May 22, 2015 - Mariposa County – The California Department of Transportation (Caltrans) has identified a way to save taxpayer money by altering the strategy for Phase 1 of the State Route 140 (SR-140) Ferguson Project.
The estimated $133 million project will provide a safe, direct route to enter Yosemite National Park, and create a unique 750-foot covered structure to protect the roadway from rockslides, and restore SR-140 between Mariposa and El Portal.
Since Caltrans kicked off the project on March 13, 2015, crews have removed approximately 63,000 tons of rock and debris.
“Visual inspection of the exposed slope has caused us to reconsider the lateral design strategy for the rock shed,” said Caltrans District 10 Project Manager Grace Magsayo. “Our design team is considering a wall structure that will require us to leave the remaining of the rock to help facilitate geotechnical bores and ultimately help construct the rock shed.”
The project is being built in two phases to help ensure a successful delivery. Originally, crews were going to remove all the loose debris by September 2015; however, Phase 1 is ahead of schedule, and the public will notice a decrease in the amount of trucks and activity. Work has NOT been suspended, and crews are still obtaining geotechnical data to determine the best way to build the structure in the second phase of the project, ensuring that future rock slides fall on or over the structure and not on the roadway.
“The contractors have exceeded our expectations and we are very pleased with the progress that has been made thus far,” added Magsayo. “SR-140 is an important roadway for locals and tourists, and we want to deliver this sustainable project on time.”
Motorists are currently constrained by one-way traffic control, using a temporary bypass route. Flaggers were used to facilitate motorists during rock removal but a temporary signal light will now be used to control traffic flow.
This is the first Construction Manager/General Contractor (CMGC) project to go to construction. This delivery method allows the contractor to collaborate early on in the design phase to find the best solution for the unique challenges that can come up in a repair project.
The first phase of the project was awarded to joint venture Myers & Sons/ R.L. Wadsworth.
Construction of the rock shed is anticipated to begin in 2016. Once the project is complete, crews plan to reopen two lanes on the original alignment.
The project was made possible by the passage of Assembly Bill 1973, which was introduced by Assembly Member Kristen Olsen and signed by Governor Jerry Brown in 2012.
SR-140 was damaged in the spring of 2006 during a series of major rockslides at the Ferguson Ridge in Mariposa County. The rock slide covered about 600 feet of the highway. A state of emergency was declared to allow Caltrans to install two temporary bridges to detour motorists around the slide. In 2008, Caltrans modified the existing temporary bridges to allow longer vehicles on the bridges, and began the process to permanently fix the state route.
The structure is currently designed to include two 12-foot-wide lanes, two 8-foot-wide outside shoulders and a 4-foot-wide emergency walkway on the river side. This is the second structure of its kind in the continental United States, and larger than the first rock shed built in 2014 on SR-1 at Pitkin’s Curve south of Big Sur, in Monterey County.
For more information: Ferguson Project Presentation to the Mariposa County Board of Supervisors by Caltrans
