Driven precast concrete piles are constructed by hammering the piles into the soil to a depth greater than 40m by an adjustable hydraulic or diesel hammer. Driven precast concrete piles are widely used because of their versatility and suitability for most ground conditions. These piles can be used for the foundation of all types of engineering structures under nearly every soil condition.
Driven precast concrete piles are particularly suited where the founding stratum is overlain by soft deposits and aggressive or contaminated soils. Piles are manufactured in factories under high-quality control, and consist of segmental lengths of reinforced concrete sections of lengths between 3m and 15m with required or standard cross-section.
Sequence of Precast Concrete Pile Production
- Tensioning work in case of prestressed pile
- Release in case of Pretensioning pile
- Marking pile
- Handling and storage of pile
Precast Concrete Pile Construction Procedure
- Before commencing the pile driving process, methods to protect the head of the pile from shattering must be decided. This can be determined from the end bearing requirements and driving conditions.
- It should be ensured that the pile has gained its full strength prior to the commencement of construction.
- Place precast concrete pile on the designated location.
- Force the pile into the ground with an impact pile driving hammer
- Special timber packing or a synthetic cushion block lends adequate protection to the pile head during driving.
- With control of driving achieved by measuring the set, the pile is driven into the resistive soil layer to a depth equal to one time the pile diameter.
- It can be used in almost all types of construction, especially in aggressive soil condition.
- Suitable for construction sites where thick soft soil and / or high water table are present and create problems for conventional pile construction.
- Large pile sizes can be used for wind turbines and pylons, river bridge foundations, bridge abutments and piers, marine construction
Advantages of Precast Concrete Piles
- No spoil generated on site
- Unaffected by groundwater
- Cost-effective form of deep foundation
- Speed of installation
- Piling unaffected by groundwater
- Suitable for small to large complex projects
- Capable of accommodating simple compressive loads or complex combined loadings
- Damage may occur in the pile at a position not visible from the surface during the driving process.
- Pile may get laterally displaced if it encounters any obstructions like rocks in the ground.
- The length of the pile is estimated before driving commences, but the accuracy of this assumption is only known on site, where short piles can be difficult to extend and long piles may prove to be expensive and wasteful.
- A large rig is required for driving piles and hard-standings are required to ensure that the ground surface is adequate for the pile-driving.