bridge-in-a-backpack royal river bridge - home - … leveraged the new bridge-in-a-backpack...
TRANSCRIPT
Kleinfelder leveraged the new Bridge-in-a-Backpack technology for the Royal River Bridge in Auburn,
Maine. The Bridge-in-a-Backpack superstructure is composed of lightweight carbon-fiber tube arches
that theoretically can be transported onsite in a backpack and filled concrete after installation.
an EfficiEnt SubStructurE to accommodatE LoadSThe Bridge-in-a-Backpack solution required an efficient and effective substructure to accommodate the loads induced by the superstructure arches. Kleinfelder designed the abutments to resist traditional vertical loads for the spanning structure, plus the high horizontal thrust forces that the system’s flat arch shape places outward on the abutments. Because the arches are embedded in the abutment concrete, our structural engineers had to design the substructure elements to handle the potential bending moments created by the continuity.
rapid conStruction and LowEr coStSKleinfelder incorporated all of the substructure design parameters and developed a cost-effective abutment design that consisted of cast-in-place concrete pile caps on a single row of steel H-piles. This style of abutment used approximately 50 percent fewer piles, enabling more rapid construction and lower material costs. Kleinfelder’s design also eliminated the added expense of battering piles, which typically are required to resist horizontal loads. Futhermore, Kleinfelder developed an effective headwall design alternative that accommodates saturated soils, is aesthetically pleasing, and has a 75-year lifespan.
Location:Auburn, Maine project cost:$1.1 Million
owner:Maine Department of Transportation
An Employee-Owned Company | © 2013 Kleinfelder. All rights reserved.
bridge-in-a-backpack Royal River Bridge
Arches embedded in the abutment Pre-construction for concrete fill
proJEct rESuLtS
The Royal River Bridge
was the first project to
incorporate the innovative
Bridge-in-a-Backpack
solution, which saved
time, money, and energy
without sacrificing the
integrity or lifespan of
the bridge. Kleinfelder
adapted the foundation
and headwall systems to
specific site constraints,
applying this proven
technology in new ways.