Public Works honored for Ortega Ridge Road TDA project
Santa Barbara County took home the top honor in the 2020 Outstanding Local Streets and Roads Project Awards.
The county was recognized for innovations in sustainability with the Ortega Ridge Mechanically Stabilized Tire Aggregate Wall, where a failed roadway embankment was reconstructed using recycled tires.
The winners were announced Wednesday by the League of California Cities, County Engineers Association of California and California State Association of Counties. Santa Barbara County was among several counties and cities throughout the state for creative and cost-effective projects that improve local streets, roads and bridges, according to officials.
The Outstanding LSR Project Awards Program also highlights cities and counties that promote fiscal and environmental sustainability in the local transportation system. Due to the coronavirus pandemic, the awards were presented virtually as the annual CEAC conference was canceled in compliance with local health orders.
“We applaud the excellence and dedication demonstrated by all of these city- and county-level award winners,” League Public Works President Rene Guerrero, the Pomona Public Works Director, said in a statement. “The projects serve as important reminders of the innovation in sustainability happening on a local level to improve safety and accessibility to roadways for residents in a way that is responsible and can be replicated across the state and nation.”
Santa Barbara County Public Works reconstructed the failed roadway embankment on Ortega Ridge Road in Summerland, restoring a 225-foot section of roadway and diverted some 81,000 tires from the state’s landfills in the form of tire-derived aggregate fill.
At the time of construction, it was the first infrastructure project in the state to use TDA material in this type of application.
“This CalRecycle grant project is a new model for how communities can transform recycled waste tires into a valuable resource to improve local infrastructure and protect public safety,” CalRecycle Director Scott Smithline said in a statement on Aug. 1, 2019, when the project was nearing completion. “This has been a collective effort with the cooperation of Santa Barbara County to be part of this first-of-its-kind project. We hope this is the first of many statewide projects that will make use of this new civil engineering technique.”
UC San Diego conducted research on the road repair techniques, which provided the engineering data for the project design. Researchers determined that TDA is seismically safe for a retaining wall and road repairs and it will not degrade due to poor underlying soils or saturated conditions.
Ortega Ridge Road had been slowly failing for over a decade. The original roadway embankment was built by filling a swale with loose, weak materials and the road sat on more than 28 feet of unstable material, according to officials.
Public Works engineering geologist Chris Doolittle and team members worked to solve the issue starting in 2014, though officials began investigating settlement at the site more than 20 years ago.
“Every few years, the road would settle to the point that it required our maintenance crews to install a pavement overlay to maintain the profile,” Mr. Doolittle said. “In 2015, the extent of road settlement forced us to realign the road and close down to one lane of alternating traffic. After the Thomas Fire Debris Flow in 2018, this was the sole access point to Toro Canyon until bridges on State Route 192 were repaired or replaced, and only after their completion were we able to close the road and construct the project. It was through coordination with CalRecycle that this pilot project was funded and we received the technical know-how to develop and construct the project.”
More than 30 inches of asphalt had been placed on the roadway over the years in attempts to fix the road. Officials said a traditional, long-term repair solution was expected to be costly and challenging, as a conventional project would require an acquisition of an additional easement for construction. The 28-foot deep failed embankment and utilities within the embankment presented a challenge for construction crews.
In addition, the site is located in a coastal zone, where permitting large retaining structures is costly and time consuming. The lightweight fill reduced the need for a large footprint, while also eliminating the need for a retaining wall and permitting requirements. CSAC praised the project for its streamlined design and construction, reduced environmental impacts, smaller construction footprint and cost savings.
Funding for the $665,000 construction project was provided by CalRecycle TDA grant funding ($110,000), TDA pilot project funding ($330,000), the county’s general fund ($43,000), and the State Transportation SB1 Fund ($182,000). Additional construction engineering costs were reimbursed by CalRecycle’s TDA grant funding in the amount of $36,000. The project was constructed by Raminha Construction and the roadway was officially reopened in August of 2019.
“I like this project because we got the departmental support to venture out away from past tried and true techniques to go for something different. This program’s success means we can solve more problems with these new techniques for future projects.” Mr. Doolittle said.
Other winners included the cities of Santa Cruz, Hayward and Santa Clarita, and Yuba County.
The infrastructure projects honored are believed to be in jeopardy due to anticipated budget cuts related to the economic downturn due to the COVID-19 pandemic. CSAC and the League are urging Congress to include funding for transportation infrastructure in the next coronavirus relief package to ensure these types of programs can continue. The parties are also encouraging Congres to ensure that infrastructure finds could be passed through to local governments of all sizes to bolster much-needed improvements on local streets and roads.