Urbantech, as part of the SUR Joint Venture, the prime design consultant for the US Army Corps of Engineer’s Green Brook Flood Risk Management Project Sub-basin of the Raritan River Segment C-1 in Middlesex NJ, provided structural design and planning services for the construction of a secondary culvert under the NJ Transit Raritan Valley Line, a main rail branch for New Jersey commuters into New York City.
The purpose of the project was to construct a 2-span concrete bridge culvert with 10ft x 21.5ft openings under the NJ Transit lines to provide additional capacity to an existing adjacent culvert in this flood plain. In order to minimize the impact to commuters as required by NJ Transit, Urbantech proposed an Accelerated Bridge Construction (ABC) approach consisting of fabricating the bridge adjacent to the rail embankment and roll in into place using Self-Propelled Modular Transporters (SPMT) during a one weekend rail shutdown.
The project included not only the structural design for final and construction conditions but also very intense coordination with all stakeholders including NJ Transit, US Army Corps of Engineers, NJ DEP, NJHPO, utility line providers, and land owners. The elements of structural design included the concrete bridge culvert and four adjacent concrete wingwalls as well as the development of a detailed and accurate construction schedule to evaluate the feasibility of moving the bridge during the 52-hour window out of which 10 hours are allotted for NJ Transit to remove and reinstall rails and ballast and only 42 hours are allotted to the contractor.
The moving started at 9PM on Friday May 21st 2021. The contractor successfully finalized the culvert and backfill installation ahead of schedule by 4PM on Sunday May 23rd. The NJTransit finalized the reinstallation of the rails on time for the commuter trains to run on the early morning of Monday.