Reinforced Soil Slope (RSS) Failure and Reconstruction: US 70 Design-Build Project, Ruidoso to Riverside, New Mexico

A major geotechnical slope failure occurred at Sta. 1663 on the US 70 Design-Build project in New Mexico a year after construction. The 1663 reinforced soil slope was 7.6 m (25 ft.) high and constructed at 0.5H:1V. A slope stability-type failure occurred, with movement associated only with severe rain storms. This case history study will describe the project site conditions, design methods, failure monitoring and analysis, and reconstruction of the RSS. The authors were involved in all aspects of design, construction, forensic evaluations, reconstruction, and claims resolution. The failure is notable because following reconstruction, the contractor was successful in a dispute claim based upon differing site conditions. This paper describes the range of project evolution from design, failure monitoring, forensic evalutions, and reconstruction, to the dispute resolution process and findings.