Classification, Composition And Structure of Rotary Drilling Pile Foundation

Rotary drilling pile foundation is widely used in modern construction engineering, featuring reliable performance and high construction efficiency. Understanding the classification, composition and structure of rotary drilling pile foundations is helpful for better grasping their working principles and application scenarios. Here is a detailed popularization of relevant knowledge for you.

1. Classified by force nature: Friction-type rotary drilling piles rely on the frictional resistance of the soil on the side of the pile to bear the load and are suitable for soft soil foundations. End-bearing rotary drilling piles are supported on hard soil or rock layers at the pile ends, and the load is borne by the resistance at the pile ends. They are often used in projects with high requirements for bearing capacity.

2. Classified by piling method: Dry operation hole-forming rotary drilling piles are constructed in soil layers above the groundwater level and do not require mud wall protection. Mud wall protection and hole formation rotary drilling piles maintain the stability of the hole wall through mud and are suitable for various complex geological conditions. They are the most common pile formation method.

3. Pile body composition: Rotary drilling piles are mainly composed of pile body concrete and steel cage. The concrete of the pile shaft provides strength and rigidity to resist external loads. The steel cage enhances the tensile and shear resistance of the pile body and improves the overall structural performance.

4. Pile head structure: The pile head is a crucial part connecting the pile body to the superstructure. It is usually enlarged to increase the connection area with the pier cap. At the same time, set the anchorage length of the reinforcing bars to ensure the effective transmission of force and guarantee the stability of the foundation.

5. Pile tip structure: There are various forms of pile tips, such as flat bottom and conical bottom, which are common. The flat-bottomed pile end is suitable for uniform soil layers and is convenient for hole cleaning. The cone bottom pile end can enhance the compaction effect of the soil at the pile end and increase the end bearing capacity, and is often used in projects with high bearing requirements.

6. Special structural treatment: Under special geological or engineering requirements, special structural treatment is carried out on the rotary drilling pile foundation. For instance, steel casings are added in areas prone to collapse, or grouting pipes are set up on the pile body for post-grouting construction to enhance the bearing capacity and stability of the pile.

The different classifications, compositions and structures of rotary drilling pile foundations enable them to adapt to diverse engineering requirements. A thorough understanding of this knowledge helps engineering personnel to rationally select and design rotary drilling pile foundations based on specific circumstances in actual construction, ensuring the quality and safety of construction projects.