Photo Courtesy of Heather McGuffin - Betkon, Inc. Stage one of the California Department of Transportation (Caltrans) and San Diego Association of Governments (SANDAG) I-805 North Express Lanes Project will likely be completed in May 2016 by Skanska USA C
Stage one of the California Department of Transportation (Caltrans) and San Diego Association of Governments (SANDAG) I-805 North Express Lanes Project will likely be completed in May 2016 by Skanska USA Civil.
The $75 million design and construction contract is also funded by the Congestion Mitigation and Air Quality Improvement Program (Federal), Regional Surface Transportation Program (Federal), the Corridor Mobility Improvement Account (State), and state and local partnerships. The objective is to improve the road network in San Diego and provide more options for motorists to avoid traffic delays.
“San Diego County is expected to add one million new residents to the region by 2030,” said Edward Cartagena, a Caltrans spokesperson. “Built in the early 60’s with fewer and slower cars this route was congestion free. Today over 215,000 use this portion of Interstate 805 to reach employment centers within the Golden Triangle.
“Caltrans and regional transportation partners understand that just widening and building new highways is not the sole answer to address congestion,” added Cartagena. “The region is focused on providing transportation options for daily commuters. SANDAGs Regional Transportation plan outlines the use of transit, development of BRT system, walkable communities, bike paths, vanpools and carpool resources.”
“Currently over 215,000 cars travel in each direction of the I-805 with over 40,000 vehicles exiting at the Mira Mesa off ramps,” said Brandon Liesemeyer, Skanska’s design manager.
“The current interchange design was built in 1965, with minor upgrades incorporated in the following decades. However the area has seen spectacular growth recently in the high-tech industry, Qualcomm has over 30 campuses within a one mile radius of this interchange. At peak times it can take 15 minutes to enter the freeway due to the congestion at the local intersections and on the ramps. The mainline 805 is similarly impacted and experiences 20 to 30 minute delay on a daily basis through the project limits. Essentially the scope of phase one added an HOV lane in each direction for a 20 percent increase in capacity and HOV on/off ramp access in the southbound direction via a newly constructed local under crossing.”
This is the first of five phases and the work on phase one covers 4 mi. (6.4 km) of road north of state Route 52 (SR 52) to Mira Mesa Boulevard in San Diego. The overall plan of the project is to widen the freeway to accommodate four carpool (High Occupancy Vehicle — HOV) lanes from SR 52 to La Jolla Village Drive and two carpool lanes from La Jolla Village Drive to join existing HOV lanes north of Mira Mesa Boulevard. It also will establish direct access ramps (DAR) at Nobel Drive and Carroll Canyon Road, a Park & Ride and Transit Station at Nobel Drive, a direct freeway-to-freeway HOV connector in the median from westbound SR 52 to northbound I-805 and southbound I-805 to eastbound SR 52, and will reconfigure the Governor Drive interchange.
The phase one work consists of constructing one carpool lane in each direction in the median from SR 52 to just north of Mira Mesa Boulevard and the south-facing DAR at Carroll Canyon Road, the widening of four bridges and construction of a new bridge, and ramp modifications.
“Regional plans call for a Bus Rapid Transit system/network,” said Cartagena, who added that SANDAG are spearheading efforts in the region.
“Phase one completes the majority of the work planned for the center median through this section of the I-805 improvements,” said Liesemeyer. With the exception of the connectors at the south end and the HOV access Nobel all of the work in the center median is done. All of the future phases are planned to improve the outside portions of the highway through this section, it’s a logical sequence from a planning and cost point of view.
Caltrans has several personnel attached to the project, particularly as this is the first design-build project for the San Diego region.
“The project was selected as Federal funded Pilot program — 10 projects were selected nationwide,” said Cartagena, who added that the design-build construction method is still being evaluated.
Recent legislation passed in California allowed for several alternative delivery projects to be let. “Caltrans identified the I-805 phase as a suitable project for design-build because it fit a series of criteria that they wanted to study,” said Liesemeyer. “The project had much of the preliminary engineering completed, so the Department was comfortable with the scope of the project and therefore felt they had low risk of scope growth or right of way issues. With a fairly well defined scope the Department also selected the project as a lump sum design build, affording some measure of cost certainty. Finally the congestion in the area was reaching untenable levels and it was determined the design-build would deliver the project faster than the traditional method.
Skanska has completed many projects for Caltrans. It was given notice to start work on the project in July 2012 and following work on the design and pre-planning, Skanska crews began actual construction work in February 2013.
“We have widened the 805 by adding an HOV lane down the median of the highway and have done so in both the northbound and southbound direction,” said David Sharpnack, Skanska’s project manager. “The northbound and southbound lanes were separated by a dirt median with guard rail initially. We filled the median with an asphalt and concrete structural section for roadway. In two instances the highway crossed existing bridges at Governor Drive and Rose Canyon and we filled in the gap, both northbound and southbound, with new structures to allow continuous flow through the HOV lane.
“Construction of these two median structures posed different risks and difficulties to our crews,” he added. “The Rose Canyon structure spans a 350 foot long canyon that has a railroad and two sets of 69 kV power transmission lines below the bridge. These complications are what led us to using precast girders instead of the standard cast in place. Precast girders drastically reduced the amount of work our crews had in the canyon next to a live rail line and eliminated the need for extensive bridge formwork around the high powered transmission lines.”
Skanska also is widening two 1,000 ft. (304.8 m) long bridges that currently span Carroll Canyon at the northern limits of the project. These structures will have 45 ft. (13.7 m) added on the outsides that will eventually hold an additional two lanes of traffic. The length of these bridges are not what complicates the construction of these two structures, but rather the height. “The distance from the soffit of the bridge to the canyon floor is in excess of 115 feet in some areas” said Sharpnack, “and at the bottom of this canyon is a creek that feeds directly into the ocean making it extremely environmentally sensitive.” To prevent debris from falling into this sensitive area, Skanska’s crews erected the falsework of the new bridge before the demolition of the existing overhang and barrier rail. This allowed the demolition crews to break directly onto the soffit forms and keep debris out of the creek. Dealing with traffic is a major aspect of the project.
“This is one of the three highly congested areas in San Diego,” said Sharpnack, “so there is bumper-to-bumper traffic in the morning and on the way home from work. We designed the work plan so that most of our access to work site was through the median. We started the design process by pushing everybody to the outside of the highway and narrowing existing lanes to allow for maximum work space in the median.
“Our crews are protected by K-rail and we were able to coordinate with Caltrans to reduce the speed limit to help us keep the project team and public safer,” he added. “We arranged for a lot of our deliveries and equipment transfers to occur at night and sometimes closed down lanes to make more access when needed. Caltrans is being very helpful with our needs.”
A standard day shift for Skanska crews is eight hours and on many occasions night shifts have been initiated to complete sections of the work. Currently there are about 70 Skanska personnel on site, along with about 30 subcontractor workers.
Some of the main subcontractors are: Condon Johnson for Large CIDH bridge foundations and soil nail walls, Empire Steel for Rebar installation, Coffman Specialties for jointed plane concrete pavement, RMA for quality assurance testing, AECOM for design. “We have been able to maintain most of our staff and personnel on the job site,” said Sharpnack, “this consistency has been key in keeping the project moving forward as this is the first design-build delivery method this Caltrans district has executed, so we have all been learning and growing together.”
Multiple Skanska managers coordinate the efforts of both Skanska crews and subcontractors to ensure that everyone is on the same page.
“I believe we have set up a very efficient project management structure here that has allowed our people to excel in what they do best” said Sharpnack.
Materials moved from the work site include milled asphalt. When the job is completed, Skanska will have recycled approximately 4,000 tons (3,628.9 t) of asphalt, removed 350,000 tons (317,514.7 t) of earth, 1,000 tons (907.2 t) of concrete, and 500 tons (453 t) of steel.
“We also removed some signs and sign foundations and are removing old metal beams and guard railing, much of which is being returned to Caltrans.
When completed, the project will have seen the use of approximately 35,000 cu. yd. (26,759.4 cu m) of concrete, six million tons of rebar, 23,000 tons (17,584.8 t) of asphalt, 51,000 cu. yd. (38,992 cu m) of Class 2 Aggregate base, and 27,000 cu. yd. (20,643 cu m) of Jointed Plane Concrete Pavement.
Where new asphalt is being laid down, it consists of a 8 in. (20 cm) layer of Aggreage base, a 3 in. (7.6 cm) layer of Hot mix asphalt base, and top cover of 10 ft. (3 m) layer of JPCP.
Utility relocation is not an issue in this project, although some utility infrastructure had to be protected. Skanska is installing a small fiber-optic cable line for Caltrans.
Also being installed are new lighting systems consisting of ramp metering, traffic counting loops and multiple lights, and a traffic light system at an intersection where the highway connects with a municipal street.
Prior to the crews arriving on site, some exploratory work was done to better understand the nature of the highway.
This project is helping Skanska to improve its construction techniques and efficiency.
“There are lessons being learned, especially through the design-build aspect of it,” said Sharpnack. “The legislature approved 10 projects — five were best value and five were low-bid design build projects. Design-build is new to Caltrans in the San Diego area, this was a learning curve for all. We’ve committed with Caltrans to sit down with them after the project is completed to do a thorough analysis of the design-build process.”
Substantial completion of the design was secured 18 months into the project, with the remainder to cover the landscaping and irrigation and water conservation issues.
The closest Skanska facility/shop is 75 mi. (120.7 m) away in Riverside and because of the distance and the amount of equipment being used, it has two mechanics on site. The equipment was checked prior to be sent to the job and the operators sign off a daily check list and immediately report any issues to the foremen and the mechanics.
All the vehicles have GPS monitoring that is connected to a blade system, which is checked frequently for vehicle use and to help with mechanical/maintenance issues.
On this project, Skanska is using: four Terex hydraulic cranes, two 328 Caterpillar excavators, one D4 Caterpillar dozer, four CS 56 Caterpillar rollers and 10 Honda generators. Save for the rental of a 270T Liebherr crane from Bigge Crane, the equipment was provided by the company’s fleet.
“Through analyzing, planning and collaboration between the job management, the foremen and craft, Skanska assesses what will be needed to complete the jobsite activity,” said Sharpnack. “This includes a risk analysis to determine the need for standby equipment.”
Skanska has sufficient space at the work site to store vehicles and equipment, spare parts, fuel and oils, temporary offices, and the storage of construction materials
As noted, Skanska has secured many Caltrans contract over the years.
“We’re here to give the public a safe passage through the job and build them a facility that they can use as soon as possible,” said Sharpnack.“We received two other pretty substantial contracts in this area due to our reputation.”