During the construction of the Bridgehampton Crossing,
a 125-acre residential subdivision, a bridge was needed at
the entrance to cross Unionville Brook. Unionville Brook
and the downstream waters provide a fish habitat, while
the adjacent wetlands and open space in the area are
of significant concern to the community and played an
important role in the layout and design of the subdivision
and structure selection for the crossing. Unionville Brook
also is a watercourse that has a defined FEMA floodplain
and floodway.
Wilson Development LLC, the owner of the high-end
home development, also wanted an aesthetically pleasing
entrance. The combination of aesthetics, hydraulic
considerations and avoidance of impact to the wetlands
and floodway led to the selection of the bridge structure.
“The footprint of the bridge supports needed to be
outside the wetlands to satisfy the local wetland agency
and to minimize the regulatory approvals required and the
time required to obtain the approvals,” said Derek Kohl, P.E.,
Director of Engineering with BL Companies.
A BEBO® arch structure with a 68-ft. span, 8-ft. -6-in. rise
and 37-ft. length was chosen over a standard steel bridge for aesthetic reasons and because the
precast arches allowed for a rapid and cost-effective construction. The bridge design incorporated
many aesthetic elements including the arch, stone form liners and capping of the parapet. All of
these elements were incorporated to seamlessly integrate the bridge with architectural features of the proposed subdivision, the surrounding environment
and suited the character of the Unionville section of
Farmington. In addition, the T series bridge allowed for
spanning from bank to bank, without disturbing the
surrounding wetlands and environment.
“The BEBO Arch provided the required geometric opening
with a cost-effective structure that also serves as an
aesthetic enhancement to this development,” added Derek
Kohl. “The Town of Farmington will also benefit from the
low maintenance required for this type of structure.”
Challenges during the project included designing the
structure to fit both the horizontal and vertical alignments
of the roadway while also meeting utility placement, FEMA
floodway requirements and a challenging site topography.
The structure also had to accommodate a steep grade
of 3.7% on the approaching roadway and be buried
deep enough to allow for utilities to pass over it, yet high
enough to span the FEMA floodway and accommodate
flows for the 100 year storm event. The structure also had
to be positioned so that sight distance requirements for
approaching vehicular or pedestrian traffic were met.
The Town of Farmington also played a significant role in
the review and approval of the overall project through
the planning and zoning process. Their Engineering
Department had significant involvement in the technical
review of the bridge project and oversight of the
construction.
The Bridgehampton Crossing project recently won an
Award of Merit in the third annual Connecticut section
of the American Society of Civil Engineers (ASCE)
Achievement in Civil Engineering (ACE) Awards under the
Transportation category. The project was chosen because
it demonstrated the innovative use of precast bridge
solutions to satisfy the functional and aesthetic needs of
the owner while minimizing adverse impact to the natural
resources of the site.