LRFD Metal Loss and Service-Life Strength Reduction Factors for Metal-Reinforced Systems

摘要

Transportation agencies use a variety of metal-reinforced systems in geotechnical applications, including soil and rock reinforcements, ground anchors, and tiebacks. These systems support retaining walls and soil and rock slopes, and they stabilize roadway cuts and fills. The precise conditions governing the deterioration of these systems are uncertain, but corrosion is known to have an impact on their service life. Engineers, faced with the task of allocating budgets to rehabilitate aging facilities, need reliable techniques for assessing corrosion and estimating metal loss. Service-life estimates for new systems need to be improved, and consideration of metal loss in their design needs to be consistent with the reliability-based approach adopted in the AASHTO LRFD Bridge Design Specifications. The objectives of this research were to (1) assess and improve the predictive capabilities of existing computational models for corrosion potential, metal loss, and service life of metalreinforced systems used in retaining structures, highway cuts and fills, and other applications; (2) develop methodology that incorporates the improved predictive models into an LRFD approach for the design of metal-reinforced systems; and (3) recommend additions and revisions to the AASHTO LRFD specifications that incorporate the improved models and methodology.