CESENA 10 & 11 Décembre 2009 1 Journée du 27 Janvier 2010, C.F.M.S Les essais de chargements en...

CESENA 10 & 11 Décembre 2009

1

Journée du 27 Janvier 2010, C.F.M.S

Les essais de chargements en vraie grandeur

Instrumentation &

paramètres de calcul

Michel Bustamante & Luigi Gianeselli


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Pile Test ProceduresStatic vertical load testingStatic lateral load testing Flat jack (1969), Osterberg cell testing (1989) Dynamic testing (driving formulae, wave equation analysis ) Statnamic test (Middendorp et al., 1992)


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Static vertical load testing

Is still considered as the most fundamental test In France by far the most commonly carried out in

spite of its limitations and drawbacks Maintained Load Procedure, specified by

various codes: ‘Essai statique de fondations profondes, 1970,

NF P 94 – 150 Essai statique de pieu isolé sous compression axiale’, 1991

Reaction systems are supplied by: kentledge, reaction piles, ground anchors (either vertical or inclined), existing structure

A strong emphasis is put on instrumentation to measure the load distribution and its mobilization in the pile


VASCO da GAMA bridge, Portugal Cachan, France

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Static vertical load testingReaction systems


MIRNA Viaduc - Croatia Abu-Dhabi Great Mosque

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Contenair Terminal, Fort de France Bridge canal, Belgium

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Instrumentations for static vertical load testing

o Tell-tales systems (rods or wire)o Vibrating wire cells (Telemac or similar) o Glued strain gages (directly on pile or as a ‘sister bar’) o Electro-levels (Price, UK) o Freyssinet flat jacks or Osterberg O-cell o Removable extensometers (LCPC or Geokon systems )

Since the early 70-ties the LCPC removable extensometer is the most used by the french Administration


Telemac cells Strain gages on steel caisson

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Static vertical load testingInstrumentation


‘Sister bar’ Telemac cells

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Static vertical load testingInstrumentation


Static vertical load testingFlat jack test

Pescaïre viaduct, 1969 Gd Littoral store, 2000

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Static vertical load testingInstrumentation : LCPC removable extensometer

Extensometer assembling Inserting the extensometer

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Static vertical load testing

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Static vertical load testingResults

-50

-40

-30

-20

-10

00 2000 4000 6000 8000 10000 12000

Tête du pieu

Pointe du pieu

Q =cS =c

7500 kN10.69 mm

uQ = 10500 kN

Q =N

NS =

6000 kN

6.87 mm

Load ( kN)

Sett

lem

ent

(mm

)

Pont Canal d'Houdeng

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Ports de Montoir et Donges. Tube battu

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

00 250 500 750 1000 1250 1500

Q

Fig.7

70.82 m m

charge en tête (kN)o

(15')

Tête du pieu

Pointe du pieu

u

Q =N

Q =c

NS =

S =c

1250 kN

1000 kN

Q = 1500 kN

9.46 mm

7.05 mm

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Centrale de Fusina - Venice (Pieu tubé vibrofoncé)

Complexe scolaire- Kaminia- GREECE

(Pieu battu moulé)

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Static vertical load testingResults (détecteur de malfaçons)


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Réalisations

Viaduc de la Mirna,Croatie


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Grande Mosquée d’Abu Dhabi


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Gare de Liège-Guillemins, Belgique (architecte : Calatrava)


19 Auditorium, Roma (architecte Renzo Piano)


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Viaduc TGV d’Arbre, Belgique

CONFÉRENCE TECHNIQUE – CESENA 10 & 11 DÉCEMBRE 2009

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Viaduc d’Ath – TGV Paris - Bruxelles


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Pont Joao Landim,Guinée

Pont Sao Vincente Guinée Bissau


23 Pont Canal d’Houdeng, Belgique

CONFÉRENCE TECHNIQUE – CESENA 10 & 11 DÉCEMBRE 2009

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Viaduc d’Argenteuil SNCF

7.Aplicaciones (12)

campos de pruebas

Corte sobre la galeria debajo del patio Real, Versailles 2009-2010

perforadora

3.00 3.00

1.50

C2

COUR DES BOUCHES

COLONNES D'ESSAI DE CHARGEMENT

COLONNES D'ESSAI DE VALIDATION

C1

3.00 3.00

1.50

ZO

NE D

U P

LOT

INTE

GR

E

Cm1

Cm2

2 sondages inclinés dans les maçonneries

2 sondages carottés + profils pressiomètriques

2 colonnes éventuelles

1.70 m 1.30 m

6.00 m

maçonneries existantes

COLONNES JET 10005.

00 m


Static lateral load testing Very rarely performed Jacking of one pile against one or more pile Applied procedure defined by code: NF P 94-151 Essai

statique de pieu isolé sous effort transversal’ Instrumentation : strain gages, inclinometer

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Static lateral load testing

Mirna viaduct, Croatia, 1998

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Dynamic load testing Rarely performed in France out of coastal and

harbour construction CALYPSO procedure derived from national

research project TUBA (1994) and ADIG - CAPWAP : used by portuary authorities mainly for predicting and controlling the driving of steel tubular piles

SIMBAT procedure : used for predicting the bearing capacity of bored piles & micropiles

Applied procedure defined by code: NF P 94-152 Essai de chargement dynamique axial d’un élément de fondation profonde

Instrumentation : accelerometer, strain equipment, optic camera

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Dynamic load testingInstrumentation

Oil terminal, Matanzas, Cuba, 1987

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CONCLUDING REMARKS1 - Pile load testing is the more efficient mean to obtain

relevant information concerning essential design issues as: axial & lateral geotechnical load capacities real performance under working load (settlement & lateral

deflection) as well as performance under ‘special’ loading conditions (cyclic, dynamic)

2 - The installation of the test pile provides ideal conditions to check in situ the constructibility conditions (driveability or drilling ability and adequacy of the chosen equipments)

3 - The drawbacks of each test procedure should not lead one to forget that the foundation cost rarely exceeds 20% of the total cost of the project with an average of 5 to 10%; hence the necessity to minimize the effect of the drawbacks

4 - Static pile load testing carried out on comprehensively instrumented piles appears to be still the right approach of obtaining representative design parameters (skin friction & point resistance)

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SUGGESTIONS FOR FUTURE PILE TESTING

First of all demand a comprehensive subground investigation before starting any load test

Further load tests on instrumented pile Improve the accuracy of the measurements

which should be carried out by engineers fully qualified in geotechnics, and reduce the effects of usual drawbacks

Additional development of group testing (or single pile in a group) + cyclic testing

Measurements made from the commencements of pile installation and if possible continued over a long period

The need in France for important development of dynamic tests of any procedure

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33 Minatitland - Mexique

Merci de votre attention

CESENA 10 & 11 Décembre 2009 1 Journée du 27 Janvier 2010, C.F.M.S Les essais de chargements en...

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