HEARTLAND CORRIDOR CLEARANCE IMPROVEMENT PROJECT James N. Carter, Jr. Norfolk Southern Chief Engineer Bridges and Structures 1200 Peachtree Street NE Atlanta, GA 30309 (404) 529-1408 [email protected]
HEARTLAND CORRIDOR CLEARANCE IMPROVEMENT PROJECT
James N. Carter, Jr.
Norfolk Southern
Chief Engineer Bridges and Structures
1200 Peachtree Street NE
Atlanta, GA 30309
(404) 529-1408
ABSTRACT
The Heartland Corridor Project is part of a regional Public-Private initiative to provide a
direct, double stack container train route from the Ports of Virginia through Virginia,
West Virginia, and Eastern Kentucky and into Central Ohio. Once complete the
Heartland route will cut approximately 230 miles off the trip and improve shipment
availability to customers by one day.
In the Preliminary Engineering stage, 42 existing tunnels were assessed and 29 were
found to need clearance improvements to allow the use of double stack trains. Alternative
tunnel enlargement methods were developed to achieve the desired clearance
improvements, while maintaining structural integrity and minimizing disruption to train
traffic. During the Final Engineering Phase the tunnels were investigated in greater
depth, and the proposed clearance improvement methods were finalized. Additionally
three overhead bridges, seven thru-trusses, and nine slide fence locations were modified
to provide adequate clearances. All of the repairs methodologies were designed based on
operation constraints on track times and operations.
Construction work began in July 2007 at Bridge N-634.74 near Waverly, Ohio. Tunnel
work began October 20, 2007 at Cowan Tunnel near Radford, Virginia. The project will
be totally completed in August 2010.
This paper briefly summarizes the development of the Public Private Partnership,
engineering investigations of the existing tunnels, and the preferred methodologies
employed to achieve the desired clearances at each of the locations, and discusses the
construction of the project.
INTRODUCTION
The Norfolk Southern (NS) Heartland Corridor extends from the Ports of Virginia
westward through Virginia, West Virginia, Kentucky, Ohio, Indiana and terminating at
Chicago, Illinois. It’s a prime rail corridor for moving freight from the East Coast of the
United States to the heartland. It’s well engineered, almost entirely double-tracked,
diligently maintained and blessed with excess capacity. But for decades, most container
freight moving by rail from the ports of Virginia to Chicago has gone by longer, less
direct routes.
The Heartland Corridor will serve the recently constructed Rickenbacker Intermodal
Facility in Columbus Ohio, a planned intermodal site at Pritchard, WV, and a planned
intermodal site near Roanoke, VA. The clearance project took place between Walton,
VA and Columbus, OH.
PURPOSE AND NEED FOR THE PROJECT
The Heartland Corridor is comprised of the former Norfolk & Western Main through
Virginia, West Virginia, and Ohio. The section of the Heartland Corridor with the
majority of the clearance restrictions is primarily a coal hauling railroad, although general
freight and intermodal trains do operate there also.
The line was originally constructed in two major segments; the line was constructed to
Bluefield in 1883, and was extended from Elkhorn to Kenova in 1890. The line was
upgraded and realigned, with the current alignment and structures predominately
constructed between 1900 and 1927. The improvements made over the course of its life
have improved the route; however it still has numerous curves with curvature up to 12
degrees, and gradients up to 1%. The line is predominately double track, and carries
about 80 MGT annually with a typical Maximum Allowable Speed of 35 MPH
During the 1980’s the route was cleared for the 19’- 6” tall covered tri-level automobile
carriers. Many of the tunnel locations were cleared by lowering the track and tunnel
invert.
In the early 1980s, American railroads discovered that they could achieve a quantum leap
in efficiency in the inland movement of international shipping containers by stacking
them on dedicated trains. This way, one intermodal train could haul twice the load
without adding to its length. But there was a catch. Wherever the stack trains ran, bridges,
tunnels and other overhead obstacles had to be modified to allow them pass. By the
decade’s end, all of the major railroads had implemented clearance projects to
accommodate stack trains, and every major port could boast stack service to inland
destinations.
Railroad intermodal traffic has grown nearly 400% since 1986, and is expected to
continue to grow. The growth in intermodal traffic, coupled with the continued growth in
the total freight handled resulted in capacity issues on specific line segments of the North
American railroad network. Capacity issues caused by the increase in intermodal traffic
are not just limited to the railroads, prior to the economic downturn of 2008/2009. The
ports along the Pacific coast of Mexico, America, and Canada were all facing capacity
issues. The container shipping companies had shifted container ship routes from
operating along the Pacific Rim, to making transits through the Suez Canal to eastern
American ports. The construction underway that will increase the maximum ship size in
the Panama Canal also promises to bring additional containers into eastern ports along
the Gulf and Atlantic Coasts.
But not every inland destination had stack service to the ports. In West Virginia,
transportation and economic development officials recognized the importance of
intermodal service to the development of the regional economy. They knew they needed
a rail-to-truck container terminal in the industrial western part of the state to attract
businesses that need efficient access to global markets. In Ohio, the city of Columbus was
in the process of expanding Rickenbacker International Airport into one of the largest
integrated logistics complexes in the U.S. The plan included a major intermodal facility
providing key access to Midwest markets.
But stack trains bypassed the region. Norfolk Southern’s line between Columbus and
Norfolk – that prime rail corridor – passes through the region, but the route also included
28 tunnels in the Appalachian Mountains and 24 other overhead obstructions such as
power lines and bridges with insufficient vertical clearance for double-stacked trains.
Norfolk Southern’s stack service to the Midwest ran from Roanoke southwest to
Knoxville, TN then north into the Midwest, or north to Harrisburg, PA before turning
west again towards the Midwest. Without stack service, an intermodal terminal in West
Virginia would be superfluous.
The Heartland Corridor route not only provides both the capacity required to
accommodate future growth in intermodal and total fright traffic, and a more efficient
route from the Ports of Virginia for containers bound for the Midwest, and offers a stack
route to the Port for West Virginia.
Figure 1
Figure 1 shows the current routes used by double stack containers via Harrisburg, PA
(1,264 miles) and Knoxville, TN (1342 miles) and the Heartland Corridor route (1,031
miles).
Funding
Funding for the Heartland Corridor Clearance Improvement Project (HCCIP) required the
formation of a Public Private Partnership (PPP) to leverage the private funding available
from NS with public funding for this important corridor. In his paper Central Corridor
Double-Stack Initiative: Final Report, Center for Business and Economic Research,
Marshall University, March, 2003, Professor Mark Burton outlined the public benefits of
a stack terminal in the West Virginia, Eastern Kentucky, and Southern Ohio region. The
PPP evolved through a series of iterations to finally include public funds from the Federal
Government, the State of Ohio and the Commonwealth of Virginia.
The HCCIP was listed in the Safe, Accountable, Flexible, Efficient Transportation Equity
Act: A Legacy for Users (SAFETEA-LU) legislation as a “Project of National and
Regional Significance”. The SAFETEA-LU funds were provided for sites in Virginia,
Ohio, and West Virginia. Ohio’s Rail Development Commission (ORDC) provided a
portion of the funding for five sites in Ohio, and Virginia’s Department of Rail and
Public Transportation (VDRPT) provided funding for four sites in Virginia. NS provided
the matching funds for all of the sites. The Federal Highway Administration’s Eastern
Federal Lands Division (EFLD) was selected as the lead agency for the project. EFLD
also provided the environmental clearance work for the project.
PPP Agency Coordination
Since the HCCIP involved both public and private monies, controls were put into place
that provided the local agencies and Eastern Federal Lands Division with the ability to
review and comment on the project design. The controls were codified in a series of
Memoranda of Agreement (or Understanding). VDRPT, WVDOT, ORDC, and EFLD
were all provided plans for review, comment and approval at 70%, 95%, and Final plans
stages. The Agencies all worked diligently to meet the aggressive schedule and the
reviews went smoothly.
PRELIMINARY ENGINEERING AND DESIGN INVESTIGATIONS
In early 2005 NS contracted with a team headed by Hatch Mott MacDonald (HMM) to
provide an investigation and analysis of the work required to achieve the needed
clearances on 30 tunnels at 28 sites that range in length from 174 LF to 3302 LF., with a
total length of 31,112 LF. Ten of the tunnels were single track tunnels; the other 20 were
double track tunnels. However, three of the double track tunnels only had a single track.
Most of the tunnels were concrete lined, but one was unlined and three were masonry
lined over some portion of their length. Twenty-three of the 28 sites are in West
Virginia, 4 are in Virginia and one is in Kentucky. The initial series of field
investigations was conducted over a six-week period in March and April 2005.
NS contracted with a team headed by HMM in late 2006 to provide the Final Design of
the work required to achieve the needed clearances. HMM’s PE team was adjusted to
reflect the needs of the final design by the addition of STV/Ralph Whitehead and HDR.
The scope of the Final Engineering Phase was also increased to include design of the
bridge modifications to seven through truss bridges in West Virginia and Ohio, and
modifications to other structures such as slide fences and two overhead bridges that have
clearance restrictions.
MILEPEOST LOCATION TRACK OBSTRUCTION METHOD
N-305.43 Cowan, VA Single Cowan Tunnel Replace Liner
N-316.15 Eggleston, VA Single Eggleston No 1 Line Track
N-317.02 Eggleston, VA Single Eggleston No. 2 Line Track
N-319.83 Pembroke, VA Single Pembroke Line Track
N-351.91 Ingleside, WV 2 Slide Fence Relocate
N-362.25 Bluefield, WV 1 & 2 OH Bridge Remove Bridge
N-364.25 Bluefield, WV 1 & 2 Wire Remove
N-374.26 Bluestone, WV 1 & 2 Cooper Tunnel Enlarge Tunnel
N-378.64 Maybuery, WV 1 & 2 Through Truss Modify
N-379.9 Maybuery, WV 2 Slide Fence Modify
N-379.72 Maybuery, WV 2 Signal Replace
N-387.15 Northfork, WV 2 Signal Replace
N-88.47 Superior, WV 2 Signal Replace
N-392.06 Kimball, WV 1 & 2 West Vivian Enlarge Tunnel
N-394.24 Big Four, WV 1 & 2 Big Four No. 1 Enlarge Tunnel
N-395.07 Huger, WV 1 & 2 Big Four No. 2 Enlarge Tunnel
N-395.56 Huger, WV 1 & 2 Huger Tunnel Enlarge Tunnel
N-398.89 Welch, WV 1 & 2 Welch Tunnel Enlarge Tunnel
N-399.9 Hemphill, WV 1 Slide Fence Modify
N-400.15 Hemphill, WV 1 & 2 Hemphill No. 1 Enlarge Tunnel
N-400.42 Hemphill, WV 1 & 2 Hemphill No. 2 Enlarge Tunnel
N-400.92 Farm, WV 1 & 2 Through Truss Modify
N-403.71 Mohegan, WV 1 & 2 Antler No. 1 Enlarge Tunnel
N-405.07 Mohegan, WV 1 & 2 Antler No. 2 Enlarge Tunnel
N-406.1 Davy, WV 2 Slide Fence Modify
N-407.71 Twin Branch, WV 1 & 2 Twin Branch No.
1
Enlarge Tunnel
N-408.11 Twin Branch, WV 1 & 2 Twin Branch No.
2
Enlarge Tunnel
N-408.79 Twin Branch, WV 1 & 2 Wire Remove
N-412.08 Roderfield, WV 1 & 2 Vaughan Tunnel Enlarge Tunnel
N-413.07 Roderfield, WV 1 & 2 Roderfield
Tunnel
Enlarge Tunnel
N-414.09 Rogers, WV 1 & 2 Laurel Tunnel Enlarge Tunnel
N-415.07 Rogers, WV 1 & 2 Gordon Tunnel Enlarge Tunnel
N-418.3 Wilmore, WV 2 Slide Fence Modify
N-422.5 Wilmore, WV 1 Signal Replace
N-434.5 War Eagle, WV 2 Slide Fence Modify
N-439.47 Glen Alum, WV 1 & 2 Glen Alum
Tunnel
Enlarge Tunnel
N-446.5 Devon, WV 2 Slide Fence Modify
N-462.09 Sprigg, WV 2 Hatfield Tunnel Enlarge Tunnel
N-462.3 Sprigg, WV 2 Through Truss Modify
N-467.2 Sycamore, WV 2 Slide Fence Modify
N-471.62 Williamson, WV 1 & 2 Williamson
Tunnel
Enlarge Tunnel
NA-3.3 Panco, WV Single Big Sandy No. 1 Enlarge Tunnel
NA-6.02 Grey Eagle, WV 2 Big Sandy No. 2 Enlarge Tunnel
NA-6.82 Grey Eagle, WV Single Big Sandy No. 3 Enlarge Tunnel
NA-12.68 Bull, WV Single Big Sandy No. 4 Enlarge Tunnel
N-576.93 Coal Grove, OH 1 & 2 Through Truss Modify
N-579.83 Ironton, OH 1 & 2 OH Bridge Shift Track
N-631.5 Glen Jean, OH 1 & 2 Wire Remove
N-634.74 Glen Jean, OH 1 & 2 Through Truss Modify
N-653.84 Lunbeck, OH 1 & 2 Through Truss Modify
N-693.96 Ashville, OH 1 & 2 Through Truss Modify
Table 1
Table 1 shows a list of all the clearance obstructions addressed in the project.
SCOPING OF INVESTIGATIONS
The impact of field investigations on the daily operations of a busy railroad, led to the
design philosophy for the project. The investigations had to develop adequate amounts of
data to support a credible design and construction estimate that had appropriate
contingencies, yet minimize disruption of the operations.
The Observational Method
There are three basic approaches that can be used to design and construct the clearance
improvements while recognizing the likelihood that the investigations will not locate
every condition that will be encountered in the field.
Minimum Risk Approach
A minimum risk approach will be very conservative from an engineering and cost
estimating standpoint. This approach assumes the worst possible conditions that could be
expected at each tunnel location based on the limited data collected, and from that data to
specify a uniform improvement method. This approach will certainly result in a safe
facility, but with unnecessary cost and disruption to the railroad during construction. The
contractual risks are reduced, but as with any underground or renovation activity, not
entirely eliminated due to the variability of existing conditions.
Extensive Testing Program Approach
The approach using an extensive testing program would conduct an exhaustive lining
thickness and rock mass evaluation prior to finalizing the design. This approach would
result in a series of differing improvement methods along the length of the tunnel based
on the results of the detailed investigations. This approach has the potential to reduce the
construction cost but at the expense of exhaustive investigations and resultant disruptions
to the railroad. The contractual risks are reduced, but as with any underground or
renovation activity, not entirely eliminated due to the variability of existing conditions.
Observational Approach
The third approach is to adopt an “observational” approach where a ‘cafeteria menu’ of
improvement methods is provided in the contract documents with the specific criteria as
to the conditions where each method can be implemented. The observational approach is
an adaptation of the standard practices used at the heading of Sequential Excavation
Tunnels (SEM), and requires Construction Phase monitoring by engineering and
inspection staff familiar with tunneling and geology.
The types of field investigations performed during the Engineering Phase were limited to
the level of detail necessary to base the final design on. The use of the observational
method allowed accommodating a short time frame for the Engineering Phase
investigations since the Investigative Probing Program (IPP) would be performed during
the construction operations.
Based on the field investigations at each tunnel location, the contract documents provide
the anticipated limits of each of the improvement methods. Contractors bid based on the
anticipated limits and expected conditions detailed in a Geotechnical Baseline Report
(GBR), but the construction process incorporates confirmations of the expected
conditions (lining thickness, joint planes, etc.) within a framework of the IPP conducted
by the contractor ahead of the construction activities at each tunnel. The contracts have
payment mechanisms that allow adjustments to the quantity of the clearance
improvement methods with appropriate compensation to the contractor when conditions
differ from those anticipated in the GBR.
DESIGN REPAIR METHODOLOGIES
Laser car data was combined with the survey data to produce a series of tunnel cross
sections and a longitudinal tunnel profile. NS supplied a clearance envelope shown in
Figure 2 that was used as the template to determine the clearance requirements.
Figure 2
Track Realignment/Lowering
Track Realignment/Lowering was evaluated as one of the primary methods of achieving
clearance at most locations. However, since many locations have bridges in the
immediate area of the tunnel, the maximum amount of lowering was limited by the run
off of the lowering to meet the bridges. The bearing configuration at the majority of the
bridges limited the amount of lowering that could be performed at the bridge. The
clearance work in the 1980’s had also lowered the track so that the bottom of the ballast
section was at, or near the bottom of footing elevations. As a result the track lowering
was limited to profile adjustments to provide vertical curves and tangents at the tunnel
approaches.
Three of the tunnels in Virginia were double track tunnels with only a single track in the
tunnel. At these locations the track was realigned to the center of the tunnel and lowered
to provide the required clearances.
Liner Notching
At lined tunnels where the amounts of additional clearance required was minimal,
notching was considered. Notching was split into either minor notching or deep
notching.
Minor Notching
Minor Notching was defined as locations where the amount of material removed for the
notch left sufficient liner thickness to allow the liner to support the tunnel without
additional modifications. Initial calculations indicated that about 4 to 6 inches can be
locally removed before shear stresses in the concrete at the notch exceed acceptable
values and additional support measures are required.
Figure 3
Figure 3 shows a typical double-width tunnel with minor notching. The single-width
tunnels would be similar.
Deep Notching
Deep Notching was defined as locations where the amount of material removed for the
notch resulted in liner conditions where additional modifications to the liner were
required to maintain the structural integrity of the tunnel.
Figure 4
Figure 4 shows a deep notching concept where untensioned rock dowels are installed to
develop arching action within the rock surrounding the tunnel, thereby allowing a stress
transfer of the current tunnel lining loads from the concrete liner to the reinforced rock
arch as the lining is notched. The maximum depth of notch has been set to maintain at
least 10” of intact concrete in the lining.
Crown Replacement
At locations where the additional clearance required the removal of more of the liner than
Deep Notching, the crown of the tunnel was removed and replaced with a series of
ground supports.
Figure 5
Figure 5 shows a liner replacement concept. A section of lining will be removed along
the length of the tunnel with any rock above the lining needed for clearance. Rock bolts
and mesh would be installed immediately and in advance of the next train. That
operation would be followed by additional excavation support measures including
multiple layers of shotcrete reinforcement, lattice girders, spiling, etc., depending on the
level of excavation support required for the actual ground conditions encountered.
Daylighting
Daylighting essentially removes the tunnel entirely, leaving a simple rock cut. Starting
from the surfaces above the tunnel, ground would be removed independent of the railroad
operations. Once the excavation exposed the roof of the tunnel, the tunnel lining would
be removed during scheduled track availability windows.
FINAL DESIGN
Underlying Philosophy
Final design, lead by Hatch Mott MacDonald, began in October 2006, and was driven by
four underlying tenets in priority order:
The safety of those working on the project and operating through the project while
construction was underway.
The ability to construct the project as designed safely within the 10 hour work blocks,
and meet the overall schedule.
The quality and reliability of the final constructed product.
Cost control.
Ground Support Types
The design team developed a set of ground support types that could be applied to the
clearance improvements at each tunnel. The ground support types are linked to the
expected rock conditions above the tunnel liners. Supplemental rock bolts will be used in
addition to the Ground Support Type to address specific detail issues, such as loose
blocks, at the tunnel locations.
Ground Support Type A
Type A support is expected to be the predominant methodology used for the HCCIP
clearance improvements. Type A is installed at locations where the rock mass above the
tunnel liner is of good quality. Figure 6 shows the arrangement of the rock bolts and
shotcrete lining.
Figure 6
Ground Support Type B
Type B support will be used at locations where the rock mass above the tunnel has a
lower quality than the Type A locations. Type B support is similar to Type A, but bolt
spacing is tightened.
Ground Support Type C
The geology of the tunnel locations are characterized by incised river valleys that form
points of lands on the inside of the river meanders, and bluffs on the outside of the river
meander. The tunnels cut through the points to create straighter track alignments. As the
points are formed, the removal of the strata allows the remaining rock strata to ‘relax’ to
equalize stresses. This relaxation produces fractures within the rock mass that parallel
the face of the point. These fractures are called ‘Hill Seams’ and can be small fractures,
or larger fissures that may be filled by alluvial materials.
The Type C support was developed to be used where fissure sized hill seams are found
and in the more weathered areas that are typical near the tunnel portals. The first design
used included spiles (horizontal piles) and grouting are used to create a support canopy to
prevent the alluvial materials in the hill seam from running into the tunnel as the lower
materials are excavated. Figure 7 show a typical Type C installation.
Figure 7
Once construction began, contractors suggested partial liner removal with steel sets and
shotcrete as an alternate to the spiling method. This alternate, shown in Figure 8 was
approved and was the predominate method of support used in Type C ground on the
project.
Figure 8
Portal Support
Support at the portals was designed to deal with the extremely variable conditions found
at the portals, and based upon the standard plans. Portal areas are difficult to construct
and severe overbreak is typically encountered. The standard plans show stacked
cordwood and dry packing above the portal. The investigations showed that the areas
above the portals contained significant amounts of broken rock.
Like the Type C support, spiles and grouting are used to create a canopy above the tunnel
that will support the loose material above the portal. Figure 9 shows the support at the
portals.
Figure 9
CONSTRUCTION MANAGEMENT
In May 2007 Norfolk Southern selected a team led by STV/Ralph Whitehead Associates
to provide construction management services for HCCIP. Other team members include
AMEC and Jacobs Associates. Their tasks included a peer review of design, which was
found to be very valuable and led to design enhancements and a more constructible final
design.
Operations
While design work was ongoing, NS’ Service Planning Group conducted an exhaustive
study along with modeling of the operations in the HCCIP area and found that through a
series of innovative solutions that the trains passing through the construction sites during
the work windows could be eliminated. NS developed a strategy to reroute several of the
general merchandise trains around the HCCIP, and reschedule others. NS also attempted
to re-route an intermodal train pair, but could not meet the customer’s needs. Coal
business in the area tends to increase from Monday through Friday, and fortunately, the
intermodal trains operate with schedule that allows a 10 hour window Saturday through
Wednesday on the HCCIP. The coal trains that form the majority of the traffic in the
project area are held outside of the work windows by the addition of more helper
locomotives and crews.
Construction Staging
The fundamental need to maintain the operation of the railroad as fluidly as possible
coupled with available contractor capacity to complete the highly specialized work
dictated breaking the tunneling work into three phases. Bridge, signal, slide fence and
other ancillary work was scheduled around the tunnel work.
Figure 10 shows the tunnels color coded by phase located on the project map.
Figure 10
CONSTRUCTION
NS B&B forces began HCCIP construction work in July 2007 with modifications to the
through truss Bridge N-634.74 near Waverly, Ohio. They also completed Bridge N-
653.84 near Lunbeck, Ohio and Fenton Rigging performed steel modifications to Bridge
N- 576.93 near Ironton, Ohio prior to the onset of winter weather in 2007.
In 2007 grading was performed for a new track alignment to provide clearance beneath
the overhead bridge at Milepost N-579.83 in Ironton, Ohio. The track will be shifted in
2008.
Tunnel Work
Since the tunnel work by its nature, grinding and demolishing concrete, pumping grout to
fill voids behind liner portions that would remain, and applying shotcrete overhead,
would tend to foul ballast, the track in all tunnels was flooded with ballast prior to the
advent of contractor activity. This was advantageous because it provided a good working
platform for rubber tired equipment and a safer environment for contractor employees
while walking. The track through all tunnels that required structural modification was
removed and replaced by Norfolk Southern forces after the contractors completed their
work, resulting in about eight miles of total track replacement.
On October 1, 2007, NS issued notice to proceed to Johnson Western Gunite, Inc. for
work at the 3,302 ft. long Cowan Tunnel, near Radford, Virginia – the first tunnel
contract for HCCIP. Johnson Western began construction at Cowan on October 21, 2007
and work was completes in September 2008. All work in Cowan was crown replacement.
NS forces began undercutting the 925 ft. long Eggleston No. 1 tunnel near Eggleston,
Virginia in November 2007. They began undercutting the 1,195 ft. long Eggleston No. 2
Tunnel and the 299 ft. long Pembroke Tunnel at Eggleston, Virginia in March 2008.
Work on these two tunnels was completed in April 2008.
In November 2007, Johnson Western Gunite was also awarded a four tunnel contract
including the 1,113 ft. long Vaughan Tunnel, the 924 Ft. long Roderfield Tunnel, the 803
ft. long Laurel Tunnel, and the 1,271 ft. long Gordon Tunnel, all near Roderfield , West
Virginia. Construction activities for this contract began January 15, 2008, and were
completed in May 2009. Tunnel modifications in this group included a combination of
deep notching and crown replacement.
In January 2008, LRL Construction was awarded a four tunnel contract for the 613 ft.
long Antler No. 1 Tunnel, the 613 ft. long Antler No. 2 Tunnel, the 760 ft. long Twin
Branch No.1 Tunnel, and the 883 ft. long Antler No. 2 Tunnel, all near Davy, West
Virginia. Construction activities began on February 23, 2008. The IPP resulted in
classification of the entire Antler No. 1 tunnel as Ground Support Type C. This contract
included a combination of deep notching and crown replacement. Construction was
completed in May 2009.
A bypass was built around the 380 foot long Big Sandy Tunnel 2 that only carried Main 2
track. The bypass was completed in January 2008.
In May 2008, R. J. Corman Railroad Construction was awarded a two tunnel contract for
the 864 ft. long Hemphill No. 1 Tunnel and the 1,142 ft. long Hemphill No. 2 Tunnel
near Welch, West Virginia. The work started in early July 2008 and the contract has a
completed in April 2009. This contract included a combination of deep notching and
crown replacement. Corman was also awarded a contract for the 1,335 foot long Welch
Tunnel included a combination of deep notching and crown replacement that also
included a combination of deep notching and crown replacement. Work began in October
2008 and was completed in July 2009.
LRL was awarded a four tunnel contract for the 698 ft. long Cooper Tunnel, that was
entirely Class C ground except for the tunnel portals, the 680 foot long West Vivian
tunnel that included a combination of deep notching and crown replacement, and the 645
foot Big Four No.1 and 174 foot Big Four No. 2 that were predominately notching.
Cooper had extensive voids above its brick lining that reached as high as 20 feet. A steel
set and channel lagging liner was initially installed as construction progressed, and in the
area of the large voids, four feet of concrete above top center of the sets was placed, in
addition to a four inch minimum steel fiber reinforced shotcrete layer below so that the
liner can withstand the rock falls that will occur in the future. Work began in January
2009 and was completed in April 2010.
It was decided to award a contract for the IPP alone to take advantage of the track outage
that was required for the construction underway, and Johnson Western was awarded that
contract for Glen Alum, Hatfield, Williamson, Big Sandy Tunnel 1, Big Sandy Tunnel3,
and Big Sandy Tunnel 4. Work began in November 2008 and was completed in April
2009.
Johnson Western was awarded the contract for the 1,302 foot long Glen Alum tunnel that
was entirely notching. Work began in May 2009 and was completed in September 2009.
Johnson Western was also awarded the work at the 977 foot long Hatfield Tunnel for
track two. This tunnel was the only part of the project located in Kentucky and was the
only unlined tunnel on the route. The shale tunnel was enlarged and a rock bolt and steel
fiber shotcrete liner installed. Work began in May 2009 and was completed in September
2009.
Johnson Western was awarded the 678 foot long brick lined Williamson Tunnel that
required crown replacement throughout. Work began in June 2009 and was completed in
March 2010.
Johnson Western was awarded the work at the 2,627 foot long Big Sandy Tunnel 1, and
the 1,848 foot long Big Sandy Tunnel 3. Work began at Tunnel 1 in July 2009 and at
Tunnel 3 in August 2009. Both of these tunnels required crown replacement throughout,
and Tunnel 1 included C ground beneath US Highway 52 at the east portal, where
extensive spiling was required, along with lane closure on 52 as the work was done
beneath the highway. Both tunnels should be completed in August 2010.
R. J. Corman was awarded the work at Big Sandy Tunnel 4. Tunnel 4 is 2,068 feet long
and the majority of the clearance improvement needed was achieved by notching.
However the west end of the tunnel included some C ground and 100 feet east of the west
portal received a new precast concrete lining that was installed by cut and cover after a
micropile foundation was installed. The tunnel is on a very sight grade and has a large
amount of water intrusion. A pumping system was installed to improve drainage. The
tunnel floor is shale rock and is degraded rapidly by ballast. An asphalt underlayment
will be installed when the track is replaced. Work began in October 2009 and will be
completed in July 2010.
While the different contractors have different methodologies and equipment, the similar
nature of the work led to similarities in the progression of the work. The IPP was always
the first activity in those contracts that included it and generally consisted of vertical core
holes and recovered cores which were drilled up through the liner at 250 ft. centers. In
addition, two inch diameter radial probe holes were installed at 45 degrees to the spring
line, and forward incline probe holes were drilled near the center line of the tunnel in
single track or staggered over track centers in double track at intervals ranging from 17.5
ft. to 23.5 ft. These probe holes varied in depth from 29 to 38 feet dependent upon the
void or loose material behind the liner, and all were video logged. The probe hole
information was used by, the Construction Management team to classify the ground and
specify the type of support needed within designated limits from the contract menu.
A single tunnel may have had several different repair methodologies, and several
different types of support for each methodology. Sidewall grouting and bolting would be
one of the first activities beginning soon after the IPP, and was generally conducted
simultaneously within a contract package. If the tunnel was to be notched, roof grouting
would follow as the next activity, before the notching began. Where crown removal was
the required method, a sufficient amount of sidewall bolts must be installed. A cut line
was established by saw cutting or line drilling before any crown demolition began. Once
the crown removal process started, the specifications required that all required roof bolts
and an initial layer of shotcrete or wire mesh must be installed within the panel removal
limits before the end of the shift to allow safe passage of trains.
Contractors elected to use either rail mounted or hyrail equipment to perform tunnel work
and the IPP drilling was performed from high platforms on hyrail trucks. At the Johnson
Western sites, crown demolition was been primarily performed by road headers or
pavement breakers mounted on excavators. Material being demolished fell directly into
side dump cars or gondolas fitted with side wings. The gondolas were emptied between
track windows. Crown rock bolts were installed from high platforms on hyrail trucks.
Grouting and shotcrete operations were been flatcar mounted. LRL elected a different
method using breakers for demolition, letting the demolished material fall onto protective
mats, and then reloading muck into hyrail rotary dumps.
Work on all the projects has progressed substantially as planned, and remains on schedule
to meet the 2010 planned completion. Variations from the planned five day per week, ten
hour per day work schedule have been very limited on the part of either NS or the
contractors. With very few exceptions, the track windows have been available as
scheduled and have been returned for rail service as planned. The extensive planning on
the part of NS’s Service Planning group and Division Transportation employees allowed
the railroad to operate successfully as planned.
CONCLUSIONS
The Heartland Corridor Clearance Improvement Project was a complex project. There
were 57 project sites spread along 379 miles of railroad. The nature of the public private
partnership, the inherent risk associated with any tunnel modification project, the need for
exclusive, uninterrupted long daily windows of track occupancy over a long period of
time for the tunnel work, and the sheer scope of the project necessitated extremely close
cooperation between planners, designers, various government agencies, railroad
transportation planners, construction managers, and contractors, from the conception of
the project to its ongoing construction phase. The level of cooperation required is
exceeded by few construction projects.
The scope of the project is exemplified by the material quantities. The contractors
installed about 32,000 rock bolts that would stretch over 94 miles laid end to end. They
also installed another 1,900 cable bolts that would stretch an additional 10 miles. They
installed over 500 steel sets, weighing over 830 tons. They used over 81,000 tons of
cement for grout, and over 24,000 tons of cement for shotcrete.
The benefits will begin immediately. Norfolk Southern intermodal trains will knock more
than 200 miles off their current routes, improve transit time between Norfolk and
Chicago from three days to two, and free up previously unavailable capacity. The
Virginia ports, where a new container terminal is set to begin construction in 2017, can
immediately begin touting a competitive advantage, while localities along the corridor
can tout their access to world markets. Trucking companies will take advantage of the
economics of rail and move more of their containers to rail for intercity transport,
relieving the stress on the nation’s highway infrastructure, making the roads safer,
improving air quality and easing the demand for fuel.
From “what if” speculation a decade ago to the grinding away of solid rock, the
Heartland Corridor saga is one of shared vision, careful negotiations, public and private
commitment, thorough engineering, and imaginative solutions to operational challenges.
The result is an environmentally and economically beneficial project certain to help a
nation meet a looming infrastructure crisis and serve as a model for more such projects to
come.
TABLE AND FIGURE LIST
Table 1 – List of clearance obstructions initially identified.
Figure 1 - The current routes used by double stacks and the Heartland Corridor route.
Figure 2 - The template to determine the clearance requirements.
Figure 3 - Typical double-width tunnel with minor notching.
Figure 4 - Typical double-width tunnel with minor notching.
Figure 5 - A liner replacement concept.
Figure 6 – Crown Removal – shotcrete and rock bolt arrangement
Figure 7 – Type C installation
Figure 8 – Alternate Type C installation
Figure 9 – Typical portal support
Figure 10 – Tunnel location map with phases color coded