CivilFEM Geotechnical WebinarWebinar
Peter R. Barrett, M.S.C.E., P.E., ,
2009 CAE Associates
What is CivilFEM?
CivilFEM is an integrated Pre Solu and Post processor add on to CivilFEM is an integrated Pre- , Solu - and Post-processor add-on to traditional ANSYS developed by ANSYSs Spain distributor INGECIBER
100110120130AASHTO LRFDBridge Design Specifications
N /CivilSYS FEM
55
2.5
40
5
15
15
5
8060
50
60
5
5
5
2.5
5
2.5
60
CANADA
100110120130
50
40
30
Bridge Design Specifications (Western USA)
Tropic of Cancer
52.5
2.5
MXICO
AAcceleration Coefficient
Seismic Zone
1
2
3
4> 0.29
> 0.19 and < 0.29
_> 0.09 and < 0.19
_
< 0.09
_
2
INGECIBER- CivilFEM Developer / ANSYS Partner
Ingeciber S.A. is a CAE company and ANSYS Channel Partner with more than 20 years of experience using and developingwith more than 20 years of experience using and developing CAE Software
Ingecibers Quality Assurance System is ISO 9001 certified. g Q y y
Ansys, Inc and Ingeciber, S.A. have a long standing OEM Agreement and established a strategic alliance for FEA solutions i h i i d S ld id Cin the construction industry. Some worldwide Customers:
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ANSYS Today
Worlds Largest Simulation CommunityWorld s Largest Simulation Community
>10,000TotalCustomers
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>10,000CommercialSeats
4
ANSYS/CivilFEM
ANSYS/CivilFEM combines the world leading general ANSYS/CivilFEM combines the world leading general purpose structural analysis features of ANSYS (ISO-9001) with high-end civil engineering-specific structural analysis capabilities of CivilFEM (ISO-9001).
Current Customers include: AREVA, AECOM, Parsons, L li E R bi W ti h
5
Leslie E. Robinson, Westinghouse
CivilFEM & ANSYS
6
CivilFEM Help
Interactive Online Help Interactive Online Help Examples Manuals Advanced Workshops Training Courses
7
Current CivilFEM Distributors
8
CAE Associates, Inc.
One of first 4 ANSYS Channel Partners Since 1985
Engineering Co
9
Engineering Co. Since 1981
CAE Associates CivilFEM / ANSYS Partner
25 years Structural Thermal and Fluid engineering consulting 25 years Structural, Thermal and Fluid engineering consulting One of the original ANSYS Channel partners The US leader in ANSYS Finite Element Training The US leader in ANSYS Finite Element Training Custom Training of ANSYS and CivilFEM
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Sampling of CAE Consulting Services
NIST Structural Fire Response and Probable Collapse Sequence of the World Trade Center Towers Investigation
Steam Generator Replacement in Nuclear C t i t B ildi Containment Buildings
Pre-stressed Concrete Pipe Simulation Concrete Dam simulation to meet
FERC /C f E i li iFERC /Corps of Engineers licensing
11
CAE Associates Senior Technical Staff
Nicholas M. Veikos, Ph.D., President
Peter R. Barrett, M.S.C.E., P.E., Vice President
Michael Bak, Ph.D., Project Manager
P t i k C i h M S M E P j t MPatrick Cunningham, M.S.M.E., Project Manager
Steven Hale, M.S.M.E., Project Manager
James Kosloski, M.S.M.E., Project Manager, , j g
Hsin-Hua Tsuei, Ph.D., CFD Manager
Jonathan Masters, Ph.D., Project Manager
George Bauer, M.S.M.E., Project Manager
Eric Stamper, M.S.M.E., Project Manager
Michael Kuron M S M E Project EngineerMichael Kuron, M.S.M.E., Project Engineer
Lawrence L. Durocher, Ph.D., Director
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ANSYS Strengths
Nonlinear Stress Analysis Contact Plasticity Creep
L D fl i P D l Eff Large Deflection P-Delta Effects Element Birth and Death
Full Element Library (over 200)B Pi & Sh ll Beams, Pipes & Shells
2D and 3D Solids Springs, Contact, etc
Dynamic Analysis Response Spectrum Nonlinear Transient Dynamics
Thermal-Stress Analysis Indirect and direct coupled field simulations
Large Model Simulations
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Large Model Simulations Solvers, meshing, Postprocessing, Graphics
ANSYS Strengths Development 12.0
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CivilFEM Strengths
CivilFEM Capabilities CivilFEM Capabilities Entire suite of ANSYS capabilities including nonlinear analysis
and dynamicsB ilt i S ti P ti M t i l M d l d C d Ch ki Built-in Section Properties, Material Models and Code Checking
Industry Specific CivilFEM Modules Nonlinear Bridge Simulation Pre-stressed Concrete
Geotechnical Applications
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Geotechnical Applications Nuclear Applications
CivilFEMG t h i l Geotechnical
Module
Introduction
The geotechnical module is one of 4 add-on ANSYS CivilFEM modules The geotechnical module is one of 4 add-on ANSYS CivilFEM modules Geotechnical, Nonlinear Bridge, Advanced Pre-stress, and Nuclear
The CFACTIV command is used to activate and deactivate each module The ~CFACTIV command is used to activate and deactivate each module.
~CFACTIV,GETC,Y
17
Geotechnical Capabilities Summary
Materials library (soils and rocks) Materials library (soils and rocks) Layered terrains Soil foundation stiffness (ballast module) Retaining wall design / analysis Seepage analysis Slope stability analysis Tunneling -Hoek & Brown failure criteria Earth pressures Terrain Initial Stress Terrain Initial Stress Foundation Piles
18
Geotechnical Materials
~CFMP command ~CFMP command. This command defines the soil or rock material properties in ANSYS
and CivilFEM. It can be applied sing one of the follo ing options It can be applied using one of the following options:
From library: reads from the library the material properties for a given material reference.
~CFMP,1,LIB,SOIL,,...
~CFMP,1,LIB,ROCK,,...
User defined: the material looses its library reference and the user can h f it tichange any of its properties.
M t i l I l d St d d ANSYS ll i Ci ilFEM M t i l
~CFMP,1, USER
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Material Include Standard ANSYS as well as unique CivilFEM Materials
Soil Material Properties
Soil Library Soil Library
~CFMP,1,LIB,SOIL,,...
Material Material number
Soil classification according to Casagrande
Delete materials
CasagrandeModify selected material
List of defined materials
Save materials
20
Copy materials
Rock Material Properties
Rocks library Rocks library
~CFMP,1,LIB,ROCK,,...
M t i l Material number
Rock classifications
Delete materials
classifications
Copy materials
Modify selected material
List of defined materials
Save materials
21
Geotechnical Material Wizard
22
Soil and Rock Material Properties
Soil /Rock properties are divided into 7 different groups: General properties:
common for all the materials (number, reference, type,) Structural analysis properties: .
St ti d d i ti t i l b h i t Static and dynamic properties, material behavior, etc. Specific weight properties:
specific weight, density, porosity, etc.Properties: Properties:
test parameters, materials laws, etc. Grain-size or Hoek & Brown properties :
grain-size parameters and Atterberg limits or Hoek & Brown & Dilatancy parameters grain-size parameters and Atterberg limits or Hoek & Brown & Dilatancy parameters Correlations:
relationships between geotechnical parameters. FLAC3D:FLAC3D:
Flac3D properties. Soil Menu
23
Rock Menu
Soil and Rock Material Properties
Structural Analysis Structural Analysis properties are divided into:
Elasticity modulus Elasticity modulus, Poisson ratio and density used for the structural analysis.
Plastic behavior Static properties Seismic properties
24
Soil and Rock Material Properties
Specific Weight Specific Weight properties are divided into:
Specific weights Specific weights Density Porosity
Water content Water content
25
Soil and Rock Material Properties
Material Properties are Material Properties are divided into:
Test propertiesMohr-Coulomb parameters Mohr-Coulomb parameters
Drucker-Prager parameters Mohr-Coulomb in plain
strain models parametersstrain models parameters Earth pressure data Seepage
26
Soil and Rock Material Properties
Grain-size properties are grouped into: Grain-size properties are grouped into: Grain-size parameters Atterberg limits
These properties are only defined for soils
27
Soil and Rock Material Properties
Hoek & Brown properties are grouped into: Hoek & Brown properties are grouped into: Hoek & Brown parameters Dilatancy parameters
These properties are only defined for rocksonly defined for rocks
28
Soil and Rock Material Properties
The correlations can be selected from the CivilFEM library or from a user The correlations can be selected from the CivilFEM library or from a user defined file.
Select between CivilFEMcorrelations or user defined
Relates the SPT valueRelates the SPT value with the elasticity
module applying the correlation to the specified property
Applyy
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Correlations
User defined correlations User defined correlations
5- Correlation number 6- Function
International SystemUNITSU S
7- Comment
4 S l t
(Optional)
The right hand menu assists in writing a
correlation
30
4- Select new correlation
correlation
Example - Cap Drucker-Prager Model
Cap Drucker-Prager plasticity model applicable to Cap Drucker Prager plasticity model applicable to Simulation granular materials such as soils Introduce cap for both tension and compression
I l d h d i Include cap hardening Include shear envelope hardening
31
CivilFEM Soil Materials Example Help
32
Terrain
Layered Terrain Definition
Terrain Number of
layers. (Maximum,
20)
Terrain number
Terrain name
Pitch
Terrain general properties
)
W t
Location
Water Table
L Thickness
SurfaceLoad
LayerProperties
Layer number
Material
Horizontal Ballast M d l
p
Coulomb theory for earth
Module
33
pressure calculation
Layered Terrains Definition
Allows the definition of soils without having to discretize them as finite Allows the definition of soils without having to discretize them as finite elements in the model.
New Terrain
Modify selected Terrain
lDelete Terrain
Copy Terrain
Properties list
34
Earth Pressures Earth Pressures, Ballast Module, Soil F d i S iffFoundation Stiffness
Automated Earth Pressures
CivilFEM Model: Earth column contribution over this point At rest earth pressure Active earth pressure Passive earth pressure
qKhKE 0ni
1iii00
Earth column contribution over this point
p The soil weight on the selected elements of the model. Dry and flooded earth
ELEMENT TYPES:
1
1
Beams Shells Solids YSolids Surface elements:
3D BEAM ELEMENTS5
2
5
SHELL ELEMENTS
XZ
X
Y
Z
xz
21
3x
y z
4
6
5
36
y
43
1
Earth Pressures
ACTIVE AND PASSIVE EARTH PRESSURES CALCULATION: ACTIVE AND PASSIVE EARTH PRESSURES CALCULATION: Calculated considering:
Earth column contribution over this point.C h i Cohesion
Surface load over the terrain.
q
2LLqK
2LLcKLhKE 21hq21hc1n
1ni
1iiih
h1
h2Layer2
Layer1
Kh: Horizontal earth pressure coefficient due to the earth weight
K l h
hn-1Layern-1
EL1
Khc: Horizontal earth pressure coefficient due to cohesion
Khq: Horizontal earth pressure coefficient due to the surface load
ELayernL2
L2 L22+
37
coefficient due to the surface load
Ballast Module
CivilFEM calculates an estimation value of the ballast module (soil foundation stiffness), that allows approximating the elastic soil model (E and ) by means of Winklers model (beam on an elastic foundation)foundation).
Calculation steps:1. Model definition (materials,
l b & h llelements, beam & shell properties)
2. Terrains definitionSelect the elements and nodes3. Select the elements and nodes that make up the foundation
4. Ballast module calculation5 Ballast module application5. Ballast module application
38
Ballast Module
C l l t th b ll t d l f f d ti i l d fi d b th Calculates the ballast module for a foundation previously defined by the user. The elements and nodes that make up the foundation must be selected beforehand.
~EFSCALC, UCIM, UTER
Enter foundation and terrain numbers
39
Ballast Module: Results
Plot and list results Node Plot and list results Close the window
Element results
Node results
Activated
Foundation not created List
Activated foundation
Deactivated
results
foundation
Results scale
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Retaining Walls
Retaining Wall Calculation
Non-linear Analysis Non-linear Analysis Construction Sequence Automated Simulation changing with excavation level
It takes into account the soil-structure
The wall may be id d the soil structure
interaction using non-linear springs
with contact elements
considered as a non-linear structure and analyzed by the non-linear module of
Ci ilFEMCivilFEM
42
Retaining Wall Calculation
Calculation of Sheet Piles 2D (automatic wizard) -3D Calculation of Sheet Piles 2D (automatic wizard) -3D Non-linear construction sequence analysis One or two sheet piles can be analyzed simultaneously
Simulation of anchors water level layered soils other applied loads Simulation of anchors, water level, layered soils, other applied loads.
The excavation or backfilling process canbackfilling process can be visualized in each calculation step.
43
Retaining Wall Calculation
Calculation of Sheet Piles 2D (automatic wizard) -3D Calculation of Sheet Piles 2D (automatic wizard) -3D With any ANSYS/CivilFEM cross section Interaction with other structures
44
Retaining Wall Calculation
The systems generated may consist of one or two walls that can be y g yintegrated inside other ANSYS models like a subset.
The model is solved by means of an evolving calculation, where each calculation stage represents a step in excavation or backfill.g p p
The reinforcement of the retaining walls can be later designed by CivilFEM.
Applicable to any ANSYS/CivilFEM cross section Applicable to any ANSYS/CivilFEM cross section
45
Retaining Walls: Modeling
The retaining wall is modeled with 2D Retaining Wall Modeling The retaining wall is modeled with 2D beam elements applying:
Boundary conditions Actions
Retaining Wall Modeling
PPT1 PPT2
Actions
The interaction with the terrain is simulated by the action of two pairs of
APT1APT2
simulated by the action of two pairs of springs (LINK1 element) linked to gaps (work in compression)
Organic Low
W ll d t d l
Terrain 1 Terrain 2
Each pair of springs is in charge of reproducing :
P i th
Well graduated gravel
Silt
Passive earth pressure Active earth pressure (Earth Pressures described
previously)
Peat (Low)
46
previously) The soil is defined as layered terrain
Retaining Walls: Earth Pressure
Material behavior law Material behavior law The introduction of the material law for each spring is carried out using a
nonlinear elastic behavior model
-(E -E )0 aF
d
(E E )
d
HBM-(E -E )p 0
47
Retaining Walls: Calculation Procedure
~WALLINI
Initializes the data in the retaining wall analysis
G lGeneral Properties
Wall 1 Properties
Wall 2 Properties
48
Retaining Walls: Calculation Procedure
~WALLGEN command ~WALLGEN command Defines the elements forming the retaining wall: Material:
Concrete Concrete Steel
Type Real constant
~WALLGEN, IWALL, ISEC, LENGTH, MAT, TYPE, REAL
WallnumberReal constant
Section Lengthnumber
It is possible to use any nonlinear behavior any nonlinear behavior in the Retaining Wall
49
Retaining Walls: Calculation Procedure
ANCHORAGE TYPES
Articulated(ANCHTYPE = 1)
Fixed(ANCHTYPE = 0)
The anchorage is created as a beam with one of its ends fixed to the soil
A support will be placed on the wall. The node will be moved to its initial fixed to the soil. moved to its initial location.
Delete(ANCHTYPE = -1)
All anchorages at
Fixed with no movement restoringAll anchorages at
the chosen level will be deleted at this construction step.
restoring(ANCHTYPE = 2)
A support will be placed on the wall.
50
placed on the wall.
S A l iSeepage Analysis
Seepage Analysis Capabilities
Calculate hydraulic heads and pore water pressures Calculate hydraulic heads and pore water pressures.
Calculate filtered flows through boundaries.
Obtain the water table for 2D models.
Export the obtained pore water pressure to slope stability analysis. The finite element mesh used in both analysis can be different.
Darcys law with anisotropy of the permeability coefficient (different permeability in x, y, z directions).
HK-v,HK-v,HK-v zzzyyyxxx zyx
52
Seepage Analysis: Boundary Conditions
Impermeable surface: Impermeable surface:
Upstream surface: H = H
0
nH
Upstream surface: H = H0 Seepage surface: H = geometric height Downstream surface: H = H1
ySaturation surface
H0 AHn H(x,y) = H0
H(x,y) = y(x)Seepage surface
Upstream surface
xH1B
H Downstream surface
H( ) H
Impermeable surface
53
n H(x,y) = H1
Seepage Analysis: CivilFEM Elements (II)
Equivalence table of available element types Equivalence table of available element types
ANSYS Thermal SolverCivilFEM Seepage Solver
ANSYS Thermal Solver for Seepage Analogy
CivilFEM SEEPAGE Elements
ANSYS STRUCTURAL Elements
ANSYS THERMAL Elements
2D PLANE 42 - SEEP PLANE 42 PLANE 55
3D SOLID 45 - SEEP SOLID 45 SOLID 70
54
Seepage Analysis: CivilFEM Elements (III)
Building a model for CivilFEM seepage solver: Building a model for CivilFEM seepage solver: The model is created using ANSYS structural elements
El t t t ti ll h d b th l Element types are automatically changed by the solver.
ANSYS/Structural Elements CivilFEM Elements
PLANE 42 PLANE 42 SEEPSOLID 45 SOLID 45 SEEP
Available degrees of freedom:
ANSYS D.O.F. CivilFEM D.O.F.UX H (Hydraulic head)UY Not Used
55
UZ Not Used
Seepage Analysis: CivilFEM Elements (IV)
K L
x
y
J
I
I
J 4 nodes triangle option
Degenerated shape
x
y
F d t di i l l t
J
Second grade shape function
M,N,O,P
Triangular prism
Basic shape
Four nodes two-dimensional element
Three-dimensional
K,L
I
JTetrahedron
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Three dimensional
Seepage Analysis: Saturation Line
DAM EXAMPLE:DAM EXAMPLE: The saturation line has two end points that must comply with the following
boundary conditions:a) Fixed: Point A in the figure a) Fixed: Point A in the figure
b) Sliding along a seepage surface: Point B in the figure
t 1
y
H0y(x)
Saturation line
Seepage surfaceA
1
xH(x,y
)=H
H(x,y)=H1
0
H(x,y)=y(x) H1
x a
y(x) p g
Byyyy
yy
A
B4321
Hn = 0
Hn = 0
2D Seepage (Without drains)
n
57
Slope Stability
Slope Stability
Slope stability can be calculated by means of two methods conceptually Slope stability can be calculated by means of two methods, conceptually different:
1 CLASSICAL METHODS1. CLASSICAL METHODS Fellenius Bishop
Simplified and Modified Janbu Simplified and Modified Janbu
2. FINITE ELEMENT METHODEquivalent results to the one obtained with classical methods Equivalent results to the one obtained with classical methods.
59
Slope Stability
Fellenius Method (Swedish or independent slice method): Fellenius Method (Swedish or independent slice method): Sliding surface: CIRCLE. Independent slices.
Equilibrium of moments in relation to the circle center Equilibrium of moments in relation to the circle center. Recommended: cohesive homogeneous materials. NON iterative process
N calculation:
Bi h M th d
cossinsincos yx DDkWWN
Bishops Method: Sliding surface: CIRCLE. Equilibrium of moments in relation to the circle center.
It ti N d d th f t f t F Iterative process N depends on the safety factor F.
DF
uLcLWN
y
i
tansinsin
60
F
N tansincos
Slope Stability
Janbus Simplified Method: Janbu s Simplified Method: Sliding surface: ANY POLYGONAL. Forces equilibrium.
Iterative process N calculation is the same as for the Bishops method Iterative process N calculation is the same as for the Bishop s method.
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Slope Stability
2 FINITE ELEMENT METHOD:2. FINITE ELEMENT METHOD:
Safety factor
a.
a . u)tg(cF n
n = Normal stress on the bottom
of the slice
= Tangential stress on the = Tangential stress on the bottom of the slice
a = Slice width
-.378E+ 07-.336E+ 07-.294E+ 07-.252E+ 07-.210E+ 07-.168E+ 07-.126E+ 07-836853-4167583338
u = Pore water pressure
62
Slope Stability
How to perform a stability analysis? How to perform a stability analysis?
Create the model (geometry, mesh, loads)S l O l f FEM A l i Solve
Capture the model for slope stability Slope stability needed data:
Sliding surfaces definition
Only for FEM Analysis
Sliding surfaces definition Pore water pressure
Solve slope stabilityPostprocess results Postprocess results
Differences among classical methods
63
Slope Stability
Capture the model for slope stability Capture the model for slope stability
~SLPIN N1 N2 N3 ~SLPINK K1 K2 K3~SLPIN, N1, N2, N3
Valid sliding surface
~SLPINK, K1, K2, K3
Invalid sliding surface
jobname.db jobname.cfdbjobname.slp
Invalid sliding surface
64
Slope Stability
Results Pl t Results Plot press. lines
Sliding direction
Previous and next Circles and Centers
Plot complete circles
Plot loads Sliding surfdirection
List
Sliding surf. number and safety factor
Min Coef. Export plotSafety Fact. map
Number of colors
Maximum safety factor shown
65
Tunneling
66
Wizard for Tunnel Design
Tunnel section PLOT NO. 1-909.174-878.511-847.848-817.185-786.522-755.859-725.196-694.533-663.87-633.207
COL 3
Tensin vertical. Frente de avance
Longitudinal Section
Vertical Stress. Tunnel Advancement
Forces and Moments on Concrete
COL 1
COL 2
PLOT NO. 1-.018494-.014481-.010468-.006455-.002443.00157.005583.009596.013609.017621
COL 2
Forces acting on Movimiento vertical. Frente de avanceVertical Movement. Tunnel Advancement
67
concrete tunnel LongitudinalSection
Underground Structures (Tunnels)
Element Birth and Death capability (non-linear construction sequence Element Birth and Death capability (non-linear construction sequence analysis)
1
68
11CERROGORDO
Underground Structures (Tunnels)
Terrain Initial Stress Terrain Initial Stress Hoek & Brown Failure Criteria (rocks) Plastic Constitutive models: 2D/3D Drucker-Prager and Mohr-Coulomb Element Birth and Death capability (non-linear construction sequence
analysis)
69
Wizard for Tunnel Design
70
Wizard for Tunnel Design
71
Hoek & Brown Hoek & Brown Failure Criterion
Hoek & Brown Failure Criterion
This tool offers the possibility to work with rock foundation models, satisfying the Hoek and Browns failure model, original (1980) or modified (1992).
RMR Rating used to select failure model
The procedure followed by CivilFEM, is based on using, at each load step, a Drucker-Prager material, whose properties change according to its load level.
73
Hoek & Brown Failure Criterion
HOEK & BROWNS CRITERION VALIDITY
The Hoek and Browns criterion is valid only for low confinement pressures.pressures.
In rock mechanics, four structural situations of the rock massifs are generally distinguished according to the defects and discontinuities shown.
Group I:Intact Rock
Rocky Massif State Classification
sm
331
Group II:One single discontinuity
Group III:Two discontinuities
cc
c: Compression resistance of the matrix rockTwo discontinuitiesGroup IV:Several discontinuities
Group V:
matrix rock.m,s: Constants that depend on the
characteristics of the rock and on its cracking state
74
pFractured Massif
g
Hoek & Brown Failure Criterion
MODEL OPERATIONMODEL OPERATION
For each element in the model a stress state is read (1, 3) Using Hoek & Brown criteria, the parameters of Mohr Coulomb are
obtained, and from this values, the Drucker Prager equivalent parameters.
Hoek-Brown c, 1, 3 ,
Mohr-CoulombS l
Drucker-Prager
Solve
75
Hoek & Brown Failure Criterion
CALCULATION PROCEDURECALCULATION PROCEDURE After creating the model, the Hoek & Brown solver should be used.
Read material properties at the
Write material
p pend of a Hoek & Brown analysis, for other calculations.
Write material properties at the end of the Hoek & Brown analysis
76
Terrain Initial St essStress
Terrain Initial Stress
Develop Stress with no Strain Develop Stress with no Strain
Gravity
Gravity
Terrain Initial Stress
78
Terrain Initial Stress
In order to simulate excavation processes and real terrain behavior the In order to simulate excavation processes and real terrain behavior, the initial stresses (without strain) can be considered.
Terrain Initial Vertical Stress at each point is calc lated regarding the Terrain Initial Vertical Stress at each point is calculated regarding the weight of terrain above the point.
n
h Terrain Initial Horizontal Stress at each point depends on the vertical
i1i
iV h
stress. V
VoH k
H
79
H
Terrain Initial Stress
Initial Stress is calculated Initial Stress is calculated using the ~TIS command.
It will create a file (jobname IST) with the(jobname.IST), with the stresses for each element.
Gravity direction needs to be specified
80
specified
Foundation Piles
Deep Foundations
Pile Cap Wizard: Pile Cap Wizard: Automatic generation of rectangular, polygonal or circular pile groups
82
Piles
Driven piles Excavated/Drilled foundations Micropiles
Example Pile Cap Load Test Load Test Reinforcement Example Pile Cap Load Test Design
83
Foundation Piles
Geometry of the pile cap: Geometry of the pile cap: Polygonal or circular
RAD
DIAPIL
Y
1
DPOL
RADPIL
H i htE
X2
3 4
5
HeightEn
HeightT (1) WidPLA
HeightPil
LenPIL
HeightT (NumStr)
HeightT (NumStr+1)
Z
84
X
Poligonal pile-wailing
Foundation Piles
Rectangular pile cap DistPilx (1...Npx-1) Rectangular pile cap
_
_
|
DExtRig
DE
xtTo
p
DIAPIL
Y(3,4)
Piles identified withtwo numbers (I,J):Horizontal and vertical
(I,J)
Dis
tPily
(1...
Npy
-1)
_
_
PosXCol
Pos
YCol
Column
DEx
tBot
X
(1,1) (1,2)
(2,2)
DExtLef
D
HeightEn
HeightT (1) WidPLA
HeightPil
HeightT (NumStr)
HeightT (NumStr+1)
LenPIL
Z
85
Rectangular wiling of Npx x Npy piles
X
Z
Foundation Piles
Terrain definition: Cohesive SoilsConsistency qu (kPa) NSPT () c (kPa)
Very soft 30-50 2-4 15-20 0-10
Soft 50-100 4-8 20-25 10-20
Medium 100-200 8-15 25-30 20-30
Hard 200-400 15-30 30-35 30-50
Cohesionless Soils
Hard 200-400 15-30 30-35 30-50
Very hard >400 >30 >35 >50
Compacity NSPT () c (kPa)
Very low 0-4 50 >41 0-20
Foundation Piles
Internal Friction Angle vs Cohesion Internal Friction Angle vs. Cohesion
Cohesionless soilsj ( )
Limit can be changed
35
40
45
Cohesionless soilsj ( )
20
25
30
35
(c , )j L L
5
10
15Cohesive soils
CivilFEM's soil clasification
010 20 30 40 50 60 70 80 900 c (kPa)
87
Foundation Piles Force - Deflection
Load capacity: Cohesive soils Load capacity: Cohesive soils Skin friction and point resistance
LOAD
Q
QP
QT
QS
P
wS wP SETTLEMENT, w
Load capacity vs. settlement in piles
88
Foundation Piles
Load capacity: Cohesive soils Load capacity: Cohesive soils Skin friction
0.6
0.7
a =
f
/Cs
u
0 200 400 600 8000.2
0.3
0.4
0.5
Undrained shear strength, Cu (kPa)
Piles adhesion factor
g (%)fS
1.0
1.5
2.0
aC ~ 50 kPauaC ~ 200 kPau
w = Dgs p.
Shaft deformability factor (%)gUndrained shear strength, Cu (kPa)
0 200 400 600 8000.0
0.5
aC ~ 100 kPau
Value can be changed
89
Shaft deformability factor (%)g Value can be changed
Foundation Piles
Load capacity: Cohesive soils Load capacity: Cohesive soils Point resistance
Values can be changed
90
Foundation Piles
Load capacity: Cohesionless soils Load capacity: Cohesionless soils
Skin friction
Point resistance Values can be changedg
91
Foundation Piles
Pile capacity: Depends on the piles length Pile capacity: Depends on the pile s length
z1zp Q QS P
z2
z3
znL
92
-z -z
Ultimate static pile capacity
Foundation Piles Base Soil
Point effect correction Point effect correction
( )
a .D1 p Passive zone
_
_
_(a)
(b)
La
Lb
a .D2 p Active zone
_(c)
Lc
a .D3 p Security zone
P i t i t d l t
93
Point resistance development
Foundation Piles Grouping Effect
Grouping effect correction Grouping effect correction
h < 1f h < 1f
_h > 1
w_
Uni
t bea
ring
capa
city
(w, f)f
U
( .w, .f)h h w f
f*
Groupping effectSettlement, ww w*
Unit bearing capacity is reduced as settlement increases
94
Foundation Piles Stress Check
Mean Design Stress Checking Structural Capacity vs. Pile diameter
sc(MPa)ci
ty
7
8
9
Stru
ctur
al C
apa
Canadian code (Extraordinary loads)
Recommended forExtraordinary Loads (Earthquake, etc)
5
6
French Code
Recommendedfor Service Loads
2
3
4Spanish Construction code NTE
Recommended forsingle pile(Service Loads)
D (m)p
10.400.20 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
( )
Recommended Structural Capacity
95
Recommended Structural Capacity
Foundation Piles FEA Model
Equivalent springs Equivalent springs Horizontal skin springs
Horizontal Ballast module: Chadeysson Ski V ti l S iChadeysson
Vertical skin springs Vertical point springs Finite Element Node
Skin Vertical Spring
Skin Horizontal Springs
x
y
z
Finite Element Node
Point Vertical Spring
96
Springs on nodes
Foundation Piles - Loads
Loads on Columns: Forces and Moments Loads on Columns: Forces and Moments
ZF z
Other loads:Mz
Mx
Other loads:
Pressure on slab
X Y
Myx
F F
Self weight
Seismic F x F y
Forces and Moments sign convention
acceleration
97
Forces and Moments sign convention
Foundation Piles
Reinforcement Groups:Reinforcement Groups:
Rigid Cap Flexible Cap
Top side Top side
Secondary reinforcement A2sClosed
Secondary reinforcement A2sPunching reinforcemente A2p
Bottom side
Closedstirrups
Bottom side
Primary reinforcement A1p Secondary reinforcement A1s Secondary reinforcement A1sPunching reinforcemente A1p
98
Rigid wailing: Reinforcements Flexible wailing: Reinforcements
Foundation Piles
99
Foundation Piles
100
Foundation Piles
101
Foundation Piles
102
Foundation Piles
103
Foundation Piles
104
Foundation Piles
105
Integration with FLAC3D
106
Foundations & Dams
Footing and continuous foundations: Footing and continuous foundations: - 2D/3D soil-structure interaction models
Dams
107
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