What are the different kind of Piles?

Foundations are often too weak to support the weight of a superstructure alone. However, robust methods exist to reduce the intensity of loads and fortify the soil. One of the most widely used deep foundation techniques worldwide is piling. Modern piling solutions are highly advantageous to construction projects because they are the most efficient method for deep foundations.

How are Piles used within Construction?

Piles are the foundation of deep construction projects. Piles are the solution when the soil's load-bearing capacity is insufficient to support the building's weight. By driving or drilling piles through the ground to a depth of solid earth, the loads are efficiently transferred to the underlying soil.

Piling is a critical technique for ensuring the structural integrity of buildings above and below ground. Piling rigs are inserted into the earth down to the bedrock, providing a secure and stable base to support the weight of the entire structure. Additional attachments, such as conical tips, are often welded to the pile ends to enhance their driving capability, as specified by the project contractor's design requirements. It is a proven and essential method for transferring the building's weight to the underlying soil, guaranteeing the safety and stability of the structure.

The Birth of Piling

Piling has been the foundation of construction since prehistoric times. When faced with weak, marshy soils near rivers and lakes, our ancestors used timber piles to fortify the ground and safeguard settlements. From the Swiss lake dwellers to villages across Britain, piling has long been the solution to build on challenging terrain.

Today, the relentless demand for developable land has driven governments and organizations to utilize properties with poor soil quality. Piling is now integral to modern construction, providing the sturdy foundations required for our built environment. This robust technique has stood the test of time, evolving alongside the demands of advancing civilizations.

The history of piling is one of resilience and innovation, as humanity has continuously adapted this method to overcome the limitations of the landscape. It is a testament to the ingenuity of our forebears and the vital role piling continues to play in shaping the infrastructure of the modern world.

What are the types of Piling?

Building engineers must rigorously evaluate the parameters of their construction site, including the soil, climate, and other critical elements, before decisively determining the appropriate piling type. To fully comprehend the scope of their infrastructure project, they must engage directly with architects. This essential knowledge enables them to confidently plan for effective building solutions and select the ideal piling type. The two primary forms of piling used in construction are friction piles and end-bearing piles, and engineers must choose the most suitable option with unwavering conviction.

Friction Piles

Friction piles effectively withstand the loads placed on buildings by harnessing the power of skin shear stresses. The surface of the pile adheres to the surrounding soil, creating a robust friction or adhesion that allows the entire pile surface to resist the load efficiently. This friction-based mechanism also reduces the bulb pressure on the pile surface. A cylindrical pressure zone forms around the pile surface when utilizing friction piles, further enhancing the pile's capacity to support the structure.

End Bearing Piles

End-bearing piles are a powerful solution for transmitting superstructure loads from weak strata, such as rock or extremely dense sand and gravel, to strong strata with higher bearing capacities. These piles rely on the resistance of the dense soil layer at the pile's end as the primary indicator of their load-bearing capabilities. To fully exploit the ultimate strength of the underlying layer, the pile's end must be embedded at least three times the pile's diameter into the hard strata. End-bearing piles can be swiftly constructed using prefabricated piles, making them a reliable and efficient choice for construction projects.

What are the Pile Construction Techniques?

Diverse soil types and structural requirements demand various reliable pile types. The fundamental design purpose determines the appropriate pile technique to be employed.

Driven Piles, Aggregate Piles, Bore Piles, and Screw Piles offer robust solutions tailored to specific project needs. Engineers must confidently select the most suitable pile type to ensure any construction endeavor's structural integrity and safety.

Driven Piles

Driven piles, or displacement piles, are the premier choice for deep foundations. They effortlessly transfer the weight of structures to robust rock or soil strata, ensuring unwavering support and optimal settlement properties. This economical deep foundation method is the go-to solution for buildings, walls, towers, and bridges. Driven piles also excel in cofferdam and anchorage applications. Furthermore, they are unparalleled for retaining walls, bulkheads, and embankments.

Bore Piles

Replacement or bore piles are the go-to solution for building foundations. They can support structures by transferring their weight to the most suitable soil, ensuring a sufficient bearing capacity. Bore piles are created by removing debris and forming a hole into which reinforced concrete is poured. In contrast to displacement piles, which push the soil aside, replacement piles replenish the spoil. Bore piles are the preferred choice for cohesive subsoils, enabling the creation of friction piles and the construction of pile foundations adjacent to existing structures.

Two highly effective methods of bored pile foundations are widely utilized: rotary bore and CFA piling. These techniques provide a decisive, reliable, and versatile solution for constructing robust foundations that can withstand the demands of modern structures.

Rotary Bore Piling

Rotary bore piling is the premier solution for construction companies facing severe ground impediments. This piling rig swiftly installs a robust temporary shell to provide unwavering support for the structure. A revolving cage is forcefully driven into the unstable soil to reinforce it, and the pile is then extracted using a powerful auger unit. Once the bore has been meticulously cleaned to the precise depth and the pile firmly inserted, the casing is resolutely removed, leaving the unyielding pile in place. Rotary Bore Piles are the definitive choice to fortify the ground, ensuring it can confidently bear the structure's load to be erected. In this decisive method, drilling is assertively conducted to the designated depth using a crane-mounted or track-mounted hydraulic drill.

Screw Piles

Screw piles feature a helix near the pile toe, enabling them to be efficiently driven into the earth. Depending on the application and soil conditions, screw piles may incorporate multiple helices, known as screws. Additional helices are incorporated to enhance performance when heavier loads or softer ground are encountered.

High-powered hydraulic motors apply substantial torque to drive screw piles deep into the soil. Rigorous engineering is required to optimize the interface between the pile and the supported structure. Key considerations include the building and the ground conditions for installing the piles.

The most common method of connecting screw piles to a building's foundation is by casting the pile head directly into the concrete footing. This is achieved by embedding steel reinforcing bars into the piles, with the bars extending into the building's foundation.

Aggregate Piles

Aggregate piles are powerful columns of compacted stone erected in groups within poor soil to boost bearing pressure and minimize settlement under structural footings. These robust installations, known as Bibro stone columns or rammed piles, are collectively called aggregate piles. The materials used in aggregate piles enable rapid construction, making them a highly cost-effective solution for building on soft soils. To create a dense bulb, the aggregate is forcibly driven into a casing, leaving no doubt about the strength and efficiency of this approach.

What are the Pile Installation Techniques

There are numerous techniques for installing piles, and each must be chosen according to the specific soil conditions. The depth of the excavation, the materials used for the piles, the steepness of the pile driving, and any environmental factors are critical variables that determine the appropriate installation method.

Installing displacement piles involves driving them directly into the earth without removing soil or other materials. Driven piles must be hammered, jacked, or vibrated into the ground to overcome the underlying soil resistance and allow the pile to slide smoothly into place. Specialized tools such as percussive hammers, hydraulic motors, and rams are essential.

Careful consideration of the relevant factors and the judicious application of the proper techniques are paramount to the successful and reliable placement of piles.