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Settlement prediction of a pile foundation for bridge abutment
A large scale 3D modelling using ZSoil
Rafal OBRZUD
Claude CHAPPUIS
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Project overview
Project: Replacement of the existing bridge with a new one
Junction A9 motorway and N9 road in Villeneuve (Vaud)
Client: Federal Roads Office (CH)
General project manager: IUB Engineering (CH)
Numerical modelling: GeoMod (CH)
FE modelling of a pile foundation for the new bridge
Content
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Bridge replacement at A9 motorway in Villeneuve
Existing bridge
Villeneuve
Dents du midi
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Existing old overpass at A9 motorway in Villeneuve
Facts: - 2 spans - abutment founded on micropiles
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Concept of pile foundation for the new bridge
Single-span deck
Precast concrete elements
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Concept of pile foundation for the new bridge
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
3D FE mesh at initial state
Drainage along the motorway
Abutement of existing bridge
N09
NB. All natural soils were described with the Hardeninig –Soil model with small strain stiffness extension
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
T=1 Initial state
NB. Weight of existing bridge neglected Soil overconsolidation taken into account Existing micropiles neglected
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
T=2 Demolition of the upper part of the existing abutment
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Shotcrete h = 10cm
NAILS Ø20mm interval=2.0m, length =8.0m
T=3 Demolition of the existing abutment and realisation of 1st row of nails
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Shotcrete h = 10cm
NAILS Ø20mm interval=2.0m, length =6.0m
T=4 Demolition of the existing abutment and realisation of 2nd row of nails
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
NAILS Ø20mm interval=2.0m, length =2.0m
Shotcrete h = 10cm
T=5 Demolition of the existing abutment and realisation of 3rd row of nails
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Bored piles Ø1200mm
L=18m (under footing level)
Bored piles Ø1200mm
L=16m (under footing level)
f = 2.7m
Work platform
Secant piled wall (Ø750mm) ELASTIC SHELLS heq=0.65cm
T=6 Realisation of secant piled wall and bored piles
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Anchors: As = 450 mm2
F0 = 100 kN Lf = 11.0 m Lv = 4.0 m Borehole diameter 0.18 mm Interval= 1.3 m
Excavation 1.2m
T=7 1st stage of excavation and installation of anchors
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
T=8 Excavation down to the bottom of the excavation
Bottom of the excavation
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
NB. Weightless structural elements because loads related the self-weight were applied at the foundation level
Foundation
Plastic hinge (connection
ensured by NODAL LINK)
T=9 Realisation of the footing and pillars
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
1st filling subgrade
T=10 Filling inside the excavation
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
2nd filling subgrade
T=11 Filling inside the excavation
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
External load applied at the foundation level
T-11.5: Self weigth of the bridge (SLS)
T-12.0 :Traffic load (SLS)
T-13.5: Wind load (SLS)
T-14.0: All loads with ULS security coefficients
Loads at the footing –pillar joint level provided by bridge’s designer (reactions from structural model)
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Final backfill
T=13 Final backfilling
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Nails Ø20mm e=2.0m, L=8.0m
Secant piled wall (Ø750mm) heq=0.65cm
Bored piles Ø1200mm L = 18.0 m
f = 2.7m in alluvium fluvial
Bored piles Ø1200mm L = 16.0 m
View on structural elements
Anchors: As = 450 mm2
F0 = 100 kN Lf = 11.0 m Lv = 4.0 m Borehole diameter 0.18 mm Interval= 1.3 m
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Drainage along the motorway
GWT 1.0m below soil surface
Groud water level at initial state
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Pumping below the excavation
1.3m
Groud water level lowering due to pumping
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Main results
Excavation stage
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
X
Y Z
uz = 1.5cm
DT = 8 - 6 Horizontal displacement due to excavation (“average soil parameters” scenario)
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Y Z
uz = 3.3cm
DT = 8 - 6 Horizontal displacement due to excavation (“unfavourable parameters” scenario)
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
X
Y Z
uz = 0.6cm
uz = 1.1cm
DT = 8 - 6 Horizontal displacement due to excavation (“unfavourable parameters” scenario)
with a strut in the middle
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Y
un = 3.3cm
un = 2.0cm
DT = 8 - 6 Horizontal displacement due to excavation (“unfavourable parameters” scenario)
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
X
Y Z
uz = 1.1cm
uz = 0.6cm
Strut
DT = 8 - 6 Horizontal displacement due to excavation (“unfavourable parameters” scenario)
with a strut in the middle
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
NB. P0=100kN
fc 235MPa
FHEB400 2440kN
AHEB400 19800mm2
FHEB400
AHEB400
123MPa
1.35 166MPa <fc
1.1214MPa
DT = 8 - 6 Horizontal displacement due to excavation (“unfavourable parameters” scenario)
with a strut in the middle
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Mmax = 204 kNm / m’
Mmax = -132 kNm / m’
T = 8 Horizontal displacement due to excavation (“unfavourable parameters” scenario)
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Mmax = 318 kNm / m’
Mmax = 230 kNm / m’
T = 8 Horizontal displacement due to excavation (“unfavourable parameters” scenario)
with a strut in the middle
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Main results
Construction of bridge and external loads stages
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 11 – 8 Filling accomplished
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 11.5 – 8 Self weigth of the bridge
36
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 12 – 8 Traffic load
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 13 – 8 Backfilling
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 13.5 – 8 Wind load
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 14 – 8 Load increment from SLS to ULS level
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 11 – 8 Filling accomplished
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 11.5 – 8 Self weigth of the bridge
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 12 – 8 Traffic load
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 13 – 8 Backfilling
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 13.5 – 8 Wind load
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 14 – 8 Load increment from SLS to ULS level
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
DT = 12 – 8 Traffic load
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Settlement at the pillars – footing level Settlement [m]
Reali
sati
on
of
foo
tin
g
Filling up to the
motorway level
Self
weig
ht
of
bri
dg
e
Tra
ffic
lo
ad
Realisation of
final
backfilling
Win
d l
oad
Lo
ad
in
cre
men
t fr
om
SL
S t
o U
LS
Min J11
Max J16
J11
J17 J27
0.45cm
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Horizontal displacement at the pillars – footing level
[m]
Reali
sati
on
of
foo
tin
g
Filling up to the
motorway level
Self
weig
ht
of
bri
dg
e
Tra
ffic
lo
ad
Realisation of
final
backfilling
Win
d l
oad
Lo
ad
in
cre
men
t fr
om
SL
S t
o U
LS
Min J27
Max J14
J11
J17 J27
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Drainage
Pore pressure excess after stopping
pumping
GWT 1.0m below soil surface
T=13.5 Ground water level (all SLS loads applied)
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
2.0m of ground water lowering
T=13.5 Ground water lowering (all SLS loads applied)
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Settlement at the pillars – footing level (GWT lowering scenario for “unfavourable parameters”)
Settlement [m]
Reali
sati
on
of
foo
tin
g
Filling up to the
motorway level
Self
weig
ht
of
bri
dg
e
Tra
ffic
lo
ad
Realisation of
final
backfilling
Win
d l
oad
« D
rou
gh
t » s
cen
ari
o:
2.0
m o
f G
WT
lo
weri
ng
0.65cm
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Settlement at the pillars – footing level (overloading scenario)
[m]
Vertical load /
Vertical load ULS [%]
100
200
300
0
Settlement
100 % of
ULS load
200 % of
ULS load
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
X
Y
Z
Mzmax = 1043 kNm
X’ Y’
Z’
Local axes for piles
Bending moments
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
X Z
Mymax = 1171 kN
X’ Y’
Z’
Local axes for piles
Bending moments
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
X
Y
Z
X’ Y’
Z’
Local axes for piles
Normal forces
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Tymax = 545 kN
X’ Y’
Z’
Local axes for piles
Shear forces
Settlement prediction of a pile foundation for a bridge abutment
Rafal Obrzud, GeoMod SA
30.08.2013, Lausanne, Switzerland
Summary
Numerical model allowed to account for :
Actual geometry of both, excavation and foundation
Actual subsoil stratigraphy and hydro-geological conditions
Realistic behaviour of soil (HSS)
Earthwork and construction stages
Soil-structure interaction
FE modelling revealed :
Small horizontal displacements at the foundation level
Expected bridge settlements: 1.7 et 2.2cm (3.0cm)
Internal forces in the piles are not excessive