Research & Innovation

Development of Cost-Effective Timber Bridge Repair Techniques for Minnesota: Manual for Repairs

Summary:

2015-45A: The primary objective of this work is to provide formal guidance to county engineers throughout Minnesota for repairing timber bridge components. The benefit of having such a resource will be measured by improving the overall condition of the transportation system and reducing system failures through implementation by local officials. As is often the case, funds required to complete repairs are limited and, as a result, any method used must not only be structurally feasible but also economically feasible. This report provides bridge owners and caretakers several routine maintenance and repair options aimed to meet the goals of simplicity and affordability. The economic impact of repairing timber bridges was assessed for multiple scenarios: a comparison was made between the net present value of repair at varying repair costs over time and the net present value of varying reconstruction costs over time. Through this exercise, for each scenario, a point in time was identified when repair or reconstruction makes most economic sense. An additional assessment of overall costs (direct plus indirect) was completed, which included the increased user costs due to bridge posting or closure. This assessment made clear that when indirect costs are included, the benefits of maintaining or repairing a bridge to prevent posting or closure become great. A standalone manual, Cost-Effective Timber Bridge Repairs: Manual for Repairs of Timber Bridges in Minnesota, was also developed for this project. ::: 2015-45B: One of the primary objectives of this project, Development of Cost-Effective Timber Bridge Repair Techniques for Minnesota, was to produce a timber bridge repair manual. This manual is comprised of some of the content from the final report for the project, along with an extended presentation of timber maintenance options. This final manual is a standalone document from which the maintenance and repair options can be implemented. A final report (2015-45A, Development of Cost-effective Timber Bridge Repair Techniques for Minnesota) was also developed.

Final Deliverables:

• Cost-Effective Timber Bridge Repairs: Manual for Repairs of Timber Bridges in Minnesota (Manual #2015-45B)
• Development of Cost-Effective Timber Bridge Repair Techniques for Minnesota (Report #2015-45A)
• Cost-Effective Repairs of Timber Bridges: Solutions for Minnesota Timber Bridges (Other #201545PP)
• Manual Gives Cost-Effective Techniques to Extend Timber Bridge Life Spans (Research Summary)

Related Materials:

• Timber Bridge Inspection: Stress Wave Timer Demonstration  (Video/Webinar)
• Timber Bridge Inspection: Resistance Microdrilling Demonstration  (Video/Webinar)

Related Research:

• Cost-Competitive Timber Bridge Designs for Long-Term Performance
• Development and Integration of Advanced Timber Bridge Inspection Techniques for NBIS Purchase Equipment and Train Users
• Development and Integration of Advanced Timber Bridge Inspection Techniques for NBIS
• Load and Resistance Factor Design (LRFD) Pile Driving Project - Phase II Study
• Developing Flexural Vibration Inspection Techniques for Wooden Bridges
• Development of Flexural Vibration Inspection Equipment, Techniques to Assess Structural Health of Rural Bridge Sys II.
• Load and Resistance Factor Design (LRFD) Pile Driving Project-Phase II Study
• Development and Integration of Advanced Timber Bridge Inspection Techniques for NBIS
• Development and Integration of Advanced Timber Bridge Inspection Techniques for NBIS purchase Equipment and Train Users
• Cost-competitive Timber Bridge Designs for Long Term Performance

Project Personnel:

Principal Investigator:  Brent Phares
Technical Liaison:  David Conkel
Project Coordinator:  Daniel Warzala
Panel Members: 
    Ahman Abu-Hawash - Bridges and Structures
    Alan Forsberg - 
    Art Johnston - USDA Forest Service, Retired
    Brent Phares - Iowa State University/CTRE
    Brian Brashaw - University of Minnesota Duluth
    Brian Keierleber - Buchanan County Engineer
    Christopher Werner - HDR Engineering, Inc.
    Daniel Dorgan - HDR Engineering, Inc.
    Greg Isakson - Goodhue County
    James Wacker - USDA Forest Service
    Jim Grothaus - Hancock Concrete
    John Welle - Aitkin County
    Mark Dunn - Iowa Department of Transportation
    Mark Nahra - Woodbury County Engineer
    Matthew Hemmila - St. Louis County
    Robert Vatalaro - U of M Duluth
    Susan Miller - SRF