Hawaii DOT Finds Innovative Precast Solution to Replace Portions of H-1
A Permanent Settlement Solution: Hawaii DOT Adopts Precast Panels to Rehab 60-Year-Old Interstate Route H-1
Using an innovative method for resurfacing a major highway, the Hawaii Department of Transportation (HDOT) significantly reduced the time required and minimized traffic disruptions on the $63.7 million Interstate Route H-1 Shoulder Work and Portland Cement Concrete Pavement Rehabilitation Project from Waimalu to Halawa.
“A portion of the road has been in poor condition for a long time,” said Ed Sniffen, Deputy Director of the Highway Division at the HDOT. “Areas settled between 3 and 18 inches.”
Settlement had occurred in multiple locations. The highway was originally built in 1959.
“Taking action to preserve this roadway and its safety features is critical to the many West and Central Oahu residents and businesses who depend on this vital lifeline,” said Jade Butay, HDOT Director, at the groundbreaking ceremony.
For the past 12 years, HDOT has patched with asphalt concrete, but it kept breaking up, creating holes in the road. A more permanent solution was needed. However, closing the road for a rebuild was not an option. The 2-mile stretch of highway carries 250,000 vehicles per day.
HDOT performed geotechnical surveys to ensure the soil was not going to settle any more before proceeding with a rehabilitation plan. The department searched for a solution and met with officials from Caltrans (the California Department of Transportation), which had used precast concrete panels for road repairs in the past.
“We determined using precast concrete would be the best way to repair this highway,” said Sniffen.
The department tried the precast process on another section of H-1, requiring 80 panels, and it was successful. Then the department tried it on a local road with 350 panels, and it also went well. The second project received funding from the Federal Highway Administration’s Highways for LIFE program.
Once these jobs were completed, “we were comfortable enough, we were ready to do the H-1 Freeway,” said Sniffen.
Kiewit Pacific in Honolulu, Hawaii, received the design-build contract, which stipulated this phase of the work must finish within six months. The company completed it in five months. The current H-1 project was planned to require 1,280 panels, but with the early finish, the department added 180 more panels.
“The technology worked out really well,” Sniffen said. “If we could not have used the precast concrete panels, we never would have touched this project.”
HDOT divided the work into two phases; the first began in March 2018 and finished in August 2018. The second is expected to be completed by the end of summer 2020. The first phase includes rehabilitating about 2 miles of H-1 in both eastbound and westbound directions, upgrading drainage and shoulders, and adding lighting.
The second phase will continue widening of the shoulder for an additional .66 miles of eastbound H-1, with drainage, shoulder and lighting upgrades. In the future, HDOT plans to add another travel lane, after completion of an environmental assessment. That project will require widening two bridges.
Before proceeding with construction, the department verified the location of utilities using radar and a backhoe to find the lines. Then, the contractor paved the roadway to bring it up to the required grade.
“It gave the public a smooth highway to ride on as soon as we started the project, and it gave us a grade to match up to,” Sniffen said. Drivers saw activity and progress throughout the project.
Crews worked from the inside lane to the outside lanes on both eastbound and westbound lanes at the same time.
The department monitored noise levels and adjusted buffers to ensure levels did not exceed ambient noise levels to minimize interruptions to nearby residents’ lives. Operation of noisy equipment had to stop by midnight.
During the first phase, “the contractor laid out the panel sections, the majority in typical shapes, and built the concrete panels under the viaduct,” Sniffen said.
Every day, casting the precast panels began at 3 a.m. and continue until 11 am. Trucks delivered the regular concrete mix.
“At night, they would cut out portions of the road, pull it up, prep the bottom with a low-strength concrete and then drop the panel on top of it,” Sniffen explained.
The panels weighed between 13 tons and 20 tons. Most of the panels were 12 feet wide, lane width, by 12 feet long. The largest one was 12 feet wide by 19 feet long. The panels were 9.5-inches thick. A crane could set about three panels before needing to be reset up in a different location.
“It’s a really cool operation,” Sniffen said. “We are an early adopter of this technology.”
The department could open the road almost immediately, Sniffen said. There might be a half-inch gap between the panels. The following night, the contractor would level the slabs and fill any gaps with grout. Then lane striping was added.
“We are proud to be giving the public a road they can be proud of, one that had been poor for a long time,” Sniffen said. “I’m also proud of how our staff and contractor stepped up. Hawaii moved forward with an innovative technology to improve the quality of life for our people.”
HDOT plans to use precast concrete panels on future projects. It currently is investigating other roads in its highway system that could benefit from reconstruction using the panels. Area ports also are considering using the precast panels to reconstruct harbor yards, which will require 22-inch thick panels.
“We know we have to adopt new ways of doing things and be innovative,” Sniffen said. “Otherwise we cannot preserve the system we have or increase capacity we need.”
- Owner: Hawaii Department of Transportation
- Design-Builder: Kiewit Pacific, Honolulu, Hawaii
Photos courtesy of the Hawaii Department of Transportation