DIsplacement piles

1. Set into ground by forcing or driving a solid pile or hollow casing to the required level below ground , thus displacing the surrounding earth.
2. Generallly driven into the ground by holding them in the correct position against the piling frame and applying hammer blows to the head of the pile .
3. Includes those piles that are preformed or driven in-situ piles

Preformed piles

1. Precast piles of required length may be drive into the ground using a driving rig .
2. ALternatively , the rig may be used to drive a series of short precast sections , which are connected as the work proceeds.
3. The use of second method is the most efficient , since the length required may vary from pile to pile
4. THe use of one piles precast piles inevitably necessitates adjustment of length on site
5. Trimming or extending of one-pieces piles is a difficults task on-sites

Driven in-situ piles

1. The difficulties of providing piles of exactly the correct length , together with the danger of damage to the pile resulting from the percussive driving force , have resultted in the adoption of the use of driven shell or casing piles .
2. With this method , a hollow shell or casing is driven into the ground , using a percussive rig , in a number of short sections , concrete is then poured into the void as the casing is withdrawn , the steel reinforcement having already been lowered into the hole .
3. By this method , an in-situ driven pile is formed in the ground
4. The vibration of the pile casing as it withdrawn from the ground , results in the creation of riged surface to the pile sides , thus taking the most advantage of any frictional support provided by yhr ground