Prof. Roger FRANK Prof. Roger FRANK

CERMES (ENPC-LCPC)CERMES (ENPC-LCPC)

Tokyo IWM August 2004Tokyo IWM August 2004

PRESENT ISSUES INPRESENT ISSUES INDESIGN AND CONSTRUTION OF DESIGN AND CONSTRUTION OF

MICROPILE SYSTEMSMICROPILE SYSTEMS

1) Present state of European Norms (design, 1) Present state of European Norms (design, construction and testing)construction and testing)

2) Need for well documented field tests and case 2) Need for well documented field tests and case historieshistories

3) Control of installation effects3) Control of installation effects

1) CEN European standards1) CEN European standards

CEN/TC 250CEN/TC 250Date:  2004-08Date:  2004-08

EN 1997-1EN 1997-1CEN/TC 250CEN/TC 250

Secretariat:   NENSecretariat:   NEN

Eurocode 7 Geotechnical design - Part 1: General rulesEurocode 7 Geotechnical design - Part 1: General rulesEurocode 7 Entwurf, Berechnung und Bemessung in der Geotechnik – Teil 1: Eurocode 7 Entwurf, Berechnung und Bemessung in der Geotechnik – Teil 1: Allgemeine RegelnAllgemeine RegelnEurocode 7 Calcul géotechnique - Partie 1: Règles généralesEurocode 7 Calcul géotechnique - Partie 1: Règles générales

ICS :  93.020; 91.080.01ICS :  93.020; 91.080.01

Under preparationUnder preparation : :

Euronorm on pile load tests (from ETC3 work)Euronorm on pile load tests (from ETC3 work)

2) Micropile design from well documented2) Micropile design from well documented

load tests and case historiesload tests and case histories

1,75 m

,50 m

,25 m

,40

m

,40

m

3,50

m

2,84 m 4,00 m

4,00

m

34,21 NGF

35,10 NGF

20 °

13,5 °

0,65 m0,60 m

LATERAL LOADING TEST

-2

0

2

4

6

8

10

12

14

16

0 100 200 300 400

effort (kN) pr

ofon

deur

sous

la se

mel

le (m

)

AXIAL LOAD ON VERTICAL PILEForce (kN)

Depth

z (m)

( compression )

-2

0

2

4

6

8

10

12

14

16

0 100 200 300 400

AXIAL LOAD ON INCLINED MICROPILE

Depth

z (m)

Force (kN) ( traction )

3) Installation effects3) Installation effects

_______

Movement of the water level

( sea tide, river flow)

_______

Wooden piles :

B = 0,30 m s/B = 4

Micropiles : B = 0,22 m s/B = 10

STABILIZATION OF THE SETTLEMENTS AFTER MICROPILES INSTALLATION

RAILWAY EMBANKMENT STABILIZED BY MICROPILES :

Additional settlement due to the installation of the micropiles

Thank you for your attention !