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ANALYSIS AND MITIGATION OF RISKS IN INFRASTRUCTURES | INFRARISK- !
Influence of infill masonry walls on RC buildings
João Mário Humberto Varum Panagiotis Asteris
Summer Workshop
ANALYSIS AND MITIGATION OF RISKS IN INFRASTRUCTURES | INFRARISK- !
Influence of infill masonry walls on RC buildings
Motivation Literature review Research plan
Summer Workshop
3 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Research field
Seismic engineering Mitigation of seimic risk
Numerical modelling
4 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
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Earthquake of Kobe
Geophysical disasters Economical impact
Earthquake of Japan and New Zealand
Motivation – Natural disasters
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Motivation – Scientific attention
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6 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Hazard “x” Vulnerability “x” Exposure
Low R
isk H
igh Risk
Thierry Legault, 2012 (legault.perso.sfr.fr). Dabarti CGI (www.shutterstock.com). Unknown. AP Photo/Itsuo Inouye, 2009. Unknown. Unknown.
Seismic Risk
7 João Mário | Influência de paredes de enchimento de alvenaria em edifícios de betão armado
Structural elements Non-structural elements
Boundary (foundation, soil, pounding,…)
Seismic risk = Hazard x Vulnerability x Exposure
8 João Mário | Influência de paredes de enchimento de alvenaria em edifícios de betão armado
Seismic risk = Hazard x Vulnerability x Exposure
Interaction Structural elements Non-structural elements
Boundary (foundation, soil, pounding,…)
9 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Influence of infill walls
Globally Locally
10 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Influence of infill walls
11 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Failure modes
In-plane Out-of-plane
12 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Failure modes
In-plane Out-of-plane Combined
13 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Literature review
Lessons from earthquakes ~20 Seismic standards ~20 Experimental work ~125 Numerical modelling ~70
Macro-modelling ~40 Micro-modelling ~30
Example
14 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Lessons from earthquakes
Earthquakes in study World 16 Europe 4 Low quality of materials Insufficient constructive detailing Insufficient shear strength Vulnerability of infill walls Collapses: Due to irregularities on the
distribution of the infill walls
15 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Seismic recommendations
Philosophies Standards ~20 1 – Isolation of infill masonry walls 2 – Allow the use of infill walls on the designing 3 – Connection between infill walls and structure is mandatory Formulations of different natural frequencies Irregularities in height and plan (structural and non-structural elements) Minimal strength capacity for the infill walls Deformation limitation to control damages Recommendations regarding positioning of openings on infill walls
16 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Experimental work
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Dynamic"Cyclic"Monotonic"
Number of experimental campaigns ~125 Linear growth with time Monotonic testing dropped and cyclic testing
17 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Experimental work
Decrease of aspect-ratio (h/l) leads to an increase of the ultimate capacity Gaps on infill-frame interface decreases considerably the horizontal strength Building’s stiffness do not increase linearly with the number of walls Openings close to edges reduce more the capacity of the wall than centred Openings usually increase the ductility of the system Vertical loading on columns increase of stiffness and resistance of the
system due to increase of confinement of the wall Eccentricity of the wall relative to the frame plane centre-line leads to out-of-
plane bending effects, reducing both initial stiffness and ultimate capacity Horizontal bond beam increase the ductility of the system
...
18 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Refined models vs Simplified models
Micro-modelling (refined) ~ 30 Macro-modelling (simplified/analytical) ~40
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Numerical limitations
Models with combined in-plane and out-of-plane’s behaviour Failure curve of infill masonry walls for actions in both directions
Parametric studies (and experimental) of double-leaf walls Calibration of simplified models for retrofitting interventions
20 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Research plan
Parametric study with a semi-refined model Abaqus
Development of a macro-model
OpenSees
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Parametric study
Volume elements Continuum element for infill wall Study: Dimensions Properties of materials Infill-frame interface conditions Eccentricities Single- and double-leaf walls Used on the calibrations of the simplified model
22 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Simplified models
InfillDouble Model
4 Exterior Connections (nodes)4 Dummy nodes12 ( +2+2)8 Elements(8 Elastic Struts)(2 Nonlinear Central Elements)(2 ZeroLength Elements)
BeamN
BeamS
Colu
mnW
Colu
mnE
NodeNW
NodeSE
NodeNE
NodeSW
2xElasticStrutNW2xElasticStrutNE
2xElasticStrutSW2xElasticStrutSE
2xDummyNodeWZeroLengthW
2xDummyNodeEZeroLengthE
2xNonLinear
2xDummyNodeEZeroLengthE
(Limitations of models with single-struts) Out-of-plane behaviour Interaction between two masonry walls and its connections
23 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Interaction curve
OOP
IP
#1
#2
#3
Simplified approach for assessment of failure’s strength for actions combined in both directions: in-plane and out-of-plane
Applicability on the simulation of real (and complex) study cases
24 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
FEMuA++
Software for structural analysis Programming language: C++ (used in OpenSees) (Pre- e post-processing in GiD) “Testing platform”
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Numerical developments
Semi-refined modelling Macro modelling Abaqus OpenSees
26 João Mário | Influence of infill masonry walls on the behaviour of reinforced concrete buildings
Conclusions Objectives
Compilation and organization of the state-of-the-art in a database Development of a parametric study Development of a macro-model able to describe the behaviour of infill
masonry walls with combined in-plane and out-of-plane actions Improve the knowledge regarding the influence of infill masonry walls on
the behaviour of reinforced concrete buildings Creation of new methodologies for the designing and assessment of
reinforced concrete structures with infill masonry walls
ANALYSIS AND MITIGATION OF RISKS IN INFRASTRUCTURES | INFRARISK- !
Influence of infill masonry walls on RC buildings
João Mário Humberto Varum Panagiotis Asteris
Summer Workshop
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