The Unofficial
I-26 Construction
Madison County
North Carolina
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Project Update: February 2003

A-10BB

The project between Mars Hill and US 19 is complete. All the signs, paint striping, fencing and paving has been finished and traffic is now using the road. Except for an inch of pavement that will be added on the northbound lanes south of US 19 on the paving project, everything is completed.

A-10C

The project between US 19 and Laurel Creek Road is now complete. All the grading has been finished and the contractor (Gilbert-Southern) has left the project site. Any remaining construction involving hydraulic pipes or final grading will be handled by the paving contractor (APAC of Asheville).

The total amount of unclassified excavation removed on this project is 24,607,843 cubic yards. This includes both soil and rock removal. This total is nearly 2 million cubic yards higher than the original estimate, but additions such as the welcome center and widening through the big cuts for six lanes added to that total.

The total undercut excavation amount is 1,960,000 cubic yards, about half a million cubic yards less than the estimate.

The total for erosion control stone is 44,000 tons, much higher than the original estimated amount. The contractor had to rebuild many of the erosion control devices several times during the life of the project, and others were added during construction as well.

Presplitting ended up at 128,790 square yards, close to the expected amount. Presplitting is the forming of the steep and smooth rock slopes in the big cuts, which requires a specific operation to prevent shattering the rock remaining.

Over 1,300,000 square yards of erosion control matting has been used on this project, a increase over the estimated amount by more than 36 times (estimated amount of 36,000 sy). The reason for the enormous overrun is simple; every soil slope has had erosion control matting placed on it when it was completed to hold it in place, and the initial estimate did not provide for this use. Although this quantity has been massively overrun, it is well worth it since the slopes have not shown much erosion if at all, and the erosion control matting helps give the new grass a stable place to get started growing.

The contractor has finished installing masonry drainage structures (the drop inlets and catch basins along the ditches). 300 of the 384 proposed structures were built on the grading project. Several of them have had to be installed multiple times due to building them at the wrong elevation and when they were damaged by vehicles driving over them. The remaining ones will be built by the paving contractor.

The concrete planters along the project are now completed. These planters are in front of the rock fence, so knowing how much of these have been built gives you an indication of how much fence has been installed as well. The final quantity is right at 6200 feet. The rock fence has also been installed on top of the planters.

Gilbert-Southern placed over 200,000 tons of aggregate on top of the graded soil to act as the first layer for the pavement. It was added on the grading contract to create a solid surface for the paving contractor and allow easier access to the whole project.

A-10D

The project from Laurel Creek Road to the Tennessee State line is completed. The total amount of excavation came to 9,125,780 cubic yards on this project. A total of 1,179,156 cubic yards of undercut was also removed, which was fairly close to the amount estimated. The presplitting quantity has increased to 24,017 square yards, which was also close to the amount estimated.

A total of 118 drainage boxes were constructed, and 1007 linear feet of concrete planter and barrier, 9,186 tons of erosion control stone and 279,807 square yards of erosion control matting were used to build this project.

The Laurel Creek Bridge is complete, and has been since October. A total of 9,659 cubic yards of concrete went into the building of this large bridge, which is the highest highway bridge in North Carolina at 220'. The concrete was used to build the drilled piers, stems, approach slabs, deck, median barrier and railings. The access ladders within the hollow columns are being installed, and the de-icing system has been completed.

A-10CA

The paving contract is virtually complete now. All the concrete pavement, guardrail, median barriers, signs and paint striping has been finished, and only minor work remains at the tie-in to the freeway at Sams' Gap. The official opening ceremony has been set for August 5, 2003.

Here are some of the quantity totals used in paving this project:

84,000 cubic yards of embankment (for the shoulders and tie-in at Sams' Gap)
124,300 tons of aggregate (84,500 tons were stockpiled by the grading contractor; the rest came from quarries)
380,000 square yards of concrete pavement
89,200 tons of asphalt base material
39,000 tons of asphalt intermediate material
33,000 tons of asphalt surface material
49,800 linear feet of guardrail
42,063 linear feet of concrete median barrier
37,150 linear feet of shoulder berm gutter (under the guardrail)
7,200 linear feet of curb and gutter (in the rest area and scenic overlooks)
591,400 square yards of erosion control matting
168 acres of seeding and mulching
42.3 acres of reforestation
5,030 cubic yards of mulching (for the plants in the rest area and scenic overlook)

Over 50,000 manhours of time were charged to these projects during design, by a large group of technicians, engineers and administrative personnel from nearly every unit of NCDOT, as well as consultants who created the EIS, bridge plans for the Laurel Creek Bridge, and traffic control plans. When the construction and inspection times are added to this amount, however, the total number of manhours that went into the planning, design and construction of these four projects (A-10C, A-10D, A-10CA and the rest area K-3304), exceeds 3,000,000 manhours, spread out between 1990 and 2003.

Now that I-26 is about to open to traffic in a few short days, I want to thank those who worked so hard and long to plan, design and build these projects. All of you dedicated yourselves to making sure the projects were as high a quality as possible, from the technicians calculating the quantities to the workers and inspectors building the road. As the Project Design Engineer, I got to know a lot of you over these years through conversations and meetings, and am convinced these projects could not have been done as well without all your hard work. To all of you, I want to say, thanks for your contributions, and you can all take pride in these projects as they finally reach completion.

John Lansford, PE
Project Design Engineer
A-10C, A-10D, A-10CA, K-3304
1990-2003

Previous Project Updates:

John Lansford
Guestbook
August 2003