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Projects

Geotechnical Services for Portal Bridge Capacity Enhancement

This massive new alignment requires more than 8,000 linear feet of retaining walls.
  • Portal Bridge-Gannett Fleming

    A 100-year-old, double-track swing bridge will be replaced.

Client
New Jersey Transit
Partner(s)
Joint-venture with Jacobs Engineering Group and HNTB Corporation
Location
Secaucus and Kearny, New Jersey
Our Role
Engineering, Design, Geotechnical.
Data
Construction Cost:
$1.65 billion
Completed:
In Progress
Type:
Rehabilitation
Outcomes
  • Embankment support alternatives
  • Multiphase subsurface investigation program
  • Preliminary foundation parameters for river crossings and other track crossings. 

The Portal Bridge is a 100-year old, two-track, moveable swing-span rail bridge spanning the Hackensack River in New Jersey between the cities of Kearny and Secaucus. Four of New Jersey Transit's rail lines, including 393 trains daily in each direction, utilize the Portal Bridge. Amtrak operates 103 scheduled trains in both directions through this segment of the Northeast Corridor.  

The century-old structure is nearing the end of its economic life and has insufficient capacity to accommodate future transportation needs. In addition to heavy usage by New Jersey Transit and Amtrak, the Hackensack River crossing must also be opened to allow marine traffic to pass. 

What We Did

Gannett Fleming is providing geotechnical services to design the replacement of 2.5 miles of the Amtrak Northeast Corridor. The existing two-track railroad will be expanded to five tracks, and elevated to allow for the replacement of the existing 100-year-old swing bridge with two fixed bridges, one north and one south of the existing alignment. 

The east and west river-crossing approaches will be viaduct structures supported on driven-pile foundations. The new alignment requires nine retaining walls, totaling more than 8,000 linear feet. The multiphase subsurface investigation program included 360 test borings, wells, soundings, and in situ test locations. The subsurface investigation included cone penetrometer and dilatometer test soundings, as well as field vane shear, pressure meter, and rock borehole shear testing. Borings were performed using a combination of rigs mounted on truck, track, skid, and barrel float platforms, along with a jack-up barge for borings and soundings in the Hackensack River.

Key Features

  • Highly compressible peat deposits
  • Compressible clay deposits up to 80 feet thick
  • Potentially liquefiable soil deposits
  • Very high axial and lateral bridge pier loads
  • Localized scour conditions in Hackensack River
  • Large expanses of wetlands and shallow lagoons
  • Construction over several highly contaminated industrial properties and two existing landfills
  • Coordination with more than 20 property owners.

Sustainability Features & Outcomes

  • The project involves resolution of significant environmental issues, including land acquisition, wetlands, contaminated sites, and landfills.

Similar Projects: Geotechnical: Foundations, Geotechnical, Geotechnical: Geotechnical Testing, Geotechnical: Site Evaluation, Transportation: Transit & Rail, Transit & Rail: Transit & Rail Systems, Transportation