seismic rehabilitation of concrete buildings byyg y converting …2... · 2012-04-27 · ¾often by...
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SERIES workshopSERIES workshopRole of research infrastructures in seismic rehabilitationRole of research infrastructures in seismic rehabilitationRole of research infrastructures in seismic rehabilitationRole of research infrastructures in seismic rehabilitationIstanbul, 8Istanbul, 8--9 February 20129 February 2012
Seismic Rehabilitation of Concrete Buildings Seismic Rehabilitation of Concrete Buildings by Converting Frame Bays into RC Wallsby Converting Frame Bays into RC Wallsy g yy g y
Michael N. Fardis, Antonis Michael N. Fardis, Antonis SchetakisSchetakis, Elias , Elias StrepeliasStrepelias,, ,, ppUniversity of Patras, GreeceUniversity of Patras, Greece
Strategies for seismic retrofitStrategies for seismic retrofitStrategies for seismic retrofitStrategies for seismic retrofitBaseShear
displacement demand of retrofitted structure
BaseShear
displacement demand of retrofitted structureShear
displacement capacity of existing
t
retrofitted structure
Shear
displacement capacity of existing
t
retrofitted structure
displacement demand
components
existing displacement demand
components
existingIncrease member deformation capacity
Roof Displacement
displacement demand of existing structure
existing structure
Roof Displacement
displacement demand of existing structure
existing structure
Base displacementBase displacement
deformation capacity (eg, w/FRPs)
Roof DisplacementRoof DisplacementSheardisplacement demand
retrofitted structure
Sheardisplacement demand
retrofitted structure
Increase building global stiffness to reduce member
deformation demandexisting structureexisting structure
deformation demand
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 2
Roof DisplacementRoof Displacement
Addition of new concrete wallsAddition of new concrete wallsAddition of new concrete wallsAddition of new concrete wallsMost effective for the reduction of deformation demands in the rest of the structure & avoidance of member strengtheningrest of the structure & avoidance of member strengthening.Often by filling bay of existing frame, encapsulating its beams & columns.“Collector elements” may need to be provided for the transfer of inertia forces from floors to the new wall.
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 3
Added walls
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 4
Most serious problem of added walls: FoundationMost serious problem of added walls: Foundation(transfer of large M with low N, w/o large uplift & base rotation that (transfer of large M with low N, w/o large uplift & base rotation that
k th l f th ll)k th l f th ll)may weaken the role of the wall)may weaken the role of the wall)
Possible solutions:Large & heavy
footing, encapsulating those of neighbouringthose of neighbouring vertical elements.
Connection to other footings via strong & stiff tie-beams.
Mi il tiMicropiles or tie-downs to the soil.
Uplift of footing of new walls should be modelled in nonlinear analysis
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 5
analysis
Example of building with 2 strong walls added in the Example of building with 2 strong walls added in the t di tit di titransverse directiontransverse direction
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 6
Footings of strong walls to avoid upliftFootings of strong walls to avoid upliftFootings of strong walls to avoid upliftFootings of strong walls to avoid uplift
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 7
X ti f ll / d t il fX-section of new wall w/ detail of boundary element encapsulating the
edge of an existing cross walledge of an existing cross-wall.Note large thickness of new wall
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 8
Desirable & most economic solution for the new wallDesirable & most economic solution for the new wallDesirable & most economic solution for the new wallDesirable & most economic solution for the new wall
The flange width of the new wall is equal to the minimum width of beams or columns in the existing frame
Objective: fully monolithic behaviour of the new wall with the beams and the columns of the existing frame
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 9
Connection of new “web” to existing Connection of new “web” to existing frame for monolithic behaviourframe for monolithic behaviourframe for monolithic behaviourframe for monolithic behaviour
Dowels along the perimeter, at the wall centreline, transfer the web shear
1) Orthodox solution: Direct connection of web bars to frame via overlapping with starter bars
2) Indirect connection of web bars to the frame – dowels double as anchorageDowel depth: 8Φ in frame length in wallpp g
anchored in the frame + dowelsDowel depth: 8Φ in frame or wall
Dowel depth: 8Φ in frame, length in wall = lapping of web bars (but max distance between spliced bars violated)
or
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 10
Design shear for dimensioning the dowelsDesign shear for dimensioning the dowelsDesign shear for dimensioning the dowelsDesign shear for dimensioning the dowels
Calculate max moment of wall at the base, maxMw
1. either from the “overturning” moment of its footing, Μ0=0.5BN, the footing height and the wall “shear span” Ls=M/V ~Hw/2:
M Μ /(1+h/L )Mwo= Μ0/(1+h/Ls)2. or from the moment capacity at the base, MRwd, for the new web
reinforcement and the reinforcement of the 2 existing columns. e o ce e t a d t e e o ce e t o t e e st g co u sIf Mwo< MRwd → maxMw=Mwo, no plastic hinge develops at the base. Design shear at the wall base: Vd=maxMw/Ls.If Mwo> MRwd → maxMw=MRwd, a plastic hinge forms at the base. The design shear at the base includes the shear magnification factor for higher modes (Keinzel): Vd=√[1+0 1(qS (T )/S (T1))2] maxM /Lhigher modes (Keinzel): Vd √[1+0.1(qSe(Tc)/Se(T1))2] maxMw/Ls
• Se(T): elastic spectral value, T1: building fundamental period, • Tc: T at upper limit of the spectrum constant-acceleration range,
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 11
c pp p g ,• q: calculated from yield & ultimate wall chord rotations: q ~ θu/θy.
Dimensioning of dowels in shearDimensioning of dowels in shearDimensioning of dowels in shearDimensioning of dowels in shear
Shear resistance of one dowel (design value)( g )1. working as dowel only (solution 1)
ss
maxmaxmax,0 6.1)(
ssffA
ssFsF ydcds=≈ s: slippage, smax ~ 0.1db
2. transferring the tension resistance of web bars (diameter dbw) to the existing frame (solution 2) through tensile stress σs=fyd(dbw/db)2
4
max,0
2
max,0max 11 ⎟⎟⎠
⎞⎜⎜⎝
⎛−=⎟
⎟⎠
⎞⎜⎜⎝
⎛−=
d
bw
yd
sdd
Ff
FFσ
If slippage is large the design shear resistance of the two existing
⎠⎝⎠⎝ dydf
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 12
If slippage is large, the design shear resistance of the two existing columns is activated (and added to the total capacity of the dowels)
NonlinearNonlinear modellingmodelling of footing upliftof footing upliftNonlinear Nonlinear modellingmodelling of footing upliftof footing uplift
nonlinear springs connecting the soil to the foundation
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 13
Nonlinear spring constitutive lawNonlinear spring constitutive lawNonlinear spring constitutive lawNonlinear spring constitutive law
End moving downwards (δ2>0) End moving upwards (δ1>0)
2d θ ⎛ ⎞
50
100
FB⎛ ⎞⎜ ⎟⎛ ⎞0
22 0
2 2KdF FBd B M
θδ
⎛ ⎞= −⎜ ⎟
⎝ ⎠
50
0 0 01
0
ln 22 2
B M FBFB MM
θδ⎜ ⎟⎛ ⎞⎜ ⎟= + −⎜ ⎟⎜ ⎟⎝ ⎠−⎜ ⎟⎝ ⎠2
⎛ ⎞
-100
-50
F(kN
) 0M⎝ ⎠2
002
22
FBMKdF
FBd Bθ
δ
⎛ ⎞−⎜ ⎟
⎝ ⎠=02 1 ln 2B FBθδ
⎛ ⎞⎛ ⎞= − −⎜ ⎟⎜ ⎟⎜ ⎟
02
2 2KdF FBd B M
θδ
⎛ ⎞= −⎜ ⎟
⎝ ⎠200
-150
21
0
FBd BM
δ202 M⎜ ⎟⎜ ⎟⎜ ⎟⎝ ⎠⎝ ⎠
02
2 2KdF FBd B M
θδ
⎛ ⎞= −⎜ ⎟
⎝ ⎠2
2 0d B Mδ ⎜ ⎟⎝ ⎠
-0 01 -0 008 -0 006 -0 004 -0 002 0 0 002 0 004 0 006 0 008 0 01-250
-200 22 0d B Mδ ⎜ ⎟
⎝ ⎠θ0=Μ0/Κθ00 0.25Μ ≈ ΒΝ
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 14
0.01 0.008 0.006 0.004 0.002 0 0.002 0.004 0.006 0.008 0.01Μετατόπιση (m)Displacement (m)
Application to prototype building of 4 frames, converting Application to prototype building of 4 frames, converting the central bay of exterior frames into walls ( SERFIN)the central bay of exterior frames into walls ( SERFIN)the central bay of exterior frames into walls (~SERFIN)the central bay of exterior frames into walls (~SERFIN)
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 15
Nonlinear static analysis with fixed or uplifting footingsNonlinear static analysis with fixed or uplifting footingsNonlinear static analysis with fixed or uplifting footingsNonlinear static analysis with fixed or uplifting footingsEnd moving
upwardsWall fixed upwards
Wall uplifting
Μ-θ diagram of wall at the base
End moving downwards
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 16
End moving downwards
Nonlinear static analysis with fixed or uplifting footings (Nonlinear static analysis with fixed or uplifting footings (1.51.5xx1.51.5xx0.80.8mmnder col mnsnder col mns 1 51 5 44 00 0 80 8mm nder allsnder alls / or /o/ or /o 0 250 25 0 60 6m tiem tie beam)beam)under columnsunder columns, 1.5, 1.5x4x4..0x0x0.80.8mm under wallsunder walls,, w/ or w/o w/ or w/o 0.250.25xx0.60.6m tiem tie--beam)beam)
Green circle: “Damage :imitation” per EC8-3Yellow circle: “Significant damage” per ΕC8-3
2500
Yellow circle: Significant damage per ΕC8 3Red circle: “Near Collapse” in bending per EC8-3Purple square: “Near Collapse” in shear per EC8-3
2000Δ-0 22g
Δ-0.28gΔ-0.3gK16-0.32gΔ-0.34g
ΠακτωμένοΜε αποκόλληση-με συνδετήρια δοκάριαΜε αποκόλληση-χωρίς συνδετήρια δοκάρια
FixedUplift – w/ tie-beamsUplift – w/o tie-beams
1500
σης
(kN
)
T1&T2-0.15gT1&T2-0.15g
T1-0.19gΔ-0.22g
K16-0.22g
Κ16-0.22gΔ-0.26g
Δ-0.32g
ear (
kN)
1000
Τέμνουσα
Βάσ
Δ-0.09g Δ-0.09gΔ-0.09gBas
e sh
500
Τ
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 170 0.05 0.1 0.15
0
Μετατόπιση (m)
Displacement (m)
Flexural Flexural damage index for Significant Damage damage index for Significant Damage -- Nonlinear dynamic Nonlinear dynamic l i 0 25l i 0 25 fi dfi d f tif ti (( 1414 dd ))analysis, 0.25g analysis, 0.25g -- fixed fixed footingsfootings ((averageaverage over over 14 14 recordsrecords))
Beams
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 18
Vert. elements
FlexuralFlexural damage index for Significant Damage damage index for Significant Damage -- Nonlinear dynamic Nonlinear dynamic l il i liftilifti f tif ti / ti/ ti bb (( // 1414 dd 0 25 )0 25 )analysis, analysis, upliftinguplifting footings footings w/ tiew/ tie--beamsbeams ((av/geav/ge over over 14 14 records, records, 0.25g)0.25g)
Beams
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 19Vert. elements
FlexuralFlexural damage index for Significant Damage damage index for Significant Damage -- Nonlinear dynamic Nonlinear dynamic l il i liftilifti f tif ti titi bb (( // 1414 dd 0 25 )0 25 )analysis, analysis, upliftinguplifting footings, footings, no tieno tie--beamsbeams ((av/geav/ge over over 14 14 records, records, 0.25g)0.25g)
Beams
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 20Vert. elements
ShearShear damage index for Significant Damage damage index for Significant Damage -- Nonlinear dynamic Nonlinear dynamic l il i fi dfi d f tif ti (( // 1414 dd 0 25 )0 25 )analysis, analysis, fixedfixed footingsfootings ((av/geav/ge over over 14 14 records, records, 0.25g)0.25g)
Beams
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 21
Vert. elements
Shear Shear damage index for Significant Damage damage index for Significant Damage -- Nonlinear dynamic Nonlinear dynamic l il i liftilifti f tif ti / ti/ ti bb (( // 1414 dd 0 25 )0 25 )analysis, analysis, upliftinguplifting footings footings w/ tiew/ tie--beamsbeams ((av/geav/ge over over 14 14 records, records, 0.25g)0.25g)
Beams
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 22Vert. elements
ShearShear damage index for Significant Damage, nonlinear dynamic analysis,damage index for Significant Damage, nonlinear dynamic analysis,liftilifti f tif ti titi bb (( // 1414 dd 0 25 )0 25 )upliftinguplifting footings, footings, no tieno tie--beamsbeams ((av/geav/ge over over 14 14 records, records, 0.25g)0.25g)
Beams
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 23
Vert. elements
Conclusions from analysisConclusions from analysiswith fixed or uplifting footings with or w/o tiewith fixed or uplifting footings with or w/o tie beamsbeamswith fixed or uplifting footings, with or w/o tiewith fixed or uplifting footings, with or w/o tie--beamsbeams
Rocking of the foundation is beneficial for the walls, but increases the demand on columns, particularly at the base
Damage index values are smaller at the base of the walls without tie-beams
Columns: the maximum damage index values are at the base of the exterior columns in building with tie-beams or at the interior frames in building without tie-beams
Uplifting does not have a major effect on beams.
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 24
Seismic assessment and retrofitSeismic assessment and retrofitof 2 real irregular buildingsof 2 real irregular buildingsof 2 real irregular buildingsof 2 real irregular buildings
2-storey buildingith i li d fwith inclined roofs
7-storey buildingith 2 t b k
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 25
with 2 set-backs
77--storey buildingstorey building
2nd setback
Foundation planFoundation plan
1st - 5th storey plan
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 26
Pushover analysis, asPushover analysis, as--built, built, ±±Χ, Χ, ±±ΥΥ, fixed v uplifting footings, fixed v uplifting footingsFixedUplift
FixedUplift
ar (k
N)
Uplift UpliftB
ase
she
Displacement (m) Displacement (m)Green: Damage Limitation per EC8–3 Yellow: Significant Damage per EC ΕK8–3Red: Near Collapse in bending Purple: Near collapse in shear
p ( ) p ( )
FixedU lift
FixedU lift
ear (
kN)
Uplift Uplift
Bas
e sh
e
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 27Displacement (m) Displacement (m)
Shear & flexural damage index of vertical elements Shear & flexural damage index of vertical elements -- asas--built building for built building for Significant Damage nonlinear dynamic analysis (av/ge over 14 records 0 25gSignificant Damage nonlinear dynamic analysis (av/ge over 14 records 0 25g
FlexureFlexureShearShear
Significant Damage, nonlinear dynamic analysis (av/ge over 14 records 0.25gSignificant Damage, nonlinear dynamic analysis (av/ge over 14 records 0.25g
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 28
Seismic retrofit of 7Seismic retrofit of 7 storey building with new wallsstorey building with new wallsSeismic retrofit of 7Seismic retrofit of 7--storey building with new wallsstorey building with new walls
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 29
Foundation of new wallsFoundation of new wallsFoundation of new wallsFoundation of new walls
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 30
Static eccentricity between C M and C SStatic eccentricity between C M and C S
RetrofittedRetrofittedAsAs--builtbuilt
Static eccentricity between C.M. and C.S.Static eccentricity between C.M. and C.S.
No improvement (the contrary).But, although as-built building is torsionally flexible (torsional
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 31
mode T > 1st translational mode T), the retrofitted one is not !
3000Αρχικό Πακτωμένο
2000
Pushover analysis, as built v retrofitted, Pushover analysis, as built v retrofitted, ±±Χ, Χ, ±±Υ, fixed v uplifting footingsΥ, fixed v uplifting footingsPGA at 1st exceedance of Limit State in PGA at 1st exceedance of Limit State in vertical elementsvertical elements
A b ilt fi d
2000
2500
(kN
)
Y-0.26g
Y-0.34g
Y 0 29Y-0.36g
Αρχικό ΠακτωμένοΑρχικό με ΑποκόλλησηΕνισχυμένο ΠακτωμένοΕνισχυμένο με Αποκόλληση
1200
1400
1600
1800(k
N)
Y-0.28gY 0 28
Y-0.14g
Y-0.16g
Y-0.23g
Y-0.31g
Y-0.14g
Y-0.22g
Y-0.3g
Y-0.38gkN
)As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
1000
1500
Τέμνουσα
Βάσης
Y-0.16g
Y-0.23g
Y-0.31g
Y-0.17gY-0.21g
Y-0.24gY-0.28g
Y-0.17gY-0.17g Y-0.21g
Y-0.22gY-0.29g
600
800
1000
1200
Τέμνουσα
Βάσης
Y-0.09g
Y-0.13g
Y-0.2gY-0.2g
Y-0.22gY-0.24g
Y-0.28g
Bas
e sh
ear(
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.450
500
Μετατόπιση (m)
Y-0.09g
-0.4 -0.35 -0.3 -0.25 -0.2 -0.15 -0.1 -0.05 00
200
400
Μετατόπιση (m)
Αρχικό ΠακτωμένοΑρχικό με ΑποκόλλησηΕνισχυμένο ΠακτωμένοΕνισχυμένο με Αποκόλληση
Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Displacement (m)
4000
4500
Y-0.5g4000
4500
Y-0.37g
η ( )Μετατόπιση (m)
Green: Damage Limitation per EC8-3 Yellow: Significant Damage per EC8-3Red: Near Collapse in bending Purple: Near collapse in shear
Displacement (m)
2500
3000
3500
σης
(kN
)
Y-0.19g
Y-0 27gY-0 15g
Y-0.22g
Y-0.26g
Y-0.35g
Y-0.19g
Y-0.36g
g
2500
3000
3500
σης
(kN
)
Y-0.21g
Y-0.26gY-0.31g
Y-0.27gY-0.32g
Y-0.29g
Y-0.35gY-0.39g
ar(k
N)
1000
1500
2000
2500Τέμνουσα
Βάσ
Y-0.07g
Y-0.13gY-0.17g
Y-0.23gY 0.27gY 0.15g
Y-0.16g
1000
1500
2000
2500
Τέμνουσα
Βάσ
Y-0.08g
Y-0.16g
Y-0.18g
g
Y-0.14gY-0.13g
Bas
e sh
ea
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 320 0.05 0.1 0.15 0.2 0.25 0.30
500
1000
Μετατόπιση (m)
Y-0.04g Y-0.04gΑρχικό ΠακτωμένοΑρχικό με ΑποκόλλησηΕνισχυμένο ΠακτωμένοΕνισχυμένο με Αποκόλλ
-0.35 -0.3 -0.25 -0.2 -0.15 -0.1 -0.05 00
500
1000
Μετατόπιση (m)
Y-0.04Y-0.05gΑρχικό ΠακτωμένοΑρχικό με ΑποκόλλησηΕνισχυμένο ΠακτωμένοΕνισχυμένο με Αποκόλληση
Displacement (m)Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Pushover analysis, as built v retrofitted, Pushover analysis, as built v retrofitted, ±±Χ, Χ, ±±Υ, fixed v uplifting footingsΥ, fixed v uplifting footingsPGA at 1st exceedance of Limit State in PGA at 1st exceedance of Limit State in beamsbeams
kN)
Bas
e sh
ear(
Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Green: Damage Limitation per EC8-3 Yellow: Significant Damage per EC8-3Red: Near Collapse in bending Purple: Near collapse in shear
Displacement (m) p ( )
ar(k
N)
Bas
e sh
ea
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 33Displacement (m)Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Shear & flexural DI of Shear & flexural DI of vertical elementsvertical elements in retrofitted building for Significant in retrofitted building for Significant D li d i l i (D li d i l i (fi dfi d f ti / 14 d 0 25 )f ti / 14 d 0 25 )
ShearShear FlexureFlexureDamage, nonlinear dynamic analysis (Damage, nonlinear dynamic analysis (fixed fixed footings, av/ge over 14 records 0.25g)footings, av/ge over 14 records 0.25g)
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 34
Shear & flexural DI of Shear & flexural DI of vertical elementsvertical elements in retrofitted building, Significant Damage, in retrofitted building, Significant Damage, li d i l i (li d i l i ( liftilifti f ti / 14 d 0 25 )f ti / 14 d 0 25 )
ShearShearnonlinear dynamic analysis (nonlinear dynamic analysis (upliftinguplifting footings, av/ge over 14 records 0.25g)footings, av/ge over 14 records 0.25g)
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 35Flexure Flexure -- Significant DamageSignificant Damage
Flexural DI in Flexural DI in beamsbeams of retrofitted building for Significant Damage, nonlinear of retrofitted building for Significant Damage, nonlinear d i l i (fi d lif i f i / 14 d 0 2 )d i l i (fi d lif i f i / 14 d 0 2 )dynamic analysis (fixed v uplifting footings, av/ge over 14 records, 0.25g)dynamic analysis (fixed v uplifting footings, av/ge over 14 records, 0.25g)
Fi dFi dSERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 36
UpliftUpliftFixedFixed
Conclusions from retrofitted 7Conclusions from retrofitted 7--storey buildingstorey buildingwith fixed or uplifting footingswith fixed or uplifting footings
Fixed footingsNew walls ΤΝ2 ΤΝ3 the elevator wall & some columns of the
with fixed or uplifting footingswith fixed or uplifting footings
New walls ΤΝ2, ΤΝ3, the elevator wall & some columns of the setbacks, don’t meet the flexure limit at Significant Damage LS.New wall ΤΝ1 fails in shear.More damage in beams compared to the as-built building.
Uplifting footingsUplifting footingsAlthough column DI-values increase, “Significant Damage” LS is met, except for few columns at the setbacks.met, except for few columns at the setbacks.Wall DI-values drop < 1.0, except for elevator shaft wall (DI=1.08)Elevator wall & few columns of top floor ~fail to meet shear LS.pFlexural damage in beams increases significantly.
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 37
In both cases CFRPs are added to fix the local shortfalls
Cost of retrofitting 7Cost of retrofitting 7 storey building forstorey building for fixedfixed footingsfootingsCost of retrofitting 7Cost of retrofitting 7--storey building for storey building for fixedfixed footingsfootingsCost of added walls:
3
Wall Starter bars plus dowels Dowels doubling as starter barsΤΝ1 13600 € 9300 €
@ 90€ /m3 concrete@ 1€ /kg steelepoxy grouting: @ 9€/Φ20mm dowel
@ 7€/Φ12mm dowel
ΤΝ2 12700 € 8400 €
ΤΝ3 26200 € 19500 €
Total 52500 € 37200 €@ 7€/Φ12mm dowel
Cost of adding CFRPs: @ 40€/m2 CFRP ply
Total 52500 € 37200 €
Cost of adding CFRPs: @ 40€/m CFRP plyVertical element Story DI to be made <1.0 required v provided CFRP Cost €
Column 156 7th - base 1.18 0.08mm → 1 ply 0.12mm 20
Column 157 7th - base 1.29 0.14mm → 2 plies 0.24mm 40
Column 157 7th - top 1.57 0.24mm → 2 plies 0.24mm 40
C l 132 6th b 1 13 0 73 6 li 0 72 260Column 132 6th - base 1.13 0.73mm → 6 plies 0.72mm 260
Elevator wall 1st 1.40 1 ply, 150mm strips / 125mm 1150
Elevator wall 2nd 1.16 1 ply, 100mm strips / 200mm 370
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 38
Elevator wall 2 1.16 1 ply, 100mm strips / 200mm 370
Total 1880
Cost of retrofitting 7Cost of retrofitting 7--storey building forstorey building for upliftinguplifting footingsfootingsCost of retrofitting 7Cost of retrofitting 7--storey building for storey building for upliftinguplifting footingsfootingsCost of added walls the same as for fixityCost of adding CFRPs @ 40€ /m2 CFRP plyCost of adding CFRPs, @ 40€ /m2 CFRP ply
Vertical element Story DI to be made <1.0 required v provided CFRP Cost €
Column 163 7th – base 1.71 0.52mm → 4 plies 0.48mm 100 thColumn 163 6th – top 1.06 0.05mm → 1 ply 0.12mm 30
Column 161 6th – base 1.21 0.184mm → 2 plies 0.24mm 50
Column 161 7th – base 1.22 0.19mm → 2 plies 0.24mm 50Column 161 7 base 1.22 0.19mm 2 plies 0.24mm 50
Column 161 7th – top 1.26 0.22mm → 2 plies 0.24mm 50
Column 127 6th – base 1.14 0.58mm → 5 plies 0.60mm 200
Column 154 7th – base 1.70 0.51mm → 4 plies 0.48mm 200
Column 154 6th – top 1.40 0.33mm → 3 plies 0.36mm 80
C l 157 7th b 1 54 0 24 2 li 0 24 40Column 157 7th – base 1.54 0.24mm → 2 plies 0.24mm 40
Elevator wall 1st 1.15 1 ply, 100mm strips / 200mm 500
Elevator wall 2nd 1.10 1 ply, 100mm strips / 300mm 250
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 39
p y, p
Total 1550
22 storey buildingstorey building22--storey buildingstorey building
2nd storey
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 40
11stst storey slabstorey slab C M and C SC M and C S11stst--storey slab storey slab –– C.M. and C.S.C.M. and C.S.Torsionally flexible: T i l d T > T f 1stTorsional mode T > T of 1st
translational mode in both directions
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 41
5000Πακτωμένο
6000Πακτωμένο
Pushover analysis of asPushover analysis of as--built building, built building, ±±Χ, Χ, ±±ΥΥ, fixed v uplifting footings, fixed v uplifting footingsFixed Fixed
3000
3500
4000
4500
ης (k
N)
Δ-0.28gY-0.35g
Δ-0.49g
Δ-0.63g
Y-0.51gΔ-0.6g
Y-0.71g
ΠακτωμένοΜε αποκόλληση
4000
5000
ης (k
N)
Y 0 26gΔ-0.34g
Δ-0.58gΔ-0.72g
Δ-0.7gY-0.73g
ΠακτωμένοΜε αποκόλληση
kN)
FixedUplift
FixedUplift
1500
2000
2500
3000
Τέμνουσα
Βάσ
η
Δ-0.11g
Y-0.13g
Y-0.16g
Y-0.24gg
Δ-0.1g
Y-0.22gΔ-0.26g
Y-0.36gΔ-0.47g
Y 0.51g
2000
3000
Τέμνουσα
Βάση
Δ-0.1gY-0.12g
Y-0.21gY-0.26g
Y-0.18gY-0.26g
Δ-0.33g
Y-0.51gΔ-0.57g
Y 0.73g
Bas
e sh
ear(
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.090
500
1000
Μ ό ( )
Τ
-0.12 -0.1 -0.08 -0.06 -0.04 -0.02 00
1000
ό ( )
Τ
gΔ-0.09g
Displacement (m) Displacement (m)Μετατόπιση (m)Μετατόπιση (m)Green: Damage Limitation per EC8-3 Yellow: Significant Damage per EC8-3Red: Near Collapse in bending Purple: Near collapse in shear
Displacement (m) Displacement (m)
Fixed FixedU lif
ar(k
N)
Uplift Uplift
Bas
e sh
ea
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 42Displacement (m)Displacement (m)
Shear & flexural damage index in asShear & flexural damage index in as--built building, Significant Damage, built building, Significant Damage, li d i l i (fi d f ti / 14 d 0 25 )li d i l i (fi d f ti / 14 d 0 25 )nonlinear dynamic analysis (fixed footings, av/ge over 14 records 0.25g)nonlinear dynamic analysis (fixed footings, av/ge over 14 records 0.25g)
Flexure Flexure -- Significant DamageSignificant DamageShearShearShearShear
ShearShear
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 43
Seismic retrofit with wallsSeismic retrofit with walls C M v C SC M v C SSeismic retrofit with walls Seismic retrofit with walls -- C.M. v C.S.C.M. v C.S.
Only @ ground storey
Remains torsionally flexible(torsional mode T > 1st translational
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 44
(mode T in one direction)
Pushover analysis of asPushover analysis of as--built building built building ±±Χ, Χ, ±±ΥΥ, fixed v uplifting footings, , fixed v uplifting footings, PGA at 1PGA at 1stst exceedanceexceedance of LS in of LS in vertical elementsvertical elements
A b ilt fi dkN
)As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Bas
e sh
ear(
Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Displacement (m)Green: Damage Limitation per EC8-3 Yellow: Significant Damage per EC8-3Red: Near Collapse in bending Purple: Near collapse in shear
Displacement (m) Displacement (m)
As-built, fixedAs-built, uplift
ar(k
N)
Retrofitted, fixedRetrofitted, uplift
Bas
e sh
ea
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 45Displacement (m)Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Pushover analysis Pushover analysis ±±Χ, Χ, ±±ΥΥ, fixed v uplifting footings,, fixed v uplifting footings,PGA at 1PGA at 1stst exceedance of Limit State in exceedance of Limit State in beamsbeams
kN)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Bas
e sh
ear(
Displacement (m)
As-built, fixedAs-built, upliftRetrofitted, fixedRetrofitted, uplift
Displacement (m)Green: Damage Limitation per EC8-3 Yellow: Significant Damage per EC8-3Red: Near Collapse in bending Purple: Near collapse in shear
Displacement (m) Displacement (m)
As-built, fixedAs built uplift
As-built, fixedAs built uplift
ar(k
N)
As-built, upliftRetrofitted, fixedRetrofitted, uplift
As-built, upliftRetrofitted, fixedRetrofitted, uplift
Bas
e sh
ea
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 46Displacement (m)Displacement (m)
Shear & flexural damage index in retrofitted building for Significant Damage, Shear & flexural damage index in retrofitted building for Significant Damage, li d i l i (fi d f ti / 14 d 0 25 )li d i l i (fi d f ti / 14 d 0 25 )nonlinear dynamic analysis (fixed footings, av/ge over 14 records, 0.25g)nonlinear dynamic analysis (fixed footings, av/ge over 14 records, 0.25g)
Flexure Flexure -- Significant DamageSignificant Damage
ShearShear
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 47
Conclusions from retrofitted 2Conclusions from retrofitted 2--storey buildingstorey buildingwith fixed or uplifting footingswith fixed or uplifting footings
Flexural damage indices at column bases are reduced compared to as built but the “Significant Damage” Limit State
with fixed or uplifting footingswith fixed or uplifting footings
compared to as-built, but the “Significant Damage” Limit State still not met.
Adding new walls does not prevent failure of the interior large wall.
Flexural damage indices in beams increase compared to the as-built
R t fit ith ll t th i t i i ffi i tRetrofit with new walls at the perimeter is insufficient. Additional retrofit of other members w/ FRP jackets is necessary; it turns out to be very cost-effective
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 48
necessary; it turns out to be very cost effective.
Cost of retrofitting 2Cost of retrofitting 2--storey building storey building (considered with uplifting footings)(considered with uplifting footings)(considered with uplifting footings)(considered with uplifting footings)
Wall Starter bars plus dowels Dowels doubling as starter bars ΤΝ1 6730 € 4550 €
Cost of added walls:@ 90€ / 3 t ΤΝ2 2470 € 2230 €
ΤΝ3 1720 € 1640 €
ΤΝ4 1230 € 1230 €
@ 90€ /m3 concrete@ 1€ /kg steelepoxy grouting @ 9€/Φ20mm dowel
@ 7€/Φ12mm dowelTotal 12150 € 9650 €
@ 7€/Φ12mm dowel
Cost of addingCFRP
Vertical element Story DI to be made <1.0 required v provided CFRP Cost €
Column 7 1st - base 1.11 0.184mm → 2 plies 0.24mm 60 CFRPs:@ 40€ /m2 CFRP ply
p
Column 7 2nd - base 1.23 0.364mm → 3 plies 0.36mm 90
Column 17 1st - base 1.01 0.005mm → 1 ply 0.12mm 25
Column 11 1st - base 1.04 0.02mm → 1 ply 0.12mm 25
Column 9 1st - base 1.03 0.016mm → 1 ply 0.12mm 25
Column 39 1st base 1 04 0 02mm → 1 ply 0 12mm 25Column 39 1 - base 1.04 0.02mm → 1 ply 0.12mm 25
central wall 1st - base 1.49 1 ply, 100mm strips / 125mm 2200
central wall 2nd - base 1.09 1 ply, 50mm strips / 250mm 400
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 49
Total 2850
Thank you !Thank you !Thank you !Thank you !
SERIES workshop “Role of research infrastructures in seismic rehabilitation”, Istanbul, 8-9 February 2012 50