Project Purpose: Accelerated Construction of a Piled Jetty for Panamax Vessels
Completed in 2016, the 350 m long piled jetty at Puerto Quetzal, Guatemala, was developed to accommodate Panamax-class vessels with drafts up to 15.0 m and installed propulsion power exceeding 70,000 kW. The wider project faced significant technical and logistical challenges associated with fast-track delivery, limited access for marine works, and the need for long-term slope stability. One of the most critical challenges was protecting the vulnerable medium sand seabed from scour caused by intense propeller and thruster action beneath the open piled quay structure—an issue that demanded a robust and constructible solution for scour protection.
To accelerate construction and reduce marine working durations, the contractor COPISA Guatemala employed the Land Infill method. By using local sand as temporary backfill, the reinforced concrete piles (1.2 m Ø), beams, and platform slab were constructed from land, enabling dry working conditions. This strategy enabled full quay completion—from initial piling to the first vessel call—within approximately 20 months. As soon as the platform deck was completed, cranes were erected while dredging and slope protection works proceeded below.
Concrete Mattress Solution
To provide reliable scour protection below the platform and in the wave zone, Proserve’s in-situ concrete mattress system was selected over rock armour due to its practical installation and sealed performance. It proved especially effective for protecting large sloping areas with limited underdeck access.
The system used 59 tailor-made panels—each 6.05 m wide (matching pile bay widths) and 55 m long. These were installed in sequence and interlocked with robust ball-and-socket zip joints. Constant Thickness (CT150) mattress was installed along the main dredged slope where vessel propulsion effects were greatest. Above this, in the wave zone, a 220 mm thick Open Hole (OH220) mattress with 90 mm Ø openings at 1 m centres was used to facilitate wave rundown and relieve hydraulic uplift.
A rock falling edge apron was applied along the mattress toe and perimeter to resist edge scour and improve long-term performance.
Design Principles of the Concrete Mattress
The mattress system followed PIANC 180 guidance and was tailored to suit the specific constructability and scour conditions beneath the platform. The mattress fabric allowed excess water to bleed during filling, but retained the 2:1 sand:cement micro concrete, forming a high-strength, robust concrete apron.
Key design features included:
- Ball-and-socket joints between panels to distribute shear and accommodate differential movement.
- Custom pile seals to form a sand-tight interface around the 500+ reinforced concrete piles.
- Slope tolerance of ±0.45 m, supported by panel flexibility and construction planning.
- Additional formwork allowances to cater for pile positional tolerances and on-site conditions.
The in-situ mattress system enabled ‘sealed’ scour protection, resisting uplift and flow penetration. Construction was managed using a marine quality control process that included diver checklists, photographic records, and independent verification, ensuring build quality under challenging underwater conditions.
Installation Detail
Infill sand beneath the platform was first excavated to mid-tide level by long-reach plant. Below that, the submerged slope was dredged using Toyo slurry pumps mounted on specialised barges. Final trimming was carried out by divers using handheld Toyo pumps to achieve the design slope profile.
Underdeck mattress installation involved unrolling each panel into place, wrapping around piles, and zipping to neighbouring panels. A 2:1 sand:cement micro concrete was pumped bottom-up through 63 mm hoses, supplied by ready-mix wagons from shore. Filling each panel typically took 6–8 hours. The pile seal system ensured continuity and resistance to flow paths between mattress and pile.
In the wave zone, the OH220 mattress was laid over a geotextile and bedding stone layer. These layers were installed immediately after excavation to provide temporary cover until mattress placement. The mattress adapted well to undulating surfaces and was secured in place efficiently.
Advantages and Project Success
The Puerto Quetzal project was a success both technically and logistically. The combination of Land Infill construction and underdeck installation of in-situ concrete mattress enabled a fast-tracked build without compromising on scour performance.
Key outcomes:
- Fast Programme: The quay was delivered in just 20 months from piling start to vessel call.
- Critical Path Reduction: Scour protection was installed after deck construction, avoiding delays.
- Material Efficiency: Thin mattresses replaced heavy rock sections, enabling full vessel clearance at a 15 m draft.
- Reliability: Sealed concrete protection and edge aprons delivered high resilience to propeller scour.
- Adaptability: The system accommodated pile layout tolerances and slope variations without redesign.
The choice of in-situ concrete mattress allowed COPISA Guatemala to maintain momentum after completing the superstructure, while the ability to work beneath the deck significantly reduced delays compared to conventional marine methods. Additionally, the compatibility of the local sand with dredging pump methods further streamlined the process.
Key Takeaways
Attribute | Description |
Location | Puerto Quetzal, Guatemala |
Completion | 2016 |
Contractor | COPISA Guatemala |
Structure | 350 m long piled jetty for Panamax vessels |
Method | Land Infill with underdeck in-situ scour protection |
Protection System | CT150 and OH220 concrete mattresses with rock falling edge aprons |
Pile Count | Over 500 piles sealed within the system |
Install Area | 59 panels, each ~340 m² |
Filling | 2:1 sand:cement micro concrete, pump-filled |
Project Duration | Approx. 20 months from first pile to vessel arrival |
Outcome | High-performance scour protection installed off the critical path |
