The Delaware & Raritan (D&R) Canal State Park is one of New Jersey’s most popular recreation areas. The destination for hiking, jogging, bicycling, fishing, canoeing and horseback riding contains several pedestrian bridges, including the DeMott Lane Bridge. Located within the floodway of the Raritan River, the bridge was torn off its concrete abutments and washed downstream during Hurricane Irene. LAN was retained by the NJ Division of Property Management & Construction to provide surveying, engineering, and environmental permitting services for its replacement.
Our team’s first step included initiating an underwater assessment of the remaining concrete abutments to determine their post-hurricane condition. Since no scour or undermining of either abutment was observed, LAN performed an analysis of the flood forces including hydrodynamic, hydrostatic, and buoyancy forces on the abutments and superstructure. As a result of this analysis the abutments were deemed suitable for reuse provided the bridge seats were repaired, anchor bolt diameter increased, and adjacent embankments stabilized.
LAN prepared design plans and permitting documents for the replacement of the arch beam span superstructure. Services performed include wetland delineation and flood hazard area evaluation and permitting, historic and archaeological resource compliance, land surveying, geotechnical, civil and structural engineering, construction cost estimating, bid and award assistance, and construction observation.
The site is located within an historic district and archaeologically sensitive area. A floodway is adjacent to regulated wetlands and the canal is a source of drinking water for up to 1,000,000 residents. To obtain several authorizations necessary to complete the project, LAN coordinated with relevant agencies such as the US Coast Guard, NJ Water Supply Authority, NJDEP Division of Land Use, NJDEP Historic Preservation Office, and the D&R Canal Commission.
Since this park is so widely used, our team evaluated various construction approaches and schedules and worked closely with state representatives to develop a plan to replace the bridge with minimal disruption to the facility’s operation. Upon receipt of the necessary permits, as well as completion of project specifications and construction documents, LAN assisted the State during the bidding and contract award phase. LAN provided technical assistance during pre-bid, bid-opening, and post-bid review meetings, reviewed substitution requests, verified construction schedules and prepared a recommendation of award letter to the State.
After the contract was awarded, LAN provided construction observation services including chairing construction meetings, review and approval of shop submittals, preparation of project completion and permit closeout paperwork, and review of operation and maintenance manuals and as-builts.
State of NJ, DEP Office of Resource Development
Parks & Recreation
Civil Engineering, Land Use, Surveying