basic performance indicators:Basic performance indicators:
(a) Response displacements(a) Response displacementsDisplacement reduction, Rd
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
Normalized damper strength
R d
El Centro
Taft EW
Cekmece
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 27/44
2727Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Basic performance indicators:Basic performance indicators:
(b) Response base shear(b) Response base shearBase shear reduction, Rf
0
0.5
1
1.5
2
2.5
3
0 0.2 0.4 0.6 0.8 1
Normalized damper strength
R
f El Centro
Taft EW
Cekmece
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 28/44
2828Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Basic performance indicators:Basic performance indicators:
(c) Energy dissipation capacity(c) Energy dissipation capacityEnergy reduction index, Re
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
Normalized damper strength
R e
El Centro
Taft EW
Cekmece
Re = (Ei – Eh) / Ei = part of total input energy
not dissipated by the damper
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 29/44
2929Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Influence of brace stiffnessInfluence of brace stiffness
Rd for Cekmece NS, PGA=0.35g
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
Normalized damper strength
R d Kbd
2*Kbd
Rf for Cekmece NS, PGA=0.35g
0
0.5
1
1.5
2
2.5
3
3.5
0 0.2 0.4 0.6 0.8 1
Normalized damper strength
R f Kbd
2*Kbd
As a general rule, the increase of brace stiffness
improves the performance of the damping system
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 30/44
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 31/44
3131Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Performance of singlePerformance of single--storey frictionstorey friction--
damped frame (PGA=0.35g)damped frame (PGA=0.35g)Seismic performance index, SPI = f(Rd, Rf, Re)
0
0.5
1
1.5
2
2.5
3
0 0.2 0.4 0.6 0.8 1
Normalized damper strength
S P I
El Centro
Taft EW
Cekmece
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 32/44
3232Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Shake table testing of frictionShake table testing of friction--dampeddamped
frame in NCREE, Taiwan (2001)frame in NCREE, Taiwan (2001)
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 33/44
3333Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Experimental resultsExperimental resultsInterstoreyInterstorey drift comparison for El Centro 0.30g testdrift comparison for El Centro 0.30g test
71.114.350.1Third
76.119.079.2Second
78.417.480.4First
With FDDsW/O FDDs
Reduction (%)Interstorey drifts (mm)
Storey
71.114.350.1Third
76.119.079.2Second
78.417.480.4First
With FDDsW/O FDDs
Reduction (%)Interstorey drifts (mm)
Storey
After all the 14 tests (After all the 14 tests (PGA=0.05g to 0.30g)PGA=0.05g to 0.30g) no damage occurredno damage occurred
to the dampers, bracing bars, frame members and connectionsto the dampers, bracing bars, frame members and connections
The fullThe full--scale testing at NCREE proved the excellent capacity ofscale testing at NCREE proved the excellent capacity of
the proposed damping system to significantly reduce earthquakethe proposed damping system to significantly reduce earthquake--
induced building vibrationsinduced building vibrations
The seismic performance can be predicted reasonably well byThe seismic performance can be predicted reasonably well by
nonnon--linear time history analysis with DRAINlinear time history analysis with DRAIN--2DX2DX and SAP2000and SAP2000
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 34/44
3434Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
DamperDamper configrationsconfigrations with singlewith single
frictional hingefrictional hinge
Typical range of slip capacity from 10 to 200 kN
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 35/44
3535Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Large capacity dampersLarge capacity dampers
Range of slip capacity: from 200 to 5000 kN
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 36/44
3636Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Possible arrangements in buildingsPossible arrangements in buildings
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 37/44
3737Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Example of applicationExample of application
Seismic protection of industrial facilitySeismic protection of industrial facility
Design PGA=0.24g, I=1.0, Soil type=B (stiff soil)Design PGA=0.24g, I=1.0, Soil type=B (stiff soil)
Seismic weight W=7800Seismic weight W=7800 kNkN
Design objective: To reduce the base shear to levelsDesign objective: To reduce the base shear to levelsbelow 1100below 1100 kNkN, for which the existing supporting RC, for which the existing supporting RC--
structure was originally designedstructure was originally designedConventional design of the steel structure as CBFConventional design of the steel structure as CBFsystem with chevron braces was inappropriate due tosystem with chevron braces was inappropriate due tohigher base shear levelhigher base shear level
Design solution: use friction dampers with slip capacityDesign solution: use friction dampers with slip capacityof 50of 50--6060 kNkN per device (total slip capacity per directionper device (total slip capacity per direction ~~600600 kNkN) to protect the foundations) to protect the foundations
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 38/44
3838Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Typical FDD arrangement in XTypical FDD arrangement in X--directiondirection
31
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 39/44
3939Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Check of the energy dissipatingCheck of the energy dissipating
capacitycapacity
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 40/44
4040Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Under construction…Under construction…
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 41/44
4141Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Potential for seismic retrofitPotential for seismic retrofit
Friction dampers in two additional stories erected
over an existing residential building in Greece
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 42/44
4242Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
The European standardThe European standardEN 15129:2009 AntiEN 15129:2009 Anti--seismic devicesseismic devices
Contents:Contents:
ForewordForeword11.. ScopeScope22.. Normative referencesNormative references33.. Terms, definitions, symbols and abbreviationsTerms, definitions, symbols and abbreviations44.. General design rulesGeneral design rules55.. Rigid connection devicesRigid connection devices66.. Displacement Dependent DevicesDisplacement Dependent Devices77.. Velocity Dependent DevicesVelocity Dependent Devices88.. IsolatorsIsolators99.. Combinations of DevicesCombinations of Devices1010.. Evaluation of conformityEvaluation of conformity
1111.. InstallationInstallation1212.. InIn--service inspectionservice inspection
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 43/44
4343Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Concluding remarksConcluding remarksThe passive energy dissipation systems are now aThe passive energy dissipation systems are now amature and reliable technology for seismic protectionmature and reliable technology for seismic protection
The metallic and friction dampers offer many advantagesThe metallic and friction dampers offer many advantagesover the conventional ductilityover the conventional ductility--based seismic designbased seismic design
The analysis and design of such displacementThe analysis and design of such displacement--
dependent damping systems require increased effortsdependent damping systems require increased effortsand time but could be really rewardingand time but could be really rewarding
Addition of new chapter toAddition of new chapter to EurocodeEurocode 8 similar to Chapter8 similar to Chapter1010 ““Base IsolationBase Isolation”” would facilitate the broaderwould facilitate the broader
application of damping systems in the earthquakeapplication of damping systems in the earthquake--proneproneEuropean countries.European countries.
8/3/2019 B_BELEV_FDS_ENG
http://slidepdf.com/reader/full/bbelevfdseng 44/44
4444Balkan seminar on seismic engineering,Balkan seminar on seismic engineering,
Sofia, 6Sofia, 6--7 October, 20117 October, 2011
Thank you for your attention !Thank you for your attention !