Piles develop their capacity through a combination of side (skin) friction and end bearing. Piles driven to a very hard layer such as rock will develop their capacity primarily by end bearing, while piles driven soil will develop their capacity from both side friction and end bearing. Piles have been driven to capacities over 1,000 tons (US) in the offshore oil industry. However, most projects only require piles with less than 100-ton design loads

• Steel (over 25 tons)
• Concrete (up to 100 tons)
• Wood (up to 25 tons)

• Deep foundations (most common)
• Excavation support (Sheet and soldier piles)
• Docks and wharfs

• Skin friction and end bearing values
• Allowable stress for the pile material
• Drivability of the pile hammer, cushion, capblock, and pile system

1. Geotechnical site investigation
2. Determine load to be supported
3. Design pile-to-structure connection
4. Design pile-to-soil or rock load transfer
5. Develop a pile testing program
6. Determine the driving resistance by the Wave Equation Analysis

• Compressed air (or steam)
• Diesel
• Hydraulic fluid
• Gravity (drop hammers)

• Vibrations generally will not harm structures in good condition when using small to medium sized impact hammers.
• Vibrations pose more risk to deteriorated structures, and can interfere with nearby sensitive electronic instruments.
• Steady-state vibration produced by vibratory hammers is much more likely to cause damage to structures and cause settlement of loose soil. Predrilling greatly reduces the magnitude of the vibrations transmitted through the ground to nearby structures.
• Noise from pile driving can be cause for concern on sensitive job sites such as hospitals. Timber and concrete piles driven with air or hydraulic hammers are much quieter than steel piles driven with diesel hammers.
• Noise levels near the pile and hammer are high enough to require hearing protection for those on and near the job site.

• Consider the use Wave Equation Analysis software to model the pile – hammer – soil interaction. This program estimates ultimate load. Typically, a factor of safety of 2 is used with this analysis. This program can be used to check the driving stress in the pile, and guide hammer selection. This relationship, once established for a pile project, offers a very reliable quality control tool.
• Test selected piles to local code requirements (usually two times the static design load) ASTM standards D 1143, D 3689, and D 3966, provide standard static testing methods for compression, tension and lateral test, respectively. Also, the pile can be tested using ASTM D 4945 High-Strain Dynamic Testing of Piles. This test can be done in lieu of the static test, and is very economical for testing a large number of piles.
• Determine, from the Wave Equation Analysis and load test results, the required driving resistance for the production piles.

• High-performance
• Appropriate for a wide range of ground conditions
• Design loads up to 1,000 tons
• Suitable for land-based and marine-based structures
• Usually the fastest deep foundation