Combined Pile Systems

The combined pile system is a composite foundation structure formed by combining two or more types of pile foundation components such as steel pipe piles and steel plate piles, and concrete piles. By leveraging the structural advantages of different pile types, it compensates for the shortcomings of single pile types in terms of bearing capacity, lateral resistance, and water sealing performance. It is an optimized pile foundation solution for complex marine geology and extreme load conditions. It includes an integrated structural system consisting of pile body combination, connection nodes, and filling reinforcement. 

Application scenario

1. Heavy-duty foundations for offshore wind power and oil/gas platforms in deep and ultra-deep waters, capable of withstanding high waves and strong ocean currents;

2. Pile foundation projects in complex geological conditions such as alternating soft and hard strata and rock layers, to enhance overall bearing capacity;

3. Composite load-bearing foundations for large-tonnage upper facilities like offshore substation platforms and integrated platforms;

4. Deep-sea pile driving construction projects, using a "composite structure of engineering piles and elongated piles" to reduce the difficulty of underwater construction;

5. Renovation, reinforcement and extension projects for old offshore foundations, conducting composite reinforcement on the original pile foundations. 

Main structure

The mainstream form includes three types: steel pipe-concrete composite piles, steel pipe piles + steel plate pile interlocking composite wall, and segmented elongated composite piles; the core consists of the main load-bearing pile body, auxiliary support piles, rigid connection nodes, shear-resistant anchorage structures, and annular grouting gaps; at the connection parts of the pile body, shear keys and mortise-slot structures are set, and high-strength grouting materials are injected into the gaps to form a whole; accompanying auxiliary components such as guiding sleeves, positioning supports, and reinforcement steel plates are provided, which take into account vertical pressure bearing, lateral anti-overturning resistance, and seepage prevention performance. 

Corresponding product standards

1. General pile foundation standard: JTS 206-2-2023 "Construction Specifications for Pile Foundations in Waterborne Engineering"

2. Special standard for composite piles: DB44/T 2489 - 2024 "Technical Regulations for Steel Pipe Composite Piles"

3. Offshore connection standard: ISO 19901-8 "Requirements for Grouting Connections of Offshore Structures"

4. International pipe material standard: API 5L, ISO 3183 (Standard for Steel Pipe Matrices of Combined Piles)

5. Construction acceptance standard: DNV-ST-0119 "Design Standards for Offshore Wind Turbine Structures"