Holistic Approach to Determine an Optimal Method for Installing Pin Piles

The installation of pin piles is a critical component of jacket foundation installation, providing the necessary stability for wind turbines. Achieving an optimal installation method requires a holistic approach that considers various factors, including project-specific details, vessel capabilities and installation efficiency. This article explores these factors in detail to help determine the best installation method for pin piles.

Project-specific parameters
Every offshore wind project is unique, with specific requirements and challenges that must be addressed. Key project-specific details include the location, water depth, soil conditions, and environmental factors. Understanding these details is crucial for selecting the appropriate installation method.

• Location: The geographical location of the project influences the choice of installation method. For example, projects in regions with high seismic activity and chances of typhoons, such as Taiwan or Japan, may require more robust foundation designs and installation techniques to withstand potential earthquakes and extreme wind loads. Additionally, each country has its own regulatory framework. For example, Japan and the United States have protective legislation that restricts the operation of foreign vessels in their waters.
• Water depth: The depth of the water at the installation site affects the type of equipment and vessels needed. Shallow water installations may allow for the use of jack-up vessels, while deeper water projects might require floating vessels and specialized equipment. Floating vessels require self-leveling piling templates which are more complex than suspended templates underneath a jack-up vessel.
• Soil conditions: The seabed composition, including the type of soil and its bearing capacity, plays a significant role in determining the installation method. Detailed geotechnical surveys are essential to gather data on soil conditions, which can influence the choice of pin pile design and installation technique. For example, Taiwan’s offshore wind projects face challenges with low bearing soil conditions, while France’s diverse soil conditions range from sandy and silty soils to rocky seabeds. Low bearing soil conditions might results in challenging piling template seabed interface, while rocky seabeds require drilling solutions.
• Environmental factors: Weather conditions, wave and current patterns, and the presence of marine life can impact the installation process. For instance, larger pin piles tend to vibrate with lower wave frequencies, which can affect the installation operability. Conducting motion analyses or workability analyses is essential to account for these factors and ensure a safe and efficient installation.

Vessel capabilities and cost
The capabilities and availability of installation vessels are critical considerations in the installation process. Different vessels have varying capacities, equipment, and operational limits, which can affect the feasibility and cost of the installation method.

• Vessel type: The choice of vessel depends on the project requirements and site conditions. Jack-up vessels are commonly used for shallow water installations, providing a stable platform for pile driving. Floating vessels, on the other hand, are suitable for deeper waters and can accommodate larger equipment.
• Vessel availability: The availability of suitable vessels can impact the project timeline and costs. A shortage of specialized vessels can lead to delays and increased expenses. Past installation methods, primarily reliant on Jack-Up Vessels (JUVs), have proven effective but are currently facing limitations in handling the demands of longer, larger, and heavier piles. However, the shortage of heavy lift vessels capable of installing these larger pin piles is a pressing concern.
• Operational costs: The cost of operating installation vessels includes fuel, crew, and maintenance expenses. These costs can vary significantly depending on the vessel type and the duration of the installation process. Optimizing installation sequence and minimizing downtime can help reduce overall costs.

Installation efficiency
Efficiency in the installation process is crucial for minimizing project timelines and costs. Several factors contribute to installation efficiency, including the choice of equipment, installation techniques, and project management.

• Tailored installation equipment: The selection of installation equipment, such as pin pile templates and lifting devices, can impact the speed and accuracy of the installation. Tailoring equipment design to the specific needs of the project can enhance efficiency.
• Installation method: Different installation methods, such as pile driving and drilling have varying levels of efficiency and suitability for different soil conditions. Selecting the right method based on project-specific details can improve installation efficiency.
• Project management: Effectively managing the project’s budget, planning, risk control, QHSE requirements, and procurement, along with detailed project management practices such as planning, scheduling, and coordination, is essential for ensuring smooth project execution. Real-time monitoring and adjustments can help address any issues that arise during installation, minimizing delays and disruptions.

Unlock the Future of Jacket Installation at TWD’s Webinar
A comprehensive understanding of project-specific parameters is crucial for the success of offshore wind projects. Our experts can create customized solutions tailored to your project’s unique requirements. We aim to develop innovative installation methods and engineering designs that are specifically suited to each construction project’s unique needs.

For further details, you can download TWD’s jacket foundation track record or participate in the “Future of Jacket Installation” webinar on February 5th. This event will cover the challenges and innovations in jacket foundation installation, with a focus on the Asia-Pacific region. The webinar will provide valuable insights and an opportunity to interact with industry experts.