Project Summary/Scope:

Ortega Road is a stretch of roadway that experienced persistent settlement issues in the decades prior to the 2019 rebuild. First built in the 1950’s, the profile of the roadway was raised in 1969. Continued failure of the roadway was attributed to underlying expansive shales as well as inferior construction techniques. The road was temporarily closed in 2017 due to settlement issues and work began to design a more permanent solution. The roadway was stabilized using MSE wall technology to reinforce the roadway, and tire-derived aggregate (TDA) within the MSE wall structure to further reduce loading on the expansive shall subgrade. The project was finished on time and on-budget with no reported issues since construction was completed.

Technical Details:

Tire-Derived Aggregate (TDA): 45 pcf, φ = 35°, free-draining

MSE Wall: Height = 15’, 72° batter, 15’ geosynthetic embedment at 18” vertical spacing

Complementary Technologies Used: Mechanically Stabilized Earth (MSE) retaining structures. 

Alternate Technologies: N/A

Performance Monitoring:  Survey monument added to the site for continual monitoring of any movement along the roadway, adjacent wall, or the underlying embankment slope.

Cost Information:  Total project cost was $665,000.

Project Technical Paper:  Doolittle, C., Sneddon, C., Wright, J. Trumbull, C., (2020). “Reconstruction of Failed Roadway Embankments Using Tire-Derived Aggregate Mechanically Stabilized Earth Walls – Ortega Ridge Road Case Study.” Geosynthetics 2020, 8-10 March 2020, Charleston, SC.

Date Case History Prepared: 2021

Case History Prepared By: Melissa S. Beauregard