Skanska USA Civil, Inc. Passes Midway Point on SR-60 Truck Lanes Widening Project

By Brian Hoover, Senior Editor

Riverside County Transportation Commission (RCTC) and Caltrans are currently engaged in improving safety and traffic flow for commuters, trucks and travelers making their way to and from desert resorts on the 60 Freeway. They are accomplishing this by building truck lanes in the Route 60 Badlands in Riverside County between Moreno Valley and Beaumont. The State Route (SR) 60 Truck Lanes Widening Project will cover 4.5 miles from Gilman Springs Road to 1.4 miles west of Jack Rabbit Trail. Specific features include truck lanes in both directions, wider shoulders, flatter curves, and taller median barriers. Construction began in July 2019 and is currently scheduled for completion in April 2022.

Skanska was selected as the low bidder and general contractor to manage construction on the SR-60 Truck Lanes Widening Project. Rafael Gutierrez is the senior project manager overseeing all aspects of construction on the job. “The first order of work was to locate a water source for this project. We found an Eastern Municipal Water District hydrant on Gilman Springs Road around a mile southeast of the 60 freeway, and we ran a line from there to the job-site,” says Gutierrez. “We also drilled a 375-foot well within the limits of the project.”

Above: Skanska’s paving subcontractor, Coffman Specialties, Inc., paving a 24-foot-wide section on the SR-60 Truck Lane Widening Project, including the westbound outside shoulder and truck lane.

The total published cost for the SR-60 Truck Lanes Project is $138.4 million, with Skanska being responsible for performing approximately $99 million for the bid-build highway widening portion. Skanska’s work includes constructing a new eastbound truck climbing lane and a westbound truck descending lane. It also involves the widening of shoulders to standard widths of 12-foot exterior shoulders and 11-foot interior shoulders.

One of the more interesting aspects of this job consists of the construction of two wildlife crossings. The project lies within mountainous terrain with a curving alignment and steep grades. Skanska is flattening roadway curves to improve motorist overall comfort and sight distance as part of the project design. “The original roadway was constructed in the 1960s, and the curves were not to the current standard,” says Gutierrez. “We are performing a complete remove and replace while realigning to make the curves smoother. The vertical curves were also designed and built to new standard specifications.”

Above & Below: Excavators work in tandem to excavate the second phase of 20’ x 20’ wildlife crossings.

The area under construction on the 60 freeway was formerly a two-lane highway in each direction and lacked inside or outside shoulders. In late Aug. 2019, one westbound lane on SR-60 was closed for six months to allow Skanska the room to safely and efficiently begin the widening of the roadway. “The six-month closing of the westbound lane saved as much as one year in construction time. The existing slopes were only a few feet away from the travel lanes. The lane closure provided the necessary space to cut the slopes back on the westbound side of the highway so that we could begin construction of the new pavement section,” says Gutierrez. “1.4 million cubic yards of earth was excavated during this six-month lane closure and 2.2 million cubic yards total will be moved by jobs end. Once the lane was closed and the earth moved, we were able to add a temporary pavement section to allow working room for subsequent stages of the project.” According to Gutierrez, Skanska then proceeded to construct the westbound outside shoulder and truck lane. “We paved two lanes on the westbound side and then opened westbound traffic to these two new lanes. Next, we worked in the middle with another 24 feet of paving (two lanes wide). Eastbound traffic was then placed in these two new lanes which allowed for the construction of the remaining lanes.”

According to schedule, Skanska moved the westbound traffic to the newly constructed pavement from Aug. 2020 and then began building the new westbound number 1 and 2 lanes. In Jan. 2021, Skanska moved eastbound traffic to the newly constructed pavement and then completed excavation on the south side of the 60 freeway. During this time, Skanska will finish building the westbound inside shoulder and the entire eastbound roadway section. They will also install all of the concrete barrier, construct 2,200 linear feet of retaining wall and finish the last stage of box culvert construction. From Dec. 2021 to April 2022, Skanska will remove the temporary pavement sections and perform all final striping, signage, guardrail, and landscaping duties.

Above & Below: Backhoe fine grading invert for second phase of wildlife crossings.

The asphalt paving portion of the SR-60 Truck Lanes Widening Project was subcontracted to All American Asphalt, and the concrete paving was provided by subcontractor Coffman Specialties, Inc. The existing asphalt pavement was milled off and used as subbase material. The contract called for the placement of 80,000 tons of asphalt. Sixty thousand tons of the hot mix asphalt is being utilized as base for the concrete pavement. “The pavement design calls for a 4-inch asphalt base capped by 1 foot of concrete on the inside lanes and 1.25 feet over the truck lanes and outside shoulders,” says Gutierrez.

“The other 20,000 tons of asphalt was used to construct the temporary pavement section necessary for staging and traffic. Right now, we have a 9-foot asphalt shoulder that is being utilized for traffic, and this section will be removed later.” Gutierrez says that approximately 110,000 cubic yards of concrete will be used to pave all of the appropriate roadway sections. Skanska will also install 26,000 feet of concrete barrier.

The SR-60 Truck Lanes Widening Project includes the construction of two wildlife crossings. According to Gutierrez, these 20’ wide by 20’ tall reinforced concrete boxes were placed under the freeway section in three phases and designed to keep the traffic off the specific lane under construction. Gutierrez says that the first 30 feet of box culvert was installed after excavating slope and ground on the North side of the freeway. The underground crossings will traverse 201 feet from one side to the other while being placed around a mile and a half apart on SR-60. Beam and lagging were used to support the excavation next to and underneath the freeway. After the first 30-foot section of reinforced concrete box was successfully placed, the traffic was moved over to that new section so that phase two could begin. The following section was then excavated, and the process repeated for the third phase. “So, after the second phase was complete, we were supporting both the eastbound and westbound sides of the 60 freeway with shoring. We then moved onto the third phase, which was in the middle,” says Gutierrez. “The approximately 30-foot-deep excavation was performed with Cat 336 excavators and without much room to work in-between stages.”

Slide Rail shoring and trench boxes provided by Trench Shoring company are utilized to perform jack and bore operations on the SR-60 Truck Lane Widening Project.

Gutierrez says that there were six additional bores performed to place 24-inch, 36-inch and 60-inch drainage pipe under the freeway. “As we continue to extend the 122 different types of drainage systems ranging from 12-inch to 60-inch out across this project, we also install drainage pipe under the freeway in certain areas. This required shoring for the jacking pit to begin boring under the freeway to depths of up to 50 feet. The jacking pits are excavated to a depth of 10 to 15-feet, and we started excavating the first jacking pit using a Slide Rail system provided by Trench Shoring Company. A change from Slide Rail to trench shields was made when it was determined that the ground would allow for standard trench boxes,” says Gutierrez. “Only one of the bores required a 20-foot deep receiving pit which was also shored-up with trench shields from Trench Shoring Company. We will go back to using the Slide Rail system on the other side of the project where the ground is not as hard.”

Gutierrez points out that most of the remaining drainage pipe was installed using traditional open-cut methods. Sixteen thousand linear feet of drainage pipe will eventually be installed. This will require 750 cubic yards of drainage concrete and 5,000 cubic yards of concrete used on the wildlife crossing culvert boxes. “Some of the outside drainage pipe required the use of trench boxes, but most was open-cut,” continues Gutierrez. “The job calls for around 3-miles of culvert drainage system that requires excavation from a few feet to 25-feet deep. The deeper areas require either beam and plate shoring or trench shields.”

Above: Slide Rail Shoring System being offloaded to job-site by Trench Shoring Company.

Skanska is self-performing the mass grading and excavation work on this project. They are also doing all of the structural concrete work. “We moved a lot of earth when cutting back these slopes to make room for the additional lanes. This included several large excavation and fill areas,” says Gutierrez. “There was a small amount of export, but most of the spoils were used as fill and remained on-site. We will also build a 60,000 square foot mechanically stabilized embankment (MSE) which is made of geosynthetic straps and concrete facing.”

Gutierrez says that there have been plenty of challenges on the SR-60 widening project thus far. “I would say that our largest challenge has been keeping everyone safe while working around the active traffic lanes. We have not had any construction-related accidents, as our crews remain diligently aware of the dangers,” says Gutierrez. “The slopes were steep and starting the excavations was also a challenge. There is also very little room to work while excavating the wildlife crossing areas. We take the challenges in stride and are on track to complete this project ahead of schedule. I want to thank our subcontractors, suppliers, and everyone that has contributed to this project’s success. I would specifically like to recognize Richard Cochran, our civil superintendent, and Marty Wilkerson, our structures superintendent.” For more information on Skanska, please visit Skanska.com or call (951) 684-5360. Cc