State and federal officials are evaluating solutions to repair or replace six historic bridges between Huelo and the city of Hana to maintain a âSafe and functional pavementâ.
The bridges, which are identified by the state Department of Transportation as a high priority for upgrades, include the Kailua Stream Bridge at Mile Post 5.9, the Makanali Stream Bridge at Mile Post 8.2, Puohokamoa Stream Bridge at Mile Post 11, Kopiliula Stream Bridge at Mile Post 21.7, Ulaino Stream Bridge at Mile Post 27.9, and Mokulehua Stream Bridge at Mile Post 28.3.
In partnership with the Federal Highway Administration, Central Federal Lands Highway Division, the DOT held a virtual town hall meeting Tuesday and Wednesday evening via Zoom to discuss the Hana Highway Bridge Improvement Project and gather feedback from the community.
“The team worked very hard” Tammy Heffron, project manager consultant at HDR Engineering, said during the presentation. “It’s certainly not an easy project or an easy site, but we’re working to move this thing forward.”
Work on the project is currently in the environmental compliance and design process, with construction scheduled to begin in spring 2023; it will take a year to complete each bridge, with maybe two jobs at the same time, Heffron said.
DOT spokeswoman Shelly Kunishige said on Wednesday the estimated costs at the moment are around $ 40 million, but âAs we improve the project with community input and additional technical information from our design team, we will be able to further refine the costs. “
During the virtual meeting, the project team discussed the proposed bridge solutions and considerations on how they plan to improve aging bridges and maintain traffic.
Environmental specialist Sandy Beazley said these bridges have “Unique engineering and construction” on a very intact ring road network, which is “really no surprise because these bridges were built between 1908 and 1947.”
They have important features that contribute to the historic district of East Maui, Beazley said, such as abutments (bridge supports), rock faces, and railings.
The objective of the project is to address, improve and repair the existing structural conditions of the six bridges in a “Sensitive way”, they therefore remain functional, reliable for transport and safe under load capacities, Beazley said.
The current load capacity does not allow trucks full of fuel or water or large maintenance trucks. Bridges also do not meet current sidewalk standards and guardrails do not meet existing accident safety standards.
âAs you know, the Hana Freeway is sort of the lifeblood of East Maui communities in terms of transportation for local and regional trips – taking kids to school, going to stores, shopping centers, employment, as well as an economic engine, for better or for worse, tourism too. he said.
Throughout the project, including Tuesday evening, the community demanded minimal traffic impacts during construction, a faster construction schedule overall, and that authorities maintain the historic character of the bridges, especially by keeping them single-track and adorned with block balustrades. , if possible.
“We want solutions that are as sustainable as possible because otherwise you will see us working on a bridge every year, which I know some of us in the community (don’t) want”, Beazley said.
Two solutions were considered for the bridges – rehabilitation, which would involve maintaining as many existing characteristic elements “As far as possible” while making design improvements to achieve project objectives; or replacement, which involves keeping as many existing character features, but replacing a bridge as necessary and matching existing character features as closely as possible while realizing design concepts to achieve project goals.
Heffron said the team evaluated the replacement alternative, noting that it would be a shorter construction schedule with less traffic impact, lower costs, lower risk of impacting traffic. streams and a longer design life. The existing substructure elements would also be kept, she said.
For example, the proposed bridge renderings for the Kailua, Ulaino and Puohokamoa bridges would include single-span concrete beams extending over existing supports.
A single-span concrete beam slab is proposed for the Makanali Creek Bridge and a single single-span concrete slab over the existing supports is proposed for Mokulehua, which is the oldest structural bridge in the project, dating from 1908.
The Kopiliula Creek Bridge is the “the hardest” structurally due to the feature of the East Maui Irrigation Canal, its narrow design and historical landmark, said senior structural engineer Sean Oroho.
The team is proposing a new two-span concrete bridge adjacent to the existing bridge.
A method called “Bridge slide construction” is proposed to complete the entire project, as opposed to installing a temporary bypass bridge, Oroho said.
The construction of the slide is a “Proven offline building method” it’s safer, it costs less, it’s less risky for neighboring homeowners and it allows better access to their homes, he said.
However, this method requires overnight shutdowns and full shutdowns over multiple days.
To begin construction, temporary supports for the new bridge would be built on the side of the existing bridge, which would remain open to traffic using temporary traffic lights.
Then, new bridge supports would be built behind the existing bridge supports. The existing bridge remains open to traffic with limited night-time closures during “Off-peak hours,” Oroho said.
The next step is to remove the existing bridge, while preserving the existing bridge support system. For the moment, the roadway and the bridge are temporarily closed to traffic, “But I just want to stress that it is done as quickly as possible”, he added.
The new bridge would then be slid into place.
Specific details regarding emergency services and access will be presented at the next public meeting. This week’s meetings are the third in a series of four that began in January 2020. More will take place in 2022.
All proposals are conceptual and open to the public as departments finalize the design, Heffron said.
For more information on the Hana Highway Bridge Improvements Project, visit www.hanabridgeimprovements.com. For a copy of the full presentation, visit hidot.hawaii.gov/presentations/.
Those unable to attend meetings can provide input through the project website or by contacting the project manager, Tom Kubicz, by email at [email protected], or by phone at (720) 963- 3498 and (202) 981- 4183.
* Dakota Grossman can be contacted at [email protected]