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Historic Canton Viaduct
Canton, Massachusetts
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Historic Canton Viaduct
The Massachusetts Bay Transportation Authority undertook the Historic
Canton Viaduct Rehabilitation project to restore its 160-year-old multiple arch
masonry structure spanning across the East Branch of the Neponset River in Canton,
Massachusetts. The historic and aesthetic integrity of this structure was preserved
through the use of concrete and innovative construction methods. The viaduct,
constructed in 1835, has undergone various modifications throughout its life.
Originally designed as a single-track structure with relatively light loading,
it was modified in the 1860s to create a double-track structure. Consisting of
22 spandrel arches, it has an overall length of 615 feet, a width of 22 feet,
and a maximum height of 70 feet.
Key objectives in the design of the rehabilitation
project were to strengthen and widen the structure for future high-speed rail
use, restore the historic fabric of the structure, and facilitate fast-track construction
without impacting railroad operations. The viaduct is on a 1-degree curve
and experiencesincreased lateral loads due to high-speed rail traffic. In addition,
differential settlements of up to 2 inches were anticipated. Therefore, a group
of 4 mini-piles was installed at each side of each buttress to relieve the original
structure and to help carry the increased vertical and lateral loads.  Cast-in-place
concrete bearing pads encase the top of the mini-piles. PPC deck beams were then
installed to distribute the load, increase distance between track centerlines,
and stiffen the structure laterally. The deck was placed one side at a time to
ensure that rail service could be maintained. Critical deck placement operations
were performed at night.
The existing spandrel arches were reinforced with
cast-in-place concrete during an earlier rehabilitation, and all of these replacement
arches were demolished and replaced while the track was temporarily out of service.
Only one track was permitted to be out of service at a time. The Canton
Viaduct was placed on the National Register of Historic Places
in 1984 and dedicated as a National Civil Engineering Landmark in 1999. Now, thanks
to a successful rehabilitation project, the Canton Viaduct will serve as a functional
and beautiful structure for many years to come.
Project Credits
Owner:
Massachusetts Bay Transportation Authority / Amtrak
Engineer: HDR Engineering,
Inc.
Contractor: Middlesex Corporation
Concrete Supplier: Northeast Concrete
Products
Precaster: Northeast Concrete Products |