Advanced Foundation Engineering. Sheet-Pile Walls

Transcription

1 Shahrood University of Technology Department of Geotechnical Engineering Advanced Foundation Engineering Sheet-Pile Walls Mohsen Keramati, Ph.D. Assistant Professor 1

2 Introduction Connected or semiconnected sheet piles are often used to build continuous walls for waterfront structures that range from small waterfront pleasure boat launching facilities to large dock facilities. In contrast to the construction of other types of retaining wall, the building of sheet-pile walls does not usually require dewatering of the site. Sheet piles are also used for some temporary structures, such as braced cuts. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 2

3 Introduction Several types of sheet pile are commonly used in construction: (a) wooden sheet piles, (b) precast concrete sheet piles, and (c) steel sheet piles. Aluminum sheet piles are also marketed. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 3

4 Introduction Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 4

5 Introduction Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 5

6 Construction Methods Sheet-pile walls may be divided into two basic categories: (a) cantilever and (b) anchored. In the construction of sheet-pile walls, the sheet pile may be driven into the ground and then the backfill placed on the land side, or the sheet pile may first be driven into the ground and the soil in front of the sheet pile dredged. In either case, the soil used for backfill behind the sheet-pile wall is usually granular. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 6

7 Construction Methods Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 7

8 Construction Methods Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 8

9 Cantilever Sheet-Pile Walls Cantilever sheet-pile walls are usually recommended for walls of moderate height about 6 m or less, measured above the dredge line. In such walls, the sheet piles act as a wide cantilever beam above the dredge line. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 9

10 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 10

11 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 11

12 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 12

13 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 13

14 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 14

15 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 15

16 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 16

17 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 17

18 Cantilever Sheet Piling Penetrating Sandy Soils Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 18

19 Cantilever Sheet Piling Penetrating Sandy Soils - Absence of Water Table Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 19

20 Cantilever Sheet Piling Penetrating Sandy Soils - Absence of Water Table Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 20

21 Cantilever Sheet Piling Penetrating Sandy Soils - Free Cantilever Sheet Piling free cantilever sheet-pile wall penetrating a sandy soil and subjected to a line load of P per unit length of the wall. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 21

22 Cantilever Sheet Piling Penetrating Clay At times, cantilever sheet piles must be driven into a clay layer possessing an undrained cohesion C( =0 ). Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 22

23 Cantilever Sheet Piling Penetrating Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 23

24 Cantilever Sheet Piling Penetrating Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 24

25 Cantilever Sheet Piling Penetrating Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 25

26 Cantilever Sheet Piling Penetrating Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 26

27 Cantilever Sheet Piling Penetrating Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 27

28 Cantilever Sheet Piling Penetrating Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 28

29 Cantilever Sheet Piling Penetrating Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 29

30 Anchored Sheet-Pile Walls When the height of the backfill material behind a cantilever sheet-pile wall exceeds about 6 m, tying the wall near the top to anchor plates, anchor walls, or anchor piles becomes more economical. This type of construction is referred to as anchored sheet-pile wall or an anchored bulkhead. Anchors minimize the depth of penetration required by the sheet piles and also reduce the cross-sectional area and weight of the sheet piles needed for construction. However, the tie rods and anchors must be carefully designed. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 30

31 Anchored Sheet-Pile Walls The two basic methods of designing anchored sheet-pile walls are : (a) the free earth support method and (b) the fixed earth support method. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 31

32 Free Earth Support Method for Penetration of Sandy Soil Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 32

33 Free Earth Support Method for Penetration of Sandy Soil Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 33

34 Free Earth Support Method for Penetration of Sandy Soil Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 34

35 Design Charts for Free Earth Support Method (Penetration into Sandy Soil) Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 35

36 Design Charts for Free Earth Support Method (Penetration into Sandy Soil) Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 36

37 Design Charts for Free Earth Support Method (Penetration into Sandy Soil) Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 37

38 Design Charts for Free Earth Support Method (Penetration into Sandy Soil) Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 38

39 Design Charts for Free Earth Support Method (Penetration into Sandy Soil) Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 39

40 Moment Reduction for Anchored Sheet-Pile Walls Penetrating into Sand Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 40

41 Moment Reduction for Anchored Sheet-Pile Walls Penetrating into Sand Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 41

42 Moment Reduction for Anchored Sheet-Pile Walls Penetrating into Sand Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 42

43 Moment Reduction for Anchored Sheet-Pile Walls Penetrating into Sand Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 43

44 Computational Pressure Diagram Method for Penetration into Sandy Soil Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 44

45 Computational Pressure Diagram Method for Penetration into Sandy Soil Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 45

46 Computational Pressure Diagram Method for Penetration into Sandy Soil Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 46

47 Moment Reduction for Anchored Sheet-Pile Walls Penetrating into Sand Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 47

48 Free Earth Support Method for Penetration of Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 48

49 Free Earth Support Method for Penetration of Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 49

50 Free Earth Support Method for Penetration of Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 50

51 Free Earth Support Method for Penetration of Clay Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 51

52 Anchors Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 52

53 Placement of Anchors Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 53

54 Placement of Anchors Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 54

55 Ultimate Resistance of Tiebacks Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 55

56 Problems: Principles of Foundation Engineering, Braja M. Das, Eighth Edition , Design the resistance tieback length for the anchor force (use 10 anchor slope). Project: Design the problem system with Plaxis 2D 8.2 geotechnical software, compare the diagram of the shear, moment and anchor force with the results of the problem, check General Factor of Safety of the system, in the report. Mohsen Keramati, Ph.D., Department of Geotechnical Engineering, Shahrood University of Technology, 56