Methods of Piling

Other Methods of Piling

1. Jetting Piles - water jetting may be used to aid penetration of a pile into a sand gravel stratum. It is ineffective infirm to stiff clay or soils containing much coarse gravel, cobbles or boulders.

2. Pile Driving by Vibration - vibratory methods of driving sheet piles or bearing piles best suited to sandy or gravelly soils. Pile driving vibrators consist of pair or exciters mounted on the vibrator unit, the motors of each pair rotating in opposite directions. The amplitude of vibrations is sufficient to break down the skin friction on the sides of the pile. Vibrators will drive steel piles through loose to medium dense sands and gravel with comparative ease, but there are likely to be difficulties with dense sands, where energy may be insufficient to displace the material to permit entry of the pile. Vibrators can also be used for extracting piles and are frequently used connection with large diameter bored and cast-in-place piling work for sinking and extracting pile casings.

3. Pile Driving over Water - piles for jetty or wharf structures built over can be driven from specially designed pile frames cantilevered out from the permanent piles already driven, from ordinary pile frames operating from temporary piled trestles, from jack-up barges or from floating plant.

4. Pile Driving through difficult ground - these methods include boring a hole sufficient diameter through the difficult ground to receive the pile. In loose ground, the hole may have to be cased which sometimes leads to difficulties with extraction of the casing. Another method is to drive a heavy steel spud or joist section through the ground and to drive the pile through the loosened soil left after withdrawing the spud. Another is through the use of diamond core drills.

5. Test Piling - whenever possible, test piles should be of the same type and dimensions as the permanent piles which are intended to be used. This is the only way to ensure that the designed penetration will be attained and that the designer's estimate of the safe working load can be checked when the piles are subjected to test loading.

Posted in: Piles