Methods of Installing Pile Foundations

Pile foundations have been widely used in numerous traditional construction procedures. Different types of installation procedures are mostly involved in the piling works of several construction projects regarding bridges, houses, transmission tower bases, ports, exploration platforms, and others. The installation techniques mainly include driving, boring, jacking, screwing, and jetting.

Factors impacting Pile foundation’s installation processes

• The selection of the installation process can be influenced by the nature of the piles. As an example, if the hammers are not able to drive the close-end pipe piles into the ground, indicating that the installation of the pile foundation at the construction site is needed.
• The condition of the soil also impacts the installation process. Soil has the ability to bear structural weight. The nature of the soil indicates whether the installation process is required or not.
• The site condition is another important factor that impacts the selection of pile foundation installation methods.
• The specific pile construction procedure also depends upon the length of the pile.
• The installation cost is another crucial aspect to be considered during the installation methods selections. In this regard, the benefits of these methods have been compared against the project schedule to choose the right procedure for installing pile work.

Methods of Installing Pile Foundations

Driven pile installation

A rig is used to drive the piles into the grounds. This installation technique helps to provide support to the leads, operates the hammers, and also helps to raise the piles. Mainly three impact hammers have been used in pile driving which include the drop hammers, diesel hammers, and steam or pneumatic hammers. The proper penetration of the pile and pile consolidation has been achieved by several approaches which include dropping weights, explosion, jacking, vibration, and jetting. Diesel hammers and drop hammers are the most standard engineering equipment, whereas, the vibratory drivers are the most recent development. These vibratory drivers have been used in the pile construction process at large scale.

Figure 1: Driven pile installation

Bored pile installation

This is the non-displacement installation technique which helps to offer an alternative approach to the foundation construction. In this category, Continuous Flight Auger (CFA) is an important method that effectively works in soft ground conditions. The pile installation in various diameters across the variance soil types has been allowed by this method. Underreaming, which is one of the unique features of auger bored piles, can be employed in hard clays including London clay. Underreaming is important for ensuring the structural integrity of the constructions.

Figure 2: Spread or Isolated Footing

Jacking method

This is an innovative installation technique that is used for installing the pre-formed piles. In this installation process, hydraulic rams have been used to push the pile into the ground. The designers of the jacked piles should have predicted the short-term axial force that can resist the pile installation process.

Figure 3: Jacking method

Screwing method

The installation of the screw piles required less time and equipment as compared to the other installation methods. This method is also less expensive rather than the installation of a standard concrete foundation. In this installation procedure, different sizes of plants have been used. This method also depends on the different sizes of the piles. This screwing method is the choice of numerous industries. As an example, this method has been developed for use in the nautical industry along with use in civil engineering, road, rail, and other sectors in recent days. The screw piles also can bear the compression loads and large tensile. In this context, screw piles have been also used in signs, masts, and in retaining structures.

Figure 4: Screw pile method

Jetting method

This is the most time-saving method in pile foundation. This method has been combine with the sheet pile driving process. This process has been associated with discharging waters under pressure which is near the toe of the sheet pile. The water jets that are used in the pile foundation are involved in loosening the soil thus helping to reduce the penetration resistance of the pile toe in the meantime of driving. Therefore, jetting helps to enable the sheet pile to drive into the dense soil successfully, speed up the pile installation process, and protect piles from damage.

Figure 5: Jetting installation method

Equipements for pile installation methods

Piling Winches

The primary goal of piling winches is to support those tools that are responsible for rotation and leader raking. Different winches are used in the piling work along with their different capacities. These winches are responsible for controlling and driving the speed of the piling works.

Figure 6: Piling winches

Piling rigs

Piling rigs consist of hard boxes or tabular elements that are fixed on the crane. This equipment helps to support the hammer and pile. Piling rigs also guide the piling works in case the pile is forced into the ground.

Figure 7: Piling rigs

Piling hammer

The size of the pile, the weight, and the resistance of the ground significantly impact the decisions regarding the selection of the right piling hammers in the construction area.

Figure 8: Piling hammer

Hammer guides

An independent crane is required for controlling and guiding the piling hammer. There is also a requirement for preventing the development of inappropriate bending stress. The provision of suitable support for the pile helps to tackle this problem.

Figure 9: Hammer guides

Hanging Leader

This equipment has been designed for hanging from the jib of a crane. This helps to provide a strong connection between the machine bed frame and the leader's foot.

Figure 10: Hanging Leader

Helmet

The helmet is placed over the pile. This is used to hold the dolly and also to protect the deterioration of the pile head.

Dolly

Dolly has been placed in a square recess at the top of the helmet. The selection of the dolly depends upon the driving forces.

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Driving cap

The driving cap helps to protect the steel bearing piles. There is a chance of pile deterioration in case of the misplacement of the driving caps.

Figure 11: Helmet and Dolly