prof. Dr. Ing. Yasser El-Mossallamy 1
Professor Yasser El-Mossallamy
Slide: 1
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Foundations of High Rise Buildings
Prof. Dr.-Ing. Yasser El-Mossallamy
Professor of Geotechnical Engineering
Ain Shams Univ. Cairo, Egypt
c/o Arcadis Consult, Germany
Professor Yasser El-Mossallamy
Slide: 2
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Development of High-rise Buildings in city centers
Frankfurt New York
Hongkong Dubai
prof. Dr. Ing. Yasser El-Mossallamy 2
Professor Yasser El-Mossallamy
Slide: 3
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Development of High-rise Buildings in city centers
Although the cost of the foundation of a high rise
building is only a small fraction of the total cost
(about 10 to 15%), the foundation is one of the main
design elements, which affects the whole behaviour
of the building.
On the other hand, the construction time of the
foundation and basement floors takes about 30 to
50 % of the total construction time.
These conditions make the foundation of high rise
buildings one of the most critical construction items
regarding the risk assessment analyses and
optimization of construction schedule.
Professor Yasser El-Mossallamy
Slide: 4
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Different foundation types
Raft foundation
100 m
1
2
Piled raft
256 m
1
2
Piled foundation
259 m
1
2
Relatively incompressible soil
Compressible soil 1
2
prof. Dr. Ing. Yasser El-Mossallamy 3
Professor Yasser El-Mossallamy
Slide: 5
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
The Main Concept of Piled Raft
m
D
Q
b
qsjPl
Pk
L
Qt
qsj PlPk
Traditional pile foundation
Piled raft foundation
S
1.0
a L : Pile load share
0,0
0.5
0.2 0.4 0.6 0.0 0.8
0.0
1.0
a L P t = Q / Q
a
Settlement of piled raft
Settlement of corresponding raft a
S =
foundation Traditional raft
Professor Yasser El-Mossallamy
Slide: 6
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Interaction aspects
X
YZ
Q
Q Q
D
P,i,1 P,i,m
t
Z
Raft/soil Raft/Piles
Pile/SoilPiles/
Piles
Pile/Soil
a a
s s
(x,y)
Q =
(x,y) dA
Raft
dAy)(x,=Q Raft
ni
1i
ip,Piles Q=Q n : No. of piles
prof. Dr. Ing. Yasser El-Mossallamy 4
Professor Yasser El-Mossallamy
Slide: 7
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Frankfurt as an example for development of foundations on compressible subsoil
Professor Yasser El-Mossallamy
Slide: 8
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
b) load share
Torhaus Messe Frankfurt
c) Pile loads dependent on pile position
prof. Dr. Ing. Yasser El-Mossallamy 5
Professor Yasser El-Mossallamy
Slide: 9
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Messeturm, Frankfurt
a) View
58.8m
58.8
5.0
9.0
G.W.T
3.0
Outer pile ring
Middle pile ring
Inner pile ring
b- Longitudinal section of the foundation
c- Cross section of the tower above the foundation
Totalstructuralload=1880MN
6.0m
d) Load share
Professor Yasser El-Mossallamy
Slide: 10
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
e) Skin friction and pile forces dependent on depth
Messeturm, Frankfurt
prof. Dr. Ing. Yasser El-Mossallamy 6
Professor Yasser El-Mossallamy
Slide: 11
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
How we measure:
DG Bank, Frankfurt
89.9 m
38.4
m6
4.5
m
47.5 m
NSettlement joint
I
I
Main tower
Main tower
Side building
+ 60
14,5 m
30 m
Quaternary
Frankfurt clay
Section
Plan
Inner core
208 m
47
.5 m
64.5 m
SDG 1
EXT / INK II
EXT / INK I
EXT III
SDG 2
SDG 3
SDG 4
SDG 5
SDG 6
SDG 7
PWD 1
Settlement joint
PWD 2
PWD 3
PWD 4
PWD 5
SDG 8
SDG 9
SDG 10
SDG 11
SDG 12
SDG 13
P V P III
P II
P IV
P I
P VI
Professor Yasser El-Mossallamy
Slide: 12
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Instruments, Pile load cell
prof. Dr. Ing. Yasser El-Mossallamy 7
Professor Yasser El-Mossallamy
Slide: 13
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Measuring raft contact stresses
DG Bank, Frankfurt
Professor Yasser El-Mossallamy
Slide: 14
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Measuring water pressure beneath the raft
DG Bank, Frankfurt
prof. Dr. Ing. Yasser El-Mossallamy 8
Professor Yasser El-Mossallamy
Slide: 15
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Load-settlement behavior of piled raft, Load-time development
DG Bank, Frankfurt
0
0.1
0.2
0.3
0.4
0.5
0.6
0 500 1000 1500 2000 2500 3000 3500
Time [days]
DG Bank
a L
0
0.1
0.2
0.3
0.4
0.5
0.6
0 500 1000 1500 2000 2500 3000 3500
Time [days]
DG Bank
a L
Development of pile load share with time
Professor Yasser El-Mossallamy
Slide: 16
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Instruments, Measuring room
prof. Dr. Ing. Yasser El-Mossallamy 9
Professor Yasser El-Mossallamy
Slide: 17
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Numerical analysis of piled raft
Finite diference method
(FDM)
Finite element method
(FEM)
Boundary element method
(BEM)
- One dimensional analysis
(Load transfer method)
- Two and three dimensional
analysis
- One dimensional analysis
- Two dimensional analysis
Plane strain
Axisymmetry
- Three dimensional
analysis
- Using superposition
technique
- Complete boundary element
structure
- Hain and Lee (1978)
- Hybrid model (O'Neill et al. 1981)
- Modified hybrid model (Chow 1986)
- El-Mossallamy (1996)
Mixed technique
Mathematical procedures
Professor Yasser El-Mossallamy
Slide: 18
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Comparison between observed and calculated behavior of piled raft
0
4
8
12
16
20
24
L oad [MN]
0 4 00 8 00 1 200
Calculated undrained
Calculated, drained
16 00
Observed behavior
(a)
(b)
(b) E nd of construction
(a)1 year after end of construction
0
4
8
12
16
20
0 4 00 8 00
0
4
8
12
16
20
0 4 00 8 00
L oad [MN] L oad [MN]
a- Total load
b- Pile load share c- Raft load share
Observed behavior
Calculated, drained
Observed behavior
Calculated, drained
Set
tlem
ent
[cm
]
prof. Dr. Ing. Yasser El-Mossallamy 10
Professor Yasser El-Mossallamy
Slide: 19
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Different load settlement relationships
0
4
8
12
16
20
24
0 4 8 12 16 20
(1)
(2)
(3)
(4)
Load [MN]
Domain of measured pile loads
Legend
(1) Single pile,
(2) Average behaviorof the same pile as a member
of an equally loaded free standinggroup,
(3) Average behaviorof the same pile as a member
of the pile group below the raft of the DG Bank
(piled raft foundation)
(4) The observedaverage behaviorof
the piled raft piles.
Set
tlem
ent
[cm
]
Professor Yasser El-Mossallamy
Slide: 20
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
(2) Observed
(1) Calculated
Skin friction (kN/m²)
0 40 80 120 160
0
6
12
18
24
30
Normal force (MN)
0 3 6 9 12
0
6
12
18
24
30
15
Depth
(m
)
(1)
(2)(1)
(2)
Development of pile skin friction by piled raft
prof. Dr. Ing. Yasser El-Mossallamy 11
Professor Yasser El-Mossallamy
Slide: 21
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Comparison between measured and calculated settlement
Main Tower Side buildings
Settlement joint
1
2
3
0
4
8
12
16
20
Settlement trough along section I - I
1 Measurements , piled raft 2 Calculation , piled raft
3 Calculation , raft without piles
I I
Settlement joint
Sett
lem
en
t [c
m]
Professor Yasser El-Mossallamy
Slide: 22
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Distribution of bending moments of the piled raft and of the corresponding
raft without piles
Main tower Side buildings
1
2
Settlement jointSettlement joint
Main tower Side buildings
1
2
Settlement jointSettlement joint
Main tower Side buildings
1
2
Settlement jointSettlement joint
prof. Dr. Ing. Yasser El-Mossallamy 12
Professor Yasser El-Mossallamy
Slide: 23
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Contour lines of normalized vertical stresses beneath the center line of the piled
raft and of the corresponding raft without piles
0 . 0
0 . 1
0 . 2
0 . 3
0 . 4
0 . 5
0 . 6
0 . 7
0 . 8
0 . 9
1 . 0
n
0 . 1 0 . 2
0 . 3 0 . 4 0 . 5
0 . 6
0 . 7
0 . 8
0 . 9
0 . 1 0 . 2 0 . 3
0 . 4
0 . 5
0 . 6
0 . 7
0 . 4 0 . 3
Main Tower Side Building
Piled raft foundation
Settlement joint
n = z
o :Normalized vertical stresses
:Vertical stresses
:Average applied stresses of the main tower
n
z
o
Main Tower Side Building
Conventional raft foundation
Professor Yasser El-Mossallamy
Slide: 24
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Features of piled raft behavior:
- Pile behavior depends on pile position
- Pile capacity is completely difference than that of corresponding single pile
- Skin friction develops from pile tip to pile top
- Fewer number of piles can decrease the settlement significantly
- Pile arrangement within pile group beneath the structural elements can
reduce the raft internal stresses significantly. This has an effect on the
reinforcement grad, on the raft thickness, on the required excavation depth,
on the design of the required shoring system and on the required dewatering.
prof. Dr. Ing. Yasser El-Mossallamy 13
Professor Yasser El-Mossallamy
Slide: 25
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Application of piled raft in calcareous sand
Foundation of High Rise Building (Kuwait)
Salimia, El-Mossallamy et al.
Professor Yasser El-Mossallamy
Slide: 26
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Subsoil conditions
Application of piled raft in calcareous sand
Foundation of High Rise Building (Kuwait)
prof. Dr. Ing. Yasser El-Mossallamy 14
Professor Yasser El-Mossallamy
Slide: 27
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Traditional deep foundation of the high-rise building Salimia, Kuwait
624 piles with 0.9 m diameter
461 piles with 0.6 m diameter
Pile length = 22 m
Application of piled raft in calcareous sand
Foundation of High Rise Building (Kuwait)
Professor Yasser El-Mossallamy
Slide: 28
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Behavior of calcareous sand
Silica sand
Calcareous sand
Silica sand
Calcareous sand
prof. Dr. Ing. Yasser El-Mossallamy 15
Professor Yasser El-Mossallamy
Slide: 29
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Results of pile load tests in Calcareous sand
Application of piled raft in calcareous sand
Foundation of High Rise Building (Kuwait)
Professor Yasser El-Mossallamy
Slide: 30
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Proposal of an optimized piled raft for the high-rise building Salimia, Kuwait
250 piles with 1.2 m diameter
146 piles with 0.6 m diameter
Pile length = 17 m
Application of piled raft in calcareous sand
Foundation of High Rise Building (Kuwait)
prof. Dr. Ing. Yasser El-Mossallamy 16
Professor Yasser El-Mossallamy
Slide: 31
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Comparison between traditional piled foundation and piled raft foundation
Traditional deep foundation Piled raft foundation
Total no. piles 1085 396
Pile diameter 0.9 and 0.6 1.2 and 0.6
Pile length 22 m 17 m
Total length of piles 23870 m 6732 m
Application of piled raft in calcareous sand
Foundation of High Rise Building (Kuwait)
Professor Yasser El-Mossallamy
Slide: 32
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Application of piled raft in difficult geological conditions
Foundation of High Rise Building (Jabal Omar Complex Makkah, Saudi Arabia)
prof. Dr. Ing. Yasser El-Mossallamy 17
Professor Yasser El-Mossallamy
Slide: 33
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Application of piled raft in difficult geological conditions
Foundation of High Rise Building (Jabal Omar Complex Makkah, Saudi Arabia)
Design aspects:
1- Foundation partially on soil, partially on rock
2- High earth pressure (30 m height)
3- Unequal earth pressure
Professor Yasser El-Mossallamy
Slide: 34
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Application of piled raft in difficult geological conditions
Foundation of High Rise Building (Jabal Omar Complex Makkah, Saudi Arabia)
prof. Dr. Ing. Yasser El-Mossallamy 18
Professor Yasser El-Mossallamy
Slide: 35
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
36.9
m
52.7 m
115.3
0.0 = 98.9 mNN
Q
T
GW
-15.8 m
-23.4 m
-37.8 m
a) Cross section
b) Plan
Q = Quaternary Sand/Gravel
T = Tertiary clay
Plaxis 3D Foundation
Case history: Japan Center
Professor Yasser El-Mossallamy
Slide: 36
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Embedded piles
Embedded piles:
soil
pile
tskin
Ffoot
prof. Dr. Ing. Yasser El-Mossallamy 19
Professor Yasser El-Mossallamy
Slide: 37
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
3D FE-Model
Professor Yasser El-Mossallamy
Slide: 38
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Loads
prof. Dr. Ing. Yasser El-Mossallamy 20
Professor Yasser El-Mossallamy
Slide: 39
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Loads
Professor Yasser El-Mossallamy
Slide: 40
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Graphical presentation of the piles in different working planes
prof. Dr. Ing. Yasser El-Mossallamy 21
Professor Yasser El-Mossallamy
Slide: 41
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
3D FE-Model
Professor Yasser El-Mossallamy
Slide: 42
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Axial strain 1
(
50E
1
Asymptote
Failure line
urE
1
qf
qa
0 2 4 6 8 10 12 14 16
0
300
600
900
1200
1500
De
via
tori
c s
tre
ss (
Axial strain 1
FEM results
Test resultsCD - Triaxial test
= 400 KN/m²3
= 100 KN/m²3
= 200 KN/m²3
Hardening soil model
g g
f
n
/ ’
’ = 29° = 0,0
= 20 / 10 kN/m³
E = 30 MN/m² w = 1,0
c = 40 kN/m² E = 90 MN/m²
= 0.2 R = 0.9
’
f
ref
ref
50ref
ur
Applied Constitutive Law
prof. Dr. Ing. Yasser El-Mossallamy 22
Professor Yasser El-Mossallamy
Slide: 43
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Table 1: Geotechnical parameters a- Hardening soil mode Soil parameter Filling Quaternary
Sand/Gravel
Overconsolid
ated clay
E ref
50 [MN/m
2] 20 30 35
Eur
ref [MN/m
2] 50 75 105
ur [-] 0.2 0.2 0.2
m [-] 0.5 0.5 1.0
Rf [-] 0.9 0.9 0.9
/ ´ [kN/m3] 18/8 19/11 20/10
kx [m/sec] 10-3
10-3
2.5 x 10-5
ky [m/sec] 10-3
10-3
0.01 kx
c´ [kN/m2] - - 20
´ [°] 30 35 20
Ko [-] 0.5 0.43 0.8
where:
Eref50 Primary loading stiffness
Eurref
Unloading/reloading stiffness
ur Unloading/reloading Poisson’s ratio
m Power in stiffness laws
Rf Failure ratio
/ ´ Total / Effective unit weight of soil
c´ Cohesion
´ Angle of internal friction
Ko Coefficient of earth pressure at rest
kx, ky Permeability coefficient in the
horizontal and vertical direction
b- Mohr-Coulomb model Soil parameter Limestone
E [MN/m2] 750
[-] 0.3
/ ´ [kN/m3] 20/10
kx [m/sec] 10-3
ky [m/sec] 10-3
c´ [kN/m2] 200
´ [°] 35
Structure elements Piles:
E concrete = 30000 MN/m² and = 0.2
Anchor tendons:
E steel = 195000 MN/m²
Soil parameters
Professor Yasser El-Mossallamy
Slide: 44
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Foundation settlement under working loads
Set
tlem
ent
(cm
)
obs. 1obs. 1obs. 1
Set
tlem
ent
(cm
)
obs. 1obs. 1obs. 1
prof. Dr. Ing. Yasser El-Mossallamy 23
Professor Yasser El-Mossallamy
Slide: 45
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Piled raft of Minaret
Professor Yasser El-Mossallamy
Slide: 46
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Geological conditions (Rock surface contour lines
prof. Dr. Ing. Yasser El-Mossallamy 24
Professor Yasser El-Mossallamy
Slide: 47
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Geological Sections
Professor Yasser El-Mossallamy
Slide: 48
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Finite element model
Alluvium deposit Alluvium deposit
Igneous rock
prof. Dr. Ing. Yasser El-Mossallamy 25
Professor Yasser El-Mossallamy
Slide: 49
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Page 49
Foundation model
Igneous rock
Professor Yasser El-Mossallamy
Slide: 50
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Piled raft of Minaret
Igneous rock
prof. Dr. Ing. Yasser El-Mossallamy 26
Professor Yasser El-Mossallamy
Slide: 51
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Raft Settlement
Max. settlement = 37.1 mm
Professor Yasser El-Mossallamy
Slide: 52
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Raft Settlement
Max. settlement = 37.1 mm
prof. Dr. Ing. Yasser El-Mossallamy 27
Professor Yasser El-Mossallamy
Slide: 53
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Page 53
Pile Stiffness (MN/m)
Professor Yasser El-Mossallamy
Slide: 54
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
prof. Dr. Ing. Yasser El-Mossallamy 28
Professor Yasser El-Mossallamy
Slide: 55
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Tank cross section
Embedded piles for large tanks on soft soil
No. of piles = 376
Pile diameter = 1.5 m
Professor Yasser El-Mossallamy
Slide: 56
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Embedded piles for large tanks on soft soil
prof. Dr. Ing. Yasser El-Mossallamy 29
Professor Yasser El-Mossallamy
Slide: 57
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Embedded piles for large tanks on soft soil
Professor Yasser El-Mossallamy
Slide: 58
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
58
INFOGRAPH – Calculation
- 3-dim. finite element analysis
- Structural system modeled as an overall system
- Dynamic analysis
Embedded piles for large tanks on soft soil
a(T)
0,000
0,100
0,200
0,300
0,400
0,500
0,600
0 0,5 1 1,5 2 2,5 3 3,5 4
prof. Dr. Ing. Yasser El-Mossallamy 30
Professor Yasser El-Mossallamy
Slide: 59
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Embedded piles for large tanks on soft soil
Professor Yasser El-Mossallamy
Slide: 60
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
prof. Dr. Ing. Yasser El-Mossallamy 31
Professor Yasser El-Mossallamy
Slide: 61
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Professor Yasser El-Mossallamy
Slide: 62
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Design concept of piled rafts
Model Simulation
soil-structure interaction
Lab testing (e.g.
Triaxial tests)
Field tests(e.g. SPT)
Optimization analysis
- economic conditions
- serviceability
requirements
Back-calculation
Comparison
Structural design
Foundation design
• Serviceability limit state
• Ultimate Limit state
Determine the required structural parameter
1- pile stiffness depending on pile position
2- soil subgrade reaction modulus for the raft
Soil model
Geo
tech
nic
al
eng
inee
rsS
tru
ctu
ral
eng
inee
rs
Pile load test,
Prototype
prof. Dr. Ing. Yasser El-Mossallamy 32
Professor Yasser El-Mossallamy
Slide: 63
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Application of piled raft
Piled raft foundation
Foundation on medium to dense sandFoundation on overconsolidated clay
Foundation on heterogeneous subsoil,
uncoupled piled raftFoundation on soft clay
Raft
Compacted
soil
Raft
Compacted
soil
0
0
0
200
400
600
800
1000
1
2
3
Set
tlem
ent
(cm
)T
ota
l ap
pli
ed l
oad (
MN
)
Time
1.7.97 1.1.98 1.7.98 1.1.99 1.7.99 1.1.00
0
0
0
End of basic
construction
Final
construction
G.S. = 423.3 müM
GW cal.= 421.0 müM
403.0 müM
388.8 müM
Foundation = 420.52 müM
0.5 m
Moraine
High plastic clay
Middle plastic clay
ABCDEFGHIJ
Section 8-8
High shelves
Piles
17.0
m1
4.0
m
°
°
Tower
Neighboringbuilding
Neckar Street
Kaiser Street
Side building
Gallusa
nla
ge
Neighboringbuilding
Conclusion / Résumé
Professor Yasser El-Mossallamy
Slide: 64
The Sixth Jordanian International Civil Engineering Conference (JICEC06)
Aim of piled raft
Piled raft foundation
Optimizing the foundation designControlling the settlement
Increasing the bearing capacity
slip lineneglected
pile existence neglected
a) Prandtl zone for complete free flow failure
b) Assumed block failure with free flow at the pile base area
g t
t
F
F
Conclusion / Résumé