Modeling and Assessment of the Remaining Service Life for Steel Bridge Piles in Michigan

Steel piles have been widely used in bridge construction in Michigan. Most common are 12” & 14” inch H-pile sections, and 10”, 12” , 14” and 16” diameter pipe pile sections. Corrosion of the steel piles is becoming a major concern for the bridges, especially for those being in service for over 50 years. The localized corrosion of steel pile foundations may result in considerable loss of loadbearing capacity and eventually could lead to the collapse of the structure. Therefore, a comprehensive understanding of the population of in-service steel piles, and prediction of pile corrosion is essential to avoid excessive deflection or failure. However, there are certain challenges to investigate the corrosion of steel bridge piles, including but not limited to: Michigan Department of Transportation (MDOT) does not have a comprehensive inventory of the number, type, and age of steel piles currently in service. Existing soil type and groundwater levels and details of the pile sections used needs to be extracted case by case from as-built plans. (1) On-site measurement of corrosion extent is difficult and not cost-effective, especially for those steel piles buried in soil. Moreover, the measurement over a certain area of the steel pile may not be reliable due to pit corrosion. The pit corrosion is usually concentrated in a small area, but it can be more dangerous than uniform corrosion damage. (2) The corrosion of steel piles is influenced by numerous factors: (a) Soil resistivity. Resistivity, which is the reciprocal of conductivity, indicates the corrosion current carrying ability of the environment. Typically, lower soil resistivity promotes a higher corrosion rate and level of steel piles. (b) Chemical composition of soil. Chemical composition of the soil is of key importance to understand the influence of soil on corrosion of buried steel. Chlorides (>100 ppm) and sulfates (>200 ppm) have been identified as indicatives of corrosive soil in Federal Highway Administration guidelines for mechanically stabilized earth walls. Chloride ions, which directly participate in the anodic reaction of corrosions, could be a major threat for bridges in Michigan due to the large amount of de-icing agent applied in snow season. (c) Moisture content. Moisture is necessary for corrosion. Therefore, highest level of corrosion is usually found in water table fluctuation zone. (d) Bacteria. Microbiologically Influenced Corrosion (MIC), an electrochemical corrosion affected by the presence of biological agents, can also severely degrade the steel surfaces. (e) Pile type and loading history. The material, dimension and loading history of the steel piles can have impact on their corrosion rate. (3) There is no widely accepted method to predict pile corrosion. Current single variable or multivariable regression models do not consider all factors listed above, and thus lack generalizability. More importantly, the corrosion environment in Michigan may require its unique regression model. With these unsolved issues, the threat of influencing factors cannot be ranked. (4) There is lack of accurate prediction of the remaining load-bearing capacity of corroded steel piles. While several methods (AISC, AISI-EWM, AISI-DSM, etc.) have been developed, the localized corrosion as well as stiffness change make their assumption invalid and cause conservative prediction of the remaining life. (5) Many retrofit or repair techniques have been implemented for strengthening the corroded steel piles, but a detailed cost-effectiveness analysis (CEA) for those techniques should be conducted to minimize future construction cost in Michigan. Based on the above discussion, it is essential to investigate the effect of various factors on corrosion rate of steel bridge piles and predict the remaining load-bearing capacity of corroded piles. Consequently, proper repair technique can be applied at appropriate time to maintain and prolong the service life of bridges in Michigan.

Language

• English

Project

• Status: Active
• Sponsor Organizations:

  Michigan Department of Transportation

  Van Wagoner Building
  425 W. Ottawa Street
  Lansing, MI  United States  48909
• Performing Organizations:

  Western Michigan University

  1903 W. Michigan Avenue
  Kalamazoo, MI  United States  49008-5241
• Principal Investigators:

  Attanayake, Upul

• Start Date: 20250301
• Expected Completion Date: 20280531
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Bearing capacity; Bridge piers; Corrosion; Geotechnical engineering; Service life; Steel bridges
• Geographic Terms: Michigan
• Subject Areas: Bridges and other structures; Geotechnology; Highways; Maintenance and Preservation; Planning and Forecasting;

Filing Info

• Accession Number: 01957459
• Record Type: Research project
• Source Agency: Michigan Department of Transportation
• Files: RIP, STATEDOT
• Created Date: Jun 6 2025 2:44PM