Cost-Effective Bridge Replacement Case Study

Problem

The four bridges on Geneva Road, built between 1973 and 1976, have been significantly affected by the wet climate of Redwood National Park, leading to structural issues. Over the years, the persistent exposure to moisture has caused extensive deterioration of the steel stringers and wood decks.

The biannual Federal Highway Administration (FHWA) bridge inspections revealed several critical concerns:

• Deterioration of Steel and Wood Superstructures: The wet climate has led to rusting and weakening of the steel components, as well as rotting and degradation of the wood decks, compromising the structural integrity of the bridges.
• Safety Concerns: The deteriorated state of the bridges poses safety risks for public vehicles, bicycles, and pedestrians.
• Non-compliance with Modern Standards: The aging bridges do not meet current safety and structural standards, which necessitates their replacement or significant rehabilitation.
• High Maintenance Costs: Continuous repairs and maintenance of the existing steel and wood superstructures have proven to be costly and inefficient.
• Need for Cost-effective Rehabilitation or Replacement: There is a critical need for a cost-effective solution that not only addresses the current structural issues but also reduces long-term maintenance requirements.

Solution

HECO Structural Engineers proposed replacing the steel and wood superstructures with pre-cast concrete superstructures. This solution was identified as the most cost-effective alternative in a Value Analysis session.

Specific actions included:

• • • Conducting a Scoping report and Value Analysis
    • Designing pre-cast concrete superstructures
    • Developing detailed construction documents
    • Providing accurate Class A cost estimates

Results

The project resulted in:

• • • Enhanced durability and longevity of the bridges
    • Improved safety for visitors and park staff
    • Cost-effective solution reducing long-term maintenance needs

Ensuring Lasting Safety and Accessibility in Redwood National Park

By replacing the deteriorated bridge superstructures with durable pre-cast concrete, HECO Engineers ensured that the lower two bridges on Geneva Road would continue to provide safe and reliable access for both visitors and park staff. This project exemplifies HECO Engineers’ commitment to delivering sustainable and cost-effective infrastructure solutions.

For more information or to discuss your upcoming project, call or email HECO Engineers.