- Use of Drilled MicroPile Walls in Scandinavia Håkan Bredenberg

Transcription

1 - Use of Drilled MicroPile Walls in Scandinavia Håkan Bredenberg 1

2 Scandinavia? 2

3 Drilled MicroPile Walls 3

4 i c Index s applications & examples drilled MicroPile wall elements supports cover costs equipment design 4

5 Applications excavation temporary cut off walls same, also serving as permanent support bridge support /foundation 5

6 Excavation cut off wall 6

7 Temporary wall & permanent support 7

8 Temporary wall & permanent bridge support 8

9 Drilled MicroPile Walls, usual Drilling metods 9

10 Drilled MicroPile Walls the Klemm

11 Drilled MicroPile Walls - equipment The Basement Mouse 11

12 Drilled (micro) Pile Walls equipment, drilling rigs 12

13 Drilled MicroPile Walls equipment for drilling Pilot Casing Drill shoe (welded to casing) Ring drill crown ( left at bottom of casing) 13

14 Drilled MicroPile Walls Equipment at tube front Pilot (recovered) Ring crown welded to tube, left at tip 14

15 Drilled pile walls drill bit for 600 mm tubes 15

16 Excavation How to keep soil in place between space between tubes? Which spacing between tubes? If ground water level above excavation bottom? Which material for cover? Wood, steel, shotcrete? 16

17 Jet grouting to prevent soil inflow 17

18 Drilled MicroPile Wall extending into rock 18

19 Drilled MicroPile Wall during construction 19

20 Drilled MicroPile Wall in rock fill 20

21 Excavation before cover 21

22 5 mm steel sheet cover beeing spot welded to drilled soldier beams 22

23 5 mm steel cover plates beeing cut to size (from 2 x 1 m) 23

24 Drilled MicroPile Wall sealed with shotcrete 24

25 After excavation to final level some case pictures from

26 Drilled & driven Pile Wall, finalized (?), rock anchors 26

27 Drilled MicroPile Wall, Limmared 27

28 Liljeholmen, drilled MicroPile wall for new subway station 28

29 Drilled MicroPile Wall at Ringhals nuclear power plant 29

30 MicroPile Wall was drilled into rock 30

31 Drilled MicroPile Wall for new theatre building, Norrköping, Sweden 31

32 Drilled MicroPile Wall shotcreted note boulders. 32

33 Drilled MicroPile Wall under & close to existing building 33

34 Drilled MicroPile Wall finalized 34

35 Drilled MicroPile Wall used as formwork 35

36 Drilled MicroPiles for temporary column support 36

37 Drilled MicroPile Wall support soil / rock anchors beam struts tie-backs others 37

38 Drilled MicroPile Wall supported by drilled soil anchors 38

39 Corner supported by H-beams 39

40 Anchor rod fixed to slab 40

41 Design of drilled MicroPile walls Soil pressure active/passive Forces, bending moments Section analysis : Axial capacity Bending capacity Buckling Local buckling (thin wall structures) Deflection, soil movements 41

42 Soil tube interaction 42

43 Bending moment capacity 43

44 Drilled MicroPile Wall bending capacity 44

45 Design details 45

46 Conclusions Consider to use Drilled MicroPile walls when: Obstacles in soil prevents sheet piling Small equipment required at site Time schedule of critical importance Temporary piles can be used for permanent use If below ground water level, lowering is required If soil flow use jet grouting/small excavation steps Thats all for now drill carefully out there! 46