DEEP FOUNDATION PILLING

Structures are supported by foundations, which transfer their load to layers of soil or rock with sufficient bearing capacity and settlement characteristics. When it is not possible to construct a structure on shallow foundations, Deep Foundation Pilling techniques have been used, depending on the structure’s nature.

Dutch Foundation Dubai deals various types of Deep Foundation pilling construction methods which are mainly used for foundation load transfer and earth retention systems. They are used in marine – based structures and in land-based structures where the surface soil layers can not provide the required load -bearing capacity. In all situations, Deep foundation pilling are utilized to transfer lateral, vertical or a combination of both loads through weak soil layers to a suitable bearing layer. The most common techniques used for deep foundation pilling construction are described here.

Deep Foundation Pilling Techniques:

1. CAST-IN-SITU Bored Piles

This is the most commonly and widely used pile. Bored piles can be seen in the majority of structures built on pile foundations. The rock is socketed into the pile. The depth of embedment in the rock varies depending on the kind and amount of the load. In addition, the number of piles required to support a column is determined by the pile’s capacity and the applied weight. To begin, we determine the pile’s geotechnical and structural limitations. The pile’s limit is then determined by the lowest among these quantities. The number of piles can be determined because the applied load is known. Based on the applied loads, bored piles are built as single or group piles. Group piles are commonly used to support shear cores, shear walls, lift cores, and other types of structures.

2. Driven Piles

These are piles that have been prefabricated. When compared to bored piles, they are built when the applied load is relatively modest. Furthermore, precast piles are terminated or inserted into a hard soil layer rather than being driven up to the rock. A dense soil layer should be present to rest the pile and provide end bearing. Although there is an end bearing, these piles are primarily friction-dominated. Manually driving a load into the pile or utilizing a vibrating piling machine are both options. Piles come in a variety of sizes, starting at 400mm. Even smaller sizes are possible, depending on the nature of the structure. Furthermore, when shallow foundations are not feasible, these sorts of piling foundations are commonly used in low-rise buildings.

3. Continuous Flight Auger (CFA) Piles

A continuous flight auger (CFA) is a cast-in-situ piling method that was originally utilized in the United Kingdom in the 1960s and is now one of the most widely deployed. The CFA procedure is well suited to environmentally sensitive areas and soft or water-bearing strata where deep casings would otherwise be required due to its low level of vibration. They are generally used for bridge building or massive structural foundations and can be built as single piles or as part of a pile group similar to driven pile foundations.

4. Pile Caps & Capping Beams

The pile cap is a thick concrete mat-like structure that fits on the pile, providing a secure foundation for the entire system. This concrete pile cap transfers the entire load of the superstructure to the piles, resulting in a stable bearing capacity. A raft foundation, which also has a concrete block-like structure, has a similar development to the pile cap. Capping beams are steel and concrete structural elements. Capping beams serve as the slab’s base and help to keep the ground and adjacent structures in place. The steel reinforcing bars are installed on top of the piling cages using logs built to the experts’ standards. Once the steel reinforcement is complete, the concrete is sprayed upon it. The capping beam is formed in this manner. Once the concrete has dried, the casing can be removed and excavation for the basement can begin. This is the ground preparation step for the capping beam pour.