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Long Span Steel Girder Erection 1
LONG-SPAN STEEL GIRDER ERECTION
Typical Section Trapezoidal Box Superstructure
Typical Section Multi-Plate Girder Superstructure 2
Common Erection Methods:
Traditional Single-Plate Girder
Erection by Crane
Traditional Single-Trapezoidal Box
Girder Erection by Crane
Two-Plate Girder System Erection
by Crane
Multi-Girder System Launching
Long-Span Steel Plate Girder Erection with Cranes:
For purposes of the discussion today let us assume a long-span steel bridge has:
at least one span greater than 400-0 in length and
web depths in the 20-0 range 3
James Rumsey Bridge:
We will use the recently erected James Rumsey Bridge over the Potomac River, connecting
Maryland and West Virginia, at Shepherdstown, West Virginia as a talking point.
General Contractor: Brayman Construction Corporation,
Saxonburg, PA
Erection Contractor: Advantage Steel & Construction, LLC,
Saxonburg, PA
Erection Engineer:
Gannett Fleming, Inc.,
Construction Services, Pittsburgh, PA
Bridge Specifics:
Three-span 1,085-foot long curved steel haunched multi-plate girder bridge
330-0 : 425-0 : 330-0 span configuration
18-4 maximum web depth
Slight horizontal curve at each end of the bridge
Highly historic location
James Rumsey Bridge Contd:
The James Rumsey Bridge is situated in the heart of American history. It was at this location
during the Revolutionary War that British and German prisoners were marched across the
Potomac River en route to Maryland military prison camps. During the Civil War the entire
Northern Virginia Army withdrew from here into Virginia following the Battle of Antietam.
Additionally, the historic C&O Canal, and its tow path, stretching
from Washington, D.C. to Cumberland, Maryland passes
beneath the bridge and could not be disturbed and only
intermittently disrupted during construction. 4
James Rumsey Bridge Contd:
This new James Rumsey Bridge, which replaces one of the last known Wichert Truss bridges,
represents a bridge alternative type that is being increasingly selected by Owners over more
established long-span structure types such as box girders, arches, and trusses.
Reduced fabrication costs coupled with the increased reluctance of Owners to undertake
complex/time consuming design and shop drawing reviews, as well as desired structural
redundancy and a greater focus on bridge aesthetics have resulted in an increased number of
these bridges being built; the following three bridges within a 250-mile radius of Pittsburgh,
Pennsylvania are examples of this trend:
James Rumsey Bridge in Shepherdstown, West Virginia,
Star City Bridge in Morgantown, West Virginia, and
Pennsylvania Turnpike Commissions Monongahela River Crossing
(currently in final design)
GENERAL OVERVIEW
OF THE JAMES RUMSEY BRIDGE WITH
ERECTION HALF-COMPLETED 5 6 7 8 9
HEIGHTENED SENSITIVITY 10
Lateral Compression Flange Displacement:
Shallow Girders
Deep Girders
X
>X
Typical Diaphragm Configuration Shallow Girder Depth
Intermediate Diaphragms: 11
Typical Diaphragm Configuration Excessive Girder Depth
Intermediate Diaphragms:
Typical Diaphragm Configuration Excessive Girder Depth
Intermediate Diaphragms: 12
Typical Diaphragm Configuration James Rumsey Bridge
Intermediate Diaphragms:
Long-Span Steel Girder Bridges are commonly located adjacent to existing truss bridges.
First-Girder
Bracing Details: 13
Access to such a potential bracing element frequently results in ill-conceived lateral bracing
details (bracing the first erected girder to the existing structure) which:
Do not provide true lateral stability and/or
Do not permit vertical girder deflections without inducing lateral deflections
First-Girder
Bracing Details:
Existing Bridge
Handrail
Pin
Pin
Control of Lateral-Torsional Buckling:
Lateral-torsional buckling is best controlled by reducing distances between points of contraflexure,
in effect controlling strong-axis moments, either with:
Hold Cranes or
Temporary Towers/Bents
Given the spans
generally associated
with long-span steel
bridges, temporary
towers/bents provide a
better means of reducing
these distances because
required hold crane
capacities can become
excessive.
Temporary bents also
permit the opportunity to
introduce a brace point
against wind forces, thus
reducing wind stresses
and lateral
displacements during
erection. 14
Control of Lateral-Torsional Buckling:
The following strong-axis moment diagrams demonstrate the differences between the use of hold
cranes and temporary towers/bents in reducing distances between contraflexure points.
Note the differences in the vertical forces applied and in the distances between contraflexure points.
38-kip HOLD CRANE
47-kip TEMPORARY
TOWER/BENT REACTION
CONTRAFLEXURE
POINT (TYP.)
ERECTION CONSTRUCTIBILITY 15 16
GENERAL OVERVIEW
OF THE JAMES RUMSEY BRIDGE WITH
ERECTION COMPLETED 17 18
James Rumsey Monument 19 20
The new James Rumsey Bridge was successfully erected from June to November 2004,
and withstood the effects of Hurricanes Charley, Frances, and Ivan, as well as the
resulting flood from Hurricane Ivan, which destroyed the construction causeway and two
temporary bridges on the causeway.
Wichert Truss Bridge Constructed 1937 21
Jared G. Fasick, P.E.
Project Manager
Bridges/Construction Services/Forensic Investigations
Foster Plaza III, Suite 200
601 Holiday Drive
Pittsburgh, Pennsylvania 15220
Tel: 412-922-5575
Fax: 412-922-3717
E-mail: jfasick@gfnet.com