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Sezione STRUTTURE E AMBIENTE

Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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Page 1: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Sezione STRUTTURE E AMBIENTE

Page 2: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

S&A – Permanent staff

Giovanni di Luzio RIPatrick Bamonte RI

Giacomo Boffi RI

Francesco Calvetti PA

Gabriele della Vecchia RI

Claudio di Prisco PO

Marco di Prisco PO

Roberto Felicetti PAMatteo Colombo RI

Liberato Ferrara PA

Page 3: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

S&A – Permanent staff

Roberto Paolucci PO

Cristina Jommi PA

Luca Martinelli RI

Paolo Martinelli RI

Federico Perotti PO

Lorenza Petrini PA

Donatella Sterpi RI

Maria Gabriella Mulas PA

Andrea Galli RI

Page 4: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Page 5: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Page 6: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Concrete and Advanced Cement Based Materials

Concept and mechanical characterization of collapsible concrete

Page 7: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Concrete and Advanced Cement Based Materials

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 containerwith anti-wallslip serration

10 mm

50 mm

10 mm

Rheological Building Materials Cell

Rheological Unit

Page 8: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Concrete and Advanced Cement Based Materials

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.)

Page 9: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Concrete and Advanced Cement Based Materials

experimental characterization of HP concreteat 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

Page 10: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Concrete and Advanced Cement Based Materials

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

small furnace (BBQ) for fire testing

of panels and protective materials

assessment of thermal diffusivityin the range 20-1000°C

Page 11: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

11Alkali Silica Reaction / GDL

Concrete and Advanced Cement Based Materials

Self healing of cementitious composites

after 1 month in water

after 3 months in water

after 6 months in water

Page 12: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Concrete and Advanced Cement Based Materials

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

Page 13: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

13Alkali Silica Reaction / GDL

Concrete and Advanced Cement Based Materials

Damage modelling of concrete behaviour

… vs. DIC

Page 14: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Page 15: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

15Alkali Silica Reaction / GDL

Concrete and Advanced Cement Based Materials … and Structures

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

in situ load testslaboratory load tests

fire testingstructural monitoring

Page 16: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Advanced Cementitious Composites In

DEsign and coNstruction of safe Tunnels

Page 17: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Advanced Solutions for Outdoor Energetic Retrofit of façade

Concrete and Advanced Cement Based Materials … and Structures

Page 18: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Design of FRC retaining structure (Caslino Lab)

Concrete and Advanced Cement Based Materials … and Structures

Page 19: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Concrete and Advanced Cement Based Materials … and StructuresDevelopment and Analysis of new cement based materialsfor seismic retrofitting – coupling beams

Page 20: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

development of Non-Destructive toolsfor structural inspection and damage assessment

time of flightof the drill pulses

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

Concrete and Advanced Cement Based Materials … and Structures

Page 21: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

onsite assessment of damaged structures

delamination in floorings and tilesfire damage assessment

debris inspectionmodelling of fire scenarioload/vibration testsresidual deformationultrasonic pulse transmission/refractiondrilling resistancerebound hammerpull-outrebars hardnessdiscoloration, chemo-physical analysis

mobile robotsfor flatness and delamination survey

Concrete and Advanced Cement Based Materials … and Structures

Page 22: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

Seismic Hazard Assessment for critical facilities

Approaches to account for site effects in the Probabilistic Seismic Hazard

Assessment

Page 23: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

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

Page 24: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

Earthquake ground-shaking scenarios in large urban areas

~ 5 hours on FERMI using 512 cores

SANTIAGO DEL CILE

Page 25: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

Guidelines for gas pipeline design

expected earthquake induced slope displacements

pipeline response under dynamic and fault-rupture loading

seismic hazard assessment

Page 26: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

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

The project DPC-RELUIS

Page 27: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

The project DPC-RELUIS

Integrated seismic design and assessment of foundations and structures

Experimental results

Page 28: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

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

Page 29: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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)

Earthquake engineering and structural dynamics

Page 30: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

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

Page 31: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

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 interactionCurrently: 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/c

ycl

e]

Honda spectral density

EC1 AB spectral density

lower limit

upper limit

Pavement roughness PSD

Coupled approach - Solution based on iterative uncoupled procedures

Page 32: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

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)

Page 33: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

Response of RC wallto 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

nR

itte

r –

Moe

rsch

tru

ss

Very low reinforcement

Page 34: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

DdmeFP,1

Keff

Vd

xeff

FP,2

Fa,1

Fa,2

Ksec,P

1

Ksec,P

2Kel

VP,1

VP,2VA,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] 04090140180 00.20.40.6DDBD DisplacementPosition [m] Displacement [m]04090140180012x 105DDBD Deck MomentsPosition [m]Moment [kN*m] 0409014018000.20.40.6FBD Displacement Position [m]Displacement [m]04090140180 012x 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

0.6DDBD Displacement

Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

5

10

15

x 104DDBD 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

0.6DDBD Displacement

Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

5

10

15

x 104DDBD Deck Moments

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

0.6DDBD Displacement

Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

[

m

]

040901401902402800

5

10

15

x 104DDBD 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

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

1.5DDBD 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

1.5FBD 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]

Earthquake engineering and structural dynamics

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

Page 35: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Earthquake engineering and structural dynamics

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

Page 36: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

NORTH

WINGWEST

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

Earthquake engineering and structural dynamics

Forensic Engineering and analysis of progressive collapse

Page 37: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Geomechanics and geotechnical engineering

Page 38: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Modelling the behaviour of granular materials

Transition from solid-like to fluid-like materials

Ratcheting and cyclic behaviorInstability and degradation

Analysis of underground cavities in calcareous soft rocks

Investigation and modelling of degradation processes induced by water-saturation

Formation of sinkholes

Geomechanics and geotechnical engineering

Page 39: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Geomechanics and geotechnical engineering

Page 40: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Geomechanics and geotechnical engineering

Page 41: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

Cracking phenomena in clayey soils undergoing desiccation processes

Durability, maintanance and mitigation actions for

Barriers, Dykes, Embankments, Slopes

Geomechanics and geotechnical engineering

Page 42: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Geomechanics and geotechnical engineering

Page 43: Sezione STRUTTURE E AMBIENTE - Politecnico di Milano · - Structural Dynamics and Wind Engineering Geomechanics and geotechnical engineering - Natural hazards: prediction, prevention

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

Geomechanics and geotechnical engineering