Marine and waterfront concrete structures face unique engineering challenges due to the combination of harsh environmental exposure, dynamic loading, and evolving sustainability requirements. This technical session will focus on resilient engineering practices for the design, construction, and maintenance of offshore, coastal, and waterfront concrete structures and their foundations.
Learning Objectives:
(1) Introduce advanced methodologies for designing marine, waterfront, and offshore concrete structures to withstand extreme environmental and dynamic loads;
(2) Present innovations in high-performance and corrosion-resistant concrete, fiber-reinforced composites, and other sustainable materials suitable for marine environments;
(3) Highlight strategies that balance durability, cost efficiency, and environmental sustainability, including life-cycle assessment and circular economy practices;
(4) Summarize sustainable and resilient design strategies.
Resilient Engineering of Marine and Offshore Structures
Presented By: Abbas Mokhtar-zadeh
Affiliation: M3 Engineering & Technology Corporation
Description: Marine and offshore structures are increasingly exposed to climate-driven loading, sea-level rise, and extreme environmental events. This presentation focuses on practical approaches to improving structural resilience by integrating sustainability, reliability, and adaptability within current engineering practices. Traditional design methods, often based on prescriptive codes and historical load assumptions, are contrasted with contemporary strategies that employ performance-based design, probabilistic load assessment, advanced materials, and redundancy in structural systems to enhance durability, reduce maintenance, and support operational reliability. Lessons from hurricanes, storms, and offshore incidents over the last several decades highlight vulnerabilities in conventional designs and inform practical measures for foundations, superstructures, and hydraulic systems, accounting for major environmental factors such as temperature variation, seismic activity, wave dynamics, and seasonal fluctuations. The presentation emphasizes how computational modeling, climate-responsive load assessment, and adaptive structural detailing can be applied to evaluate and strengthen both new and existing infrastructure. Attendees will gain concrete guidance on implementing resilient engineering techniques that improve service life, maintain functionality under changing conditions, and address environmental and operational challenges using methods aligned with current industry standards. By comparing modern approaches with traditional practices and focusing on constructive strategies, this presentation provides an applied framework for designing and maintaining durable, reliable marine and offshore structures, supporting safer and more sustainable operations.
Raising a Wharf for Coastal Resiliency in Challenging Conditions at Battery Park in Lower Manhattan
Presented By: Domenic D'Argenzio
Affiliation: Mueser Rutledge Consulting Eng
Description: The Battery, located at the southern tip of Manhattan in New York City is part of a series of projects that make up the Lower Manhattan Coastal Resilience initiative and includes both climate mitigation and climate adaptation practices. The project is reconstructing the existing aging and failing timber wharf originally constructed in the 1940’s with a new elevated concrete wharf that provides upland park protection from future sea level rise scenario in year 2100 as defined by the New York City Panel on Climate Change.
Accounting for over 6 ft (1.8 m) of sea level rise required extensive coordination with the National Park Service vessel operators who ferry approximately four million tourists yearly to the Statue of Liberty from The Battery. The wharf design had to consider present day operability while planning for future climate change conditions. Those challenges led to an innovative two-gangway system that allows vessels to berth at a gangway that best suits the tidal elevations and vessel draft.
The design of the wharf accounted for several challenges including poor subsurface conditions, varying rock depth, complex wharf geometry, upland historical structures, monuments and art pieces, a vehicle underpass, and a vehicle tunnel that crosses beneath the extreme end of the wharf. Spanning the tunnel required very deep, long-span prestressed concrete girders supported by large composite concrete pile caps, one of which is a post-tensioned cantilevered pile cap extending above the tunnel.
The new wharf consists of a high-level composite concrete deck supported by precast pile caps and 24-inch (610 mm) square prestressed concrete piles fitted with a lower steel H-section driven to top of rock. Sixteen-inch (406 mm) diameter rock-socketed micropiles, and 24-inch (610 mm) and 30-inch (762 mm) diameter high-capacity caissons socketed into rock were required to support the wharf foundations within the tunnel influence zone.
Implementing Ultra-High-Performance Concrete (UHPC) Hulls for Infrastructure-Integrated and Offshore Mobile Wave Energy Converters
Presented By: Dimitrios Kalliontzis
Affiliation: University of Houston
Description: Ultra-High-Performance Concrete (UHPC) offers superior strength and durability properties compared to competing cementitious composites and other material systems. This research study investigates its use in the design of an oscillating water column (OWC) hull for infrastructure-integrated wave energy conversion and the design of a multimodal wave energy converter (MWEC) that is generating energy offshore. The OWC is prototyped for installation in the Los Angeles Port with three structural design configurations being comparatively evaluated: (1) a conventional reinforced concrete chamber, (2) a reinforced UHPC chamber, and (3) a post-tensioned UHPC chamber. Mobile MWEC hulls are prototyped for use in west and east locations of the Gulf of America and one nearshore location in Maine. All MWEC configurations are designed as self-stabilized by ensuring a positive metacentric height through a surrogate-based mass distribution algorithm. The presentation will discuss the designs of the OWC and MWEC systems along with practical considerations for fabrication and field implementation.
Use of Fiber-Reinforced-Polymer Rebars in Marine Structures
Presented By: Widianto Widianto
Affiliation: ExxonMobil
Description: Fiber-Reinforced Polymer (FRP) rebars are non-metallic reinforcing bars made from high-strength fibers (such as glass) embedded in a polymer matrix. Several key advantages of FRP rebars are non-corrosive (improving durability and reducing of overall life-cycle costs especially for structures with longer design life) and light weight (improving productivity and reducing transportation and installation costs).
The use of FRP rebars significantly enhance the resilience of structures exposed to harsh marine environments by improving durability, reducing degradation mechanisms, and ensuring functionality over long service lives with lower maintenance demands and overall life-cycle costs.
FRP rebars have been commonly used in many projects worldwide, especially in infrastructure. Design standards for FRP rebars have reached a high level of maturity, which demonstrates that FRP rebars has moved well beyond the experimental stage and are now a fully codified structural material.
The presentation will focus on the use of FRP rebars in marine structures. The following topics will be presented: properties of FRP rebars (in contrast to normal steel rebars), pros and cons, real application of FRP rebars in concrete structures exposed to sea water (such as jetty, seawalls, docks, bridges over coastal), and industry standards covering FRP rebars.
Marina Breakwater & Floating Dock Replacement utilising GFRP Rebar & Tie-rods
Presented By: Peter Renshaw
Affiliation: Pultron Composites
Description: The Tauranga Bridge Marina (New Zealand), constructed in 1996, suffered significant storm damage within a decade of operation. The subsequent rebuild focused on enhancing resilience through improved design focussing on the use of corrosion-resistant materials.
The marina comprises a floating dock system accommodating approximately 500 vessels ranging from 10.5 to 37 metres in length. The site is exposed to the North, experiencing Northerly storms and wind against tide waves, which has caused significant damage to the marina.
The floating docks are manufactured as precast concrete modules up to 12 metres in length, reinforced with Glass Fibre Reinforced Polymer (GFRP) rebars. The modulus are connected using timber walers, secured via a composite fastening system consisting of threaded GFRP tie-rods and glass-filled nylon nuts. These materials were selected for their corrosion resistance, advancing the manufacturer’s objective of a fully steel-free system.
The rebars and tie-rods are corrosion resistant, offering excellent longevity in the saltwater environment. An additional, unexpected benefit of the composite tie-rod system is its relatively low tensile modulus. This allows the system to maintain tension as timber walers shrink over time due to drying, reducing the need for periodic re-tightening—particularly after major storm events.
Noncorrosive Nonmetallic Concrete Reinforcement for Resilient Coastal Infrastructure: Case Studies in the Southeastern US
Presented By: Fabio Matta
Affiliation: University of South Carolina
Description: Noncorrosive nonmetallic concrete reinforcement is well suited for coastal infrastructure, which operates in aggressive environments exposed to saltwater, sea level rise, and storm and flood hazards. This presentation shares an overview of three large-scale projects that were recently completed in the Southeastern US, and lessons learned from designing and building with fiber-reinforced polymer (FRP) reinforcement towards enhancing coastal resilience. The projects include: (i) a novel buried glass FRP-reinforced pile wall and bulkhead cap for scour mitigation along the oceanfront Jimmy Buffett Memorial Highway (A1A) in Florida, which can accommodate 16-ft of storm scour, keeping a 3.5-mile-long section of vital hurricane evacuation and emergency response route in service; (ii) a rebuilt 0.9-mile-long seawall along downtown Charleston’s historic Low Battery waterfront in South Carolina, where construction transitioned from a hybrid steel-glass FRP in the early phases of the project to an all-FRP solution as owner, designer, and contractor gained confidence in an appealing but unfamiliar technology, and leveraged its constructability advantages; and (iii) the new 0.6-mile-long Harkers Island Bridge—North Carolina’s first concrete bridge with all-FRP reinforcement—which replaced two steel prestressed cored-slab bridges that had been in service for about 50 years, experiencing extensive corrosion that led to load postings and frequent partial closures despite repeated repairs. The success and lessons learned from such projects has resulted in new local applications of FRP reinforcement, such as the Beresford Creek bridge replacement in Daniel Island, SC, and the 3-mile-long Alligator River bridge replacement in North Carolina’s Outer Banks.