The Newburgh Beacon Bridges are twin spans which carry Interstate 84 across the Hudson River between Newburgh and Beacon, New York. The main channel spans consist of three-span steel cantilever trusses with main span lengths of 1,000 feet and side spans of 602 feet. The approach spans consist of 11 deck truss spans with average span lengths of 440 feet and two sets of short span girder units. The total length of each structure is approximately 7,800 feet between abutments.
M&M designed the First and Second Bridges in 1963 and 1980, respectively. We also provided design and construction support services for the widening of the First Bridge in 1983. M&M has been providing biennial annual inspections since 1959, A 100% hands-on visual inspection is made of all fatigue sensitive and fracture critical members during each biennial inspection, with a maintenance Inspection performed in alternating years. M&M has partnered with the authority to conduct these inspections for the entire life-cycle of both bridges.
More recently, M&M prepared a design report for the redecking of this crossing. The project consisted of preparing a design report for a total deck replacement estimated at $75 million. M&M then participated in the final design development for the redecking of the South Bridge by conducting a constructability review and preparing an independent cost estimate prior to advertisement of the project.
During construction, M&M also provided construction inspection services, including installing instrumentation. Due to concerns about possible cracks developing in newly installed precast concrete roadway panels, instrumentation was installed before the concrete was poured. Monitoring occurred through pouring and curing of concrete, during transportation by truck, during crane lifting into place, and final installation. Instrumentation consisted of 23 uniaxial welded resistance strain gages, 21 embedded concrete vibrating wire gages, 18 embedded concrete resistance strain gages, 12 vibrating wire gages mounted on steel, and 9 thermisters. Routine traffic was then monitored. Total response from initial pour of concrete through to final traffic loaded was collected and analyzed.
Bridge Geometry
| Length of Main Span | 1,000 feet |
|---|---|
| Total Project Length | 7,800 feet |
| Lanes on Structure | 6 lanes (three per bridge) |
