Combination of Dynamic in-situ Measurements on … ppt/keynote ppt... · Combination of Dynamic in-situ Measurements on Structures with Calculations-the Significance for Assessment

Combination of Dynamic in-situMeasurements on Structures with

Calculations-the Significance for Assessment of the

Earthquake Resistance

Prof. Dr. Rainer Flesch | Senior Scientist | AIT - Mobility Department | Transportation Infrastructure Technologies1

5CNIS & 1CNISSBucharest, Romania, June 19-20, 2014

Univ.- Prof. Dipl.- Ing. Dr. techn. Rainer FLESCHGraz University of Technology (TU Graz)

&Austrian Institute of Technology GmbH (AIT), Wien

Combination of Dynamic in-situMeasurements on Structures with

Calculations-the Significance for Assessment of the

Earthquake Resistance

List of Contents1. Concept2. Assessment of Dynamic Soil Behaviour3. 1999 2001: Environment & Climate Project ENV4-CT97-0574 (DG 12

EHKN): Advanced Methods for Assessing the Seismic Vulnerability ofExisting Motorway Bridges (VAB). Project ENV4-CT97-0574.

4. Assessment of Earthquake Resistance of several Hospitals in Austria5. 2005 2007: LESSLOSS Mitigation for Earthquakes and Landslides. 6th

European Framework Program. Sub project coordinator SP5: In-situAssessment of Earthquake Resistance of Important Existing Buildings.

6. Project Assessment Radioactive Waste Combuster7. 2010 2014: NERA Network of European Research Infrastructures for

Earthquake Risk Assessment and Mitigation8. Conclusions9. Literature


1. Concept2. Assessment of Dynamic Soil Behaviour3. 1999 2001: Environment & Climate Project ENV4-CT97-0574 (DG 12

EHKN): Advanced Methods for Assessing the Seismic Vulnerability ofExisting Motorway Bridges (VAB). Project ENV4-CT97-0574.

4. Assessment of Earthquake Resistance of several Hospitals in Austria5. 2005 2007: LESSLOSS Mitigation for Earthquakes and Landslides. 6th

European Framework Program. Sub project coordinator SP5: In-situAssessment of Earthquake Resistance of Important Existing Buildings.

6. Project Assessment Radioactive Waste Combuster7. 2010 2014: NERA Network of European Research Infrastructures for

Earthquake Risk Assessment and Mitigation8. Conclusions9. Literature

1. CONCEPTSteps of the assessment method:

In-situ measurements (ambient, forced excitation) existing structures dynamic behaviour of soils

Structural modeling (based on available design documents) FE models ( 1D, 2D, 3D) lumped mass models

Model updating (fitting of structural model to measured data)


Steps of the assessment method:

In-situ measurements (ambient, forced excitation) existing structures dynamic behaviour of soils

Structural modeling (based on available design documents) FE models ( 1D, 2D, 3D) lumped mass models

Model updating (fitting of structural model to measured data)

1. Concept (2)Work of AIT in the field of SDEE:

Assessment of vibration behavior/ earthquake capacity of importantexisting buildings/ structures

Health monitoring/ structural monitoring/ safety inspection:dynamic monitoring

Ultimate capacity Serviceability Maintenance (early detection of damages) Comfort/ acceptance levels

Vibration protection (especially traffic induced vibrations andstructure borne noise)

Train Simulation Interoperability checks/ serviceability checks of railway bridges


Work of AIT in the field of SDEE:

Assessment of vibration behavior/ earthquake capacity of importantexisting buildings/ structures

Health monitoring/ structural monitoring/ safety inspection:dynamic monitoring

Ultimate capacity Serviceability Maintenance (early detection of damages) Comfort/ acceptance levels

Vibration protection (especially traffic induced vibrations andstructure borne noise)

Train Simulation Interoperability checks/ serviceability checks of railway bridges

It is not possible to assess and retrofit all existing structures

Safety and Serviceability of important structures and lifelines isnecessary also during and after an earthquake

Assessment + retrofitting of safety critical structures andlifeline structures must have priority:

Buildings (importance class IV and III, EN 1998-1:2005) Bridges (importance class III, EN 1998-2:200X) Industrial facilities with secondary risks (release of toxic and/

or explosive materials) (Cultural heritage)

1. Concept (3)

Prof. Dr. Rainer Flesch | Senior Scientist | AIT - Mobility Department | Transportation Infrastructure Technologies

It is not possible to assess and retrofit all existing structures

Safety and Serviceability of important structures and lifelines isnecessary also during and after an earthquake

Assessment + retrofitting of safety critical structures andlifeline structures must have priority:

Buildings (importance class IV and III, EN 1998-1:2005) Bridges (importance class III, EN 1998-2:200X) Industrial facilities with secondary risks (release of toxic and/

or explosive materials) (Cultural heritage)

5

1. CONCEPT (4)Assessment of earthquake capacity of important existing buildings/

structures

Dynamic in-situ measurements (ambient, forced) Mathematical model (Finite Element Model, 3D) Model updating, using differences between measured and calculated

dynamic propertiesModel close to reality: linear starting pointDetection of weak points; seismic upgrading

- Force based analysis, e.g. linear iterative, considering damage(stiffness decrease) in overstressed elements

- Displacement based analysis


Assessment of earthquake capacity of important existing buildings/structures

Dynamic in-situ measurements (ambient, forced) Mathematical model (Finite Element Model, 3D) Model updating, using differences between measured and calculated

dynamic propertiesModel close to reality: linear starting pointDetection of weak points; seismic upgrading

- Force based analysis, e.g. linear iterative, considering damage(stiffness decrease) in overstressed elements

- Displacement based analysis

Pseudo-Dynamic LoadingSimulates deck motion

due to earthquake

Application for testing of bridges VT dVCBBK

3. PROJECT VAB (5): SubSub--structuringstructuring


Both are coupled through Pseudo-Dynamicnumerical model

- The remaining structure is computed- Critical parts are tested

Piers testedphysically

Deck modeledanalytically by

F.E.M.

3. PROJECT VAB (6): PsD tests with non-linear substructuring and asynchroneous

motion


4. ASSESSMENT OF HOSPITALS (5)Hospital in Innsbruck

PUBLICATIONS: [10 -12](see 9. Literature)

Prof. Dr. Rainer Flesch | Senior Scientist | AIT - Mobility Department | Transportation Infrastructure Technologies9Overload in shear (100% means available shear capacity)

5. PROJECT LESSLOSS

Research area 1Physical environment

Research area 2Urban areas

Research area 3Infrastructures

Research component 1.1

Landslide monitoring andwarning system


Landslide zonation, hazardand vulnerability

assessment


Innovative approaches forlandslide assessment


Disaster scenariospredictions and loss

modelling for landslides.

Research component 2.4a


modelling for urban areas.

Research component 2.1In-situ assessment, monitoring and typification

Research component 2.4b


modelling forinfrastructures

Buildings Bridges, Lifelines

Research component 2.2aDevelopment and manufacturing of energydissipation devices and seismic isolators

Research component 2.2bTechniques and methods for vulnerability reduction

Research component 2.3aDisplacement-based design methodologies

Research component 2.3bProbabilistic risk assessment: methods and

applications

Research activity 1Instrumentation and

monitoring .

Research activity 2Vulnerability reduction

Research activity 3Innovative approachesfor design/assessment

Research activity 4Disaster scenarios

predictions and lossmodelling

.

Buildings Bridges, Underground

Buildings Bridges, Viaducts



LESSLOSS

PUBLICATIONS: [13 -17](see 9. Literature)


Research area 1Physical environment

Research area 2Urban areas

Research area 3Infrastructures


Landslide monitoring andwarning system


Landslide zonation, hazardand vulnerability

assessment


Innovative approaches forlandslide assessment



modelling for landslides.

Research component 2.4a


modelling for urban areas.

Research component 2.1In-situ assessment, monitoring and typification

Research component 2.4b


modelling forinfrastructures


Research component 2.2aDevelopment and manufacturing of energydissipation devices and seismic isolators

Research component 2.2bTechniques and methods for vulnerability reduction

Research component 2.3aDisplacement-based design methodologies

Research component 2.3bProbabilistic risk assessment: methods and

applications

Research activity 1Instrumentation and

monitoring .

Research activity 2Vulnerability reduction

Research activity 3Innovative approachesfor design/assessment

Research activity 4Disaster scenarios

predictions and lossmodelling

.

Buildings Bridges, Underground

Buildings Bridges, Viaducts



6. Project Assessment Radioactive WasteCombuster


PUBLICATIONS: [19, 20](see 9. Literature)

Introduction Nuclear Engineering Seibersdorf GmbH (NES). RC building with an inside

radioactive waste combuster (combustion stove)

Year of construction 1978. Height 15m

Planned reconstruction: improved handling equipment for combustion stove(charging and deashing) additional masses, producing additionalearthquake loads

Reconstruction is planned for a (to some extent) safety critical facility. Henceit is necessary to assess the earthquake capacity according to the latestseismic code (EN 1998-1)


Nuclear Engineering Seibersdorf GmbH (NES). RC building with an insideradioactive waste combuster (combustion stove)

Year of construction 1978. Height 15m

Planned reconstruction: improved handling equipment for combustion stove(charging and deashing) additional masses, producing additionalearthquake loads

Reconstruction is planned for a (to some extent) safety critical facility. Henceit is necessary to assess the earthquake capacity according to the latestseismic code (EN 1998-1)

Introduction (2)

Investigations

1. Detailed modeling (first FE - model) of existing structure including a steelplatform, combustion stove and heavy equipment (additional masses)

2. Dynamic in-situ testing in order to identify the dynamic parameters, whichrepresent together with mass the actual stiffness distribution of the structure.Use of vibration generator VICTORIA of AIT; random noise excitation; use ofrod chain under 45 in order to excite the structure

3. Improvement of FE model using the measured dynamic parameters(model updating)

4. Assessment of earthquake capacity of the existing building (beforereconstruction) according to EC8

5. Estimation of earthquake capacity of the building after reconstructionaccording to EC8


Investigations

1. Detailed modeling (first FE - model) of existing structure including a steelplatform, combustion stove and heavy equipment (additional masses)

2. Dynamic in-situ testing in order to identify the dynamic parameters, whichrepresent together with mass the actual stiffness distribution of the structure.Use of vibration generator VICTORIA of AIT; random noise excitation; use ofrod chain under 45 in order to excite the structure

3. Improvement of FE model using the measured dynamic parameters(model updating)

4. Assessment of earthquake capacity of the existing building (beforereconstruction) according to EC8

5. Estimation of earthquake capacity of the building after reconstructionaccording to EC8

Vibration tests

Dynamic measurements onstructure

Connection point of exciter under45in a height of approx. 8m

42 Measuring points at five differentlevels

[Excitation Sine Sweeps (2 20 Hz)] Calculating Frequency response

function Excitation random noise (4 25 Hz)

Calculating Frequency responsefunction


Dynamic measurements onstructure

Connection point of exciter under45in a height of approx. 8m

42 Measuring points at five differentlevels

[Excitation Sine Sweeps (2 20 Hz)] Calculating Frequency response

function Excitation random noise (4 25 Hz)

Calculating Frequency responsefunction

Calculation of Response functions(Modal analysis with measured valuesfrom excitation with random noise)

Method of analysis: MDOF Frequency resolution 0.2 Hz Time window: Hanning with 30%

overlapping Identification of four Mode shapes in

frequency range of 4.6 8.6Hz

Vibration measurementson structure


Calculation of Response functions(Modal analysis with measured valuesfrom excitation with random noise)

Method of analysis: MDOF Frequency resolution 0.2 Hz Time window: Hanning with 30%

overlapping Identification of four Mode shapes in

frequency range of 4.6 8.6Hz

Mode Frequenz DmpfungHz %

1 4,6 5,12 5,6 6,63 7,5 5,64 8,6 2,7

Frequency - Hz

Rea

l /

dB R

ef 1

01.

97m

g/N

1.6 111086427

25

20

15

10

-80

0

-20

-40

-60

NewPoleFrequencyFreq-DampFreq-VectorStableSelectedFRF(FC.101.X,FC.999.X)FRF(FC.102.X,FC.999.X)FRF(FC.103.X,FC.999.X)FRF(FC.104.X,FC.999.X)FRF(FC.106.X,FC.999.X)FRF(FC.108.X-,FC.999.X)FRF(FC.109.X,FC.999.X)FRF(FC.221.X,FC.999.X)FRF(FC.222.X,FC.999.X)FRF(FC.223.X,FC.999.X)FRF(FC.224.X,FC.999.X)FRF(FC.226.X-,FC.999.X)FRF(FC.228.X-,FC.999.X)FRF(FC.229.X,FC.999.X)FRF(FC.230.X,FC.999.X)FRF(FC.30.X,FC.999.X)FRF(FC.34.X,FC.999.X)FRF(FC.36.X-,FC.999.X)FRF(FC.9.X,FC.999.X)FRF(FC.999.X,FC.999.X)FRF(FS.11.X,FC.999.X)FRF(FS.17.X-,FC.999.X)

3D FEM Modell Number of elements: 27.284 (shell, beam,

mass, spring-damper) Number of DOFs: 114.810 Active DOF

Different Materials Reinforced Concrete Steel construction Brick Walls Elastic Material for expansion joint

Material properties from building documentation Changes and modifications in service loads

(additional masses at level +4.4 and 9.4)

Structural analysis


3D FEM Modell Number of elements: 27.284 (shell, beam,

mass, spring-damper) Number of DOFs: 114.810 Active DOF

Different Materials Reinforced Concrete Steel construction Brick Walls Elastic Material for expansion joint

Material properties from building documentation Changes and modifications in service loads

(additional masses at level +4.4 and 9.4)

Model updating: using modes 1 - 4

Chosen parameter for updating:

Boundary conditions at the base, stiffness of triaxial spring elements,final value: 52 MN/ m

E- modulus of elastic material in expansion joint: 73,3 MN/ m E- modulus of combustion stove Stiffness acting between steel platform + wooden floor and RC

walls: final value: 23,363 MN/ m

Model updating


Model updating: using modes 1 - 4

Chosen parameter for updating:

Boundary conditions at the base, stiffness of triaxial spring elements,final value: 52 MN/ m

E- modulus of elastic material in expansion joint: 73,3 MN/ m E- modulus of combustion stove Stiffness acting between steel platform + wooden floor and RC

walls: final value: 23,363 MN/ m

Model updating


After model updating: good correlation between measured andcalculated eigenfrequencies; f in the range 0,65 to 5,05%, in average2,08%

Sensitive analysis Due to big deformations caused by

seismic impact, connections to adjacentparts of the building may get lost duringearthquake

Model 1: Consideration of the entirebuilding complex with adjacent parts ofthe building

Model 2: Considering the main buildingwithout the adjacent building

Model 3: Considering the main buildingwithout the adjacent building and free-standing steel structure. (No connectionat the level of +9.40 m with thebuilding). most relevant model

Structural analysis


Sensitive analysis Due to big deformations caused by

seismic impact, connections to adjacentparts of the building may get lost duringearthquake

Model 1: Consideration of the entirebuilding complex with adjacent parts ofthe building

Model 2: Considering the main buildingwithout the adjacent building

Model 3: Considering the main buildingwithout the adjacent building and free-standing steel structure. (No connectionat the level of +9.40 m with thebuilding). most relevant model

Assumption of 50% stiffness for concreteparts due to cracking during a seismic event Cracking leads to highest deformation

for combuster and steel construction Local analysis of cross sections according

requirements of Eurocode 2 and 3 Occurrence of plastic hinges in the structure

change global stiffness Recalculation of modal parameter Response spectra analysis Changing of load carrying system

Activation of load bearing capacities fromadjacent structural parts (over strengtheningeffect of material)

Introduction of three safety levels withmeaning of different degree of utilization

Seismic Assessment


Assumption of 50% stiffness for concreteparts due to cracking during a seismic event Cracking leads to highest deformation

for combuster and steel construction Local analysis of cross sections according

requirements of Eurocode 2 and 3 Occurrence of plastic hinges in the structure

change global stiffness Recalculation of modal parameter Response spectra analysis Changing of load carrying system

Activation of load bearing capacities fromadjacent structural parts (over strengtheningeffect of material)

Introduction of three safety levels withmeaning of different degree of utilization

Structural analysis

investigation of tension stresses according to EC 2. For critical regions adetailed cross section analysis was carried out. In all other regions of theRC structural elements fctd is less than 1,5 MPa.

critical regions: use of software module Inca2. It was shown, that concretewill crack and tension can be overtaken by existing reinforcement.calculation of safety factors:

Gamma I: elastic elements

Gamma II: elements with E - reduction due to cracked concrete

Gamma III: elements with E reduction due to steel plasticity


investigation of tension stresses according to EC 2. For critical regions adetailed cross section analysis was carried out. In all other regions of theRC structural elements fctd is less than 1,5 MPa.

critical regions: use of software module Inca2. It was shown, that concretewill crack and tension can be overtaken by existing reinforcement.calculation of safety factors:

Gamma I: elastic elements

Gamma II: elements with E - reduction due to cracked concrete

Gamma III: elements with E reduction due to steel plasticity

Results before reconstruction

RC Elements: compression stresses are less than existing strength.Tension strength is exceeded in several regions, resulting in concretecracking, but sufficient reinforcement is existing

Steel Construction: all demands concerning cross section behaviorand stability are fulfilled!

Combustion Stove: maximum displacement 2,1 cm


RC Elements: compression stresses are less than existing strength.Tension strength is exceeded in several regions, resulting in concretecracking, but sufficient reinforcement is existing

Steel Construction: all demands concerning cross section behaviorand stability are fulfilled!


Reconstruction: additional masses/ level +9,4 m

Beschickungsbox Masse gerundet:3.400 kg (derzeit 2900 kg)

Zufhrbox Masse gerundet:700 kg Pufferbox Masse gerundet:600 kg bernahmebox Masse gerundet:1.900

kg

Position 1: 500 kg +700 kgBeschickungsbox und Zufhrbox

Position 2: 600 kgPufferbox

Position 3: 1900 kgbernahmebox


Beschickungsbox Masse gerundet:3.400 kg (derzeit 2900 kg)

Zufhrbox Masse gerundet:700 kg Pufferbox Masse gerundet:600 kg bernahmebox Masse gerundet:1.900

kg

Position 1: 500 kg +700 kgBeschickungsbox und Zufhrbox

Position 2: 600 kgPufferbox

Position 3: 1900 kgbernahmebox

Detailed investigation of critical structural parts


Wand 2; Dach; U104 Bauteil 5 OK XX=60 modesN[kN] -518,0 horizontal Gamma I=0,47M.in[kNm] -21,0 XX+M.out[kNm] -10,0 h=1,04

Wand 2; OG; U122 Bauteil 2 OKN[kN] 273,0 horizontal Gamma II=0,74M.in[kNm] 11,5 XX+M.out[kNm] 7,0 h=1,04Wand 2; OG; Sule in Wand Bauteil 2 OKN[kN] 729,6 vertikal Gamma I=0,68M.in[kNm] 0,0 XX+M.out[kNm] 2,7 l=0,48

Wand 6; OG Bauteil 8 OKN[kN] 240,0 horizontal Gamma I=0,96M.in[kNm] -1,4 XX+M.out[kNm] 6,1 h=0,84

Wand B; OG; Sule links Bauteil 6 OK YY=57 modesN[kN] 420,0 vertikal Gamma III=0,87M.in[kNm] 0,0 YY+M.out[kNm] 9,9 l=0,35

Plastisches Gelenk

Wand B; OG; U104 Bauteil 7 OKN[kN] 358,8 horizontal Gamma I=0,72M.in[kNm] 392,3 YY+M.out[kNm] 28,9 h=1,04Wand B; OG; Sule rechts Bauteil 3 OK

N[kN] 975,0 vertikal Gamma I=0,86M.in[kNm]

85,0YY+

M.out[kNm]

6,3l=0,93

Wand B; OG; U130 Bauteil 3 OKN[kN] 717,0 horizontal Gamma II=0,8M.in[kNm] -37,0 YY+M.out[kNm] 4,0 h=1,04

Wand B; OG; links Bauteil 6 OKN[kN] 251,0 vertikal Gamma III=0,92M.in[kNm] -9,2 YY+M.out[kNm] 9,6 l=0,96

Plastisches Gelenk

Results afterreconstruction:

additional masses + 30%(variant 2)


Wand 2; Dach; U104 Bauteil 5 OK XX=60 modesN[kN] -518,0 horizontal Gamma I=0,47M.in[kNm] -21,0 XX+M.out[kNm] -10,0 h=1,04

Wand 2; OG; U122 Bauteil 2 OKN[kN] 273,0 horizontal Gamma II=0,74M.in[kNm] 11,5 XX+M.out[kNm] 7,0 h=1,04Wand 2; OG; Sule in Wand Bauteil 2 OKN[kN] 729,6 vertikal Gamma I=0,68M.in[kNm] 0,0 XX+M.out[kNm] 2,7 l=0,48

Wand 6; OG Bauteil 8 OKN[kN] 240,0 horizontal Gamma I=0,96M.in[kNm] -1,4 XX+M.out[kNm] 6,1 h=0,84

Wand B; OG; Sule links Bauteil 6 OK YY=57 modesN[kN] 420,0 vertikal Gamma III=0,87M.in[kNm] 0,0 YY+M.out[kNm] 9,9 l=0,35

Plastisches Gelenk

Wand B; OG; U104 Bauteil 7 OKN[kN] 358,8 horizontal Gamma I=0,72M.in[kNm] 392,3 YY+M.out[kNm] 28,9 h=1,04Wand B; OG; Sule rechts Bauteil 3 OK

N[kN] 975,0 vertikal Gamma I=0,86M.in[kNm]

85,0YY+

M.out[kNm]

6,3l=0,93

Wand B; OG; U130 Bauteil 3 OKN[kN] 717,0 horizontal Gamma II=0,8M.in[kNm] -37,0 YY+M.out[kNm] 4,0 h=1,04

Wand B; OG; links Bauteil 6 OKN[kN] 251,0 vertikal Gamma III=0,92M.in[kNm] -9,2 YY+M.out[kNm] 9,6 l=0,96

Plastisches Gelenk

Results after reconstructionVARIANT 1: RC Elements: compression stresses are less than existing strength.

Tension strength is exceeded in several regions, resulting in concretecracking, but sufficient reinforcement is existing

Steel Construction: demands concerning cross section behavior arenot fulfilled for all parts strengthening necessary


VARIANT 2: In general, see VARIANT 1

In addition, plastic deformations in several RC elements. But these localinfluences dont endanger the global load bearing capacity of the structure


VARIANT 1: RC Elements: compression stresses are less than existing strength.

Tension strength is exceeded in several regions, resulting in concretecracking, but sufficient reinforcement is existing

Steel Construction: demands concerning cross section behavior arenot fulfilled for all parts strengthening necessary


VARIANT 2: In general, see VARIANT 1

In addition, plastic deformations in several RC elements. But these localinfluences dont endanger the global load bearing capacity of the structure

Strengthening variant 2


NERA (2010-2014) is an EC infrastructure project that integrates key

research infrastructures in Europe for monitoring earthquakes and

assessing their hazard and risk.

28 participants

7. Project NERA


NERA (2010-2014) is an EC infrastructure project that integrates key

research infrastructures in Europe for monitoring earthquakes and

assessing their hazard and risk.

28 participants

30

NERA activities can be divided in seismological ones and engineering ones AIT is involved in 3 WPs:

NA6: Networking field testing infrastructures (leading the WP) (=WP6) NA7: Classification and inventory of European Building stock (=WP7) JRA5: Vulnerability assessment from field monitoring (=WP15)


NERA activities can be divided in seismological ones and engineering ones AIT is involved in 3 WPs:

NA6: Networking field testing infrastructures (leading the WP) (=WP6) NA7: Classification and inventory of European Building stock (=WP7) JRA5: Vulnerability assessment from field monitoring (=WP15)

31

NERA workshop in Vienna: 25. 26. September 2014

Special Session 20

THANK YOU FOR YOURATTENTION !!


[email protected]: +43 664 620 78 81

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Combination of Dynamic in-situ Measurements on … ppt/keynote ppt... · Combination of Dynamic in-situ Measurements on Structures with Calculations-the Significance for Assessment