A rational field process for corrosion evaluation of mechanically stabilized earth walls

Use of MSE Walls in the early 1970’s saved State Transportation Departments (DOTs) $270-$800/m 2 over that of conventionally designed retaining walls. As MSEW technology advanced, the original 75 -100 year service life assumptions for galvanized steel reinforcing elements were found to be invalid for certain environmental conditions. During 1985 to 1990 field research, significant corrosion in some MSE walls led to their abandonment, razing and reconstructing, or retrofitting. As corrosion influence parameters were further identified, improved design and construction practices developed, and modified guidelines helped to limit corrosion related problems in newer MSE walls. However, thousands of existing walls in the USA still need to be assessed. In this regard, some DOT’S have already initiated MSEW corrosion evaluation programs. Through FHWA sponsored research, a computerized device called the PR Monitor was developed to help identify corrosion of metallic soil reinforcements, and to simplify evaluations of new and existing retaining walls. This paper includes recommendations for establishing a systematic rational corrosion evaluation and monitoring program. If some MSE walls are identified with active metallic corrosion, new retrofit methods can be employed to economically rehabilitate walls under service conditions.