RCTC, Caltrans Expect 71/91 Interchange Finish in 2025
By Irwin Rapoport CEG CORRESPONDENT
The Riverside County Transportation Commission (RCTC) and California Department of Transportation (Caltrans) are reconstructing the State Route 71/State Route 91 Interchange in Corona, a vital corridor serving both commuter and commercial traffic.
At a cost of $137 million, the work is being performed by Skanska, with Falcon Engineering Services handling project construction management. Construction began in early 2023 and is anticipated to be completed before the year’s end.
“The 71/91 Interchange serves as a gateway between Riverside, Orange and San Bernardino counties,” said John Tarascio, RCTC’s project manager and the senior capital projects manager.
The new non-tolled interchange is designed to improve safety, expand access to other modes of travel, reduce greenhouse gas emissions and enhance traffic flow.
The project will replace the existing single-lane loop connector between eastbound SR 91 and northbound SR 71 with a two-lane, direct connector ramp; build an eastbound SR 91 auxiliary lane to improve access to the new direct connector to northbound SR 71; and realign the eastbound SR 91 onramp from Green River Road to improve access to the 71/91 Interchange and southbound SR 71 to create space for the direct connector.
Caltrans approved the project’s environmental documentation in June 2011, and RCTC completed the project’s final design in June 2015. The RCTC received the final piece of funding in December 2020.
That funding includes contributions from the state’s Solutions For Congested Corridors Program, the federal Better Utilizing Investments to Leverage Development program and the federal Infrastructure for Rebuilding America program.
The project, which was designed by Parsons Corp., has provided challenges throughout the process.
“The United States Army Corps of Engineers was a critical partner during the design phase, as there were unique
right-of-way [issues] near the Santa Ana River channel,” Tarascio said. “Another major challenge was spanning the SR 91 freeway, which has six general purpose lanes and two toll lanes in each direction. The falsework beams had to be spliced on site and spanned over 100 feet.”
The project structures’ lifespan is 50 years, and the pavement was designed for a 20-year lifespan. With the tall column heights and large bent caps, mass concrete was used, which required cooling tubes to be installed around the column during the curing process.
The construction plan works in stages to minimize motorist disruption through the heavily traveled corridor. Before work started, the corridor handled more than 100,000 vehicles per day.
The new configuration will have a similar capacity with the improved operational layout of the SR 91 to SR 71 connectors. The existing eastbound to northbound tight single-
Ironmark Earthworks Begins Collegiate Sports Project
In the heart of the Inland Empire, a local college is expanding its footprint by developing a new sports complex.
The college recently acquired a 75-acre parcel of land. This site, a former water detention basin, is undergoing a significant transformation that will elevate it by about 25 ft. and lay the groundwork for a premier sports facility.
Ironmark Earthworks, a contractor specializing in earthwork, is spearheading the initial phase of the project.
According to Timothy Pontremoli, general superintendent of Ironmark Earthworks, “We’re recycling all on-site material by crushing it to specific sizes and moving about 500,000 cubic yards of dirt. Once the land is cleared, filled and leveled, another contractor will take over to begin phase one
construction.”
This is the largest project for Ironmark Earthworks, a young and growing company just five years into its operations. Its tasks include cutting, filling and replacing the rock, as well as processing the on-site material. The groundwork phase is preparing for the infrastructure for the park, which will feature a football field, baseball and softball stadiums, a soccer field, several buildings and a parking structure. Notably, the complex also will include a tunnel that connects the park to the main campus.
“At the end of phase one, we’ll return to complete the fine grading and prepare the site for landscaping,” Pontremoli said.
“We’re also setting aside large rocks and plants from the site to incorporate into the final landscape design.”
A critical partner in Ironmark Earthwork’s success on this project — and many others — has been Western Rentals and its sales rep, Jerry Blanks.
Nicasio Sandoval, Ironmark Earthwork’s dispatcher, emphasized the role Western Rentals has played in ensuring efficiency and productivity.
“When I joined Ironmark, there wasn’t a dedicated dispatcher, and equipment rentals were chaotic,” he said. “I streamlined the process by building relationships with reliable vendors, and Western Rentals has become a key partner for us.”
Western Rentals has supplied six major pieces of equipment for the project, including a water truck, two DEVELON DA45 articulated dump trucks, a DEVELON DA30 articulated dump truck and a DEVELON DL420 six-yard loader.
Sandoval highlighted the importance of reliable equipment:
“We’ve had a great experience with Western Rentals. Their service is prompt, and their deliveries are always on time. In our line of work, downtime for equipment repairs means lost money, and Western
Rentals has been instrumental in minimizing those delays.”
The efficiency demanded by this project is immense, with Ironmark processing 8,000 to 10,000 cu. yds. of dirt per day and 1,500 to 2,000 cu. yds. of rock. Beyond earthmoving, the team is implementing new drainage plans to divert water from the basin and sorting materials for later use. Larger rocks will be repurposed as decorative landscape elements around the complex.
Sandoval praised Western Rentals for helping Ironmark maintain its momentum.
“This job requires us to be incredibly efficient,” he said. “Any downtime costs us significantly. Western Rentals ensures that our operators have the equipment they need to keep moving forward.”
As CMC’s ambitious sports complex project progresses, the partnership between Ironmark Earthworks and Western Rentals is a testament to the importance of reliable equipment and collaboration in tackling large-scale developments. The transformation of the 75-acre site is shaping up to be a milestone achievement for all involved.
(All photos courtesy of Ironmark.)
An overview of the 75-acre plot of land and the future home of a local college sports complex.
A DEVELON DA45 articulated truck takes its rounds with loads of rock for crushing and screening.
(L-R) are Nicacio Sandoval, dispatcher of Ironmark; Timothy Pontremoli, general superintendent of Ironmark; and Jerry Blanks, sales representative of Western Rentals, in front of a DEVELON DA45 articulated truck from Western Rentals.
Foundation Work Challenges Interchange Contractors
lane hook ramp will be replaced with a two-lane large radius flyover connector. The existing southbound SR 71 to eastbound SR 91 ramp will be reconfigured into two lanes. Both ramps will double in capacity.
So far, the project team has completed the following elements: the construction of retaining walls along southbound SR 71, the realignment of southbound SR 71 for the new connector and the construction of the eastbound SR 91 to northbound SR 71 connector.
The project team is finishing work on the eastbound SR 91 undercrossing and retaining wall along eastbound SR 91, as well as connecting the new ramps.
“The most challenging aspect of the work has been the foundations for the bridges,” Skanska’s team said. “The large diameter cast-in-hole piles were extremely difficult to construct because of unforeseen subsurface conditions and working room restrictions. The project is on schedule and the work is approximately 70 percent complete as of December 2024.”
“Because the 2022-2023 winter season had a lot of rain and it raised the level of the groundwater table by 10 feet compared to what was shown in the original log of test borings, that created some challenges for the foundation work of the connector,” according to Skanska.
The work to replace the single-lane loop connector between eastbound SR 91 and northbound SR71 with a twolane, direct connector ramp is going well.
“Working beside and over the Santa Ana River and spanning eastbound and westbound SR 91 has been extremely
challenging,” Skanska said. “The new bridges are being built first around the interchange and then the freeway lanes will be connected to them. The one exception is on southbound SR 71 — the existing lanes had to be moved to the west to make room for the new eastbound SR 91/northbound SR 71 connector to come into the median of SR71.”
The existing lanes will be connected to the new bridges when they are finished. The new lanes combine JPCP concrete pavement and HMA asphalt pavement.
Drainage infrastructure is being installed, too.
“There are 45 drainage systems that are either new systems or existing systems that are being modified,” Skanska said. “All of the rainwater that lands on the new connector is captured using deck drains on the bridge and conveyed to the abutment or beginning of the bridge via a drainpipe system inside the bridge. New inlets and pipes are placed along the on ramp outside the limits of the bridge that convey the water away from the roadway.”
Efforts are ongoing for the building of the eastbound SR 91 auxiliary lane to improve access to the new direct connector to northbound SR 71.
“To support this widening of eastbound SR 91,” the Skanska team said, “multiple retaining walls have to be constructed to support the new roadway and embankment. This requires working along the existing right-of-way and close coordination with the existing commercial properties that are adjacent to the project.”
These are concrete lanes that are 24-ft. wide with a 10-ft. outside shoulder. The length of the lanes transitioning into the new connector is approximately 1,400 ft.
Crews employ a variety of equipment including scrapers, excavators, motor graders, forklifts, cranes, HMA and JPCP paving machines, dozers, manlifts and drill rigs for this phase of work.
The realigning of the eastbound SR 91 on-ramp from Green River Road to improve access to the 71/91 Interchange and southbound SR 71 to create space for the new direct connector has its challenges.
“The new on-ramp requires building a new bridge over the BNSF and Metrolink tracks,” Skanska said. “This bridge will have to be built first and then the approaches will be tied into it. On the east end of the bridge, a mechanically stabilized earth retaining wall will be constructed to support the embankment of the new on-ramp.
“The biggest challenge for the construction of the on ramp is working with the railroad. The new bridge goes over the tracks, and no work is allowed while trains are going through the project. This work has to be scheduled with the railroad and closely monitored.”
Numerous Skanska and subcontractor employees are on location, with local and regional subcontractors helping.
Equipment on site includes cranes, excavators, dozers, loaders, scrapers, blades, backhoes, material handlers, HMA and JPCP paving machines, manlifts and drill rigs.
With so much equipment in use, Skanska mechanics are kept busy and complete repairs daily and ensuring that routine maintenance schedules are met.
Skanska buys and rents that equipment from numerous dealerships. CEG
(All photos courtesy of Caltrans.)
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Turner Selected for $158 Million Emergency Operations Center
Turner Construction Co. and design-build partner DGA Architects of Mountain View were awarded a contract by the Department of General Services to build a $158 million Emergency Operations Center for the Governor’s Office of Emergency Services (Cal OES).
Strategically located on 15 acres in Costa Mesa, the facility will bolster emergency preparedness and response capabilities for Southern California, providing critical infrastructure for managing disasters and emergencies. The site formerly houses the Fairview Development Center hospital.
The center will be pivotal in coordinating emergency management and disaster response at a strategic level, ensuring readiness and resilience in times of crisis. The project will include energy infrastructure such as photovoltaic panels, battery energy storage and emergency generators and will be built to Zero Net Energy standards.
There will be a 35,000-sq.-ft. office building and a 20,000-sq-ft. warehouse., along with outbuildings and a 100-ft. microwave tower. The site will require numerous infrastructure improvements, along with land-
scaping, fencing and parking lots, according to The Orange County Register.
The facility will serve Cal OES’s Southern region of 11 counties, including Los Angeles, Orange and San Diego counties, according to The Orange County Register. It will replace a temporary facility in Los Alamitos.
California Office of Emergency Services provides disaster planning, readiness and response of state resources for the various emergencies and threats of emergency facing California, including earthquakes, floods, significant wildfires, prolonged drought impacts, public health emergencies, cybersecurity attacks, agricultural and animal disasters, and homeland security threats.
“We are honored to partner with the Department of General Services and DGA Architects to deliver this critical emergency operations center,” said Reed McMains, Turner’s vice president and general manager.
“This project represents a significant step in enhancing the community’s resilience and readiness in times of need. Our team is committed to bringing our expertise and dedication to every phase of this endeavor.”
