Project summary

There are currently 71 bridges in the King County Regional Trail System. Of these, over 40 are wood structures, many of which are nearing 100 years in age and in need of repair. The rest tend to be newer concrete or steel structures that are not anticipated to need major repairs in the foreseeable future, with the possible exception of painting. The current Bridge and Trestle CIP program consists of six primary tasks:

1. Inspections & Monitoring.
2. Replacement/Rehabilitation Feasibility Studies
3. Small Bridge Repairs
4. Design and Permitting (Larger Projects)
5. Construction: Major Rehabilitation & Replacement Projects
6. Program Management

The scopes for each of these tasks are as follows:

Inspections and Monitoring: This task includes bridge structural inspections and monitoring performed by the King County DOT Bridge Engineering Unit and provides the basis of information for the program. Each of the 71 bridges is inspected a minimum of once every three years. In cases where problem areas have been identified, follow-up annual "monitoring" of the problem area will often be performed until repairs can be made.

Replacement/Rehabilitation Feasibility Studies: This task includes feasibility studies to determine the scope, design alternatives, costs, and environmental issues associated with rehabilitating or replacing those structures where inspections have found significant problems. All are larger wood trestle structures and most are located in environmentally sensitive areas.

Small Bridge Repairs: This task includes repairs and renovation of smaller structures where costs are under $70,000 and the repairs can be made by County crews. Typically these repairs are to structures under 100 feet in length and include replacement of pile caps, stringers, braces, and damaged or worn decking. To date, 16 such projects have been completed and there is a long backlog of further small repair needs. Priorities are assessed at the beginning of each year following review of the previous year's inspections reports.

Design and Permitting: This task includes preparing plans and specification in support of construction bids and contracts for major bridge rehabilitation and replacement projects. Also included are special studies needed in support of construction permits including but not limited to geotechnical investigations, wetland analyses, drainage studies, historical/archeological investigations, and fish and wildlife surveys.

Construction: Major Rehab/Replacement Projects: This task includes bidding and construction for major rehabilitation projects, which include those beyond the capabilities and dollar limits of County crews.

Program Management: This task covers staff time for program management and includes coordination with Parks staff, reviewing and maintaining bridge inspection reports and files, coordinating inspections and repairs with KC DOT staff, managing consultant and construction contracts and services, and preparing and tracking annual budgets and schedules.

Project schedule

Timeline – various activities throughout the year including:

• 14 bridge inspections
• 4 feasibility studies
• 3 small bridge repairs
• Design and permitting for 1 major rehabilitation and 1 major replacement project
• Load rating and signage for 14 bridges

Project budget

Staff contact

Jason Rich
Project Manager, Facilities Management Division
201 S. Jackson St. #700
Seattle, WA 98104
jason.rich@kingcounty.gov
Phone: 206-263-7314
Fax: 206-293-6271