Segmented casing is a critical drilling part of piling projects, particularly in the civil engineering industry. This article delves into the essential aspects of segmented casing, its features, components, classification, and installation processes, providing a comprehensive understanding of its role in modern construction.
The Three Primary Functions of Segmented Casing
Segmented casing serves three main purposes in piling projects:
- Supporting the Borehole Wall: It prevents the collapse of the borehole wall, ensuring stability during drilling and concrete pouring.
- Guiding the Drill: It acts as a guide to prevent deviation, ensuring the borehole remains straight and accurate.
- Waterproofing: It prevents groundwater from infiltrating the borehole, which could otherwise compromise the integrity of the pile.
These functions make segmented casing indispensable in projects where precision and stability are paramount.
Components of Segmented Casing
The full set segmented casing devices are composed of four main parts:
- Cardan Joint
The cardan joint is a critical component that connects the power head to the Kelly bar, transferring rotational torque while accommodating angular misalignment. It ensures smooth power transmission during drilling operations, especially when the Kelly bar and power head axes are not perfectly aligned.
- Casing Drive Adapter
The casing drive adapter is used to automate the rotation of the casing, transferring the torque and thrust force from the drilling rig's power head to the casing, effectively converting and transmitting power for efficient and precise drilling operations.
- FES can custom-build casing drive adapters interchangeably with most of the international brand rigs, including Bauer, Liebherr, IMT, Soilmec, Casagrande, Mait, XCMG, and so on.
- The welded “U” block on the casing drive adapter makes maintenance easy.
- Lock set is available.
- Casing Joints:
Casing joints are specialized connectors that link casing pipes. They are designed for high flexibility, strength, and durability, and they are capable of withstanding significant pressure and tension. Made from materials like Q355 rolled steel or 25CrMo cast or forged steel, these joints ensure a secure and stable connection. Additionally, advanced sealing technologies are employed to prevent leaks, enhancing the overall safety and quality of the construction process. 
- Casing Pipe:
The casings are designed to perform cased holes, especially for the construction of bored piles by rotary drilling rigs in the foundation piling industry. FES provides both single-wall and double-wall casing.
- The dimensions of FES casing are designed to match most casing brands in the global foundation drilling market.
- Double wall casing is for temporary use, which is designed especially for transmitting high rotational and vertical forces created by the machine. Single wall casing is usually for permanent use, which is mostly used in the soft condition and the pile doesn’t have to be too deep.
- Diameter up to 5000mm
- Regular FES casing pipes are made from Q355B steel. Heavy-duty material such as NM360 pipes and forged joints are available as options.
- Casing Shoe:
The casing shoe is a protective device used in conjunction with the casing pipe to safeguard both the casing and the drilling tools. Typically made from high-strength materials, it offers excellent wear and impact resistance, adapting to various challenging environments. Customizable to specific project needs, the casing shoe plays a vital role in maintaining drilling efficiency and equipment longevity. 
Classification of Segmented Casing
Segmented casing can be categorized based on two primary criteria:
- Wall Type:
- Single-Wall Casing: Suitable for less demanding projects where groundwater infiltration and borehole stability are manageable.
- Double-Wall Casing: Used in more complex projects where additional strength and waterproofing are required.
- Length:
Segmented casings are available in various lengths, commonly 1, 2, 3, 4, 5, and 6 meters. Custom lengths and diameters can also be manufactured to meet specific project requirements. 
Installation Process of Segmented Casing
The installation of segmented casing involves several key steps, tailored to the depth and complexity of the borehole:
- Drilling & Casing Installation:
- For depths less than 20 meters, a rotary drilling rig is typically used.
- For depths between 20 and 60 meters, a pipe oscillator is employed.
- For depths exceeding 60 meters, a casing rotator is necessary.
- Cleaning:
The borehole is cleaned to remove any debris or obstructions that could affect the integrity of the pile. - Concrete Reinforcement Cage Placement:
A reinforcement cage is lowered into the borehole to provide structural support to the concrete pile. - Concrete Pouring:
Concrete is poured through the casing to form the pile. For deep piles, a continuous pour and extraction method can be used to ensure uniformity and stability. - Casing Extraction:
The casing is gradually extracted as the concrete sets, ensuring the pile retains its shape and structural integrity. 
Conclusion
Segmented casing is an indispensable component in foundation piling projects, offering essential support, guidance, and waterproofing. By understanding the components, classification, and installation processes of segmented casing, construction professionals can make informed decisions that enhance the efficiency and safety of their projects.
For high-quality segmented casing and related equipment, trust in FES foundation drilling tools provider, who prioritize innovation, precision, and reliability. Whether you're working on a high-rise building, a bridge, or a tunnel, the right segmented casing system can make all the difference in achieving a successful and stable foundation.
