civilfem geotechnical webinar - caeai.com · civilfem geotechnical webinar peter r. barrett, ......

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:

3

ANSYS Today

Worlds Largest Simulation CommunityWorld s Largest Simulation Community

>10,000TotalCustomers

>125 000 Commercial Seats


>60 000 Commercial Seats


>10 000 Commercial Seats>125,000CommercialSeats >140,000UniversitySeats >200ChannelPartners >75IndustryPartners

>60,000CommercialSeats >70,000UniversitySeats >20ChannelPartners >80IndustryPartners

>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

10

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

12

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

13

Large Model Simulations Solvers, meshing, Postprocessing, Graphics

ANSYS Strengths Development 12.0

14

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

15

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

19

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


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


Specific Weight Specific Weight properties are divided into:

Specific weights Specific weights Density Porosity

Water content Water content

25


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


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


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


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

29

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

40

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


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


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


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


~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


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

56

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.

61

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


70


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 & 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


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


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


78


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


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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