TOP PROJECTS
leveraging consistent details to simplify design, fabrication, and construction. Most of the bridges are being replaced using Accelerated Bridge Construction (ABC) techniques, including self-propelled modular transporters (SPMTs) to move the superstructures into place. Work on two of the bridges needs to be conducted simultaneously. Two of the bridges, one at Bacon Street and one at Intervale Road, are located within just one mile of each other on the same line. Due to their proximity, work on the bridges had to progress simultaneously during each weekend outage. Although challenging to coordinate double crews and equipment needed, the bridges were designed with common details and nearly identical construction sequences to simplify the process, reduce risk, and minimize impacts to the traveling public.
SHORT LINE MAINTENANCE (RAIL)
Johnson County Railroad 286K Rehabilitation New Century Commerce Center, New Century, Kan. • Prime Contractor: TL Wallace • Prime Designer: In House • Owner: Johnson County Airport Commission The greatest challenge of rehabilitating an active, predominantly single-track short line railroad was maintaining the highest level of service to time sensitive customers on short notice. This has been accomplished with the highest level of safety and service with the cooperation and flexibility of the contractor, along with JCAX’s rail employees. Each rail customer fully understood that the key benefits of upgrading rail and turnouts from 90 lbs. (aged at nearly 100 years old) to 136 lbs. are to increase safety and prevent obsolescence. Cooperation from all stakeholders has been key in making the entire project a success. Another challenge to the process is determining what rail components must be replaced now, and what can wait until more funding is available to upgrade the entire system. Material cost increases have greatly reduced the trackage that can currently be upgraded to 286K standards. Adjustments have been made to redirect mainline traffic onto the heavier relayed rail wherever possible. Despite the increase in cost, the JCAX has been able to rerail 56% of the total system, or 9,500 track feet of the 17,000 total system trackage. Also very notable, 11 of 25 system turnouts, which are potential points of failure, have been replaced as well. Because of the activity of the work being performed and 12 Railway Track & Structures // June 2023
the overall improvements to the system, an existing food producing lessee located next to the railroad is taking notice. In the past, this national customer utilized rail delivery and stopped. Because of the and upgrades made to the system, they have approached the JCAX with the intention of beginning rail service once again.
Herzog’s Metrolink Track and Signal Infrastructure Maintenance and Support Services.
CLASS I: NEW CONSTRUCTION (BRIDGES) BNSF Bridge 81.4 Washington state • Prime Contractor: Hamilton Construction • Prime Designer: HNTB • Owner: BNSF Railway
Project development and design of BNSF Bridge 81.4 across the Cowlitz River in Washington state began in 2013 requiring significant stakeholder coordination and regulatory approval. The existing bridge consisted of 101’-8” long deck plate girders and a 250’-0” long pin-connected truss. The 100+ year old bridge had reached the end of its service life and needed to be replaced to ensure reliable service. HNTB evaluated a range of replacement options which included re-using the existing substructure, using an on-line alignment and off-line alignment to fully replace the bridge. The project was initially designed and went out to bid as an online replacement bridge with a truss span. BNSF ultimately decided on an offline alignment due to high train traffic. Working closely with Hamilton Construction, BNSF changed the delivery method from design-bid-build to Construction Manager/General Contractor. By moving into the construction phase with Hamilton, the project team was able to streamline construction and reduce project costs. The final bridge consisted of 143’-4” and 207’-6” long deck plate girders supported on large diameter drilled shafts with rock sockets and box beam approach spans supported on H-piles. Construction commenced in 2020 due to the challenge of coordinating various stakeholder interests. To address this challenge, HNTB’s design team coordinated closely with local permitting agencies as well as with the local Cowlitz and Chehalis Confederated tribes, whose tribal lands would be affected by the project. Early and often in the process, the team met with tribal representatives to understand the potential impacts on the tribes’ land, fishing access and historical or cultural resources. The bridge’s extremely remote location made it difficult to secure substructure and
geotechnical information. Virtually the only access is via rail, and it was not possible to drill a boring in the river without suitable access. The team, therefore, had to make assumptions in its foundation design for the piers in the river and get borings when construction started and a temporary work bridge was installed. To accomplish this, the team built on information available from drilled shafts along the banks of the river. However, once the team had site access, they found that the rtands.com