1. Piles and Pile-Driving Equipment
Chapter 19
Piles and Pile-Driving Equipment
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. PILES

3. CLASSIFICATION OF PILES
Piles can be classified on the basis of either their use or the materials from which they are made. On the basis of use, there are two major classifications: (1) sheet and (2) load bearing.

4. SHEET PILES
Sheet piles are used primarily to create a rigid barrier for earth and water. Typical uses include cutoff walls under dams, and for cofferdams, bulkheads, and trenching.

5. SHEET PILES

6. LOAD-BEARING PILES
Load-bearing piles, as the name implies, are used primarily to transmit structural loads.

7. LOAD-BEARING PILES

8. PILE TYPES Timber Treated with a preservative Untreated Concrete
Precast-prestressed
Cast-in-place with shells
Augered cast-in-place

9. PILE TYPES Steel H section Steel pipe Composite Concrete and steel
Plastic with steel pipe core

10. TIMBER PILES
Timber piles are made from the trunks of trees. Such piles are available in most sections of the country and the world. Ordinary lengths are 15 to 45 ft.

11. CONCRETE PILES
Concrete piles may be either precast or cast-in-place.

12. STEEL PILES
Load-bearing steel piles can be H-sections, hollow box or tubular sections, or pipes.

13. COMPOSITE PILES
Several types of composite piles are available. These are usually developed and offered to meet the demands of special situations. Two of the most common situations that cause problems, when conventional piles are used, are hard driving conditions and warm marine environments.

14. DRIVING PILES
Crawler crane w/single acting air hammer and hydraulic leads.
Driving 12-in. concrete piles.

15. DRIVING PILES
The forces that enable a pile to support a load also cause the pile to resist the efforts made to drive it. The total resistance of a pile to penetration will equal the sum of the forces produced by skin friction and end bearing.

16. DRIVING PILES
Depending on the size of the project, one or more of the test piles would be selected for load testing.

17. LOAD TEST
Reaction frame and hydraulic jacks used to load test a 54-in. concrete cylinder pile.

18. PILE HAMMERS
Variable subsurface conditions can dictate the use of different pile hammers. The function of a pile hammer is to furnish the energy required to drive a pile.

19. PILE HAMMERS Drop Single-acting steam or compressed air
Double-acting steam or compressed air
Differential-acting steam or compressed air

20. PILE HAMMERS
Diesel
Hydraulicimpact and drivers
Vibratory drivers

21. DROP HAMMERS
A drop hammer is a heavy metal weight that is lifted by a hoist line, then released and allowed to fall onto the top of the pile. Because of the high dynamic forces, a pile cap is positioned between the hammer and the pile head.

22. SINGLE-ACTING HAMMERS
These hammers rely solely on gravity acting on the striking weight to achieve their driving energy. The a freely falling weight, called a “ram,” that is lifted by steam or compressed air.

23. DOUBLE-ACTING HAMMERS
With double-acting hammers, the striking ram is driven by compressed air or steam both when rising and when falling. Thus, with a given weight of ram, it is possible to attain a desired amount of energy per blow with a shorter stroke than with a longer single-acting hammer.

24. DIFFERENTIAL-ACTING HAMMERS
A differential-acting air is a modified single-acting hammer in that the air or steam pressure used to lift the ram is not exhausted at the end of the upward stroke but is valved over the piston to accelerate the ram on the downstroke.

25. DIESEL HAMMERS
A diesel pile‑driving hammer is a self-contained driving unit that does not require an external source of energy such as an air compressor or steam boiler.

26. DIESEL HAMMERS
The downstroke of the ram compresses air and fuel to ignition heat and the resulting explosion drives the pile downward and the ram upward to repeat its stroke.

27. DIESEL HAMMERS
Diesel hammers impart compression, impact and explosion energy to the pile.

28. DIESEL HAMMERS 1 2 3 1. Raise the piston to start.
2. Injection of diesel fuel and compression.
3. Impact and explosion.

29. DIESEL HAMMERS 4. Exhaust ports exposed and gases escape.5
4. Exhaust ports exposed and gases escape.
5. Draws fresh air through the exhaust ports.

30. DIESEL HAMMERS
Fuel usage varies with the size of the hammer see Table 19.4.
DELMAG
10,500 ft-lb gal/hr
58,248 ft-lb gal/hr
107,177 ft-lb gal/hr
300,000 ft-lb gal/hr

31. HYDRAULIC IMPACT HAMMERS
There is a trend toward the use of hydraulic hammers. A hydraulic hammer operates on the differential pressure of hydraulic fluid instead of compressed air or steam.

32. HAMMER SPECS

33. HAMMER SPECS

34. VIBRATORY PILE DRIVERS
Vibratory pile drivers are especially effective when the piles are driven into water-saturated noncohesive soils.

35. VIBRATORY HAMMERS
Vibratory hammers use exciting shafts rotating in opposite directions.

36. VIBRATORY HAMMER

37. VIBRATORY HAMMER
Can be driven by hydraulic or electric motors.

38. POSITIONING PILES DURING DRIVING
When driving piles, it is necessary to have a method that will position the pile in the proper location with the required alignment or batter and that will support the pile during driving.

39. PILE LEADS
Forward
Batter
Vertical
Aft
Batter

40. POSITIONING PILES DURING DRIVING
Fixed leads have a pivot point at the crane’s boom top and a brace at their bottom that attaches to the crane. Fixed leads offer good control of the pile position and keep the pile in correct alignment with the hammer so that eccentric impacts are minimized.

41. FIXED LEADS

42. FIXED LEADS

43. POSITIONING PILES DURING DRIVING
Leads that are not attached at their bottom to the crane or driving platform are known as “swing leads.” The leads and hammer are usually held by separate lines from the crane.

44. SWING LEADS
Steam hammer used to drive 54-in. concrete cylinder piles, with swing leads.

45. PILE LEADS
Stabbing points at the end of a set of leads.

46. POSITIONING PILES DURING DRIVING
Many times a template is used to support and hold the pile in the proper position during driving. Templates are usually constructed from steel pipe or beams and may have several levels of framing to support long piles or piles on a batter.

47. TEMPLATE
Floating rig driving concrete piles using a template.

48. TEMPLATE
Three 8 ft diameter steel cylinder piles standing in the template on a batter ready for driving.

49. HANDLING PILES
Care must be exercised to prevent damage to the pile from flexural stresses.

50. POINTERS
For concrete piles the weight of the hammer ram should be one third the pile weight.
Easy to start a pile with an air hammer.
Diesel hammers will not start when the pile is in soft material.

51. POINTERS
Position the crane so it can reach the driving position and the piles with out traveling.

52. POINTERS Driving time:
45 to 50 ft piles normally can be driven in min.
But in hard material it can take 4 hr.

53. PILE-DRIVING SAFETY