Sezione STRUTTURE E AMBIENTE Structures and Environment · 2017-10-23 · Structures and...

Sezione STRUTTURE E AMBIENTE Structures and Environment Update: October 2017

S&A – Permanent staff

Giovanni di Luzio Associate Professor

Patrick Bamonte Assistant Professor

Giacomo Boffi Assistant Profesor

Gabriele della Vecchia Associate Professor

Claudio di Prisco Professor

Marco di Prisco Professor

Roberto Felicetti Associate Professor

Matteo Colombo Assistant Professor

Liberato Ferrara Associate Professor

S&A – Permanent staff

Roberto Paolucci Professor

Cristina Jommi Professor

Luca Martinelli Associate Professor

Paolo Martinelli Assistant Professor

Federico Perotti Professor

Lorenza Petrini Associate Professor

Donatella Sterpi Assistant Professor

Maria Gabriella Mulas Associate Professor

Andrea Galli Assistant Professor

S&A – research areas

Concrete and advanced cement based materials (ACBM) and structures

- Concept, development, mechanical characterization and modelling of advanced cement based materials

- Structural behaviour of concrete and ACBM elements

- Innovative structure concept for accidental events and sustainability

- Structural assessment and retrofitting

Earthquake engineering and structural dynamics

- Engineering seismology

- Earthquake engineering

- Structural Dynamics and Wind Engineering

Geomechanics and geotechnical engineering

- Natural hazards: prediction, prevention and mitigation

- Geotechnical structures

- Geo-resources, environment and underground engineering

Concrete and Advanced Cement Based Materials

Mechanical characterization of FRC,HPFRCC, TRC

0.6 3

crack opening w (mm)

0

4

8

12

16

(

N/m

m2)

0 3 6 9

beams L1/2

slab A

DEWS L1/2-B

DEWS T1/2-B

bea

m T

2

bea

m T

150 150150150 500

beam L2

beam L1

150

150

150

50

casting

direction

supposed flow lines

T1-BT2-B

T1-AT2-A L1-A

L2-AL2-B

L1-B

Slab A

0 0.002 0.004 0.006 0.008 0.01

strain

0

4

8

12

16

(

N/m

m2)

beams L1/2

slab A

arctg Ec

DEWS L1/2-B

DEWS T1/2-B

500 mm - 20 in.

150 mm - 6 in.

450 mm - 18 in.

200 mm - 8 in.

A

A sect. A-A

150 mm

6 in.

30 mm - 1.2 in7 mm

0 2 4 6

COD (mm)

0

2

4

6

8

10

(

N/m

m2)

DEWS L1/2-B

DEWS T1/T2-B

DEWS T1/T2-A

DEWS L1/L2-A

Slab A

500 mm - 20 in.

150 mm - 6 in.

450 mm - 18 in.

200 mm - 8 in.

A

A sect. A-A

150 mm

6 in.

30 mm - 1.2 in7 mm


Concept and mechanical characterization of collapsible concrete


Rheological characterization of HPFRCC

Electroacoustical Unit

for in situ measure-

ment of zeta potential

and particle

agglomeration

cement paste or

mortar (dmax < 4 mm)

paddel-shaped rotor

specimen container with anti-wallslip serration

10 mm

50 mm

10 mm

Rheological Building Materials Cell

Rheological Unit


Early age and long term behaviour of concrete

0 100 200 300Time [days]

0.0x100

4.0x10-4

8.0x10-4

1.2x10-3

1.6x10-3

Str

ain

Basic Creep - 2 days

Exp: A5+A6

Exp: A1+A2

B3 model(*)

Exp: manual meas.

(*) Il modello B3 è stato calibrato sulla base delle risultanze sperimentali

1 10 100Time [days]

0.0x100

4.0x10-4

8.0x10-4

1.2x10-3

1.6x10-3

Str

ain

Basic Creep - 2 days

Exp: A5+A6

Exp: A1+A2

B3 model(*)

Exp: manual meas.

(*) Il modello B3 è stato calibrato sulla base delle risultanze sperimentali

0 100 200 300Time [days]

0.0x100

2.0x10-4

4.0x10-4

6.0x10-4

8.0x10-4

Str

ain

Shrinkage - 28 days

B3 model shrinkage(*)

Exp: manual meas. (shrink.)

10 100Time [days]

0.0x100

2.0x10-4

4.0x10-4

6.0x10-4

8.0x10-4

Str

ain

Shrinkage - 28 days

B3 model shrinkage(*)

Exp: manual meas. (shrink.)


experimental characterization of HP concrete at high temperature and in residual conditions

0.00 0.05 0.10w (mm)0

1

2

3

4

(MPa)20°C

600°C

250°C fc20

= 90 MPa

residual tests

direct-tension tests

at high temperature

splitting test

under sustained pore pressure


characterization of thermal properties and fire testing of small structures and protective materials

small furnace (BBQ) for fire testing

of panels and protective materials

assessment of thermal diffusivity in the range 20-1000°C

11 Alkali Silica Reaction / GDL


Self healing of cementitious composites

after 1 month in water

after 3 months in water

after 6 months in water


Concept and mechanical characterization of cementitious composites reinforced with natural/recycled fibers

Natural Fibers Absorb the humidity In case of crack the released humidity

will help further hydration

Before

After 1

Month



Damage modelling of concrete behaviour

… vs. DIC

Formation and expansion of ASR gel

14

Development of cracking

Free Expansion Unrest.-20 MPa Rest.-5 mm; 0 MPa

Alkali Silica Reaction / GDL

Meso-scale modeling of Alkali-Silica-Reaction (ASR) damege in concrete



Concrete and Advanced Cement Based Materials … and Structures

development of equipment and setups for material and structural testing (in lab & onsite)

in situ load tests laboratory load tests

fire testing structural monitoring

Advanced Cementitious Composites In

DEsign and coNstruction of safe Tunnels

Advanced Solutions for Outdoor Energetic Retrofit of façade


Design of FRC retaining structure (Caslino Lab)


Concrete and Advanced Cement Based Materials … and Structures Development and Analysis of new cement based materials for seismic retrofitting – coupling beams

development of Non-Destructive tools for structural inspection and damage assessment

time of flight of the drill pulses

concrete analysis (colour, carbonation, DTA) via a sorted sample of drilling powder


onsite assessment of damaged structures

delamination in floorings and tiles fire damage assessment

debris inspection modelling of fire scenario load/vibration tests residual deformation ultrasonic pulse transmission/refraction drilling resistance rebound hammer pull-out rebars hardness discoloration, chemo-physical analysis

mobile robots for flatness and delamination survey



Seismic Hazard Assessment for critical facilities

Approaches to account for site effects in the Probabilistic Seismic Hazard

Assessment


High-performance computing tools in elasto-dynamics (SPEED code, with Dept of Mathematics)

Traffic-induced vibrations

Seismic wave propagation in complex geological configurations

L’Aquila basin


Earthquake ground-shaking scenarios in large urban areas

~ 5 hours on FERMI using 512 cores

SANTIAGO DEL CILE


Guidelines for gas pipeline design

expected earthquake induced slope displacements

pipeline response under dynamic and fault-rupture loading

seismic hazard assessment


Software for the design spectrum-compatible selection of real accelerograms (in cooperation with Università Federico II, Napoli)

The project DPC-RELUIS


The project DPC-RELUIS

Integrated seismic design and assessment of foundations and structures

Experimental results


The Submerged Floating Tunnel, also known as Archimedes Bridge,

serves as a promising alternative to cross sea-straits, lakes

and waterways in general.

Submerged Floating Tunnels (SFTs)

Engineering solutions

Bridge Underground tunnel Immersed tunnel (I.T.) Floating tunnel (Archimede’s Bridge, SFT “Submerged Floating Tunnel”)

Shallow water ▪

Intermediate depth water

Deep water ▪

Crossing problems：

Conventional tunnel

Immersed tunnel

SFT

Submerged Floating Tunnels

sqsqsq sq sq

eqeqeqeq

one section of tunnel

bars

ISSUES

• Safety assessment (e.g. flooding, fire)

• Soil-structure interaction

• Mooring system: slender members with material and geometric nonlinearity

• 3D multiple-support seismic excitation (eq)

• Seaquake: hydrodynamic pressure on the tunnel (sq)

• Control devices (at tunnel ends and in the mooring system)



Structural control of long and medium-span bridges

70 80 90 100 110 120-1

-0.5

0

0.5

1Uy (Gbz)

[s]

[m]

Damping devices

Motion reduction

Medium-span bridge


Highway RC bridge simply supported on 6 elastomeric bearings

L = 30.3m; B = 15.48 m; s = 25 cm; E = 29.4 GPa

Bridge-vehicle dynamic interaction Currently: bridge-human dynamic interaction

a1 a2a3

a4

: Lumped mass

Direction of motion

Rigid Body

Ur,1

Ur,4

Ur,2

Ur,3

G

mr,1

mr,4

mr,2

mr,3

Um

M,J,J

Kr,2

Ks,2

Cr,2

Cs,2 Kr,3

Ks,3

Cr,3

Cs,3

Kr,1

Ks,1

Cr,1

Cs,1Kr,4

Ks,4

Cr,4

Cs,4

• 3-D two-axle vehicle; 7-dof’s

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

0.01 0.1 1 10

spatial frequency [cycle/m]

PS

D [

m3

/cy

cle]

Honda spectral density

EC1 AB spectral density

lower limit

upper limit

Pavement roughness PSD

Coupled approach - Solution based on iterative uncoupled procedures


Col_Solid_1.25

-200

-150

-100

-50

0

50

100

150

200

-4 -3 -2 -1 0 1 2 3 4

Deflection [mm]

Late

ral

Fo

rce [

kN

]

Experiment

Flexure model

Col_Solid_1.25

-200

-150

-100

-50

0

50

100

150

200

-4 -3 -2 -1 0 1 2 3 4

Deflection [mm]

Late

ral

Fo

rce [

kN

]

Experiment

Shear model

Development of ad hoc finite elements accounting for flexure-shear interaction

Force-displacement response of a RC squat column with rectangular cross-section (Arakawa et al., 1989) using fibre-flexure model (on the left), and the implemented fibre-

shear model (on the right)


Response of RC wall to seismic excitation

Test Type P.G.A.

- - g

1 WN 0.10

2 Nice 0.25

3 WN 0.10

4 Nice 0.05

5 Nice 0.06

6 Nice 0.15

7 Nice 0.06

8 Nice 0.052

9 Nice 0.116

10 SF 0.066

11 SF 0.15

12 SF 0.132

13 WN 0.10

14 SF 1.11

15 WN 0.10

16 Nice 0.252

17 Nice 0.41

18 WN 0.10

19 Nice 0.72

Numerically simulated

RUN 1

RUN 2

RUN 3

RUN 4

RUN 5

back

Models for shear mechanisms compression area

tension area

Arc

h a

ctio

n R

itte

r –

Moe

rsch

tru

ss

Very low reinforcement

Dd

me FP,1

Keff

Vd

xeff

FP,2

Fa,1

Fa,2

Ksec,P

1

Ksec,P

2 Kel

VP,1

VP,2 VA,1

VA,2

Struttura reale

DP,1

DP,2

DA,2

DA,1

DDBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.5 37497 1.31

P2 2.5 37497 1.31

P3 2.5 37496 1.31

P4 2.5 37494 1.31

P5 2.5 37490 1.31

FBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.5 21471 0.50

P2 2.5 35897 1.22

P3 2.5 11135 0.50

P4 2.5 22673 0.50P5 2.5 21984 0.50

DDBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.5 37069 1.29

P2 2.5 37069 1.29

P3 2.5 37067 1.29

P4 2.5 37065 1.29

P5 2.5 37058 1.29

FBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.5 10468 0.50

P2 2.5 39634 1.43

P3 2.5 9410 0.50

P4 2.5 20501 0.50P5 2.5 31888 0.99

DDBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.7 38644 0.97

P2 2.7 38644 0.97

P3 2.7 38643 0.97

P4 2.7 38642 0.97

P5 2.7 38640 0.97

FBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.7 8324 0.50

P2 2.7 43300 1.18

P3 2.7 9786 0.50

P4 2.7 21332 0.50P5 2.7 37120 0.91

DDBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.7 40544 1.06

P2 2.7 40544 1.06

P3 2.7 40544 1.06

P4 2.7 40544 1.06

P5 2.7 40544 1.06

FBD

Pier D MN rl

[m] [kN*m] [%]

P1 2.7 5958 0.50

P2 2.7 43649 1.20

P3 2.7 8606 0.50

P4 2.7 18410 0.50P5 2.7 35250 0.83

Design THA Average EffMS

H =

7.5

mH

= 1

0.0

mH

= 1

2.5

mH

= 1

5.0

m

0 40 90 140 18000.20.40.6 DDBD DisplacementPosition [m]Displacement [m] 0 40 90 140 180012 x 105 DDBD Deck MomentsPosition [m]Moment [kN*m]0 40 90 140 18000.20.40.6 FBD DisplacementPosition [m]Displacement [m] 0 40 90 140 180012 x 105 FBD Deck MomentsPosition [m]Moment [kN*m] 0409014018000.20.40.6DDBD DisplacementPosition [m]Displacement [m]04090140180012x 105DDBD Deck MomentsPosition [m]Moment [kN*m]0409014018000.20.40.6FBD DisplacementPosition [m]Displacement [m]04090140180012x 105FBD Deck MomentsPosition [m]Moment [kN*m]

04090140190240280

0.2

0.4

0.6DDBD Displacement

Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

0.5

1

1.5

2

x 105DDBD Deck Moments

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

04090140190240280-1

0

1DDBD Elastic Mode Shapes

Position [m]

S

h

a

p

e

04090140190240280-1

0

1DDBD Effective Mode Shapes

Position [m]

S

h

a

p

e

040901401902402800

0.2

0.4


Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

5

10

15


Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

04090140190240280-1

0


Position [m]

S

h

a

p

e

04090140190240280-1

0


Position [m]

S

h

a

p

e

040901401902402800

0.2

0.4


Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

5

10

15


Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

040901401902402800

0.2

0.4

0.6FBD Displacement

Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

5

10

15

x 104FBD Deck Moments

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

040901401902402800

0.2

0.4


Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

5

10

15


Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

04090140190240280-1

0


Position [m]

S

h

a

p

e

04090140190240280-1

0


Position [m]

S

h

a

p

e

0 40 90 140 190 240 2800

0.2

0.4

0.6

0.8

DDBD Displacement

Position [m]

Dis

pla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 DDBD Deck Moments

Position [m]

Mom

ent

[kN

*m]

0 40 90 140 190 240 2800

0.2

0.4

0.6

0.8

FBD Displacement

Position [m]

Dis

pla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 FBD Deck Moments

Position [m]

Mom

ent

[kN

*m]

0 40 90 140 190 240 2800

0.5

1

DDBD Displacement

Position [m]

Dis

pla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 DDBD Deck Moments

Position [m]

Mom

ent

[kN

*m]

0 40 90 140 190 240 2800

0.5

1

FBD Displacement

Position [m]

Dis

pla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 FBD Deck Moments

Position [m]

Mom

ent

[kN

*m]

0 40 90 140 190 240 2800

0.5

1


Position [m]

Dis

pla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 DDBD Deck Moments

Position [m]

Mom

ent

[kN

*m]

0 40 90 140 190 240 2800

0.5

1

1.5FBD Displacement

Position [m]D

ispla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 FBD Deck Moments

Position [m]

Mom

ent

[kN

*m]

0 40 90 140 190 240 2800

0.5

1

1.5

DDBD Displacement

Position [m]

Dis

pla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 DDBD Deck Moments

Position [m]

Mom

ent

[kN

*m]

0 40 90 140 190 240 2800

0.5

1

1.5

FBD Displacement

Position [m]

Dis

pla

cem

ent

[m]

0 40 90 140 190 240 2800

1

2

3x 10

5 FBD Deck Moments

Position [m]

Mom

ent

[kN

*m]


Development of methods based on displacement for design and assessment of bridges


Computation of seismic fragility

50 m

23 m

22 m

21 m

56 m

1 m gap

Ground level

Flood level (1 m)

1 m thick

HDRB isolators

non-linear

hysteretic model

The failure probability is computed according to the PEER formulation - A Response Surface is adopted to model the influence of the randomness of the structural and excitation parameters on the statistical properties of the random response – For each experimental point the random vibration problem is solved via simulation – The Response Surfaces are refined in the neighborhood of the design point – The seismic input accounts for rotational components due to kinematic soil-structure interaction and to the spatial variability of free-field ground motion. De Grandis S., Domaneschi M. and Perotti F., ‘A numerical procedure for computing the fragility of NPP components under random seismic excitation’, Nuclear Engineering and Design 239, pp. 2491-2499, 2009. F. Perotti, M. Domaneschi, S. De Grandis, ‘The numerical computation of seismic fragility of base-isolated NPP buildings’, Nuclear Engineering Design, 262. pp. 189-200, 2013.

IRIS reactor building

NORTH

WING WEST

WING

SOUTH

WING

BEFORE

Nort

h

Wing

AFTER

THE COLLAPSE MECHANISM

Grey: REI 60

wall and floor

still standing

Green:

collapsed floor

In between:

cross-section

of 18-29 failed

in shear

Shear failure of beams, 1° floor

Columns failure, ground floor


Forensic Engineering and analysis of progressive collapse

Multiphysics and multi-scale experimental studies of materials and models

Internal erosion and piping

Small scale model for soil-atmosphere interaction

Chemo-electro-hydro-mechanical behaviour

Field monitoring of water exchanges


Modelling the behaviour of granular materials

Transition from solid-like to fluid-like materials

Ratcheting and cyclic behavior Instability and degradation

Analysis of underground cavities in calcareous soft rocks

Investigation and modelling of degradation processes induced by water-saturation

Formation of sinkholes


Retention, hydraulic conductivity, stiffness and strength

Simulation of pore size density function of a compacted clay

Water retention curve for Perlite at various densities

Multiscale approach: from microstructure to the field

Multiphysics actions: drying/wetting – freezing/thawing – electrical (electroosmotic) -

chemical

Water retention curve for compacted Boom clay

As compacted bentonite

Saturated 0.5M NaCl

Saturated distilled water

Modelling the behaviour of compacted materials of increasing activity


Small scale experimental setup

H=H(t) Behavior of shallow and deep

foundations subject to cyclic loads

Design of special foundations for embankment on soft soils


Cracking phenomena in clayey soils undergoing desiccation processes

Durability, maintanance and mitigation actions for

Barriers, Dykes, Embankments, Slopes


Impacts of boulders and granular flows on sheltering structures

Seismic performance of earth slopes

Experimental and numerical analysis

Discrete element and macroelement modeling

Impulsive soil-structure interaction

Numerical simulation of the seismic response

Inception of landslides and displacement assessment


Tunneling in difficult conditions

Stress in a tunnel liner in squeezing conditions

SOFTENING and SQUEEZING GROUND CONDITION

GROUND IMPROVEMENT and SOIL NAIL STABILISATION at the tunnel face

for low enthalpy geothermal energy sources

Soil thermal drift and temperature field

in a thermo-active diaphragm wall

PIPE LAYOUT OPTIMISATION

EFFECTS on SOIL TEMPERATURE

and on SOIL-STRUCTURE

INTERACTION

Thermo-active Geostructures

Design of structural intervention measures for landslide risk

mitigation


Sezione STRUTTURE E AMBIENTE Structures and Environment · 2017-10-23 · Structures and...

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