CONCEPTION DES CHAUSSÉES: Approache mécanique, caractérisation des matériaux et leur évaluation dans les plates-formes routières António Gomes Correia Université de Minho, Portugal Président TC3 - SIMSG
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
PRESENTATION INTRODUCTION PAVEMENT MODELLING AND DESIGN
NON LINEAR BEHAVIOUR OF SOILS AND UGM QUALITY ASSESSMENT - LABORATORY Simple tests Functional tests Mechanical behaviour - Cyclic triaxial tests
QUALITY ASSESSMENT - FIELD Routine analysis Advanced analysis
FINAL REMARKS
CFMSG – 04-10-20
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
EMPIRICAL PAVEMENT DESIGN
MECHANISTIC PAVEMENT DESIGN
MOVE FROM EMPIRICAL SPECIFICATIONS – INDEX PROPERTIES TO PERFORMANCE-BASED SPECIFICATIONS MECHANICAL PROPERTIES CFMSG – 04-10-20
CFMSG – 04-10-22
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
PAVEMENT MODELLING & DESIGN
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
PAVEMENT MODELLING – 2D / 3D
CFMSG – 04-10-20
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
MECHANISTIC PAVEMENT DESIGN 1. Multi linear elastic systems calculations - linear elastic models - most widely used for pavement design and back analysis calculations. Material properties: Modulus (E) and Poisson ratio (ν).
2. - FEM calculations (2D / 3D) Elastic non-linear models -
Available in some codes after Science-EC project (1993). Material properties: Elastic and elastic non-linear stress-strain relationships (K(p,q); G(p,q)) – variants of Boyce model. Visco-elastic and elastic non-linear stress-strain models Implemented in FEM codes during COURAGE (1999). Material properties: Elastic non-linear stress-strain; temperature and strain rate dependent.
3. FEM calculations (2D / 3D) - Visco-elastic and elastoplastic
models - Implemented in FEM codes and still in development to predict permanent deformations. Material properties: General stress-strain.
PAVEMENT DESIGN PROCESS
Modèles des matériaux
Routine
Dimensionnement Mod. réponse (mod. structurel)
Mod. calage Critère de dim.
Niveaux dimensionnement Avancé
Recherche
Besoin d’une coopération entre le responsable de la modélisation et le responsable des investigations in-situ et en laboratoire CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
QUALITY ASSESSMENT LABORATORY
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
QUALITY ASSESSMENT Laboratory tests ªSIMPLE TESTS:
to general material assessment (petrography, flakiness, plasticity) and fragmentation assessment (LA, MBg, DSC, MDE, Gyratory) - Uses a limited portion of material’s parent grading curve - Not able to predict the overall behaviour of the material.
ª FUNCTIONAL TESTS: ª Construction level - to assess the bearing capacity of UGM to carry loading applied (shear strength test) and spreading the loading (RLT- stifness).
ª Long term behavior - to assess stifness - capacity of spreading the loading (RTL stifness) and resistance to permanent deformation (RLT - permanent deformation )
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
SELECTION OF MOST APROPRIATED MATERIAL
based in simple tests (SOIL AND UGM) for most part experienced based Similar to AC – volumetric design (Marshall method)
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
A RATIONAL APPROACH TO LABORATORY STUDY OF MECHANICAL BEHAVIOUR Strength & Stiffness
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
NON LINEAR BEHAVIOUR OF SOILS AND UGM
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
Shear stress, τ’
NON LINEAR ENVELOPE OF MAXIMUM SHEARING STRENGTH - UGM Peak strength Strength at critical state
φ´cv
φ´p
Normal effective stress, σ’ NON LINEARITY INCREASES WITH INCREASING RELATIVE DENSITY AND GRAIN CRUSHABILITY
NON LINEAR BEHAVIOUR DEFINITIONS OF MODULUS σ
E0
E
Esec E tg E0
Esec
Etg
ε CFMSG – 04-10-20
lg ε
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CYCLIC TRIAXIAL TEST PERFORMANCE TEST
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
EUROPEAN STUDY - COURAGE Grading curves 100 90 80
Material A, granite, IST Portugal Material B, gneiss, LCPC France Material C, limestone, ZAG Slovenia
Passing [%]
70 60 50 40 30 20 10 0 0.01
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0.1
1
Sieve size [mm]
10
100
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CYCLIC STRESS PATHS
ª CYCLIC TRIAXIAL TESTS OF UGM (CEN prENV 00227413 - 1997) E4
600
D4
q (kPa) E3
500
D3
400 C4
E2
300
D2
C3 F2
200
E1 F1
D1
B4
C2
B3
100 C1
B1 A1
0 0
B2
A2
100
A3
200
A4
p (kPa) 300
VARIABLE CONFINING PRESSURE CFMSG – 04-10-20
400
CEN - method A
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CYCLIC STRESS PATHS
ª CYCLIC TRIAXIAL TESTS OF UGM (CEN prENV 00227413 - 1997)
300
q (kPa)
250
200
CONSTANT CONFINING PRESSURE CEN - method B
150
100
50
p (kPa)
0 0
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50
100
150
200
250
300
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CYCLIC TRIAXIAL TEST (ECP) Local strain measurements
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CYCLIC TRIAXIAL TEST (ECP) Results of strain measurements
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A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CYCLIC TRIAXIAL TEST (LPC)
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A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CYCLIC TRIAXIAL TEST (UMinho)
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A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
SOIL / SOIL+ROCK / ROCK
TYPICAL MOISTURE & DENSITY CONDITIONS FOR UGM - BASE
w OPM - 4
WATER CONTENT w w OPM - 2
w OPM - 1
100 % ρd OPM
1 Specimen 1 Specimen
2 Specimens 1 Specimen
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DRY DENSITY
1 Specimen
97 % ρd OPM 95 % ρd OPM
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
TYPICAL RESULTS OF CYCLIC TRIAXIAL TEST – Plastic strains STABILISATION AFTER A NUMBER OF CYCLES ? QUASI-ELASTIC BEHAVIOUR ? p
p
p
[ε1 - ε1 (100)] (10-4)
200
0
p
[ε3 - ε3 (100)] (10-4)
MFC : 5 % F 150
-50 γd = 97 %, w = 3.7 % γd = 97.2 %, w = 3.9 %
100
γd = 97 %, w = 4.1 %
-100
γd = 96.9 %, w = 3.2 % γd = 96.8 %, w = 2.1 %
50
Nº (cycles)
0 0
5000
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10000
15000
-150
Nº (cycles)
-200
20000
0
5000
10000
15000
20000
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
TYPICAL RESULTS OF CYCLIC TRIAXIAL TEST – Plastic strains 5% Fines Permanent strains* (x10-4)
0.0 50.0 100.0 150.0 200.0 250.0 0
5000
10000
15000
20000
25000
Number of cycles
95.0%; 3.82%
95.0%; 3.54%
97.0%; 3.65%
97.2%; 3.87%
97.0%; 4.1%
100.0; 3.70%
100.0%; 3.74%
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
Courage test results PERMANENT STRAIN PARAMETER, A1 RESULTS 350 Gneiss, Control Grading Granite, Control Grading Limestone, Control Grading UK RCC&A Supply Grading A - greywacke B - carboniferous limestone C - argillaceous limestone D - ryolite E - crushed limestone F - crushed granodiorite G - basalt/dolerite
PERMANENT STRAIN PARAMETER A1 x 10 (m/m)
-4
325 300 275 250 225 200 175 150 125 100 75 50 25 0 0
10
20
30
40
50
60
70
80
90
100
RELATIVE MOISTURE CONTENT (% of OMC)
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
Wheel track – University of Oulu – Fil.
AC 30 mm
1
180 mm 330 mm
UNBOUND GRANULAR MATERIAL 300 mm (test material)
3 2
FILTER SAND 270 mm Vertical deflection potentiometers
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
Courage test results PERMANENT S TRAIN RATE RES ULTS
PERMANENT STRAIN RATE PARAMETER dε p /dN x 10-5 (%/cycle)
0.16
FAILED Gneiss, Control Grading Granite, Control Grading Limestone, Control Grading UK RCC&A Supply Grading Gneiss, WT test Granite, WT test Limestone, WT test
0.14 0.12
HIGH STRAIN SUSCEPTIBILITY
0.1 0.08 0.06 0.04 LOW STRAIN SUSCEPTIBILITY
0.02 0 0
10
20
30
40
50
60
70
80
90
100
RELATIVE MOISTURE CONTENT (% of OMC) measured at 3000 cycles
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
Un.-Rel. Strains ε
v
p *n γ + 2 n − 1 = n −1 + pa 3 K a 18 G a
TYPICAL RESULTS OF CYCLIC TRIAXIAL TEST- VCP (Anisotropic Boyce model; Hornych et al., 2000)
(γ + 2 ) q * p *
Volumetric strains 50
2
γ − 1 q * + 3 G a p *
εq
2 q* 2 p *n γ − 1 n −1 2 γ + 1 q * ( ) 1 + = + γ − p* 3 p an −1 3 K a 18 Ga 6 Ga p *
NON-LINEAR BEHAVIOUR
Shear strains
20
Anisotropic Boyce model
40
15
Measurements
30 10 v
q
20 5
10 Anisotropic Boyce model
0
0
Measurements
-10
-5 0
100
200 P (kPa)
CFMSG – 04-10-20
300
400
0
100
200
300
400
P (kPa)
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
TYPICAL RESULTS OF CYCLIC TRIAXIAL TEST- CCP Un.-Rel. Strains ε = 0,001%
CFMSG – 04-10-20
CFMSG – 04-10-22
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
UGM – STIFFNESS RANKING Variation du module Esec en fonction TOTAL STRESSESde– σ EFFECTIVE STRESSES v et σv’ (ECP, Coronado, 2005)
1000
Module sécant Esec ( MPa)
Module sécant Esec ( MPa)
1000 0.50
y = 61.34x0.41
y = 36.05x
0.31
y = 46.77x
y = 97.12x
0.44
y = 228.45x0.116
Normalisé pour e=0.33
100 10
100
Contrainte verticale σv (kPa)
Soacha 30% fins d10=20µm
E plus grand en contrainte totales Servita 20% fins, d10=45µm Vista H. 10% fins, d10=80µm
0.26
y = 101.23x
Normalisé pour e=0.33
100 1000 10
100
Contrainte verticale effective σ'v (kPa)
1000
Soacha 30% fins d10=20µm
E plus petit en contrainte effectives Servita 20% fins, d10=45µm Vista H. 10% fins, d10=80µm
TYPICAL RESULTS OF COMPRESSION TRIAXIAL TEST- CCP PECULIAR BEHAVIOUR OF COMPACTED UGM
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CFMSG – 04-10-22
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
EMPIRICAL versus MECHANICAL PARAMETERS
QUALITY ASSESSMENT
DIFFERENT RANKING ! Processed materials behave in a different way to natural materials - Los Angelos and Micro-Deval. They generally give better mechanical performance in the field than would be expect from the results of such tests. Therefore performance-related tests (CLTx)
CFMSG – 04-10-20
CFMSG – 04-10-22
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
QUALITY ASSESSMENT FIELD
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
UGM – QUALITY ASSESSMENT BY IN-SITU TESTS
ªSIMPLE TESTS:
to density and moisture content material
assessment
ª FUNCTIONAL TESTS: ª Construction level - to assess the bearing capacity of
UGM to carry loading applied and the capacity of spreading the loading (LPT, FWD, SASW, …).
ª Long term behavior - to assess stifness - capacity of
spreading the loading (LPT, FWD, … -representative state conditions?) and resistance to permanent deformation (LPT permanent deformation).
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
NEED TO MOVE FROM EMPIRICAL TO MECHANISTIC-BASED SPECIFICATIONS MECHANISTIC-BASED SPECIFICATIONS (focus on the mechanical properties)
FACILITATE QUANTITATIVE EVALUATIONS (necessary to alternative construction practices and materials – reclaimed materials) Performance-based specification is required to control the long-term functional and structural performance CFMSG – 04-10-20
CFMSG – 04-10-22
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
MECHANICAL-BASED IN SITU TESTS, AIPCR, C12, 1995
PLATE BEARING TEST CALIFORNIA BEARING RATIO TEST - CBR DYNAPLAQUE FALLING WEIGHT DEFLECTOMETER – FWD DEFLECTOGRAPH CLEGG IMPACT HAMMER MEXECONE PENETOMETER DYNAMIC CONE PENETROMETER COMPACTION METERS DYNAMIC PLATE BEARING TESTS VARIABLE IMPACT TESTER
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A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
STIFFNESS - TARGET VALUES (Chaddock & Brown, 1995); Zaghloul, 1997; Flemming, 2000; Nunn et al., 1997; GTR, 1997)
STIFFNESS
50 MPa – Formation (GTR, 1997) 50 to 65 MPa – Formation (Flemming et al., 1998) 100 MPa – Foundation (Flemming et al., 1998) 80 MPa – Formation - FWD – stress=200 kPa; D=450 mm (Chaddock & Brown, 1995) 45 MPa – Ev2 – DIN - Foundation 120 MPa – Ev2 – DIN – Sub-base (light traffic) 150 MPa – Ev2 – DIN – Sub-base (heavy traffic)
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CFMSG – 04-10-22
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
CONSTRUCTION TECHNOLOGIES • Rockfill
CFMSG – 04-10-20
(experience from dam construction)
Soil and rock mixtures
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
ROCKFILL COMPACTION Punctual control: density+water content
SOIL COMPACTION Punctual control: density+water content
REQUIREMENTS FOR HOMOGENEITY Brandl (1977)
Parameters
Coefficient of variation v (%) Subgrade
Sub-base
Base
Dry density
5
4
3
Moduli (Ev1, Ev2)
30
20
15
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A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
ROUTINE ANALYSIS
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
MODULUS FROM FIELD TESTS (Jamiolkowski et al., 1988, 2003)
G0, E0 (ε < εl)
Gsec, Esec (εsec > εl)
INDEPENDANT FROM:
Strain level Stress history DEPENDANT ON: Relative density Ambient stress Compressibility Aging & Fabric
G0 = S ⋅ p
1− n a
⋅ F (e) ⋅ p ′
n
DEPENDANT ON: Strain level Stress history Relative density Ambient stress Compressibility Aging & Fabric Strain rate CORRELATIONS WITH G0, E0 are more reliable than with Gsec, Esec
Punctual control: LPT (ASTM, DIN, LCPC) 300 Module de plaque (kPa)
Module de plaque
Pression appliquée (kPa)
250
200
46000 44000 42000 40000 38000 0
100
200
300
Valeur du cycle de rechargement (kPA)
150
100
50
0 0
1
E=
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2
3 4 Déplacement moyen (mm)
(
1,5 Qappl D 2 1 − υ 2
5
6
)
δ
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
800
3,2
700
2,8
600
2,4
500
2,0
400
1,6
300
1,2
200
0,8
100
0,4
0
0,0 250
0
50
100
150
200
resilient surface deflection (mm)
resilient vertical strain (mdef)
PLATE LOAD TESTS ON THE UGM BASE Response of Soil and Granular Base
soil - gauge V7 - 12/02/97 soil - gauge V4 - 13/02/97 soil - gauge V7 - 14/02/97 granular base - gauge V8 - 14/02/97 granular base - gauge V9 - 14/02/97 granular base - deflectometers
pressure (kPa)
CFMSG – 04-10-20
A. Gomes Correia (
[email protected]) University of Minho; Campus de Azurém, Guimarães; Portugal
Spectral-Analysis-of-Surface-Waves (SASW) (Nazarian et al., 1987; Rix & Stokoe, 1990; Stokoe, 2004; Allen et al., 2000)
Principle:
Measuring the propagation velocity of surface waves of Rayleigh type, generating an experimental dispersion curve (wave velocity versus frequency), and evaluating shear wave velocity profile (G0) by matching theoretical dispersion curve with experimental curve.
Advantages:
It is non destrutive. Any layer thikness can be evaluated. Soft layers after compaction may be detected after construction. Stiffness evaluations represent moduli values which are independent of strain level (e
