Upon McLaren Engineering Group’s inspection of Grassy Point Road Bridge, it was discovered that a complete replacement of the bridge was vital to mitigate safety concerns for motorists and pedestrians. The deterioration and deficiencies discovered resulted in the current structure being marked with a reduced weight limit. Working with the County of Rockland, McLaren engineered a modern bridge design loaded to meet all standards for New York State including HL-93 loading and NYS Permit Vehicle loading, eliminating any vulnerabilities.
The current Grassy Point Road Bridge (BIN: 3346300) is approximately 70 feet long. The structure carries Grassy Point Road, also known as Beach Road, over Minisceongo Creek in the Town of Haverstraw in Rockland County, New York. The bridge inspection performed by McLaren revealed concrete spalling and delamination along the bridge fascia. Additionally, it showed concrete spalling undermining the railing supports and severely corroded girders. This included significant girder bottom flange deterioration. Due to these superstructure deficiencies, the bridge was caused to have a reduced vehicle weight limit. In effect, the current conditions posed a potential safety risk.
The new replacement bridge is a modern structure capable of carrying all legal loads. The proposed typical section includes 11-foot wide lanes and 4-foot wide shoulders with abutments supported on piles. The replacement bridge will be constructed adjacent to the existing structure. Doing so will maintain traffic during construction with little disruption to the surrounding community. It is anticipated that roughly three hundred feet of approach roadway reconstruction will be required on both sides of the bridge. Once the new bridge is complete the approaches will be realigned and the existing bridge superstructure will be removed. Once the new bridge is complete, the approaches will be tied into the new alignment and the existing bridge will be demolished.
It is anticipated that construction will begin around March/April of 2021. Accordingly, the new bridge and realigned roadway should be open for use by the end of 2021.
In lieu of a typical public information meeting and in response to the COVID-19 pandemic, McLaren worked with the client to provide a mechanism for public review for this federally funded project. The project plans and alternatives were made available online for review with public comments, concerns, and suggestions.
Since the new bridge will be built adjacent to the existing bridge, McLaren found the original concrete abutments could stay in place as is, since they will not interfere with the new design, saving the project time and money.
To show the client a 360-degree detail and structural analysis of the bridge replacement, McLaren prepared a preliminary design model in LEAP Bridge Steel.