Figure 1: LinkedIn post from Jan. 18, 2018 showing patent application
drawing and construction views of Group 1 piles consisting of wall face
and perpendicular resistance fins including cementitious backfill beneath
drainage/utility cradle
loading acting on the wall system. Each fin consists of a brace sheet
of relatively higher elevation connecting to the wall face, a series
of cradle fin sheets terminating at an elevation below the brace
fin sheet for accommodating a pipe drainage/utility cradle and
a series of predominantly resistance fin sheets terminating at an
elevation above the cradle sheets.
Between the slope of the existing embankment and the wall face
up to the top of the cradle sheets is cementitious backfill for prestressing
the wall system when fluid – and when set, supporting
the aforementioned pipe/utility cradle, from which the remaining
construction (including pavement structure) can build upon while
reducing overall earth pressure acting on the wall face (Figure 3).
Basically, this wall system consists of a one-stage rather than twostage
construction process, i.e., the installation of interconnected
sheet pile elements effectively serving as their own temporary
shoring – as compared to other types of construction including
MSE wall, T-wall or reinforced concrete cantilever wall, which
would require the installation of temporary shoring to support the
adjacent highway prior to the beginning of wall construction.
How does the sheet pile wall system work?
The sheet pile retaining wall system (exposed height above ground
a maximum of about 21 feet) on the Pennsylvania Turnpike
Mainline – with a length of approximately 1,573 feet (along front
face of wall) and a height varying from approximately 15 to 31
feet (gutter line to bottom of wall) – basically consists of an outer
row of sheets constituting the wall portion of the structure with
perpendicular sheets connected to the outer sheets via three-way
connectors at approximately 9.5-foot intervals along the length of
the wall. This wall concept is somewhat analogous to the integral
PROJECT SPOTLIGHT
As-Bid T-Wall Alternate Value Engineering
Sheet Pile Wall
Completion/
Use Dates: Scheduled September 2018 Actual March 2018
Category A
Costs: Budgeted $125,000 Actual $160,000
Construction
Costs: Total Project Budget $7,645,000 Total Project Actual $7,263,499
Key Dates
and Costs
Figure 2: Honor Award winner in Special Project’s category at ACEC
National’s 50th Engineering Excellence Awards Competition
Figure 3: Full complement of sheet pile resistance fins (with recessed
drainage/utility cradle) holding back wall face (on right)
68 | EDITION 5 2019 www.piledrivers.org
/www.piledrivers.org
