Project Context and Engineering Challenges
Al Faw Grand Port is a flagship marine infrastructure development on Iraq’s southern Gulf coast, featuring one of the longest quay walls in the Middle East. The port’s first 1.75 km quay includes over 700 vertical and raking steel piles that are fully exposed between tidal cycles — a highly aggressive marine environment subject to corrosion in the splash and tidal zones.
Conventional cathodic protection systems were deemed ineffective in this intertidal zone due to the piles’ prolonged exposure above low tide. A concrete encasement solution was selected as the most durable long-term protection method to meet the 100-year design life with minimal maintenance requirements.
However, the original approach — using precast concrete sleeves with annulus grouting — proved operationally inefficient. This method was labour-intensive, diver-dependent, and poorly suited to the tidal constraints and repetitive nature of the installation.
Proserve's Engineered Solution
To overcome these site-specific constraints, Proserve developed the Lift-In Pile Encasement Jacket System — a modular, reusable solution combining factory-fabricated steel installation frames and grout-tight fabric formwork liners.
Each pile jacket unit was assembled onshore in three stacked vertical frame segments, housing:
- A fabric formwork liner to cast a 200 mm-thick reinforced concrete encasement
- A prefabricated rebar cage to enhance structural integrity
- Quick-release ties and corner stiffeners to maintain geometry during handling and casting
Once assembled, the frame was lifted into position over each pile using mobile cranes. Concrete was tremie-pumped into the liner from the surface during low tide windows, with water bleed naturally escaping through the fabric, resulting in a low water-cement ratio (~0.4) and dense concrete finish.
The steel frame was stripped the next day and reused for the next pile, allowing rapid repeatable installation without diving works.
Technical Highlights
- Pile Types: Over 700 piles, both vertical and raking, 1.4 m in diameter and 7 m long in the exposed zone
- Encasement Thickness: 200 mm reinforced concrete, cast in situ
- Fabric Formwork: Grout-tight yet permeable, enabling water bleed and preventing grout washout
- Grout Properties: Site-batched concrete achieving dense, durable finish with reduced shrinkage
- Cycle Time: Each jacket is installed and filled within a single tide; reusability enables daily production matching frame availability
This system minimised time-critical overwater working, significantly increased productivity, and removed the need for high-risk diver activity.
Performance and Project Outcomes
The Lift-In Jacket System delivered a durable, buildable solution under challenging site constraints. Key outcomes include:
- Efficient concrete encasement of over 700 piles within tidal limitations
- Reuse of formwork across the full installation, maximising resource efficiency
- Reduced marine risk by eliminating diver-based grouting
- Uniform, dense encasement with high resistance to corrosion and chloride ingress
- Enhanced programme certainty and minimised disruption to parallel quay works
Broader Application of Fabric-Formed Pile Jackets
Beyond new-build works like Al Faw, Proserve’s pile jacket systems are also applied extensively in structural remediation and protection schemes worldwide:
- Corrosion Protection: Particularly suited to tidal and splash zone exposure where sacrificial anodes or cathodic systems are ineffective
- Structural Repair: Restores and improves capacity of degraded piles through cast-in-place reinforcement
- Material Compatibility: Applicable to steel, concrete, and timber piles in both tidal and submerged conditions
- Constrained Access: Modular lift-in designs allow retrofitting under existing structures or confined working zones