1. Prof. Roger FRANK CERMES (ENPC-LCPC) Tokyo IWM August 2004 PRESENT ISSUES IN DESIGN AND CONSTRUTION OF MICROPILE SYSTEMS

2. 1) Present state of European Norms (design, construction and testing) 2) Need for well documented field tests and case histories 3) Control of installation effects

3. 1) CEN European standards

5. CEN/TC 250Date: 2004-08 EN 1997-1 CEN/TC 250Secretariat: NEN Eurocode 7 Geotechnical design - Part 1: General rules Eurocode 7 Entwurf, Berechnung und Bemessung in der Geotechnik – Teil 1: Allgemeine Regeln Eurocode 7 Calcul géotechnique - Partie 1: Règles générales ICS : 93.020; 91.080.01

6. Under preparation : Euronorm on pile load tests (from ETC3 work)

7. 2) Micropile design from well documented load tests and case histories

9. LATERAL LOADING TEST

10. AXIAL LOAD ON VERTICAL PILE Force (kN) Depth z (m) ( compression )

11. AXIAL LOAD ON INCLINED MICROPILE Depth z (m) Force (kN)( traction )

12. 3) Installation effects

13. _______ 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

14. STABILIZATION OF THE SETTLEMENTS AFTER MICROPILES INSTALLATION

15. RAILWAY EMBANKMENT STABILIZED BY MICROPILES : Additional settlement due to the installation of the micropiles

18. Thank you for your attention !