seismic vulnerability of multi-leaf, heritage …seismic vulnerability of multi-leaf, heritage...

SEISMIC VULNERABILITY OF MULTI-LEAF, HERITAGE MASONRY WALLS USINGHERITAGE MASONRY WALLS USING ELASTO-PLASTIC DAMAGE MODEL

ByB.H. Al-Gohi1, C. Demir2, A. Ilki2, M.H. Baluch1 and M.K.

Rahman3, A.H. Al-GadhibRahman , A.H. Al Gadhib

1Department of Civil Engineering, KFUPM, Dhahran, Saudi ArabiaDepartment of Civil Engineering, KFUPM, Dhahran, Saudi Arabia2Department. of Civil Engineering, ITU, Istanbul, Turkey

3Center for Engineering Research, KFUPM, Dhahran, Saudi Arabia

OUTLINEOUTLINE

1. Introduction.

2. Subject and Scope

3. Experimental Study at ITU

4. FEM Simulations

5. Conclusions

6. Work in Progress at KFUPM

IntroductionIntroductionIntroductionIntroduction

Masonry structures are also commonly used in Saudi Arabia for the

construction of low rise buildings especially in small towns and villages dueconstruction of low rise buildings especially in small towns and villages due

to economy in the cost of construction.

There exists a rich heritage of URM structures in the Western region of

Saudi Arabia.

With only a few incidences of major earthquakes in the Kingdom in the

recent history, research into seismic retrofitting of masonry structures is

rather scant.3

Aim and ScopeAim and ScopeIn this studyy

‐ An experimental study on ‘multi‐leaf stone masonry walls’, carried out in ITU Structural and EQ Engineering Laboratory is briefly introduced.

‐ Finite element analysis results of two experimental studies (Demir et al. (2011) and Nanni et al. (2005) are ( ( ) ( )presented.

‐ Axial stress vs. Shear strength curves for both studies are obtained via FEA and compared.

‐ Ongoing efforts in KFPUM are indicated.

EXPERIMENTAL STUDYEXPERIMENTAL STUDY CARRIED OUT IN ITU (Demir

et al., 2011)

INTRODUCTION TO THE EXPERIMENTALINTRODUCTION TO THE EXPERIMENTALPROGRAMPROGRAMPROGRAMPROGRAM

• The structure of the walls in monumental

b ildi t t d i th l i l i dbuildings constructed in the classical period

of the Ottoman Empire usually consist of:

h l ll f f• The two-layer walls of stone, often

cut in the outer wall.(Tanyeli, 1990)

• Inner layer of rubble filling

• Iron clamp (and in some cases, shear

pins) connected to each other block.

• The reinforcement of stone anchors units is

molten lead.Sultanhan, 13th century

INTRODUCTION TO THE EXPERIMENTALINTRODUCTION TO THE EXPERIMENTALPROGRAMPROGRAMPROGRAMPROGRAM

Bayezid Mosque-15. century (Cut Stone Wall)

EXPERIMENTAL PROGRAMEXPERIMENTAL PROGRAM

1 / 3 scale wall specimens

Wall Model Stone blocks


• The tests were done at ITU Structural and EQ EngineeringWall Wall TestsTests

Laboratory.

• The variables are

• normal stress level,

• and clamps

F h i l l d h i t l li f i li d i th i l

Axial

• For each axial load, horizontal cyclic force is applied in the in-plane

direction

sample clampAxialLoad variable(MPa)

M-25-C Yes 0.25 axial stress



M-100-C Yes 1 00 axial stressM-100-C Yes 1.00 axial stress

M-50 No 0.50 Clamp not used


Hydraulicpump

Wall Wall TestsTests

Reactionframe

Hydraulic

Test rigSpreader beam

Hydraulic jack Loadcell

Rollers

Hydraulicactuator

Controller unit P t t i dSpecimen

Bond beamOut-of-planesupport beams

Post-tensionedrods

Reaction slab


Wall Wall TestsTests

FEM Simulations

FEM FEM SimulationsSimulations

FEM analysis has been used to model and simulate the behavior of masonry

ll bj t d t i l l diwall subjected to in-plane loading

d l i i ( ) d l il bl i h bConcrete-damage plasticity (CDP) model available in ABAQUS has been

adopted for this purpose. This model provides a good prediction for the

behavior of such structures with cyclic loading

ABAQUS software has been used for the simulation. ABAQUS provides an

extraordinary capability to simulate this type of structure under cyclic

loading using the desired model.13

ElastoElasto--Plastic Damage Plastic Damage MModelodel

The main purpose of the study is to find the interaction diagram

between the normal stress and lateral shear strength of the wall.

For this purpose, a Finite element simulation has been carried out

for two walls:

The wall tested at ITU by Demir et al. (2011)

A hollow block concrete wall studied by Nanni et al (2005)

14

ElastoElasto--Plastic Damage Plastic Damage MModelodelWall Wall tested by tested by Demir Demir et et alal. (2011). (2011)

The wall is a multilayer leafThe wall is a multilayer, leaf

wall (two leaves) with

bbl t i l fillirubble material as filling

material between the two

leaves.

The interface between the

units is dry connection.

15


Material models used in this wall in ABAQUS

Wall Wall tested by C. tested by C. DemirDemir et al et al

Bricks Compression:

Compression 8

Plastic Strain Stress (Mpa)

0 7.265

6

7

Mpa

)

0.00046 7.03

0.0029 6.58

0 0044 5 92

3

4

Stress (M

0.0044 5.9

0.006 4.83

0 008 3 47

0

1

0 0.002 0.004 0.006 0.008 0.01

Plastic Strain

16

0.008 3.47




Bricks Tension:

1 4

1.6

1

1.2

1.4

a)

Tension

0.6

0.8

Stress (M

paPlastic Strain Stress (Mpa)

0 1.5

0

0.2

0.40.001 0.5

0.003 0.1

17

00 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035

Plastic Strain

ElastioElastio--Plastic Damage Plastic Damage MModelodel



Rubble Compression:

1.4

1.6

Compression

0 8

1

1.2

(Mpa

)

Compression


0 0.93

0.4

0.6

0.8

Stress (

0.00014 1.17

0.00027 1.24

0.00061 1.33

0

0.2

0 0.001 0.002 0.003 0.004 0.005 0.006 0.007

Plastic Strain

0.00061 1.33

0.0013 1.35

0.0023 1.26

18

ast c St a

0.0058 0.74




Rubble Tension:

0.25

Tention

Plastic Strain Stress (Mpa)0.15

0.2

Mpa

)0 0.2

0.001 0.10 05

0.1Stress (M

0.003 0.050

0.05

0 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035

Plastic Strain

19

Plastic Strain


RESULTS: Wall Lateral Strength.


250

Shear Force Vs Lateral Displacement

N l St 0

200

Normal Stress = 0

Normal Stress = 0.25 Mpa



150

tren

gth (KN) Normal Stress = 1.0 Mpa




100

Shear S Normal Stress 1.75 Mpa




0

50 Normal Stress = 2.75 Mpa




20

0 2 4 6 8 10 12

Lateral Displacement (mm)Normal Stress = 3.75 Mpa


RESULTS: Interaction Curve.


250

Interaction Curve

y = ‐36.968x2 + 176.52x + 5.1917R² = 0.995

200

100

150

ength (KN)

50

100

Shear S

tre

00 1 2 3 4 5 6

21

‐50Normal Stress (Mpa)


RESULTS: Normalized Interaction Curve.


1.2

Normalized Interaction Curve

y = ‐4.0635x2 + 4.0033x + 0.0243R² = 0.995

1

0.6

0.8

F/F(max)

0 2

0.4

F

0

0.2

0 0.2 0.4 0.6 0.8 1 1.2

22

σ/σ(max)

FEM SimulationsWall Wall tested by C. tested by C. DemirDemir et al et al

FEM SimulationsWall Wall tested by C. tested by C. DemirDemir et al et al

Plastic StrainPlastic Strain

ElastoElasto--Plastic Damage Plastic Damage MModelodelWall studied by Wall studied by NanniNanni et alet al. (2005). (2005)

This wall is a single leaf wall of

hollow concrete blocks.

The interface between theThe interface between the

bricks is mortar.

27



Wall studied by Wall studied by NanniNanni et alet al. (2005). (2005)

Hollow concrete blocks:

Compression16

18


0 13.4410

12

14

pa)

0.000131 15.12

0.000502 16.3

0 001302 16 86

8

10Stress (M

0.001302 16.8

0.003702 15.8

0 007302 12 0

2

4

28

0.007302 120 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008

Plastic Strain



Wall studied by Wall studied by NanniNanni et alet al

Hollow concrete blocks:

2 5

3

2

2.5

Mpa

)

Tension


1

1.5Stress (M

0 2.459268

0.000872 1.3

0

0.5

0 0.001 0.002 0.003 0.004 0.005

0.001872 0.6

0.003872 0.1

29

Plastic Strain




Mortar:

Compression 6

7

Compression


0 4.5364

5

6

Mpa

)5.07E‐05 5.103

0.000345 5.6

0.001095 5.67 2

3

Stress (M

0.001095 5.67

0.003095 4.7

0.005395 3 0

1

0 0 001 0 002 0 003 0 004 0 005 0 006

30

0 0.001 0.002 0.003 0.004 0.005 0.006

Plastic Strain




Mortar::

1.4

1.6

Tension

Plastic Strain Stress (Mpa) 1

1.2

pa)

0 1.428706

0.000872 0.80.6

0.8

Stress (M

p

0.001872 0.4

0.003872 0.1 0

0.2

0.4

31

00 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035 0.004 0.0045

Plastic Strain


RESULTS - Wall Lateral Strength.


250

Shear Force Vs Lateral Displacement

Normal Stress = 0

200




N l S 1 0 M

150

Strength (K

N) Normal Stress = 1.0 Mpa




50

100

Shear




Normal Stress =3 5 Mpa

00 2 4 6 8 10 12

Normal Stress =3.5 Mpa




32

0 2 4 6 8 10 12

Lateral Displacement (mm)Normal Stress = 5.5 Mpa


RESULTS- Interaction Curve.


250

Interaction Curve

y = ‐11.857x2 + 96.754x + 20.204R² = 0.9774

200

100

150

ar Stren

gth (KN)

50

100

Shea

00 1 2 3 4 5 6 7 8 9

Normal Stress (Mpa)

33

( p )


RESULTS-Normalized Interaction Curve.


1.2

Normalized Interaction Curve

y = ‐3.9729x2 + 3.8256x + 0.0943R² = 0.9774

0 8

1

0.6

0.8

F/F(max)

0 2

0.4

0

0.2

0 0.2 0.4 0.6 0.8 1 1.2

/ ( )

34

σ/σ(max)

FEM SimulationsWall studied by Wall studied by NanniNanni et alet al

Plastic StrainPlastic Strain


Normalized Interaction Curve of both walls.

1.2

Normalized Interaction Curve of Both Walls

0 8

1

0.6

0.8

F/F(max)

0.2

0.4

00 0.2 0.4 0.6 0.8 1 1.2

σ/σ(max)

40

Istanbul Wall Nanni Wall


Normalized Interaction Curve of both walls.

1.2

Normalized Interaction Curve of Both Walls

y = ‐4.0036x2 + 3.8975x + 0.0637R² = 0.9847

1

0.6

0.8

F(max)

0.4

F/

0

0.2

0 0 2 0 4 0 6 0 8 1 1 2

41

0 0.2 0.4 0.6 0.8 1 1.2

σ/σ(max)

ConclusionConclusion

Masonry structure mechanics is one of the areas where limited research has

been carried out in the Gulf Region.

There exists a strong need to initiate seismic research as seismic activitiesg

could take place at any time in the Region.

ABAQUS shows promising features in handling analysis of complex

structures and loadsstructures and loads.

42

ConclusionConclusion

The effect of axial loading on the capacity of the lateral wall is independent

of the wall pattern and material used.

Walls with aspect ratios =1 0 exhibited maximum lateral resistance whenWalls with aspect ratios 1.0 exhibited maximum lateral resistance when

the axial loading was almost 50% of the wall axial capacity.

43

WORK IN PROGRESS KFUPMWORK IN PROGRESS KFUPM

As mentioned before, there is a cooperation between KFUPMand ITU.

Recently, the lab facilities are being constructed in KFUPM forcyclic load testing of masonry wallscyclic load testing of masonry walls.

In Numerical Modeling work on Nonlinear FEA of CFRPgRetrofitted masonry walls is in progress

44

WORKS IN KFUPMWORKS IN KFUPM

Reaction Reaction wall and wall and loading loading frame.frame.

WORKS IN KFUPMWORKS IN KFUPM

Wall Wall testing set uptesting set up

• Experimental study was funded by ITU Research Fund.Experimental study was funded by ITU Research Fund.

• The study being carried out in KFPUM is funded by KingFahd University of Petroleum & Minerals under projectFahd University of Petroleum & Minerals under projectnumber IN101016 “ Seismic Retrofit of Typical WallSystems in Traditional Structures in the Kingdom” which is

t f ll k l d dgratefully acknowledged.

• The authors acknowledge the mentoring provided by ITUto the KFUPM graduate students involved in this project

seismic vulnerability of multi-leaf, heritage …seismic vulnerability of multi-leaf, heritage...

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