Widening Coastal Georgia's I-95

By Steve Hudson | September 28, 2010

Interstate 95 in southeastern Georgia continues to be one of the most heavily traveled routes in the region. As a key section of one of the main routes ferrying travelers and traffic north and south, it carries a steady (and sometimes very heavy) stream of commercial and noncommercial traffic.

Recently, the Georgia Department of Transportation has been widening I-95, adding additional lanes to improve traffic flow. One such project currently under way begins about one mile south of Highway 17/State Route 82 and extends north for about five miles.

The project is being constructed by a joint venture of three firms — the Seaboard Construction division of Plant Improvement Co., Rogers Bridge, and TIC. Seaboard Construction is handling the roadway portion, while Rogers Bridge is taking care of bridge work on land and TIC is responsible for bridges over water. Additionally, TIC subbed one of the project's bridges to Scott Bridge Co.

The primary goal of the project, which is being constructed in two stages, is to add a new traffic lane and shoulder in each direction for a total of three lanes northbound and three lanes southbound. Stage one involves construction of an additional 18 feet of pavement on the outside of both the northbound and southbound portions of the existing roadway to create a new lane and shoulder. Attention is currently focused on this stage of the work. Later on, stage two of the project will add an additional six feet of width to the inside of both the northbound and southbound lanes. Initially, the added width will allow the addition of one lane in each direction. However, the widened portion is being built to Interstate specifications to allow it to carry traffic when the roadway is made four lanes in each direction at some point in the future. The project involves some significant bridge work — including two major water crossings — as well as reconstruction of a major interchange.

Steve Howard, Seaboard's project manager on the job, has more than 36 years in construction, including 10 years with the Georgia Department of Transportation and the last 16 years with Seaboard — and all but one year of that experience has been in southeastern Georgia.

"The project is going smoothly," he says, adding that the construction team is currently ahead of schedule.

This I-95 project was let in February 2005. Work began a few weeks later in mid April with about 35 acres of clearing and grubbing in the median and on both sides. Triad Supply & Services handled clearing and grubbing and also handled subsequent fencing and erosion control. Because of the location, burning of clearing debris was not permitted; instead, the decision was made to chip the debris on site for subsequent use on-site for erosion control.

Attention then turned to preliminary grading — a major project in and of itself. Seaboard's grading crew used Cat D4 and D6 dozers, as well as Cat 330 excavators, to handle this phase of the work. About 150,000 cubic yards of unclassified material had to moved using a fleet of tandem dump trucks and Cat 725 and 730 off-road dumps. Additionally, approximately 60,000 cubic yards of off-site material was required; this borrow came from another Seaboard project nearby. Initially, Howard notes, the focus was on completing infills to allow bridge construction to move ahead.

Meanwhile, work was beginning on the roadway, starting with milling of portions of the existing pavement to a depth of 23 inches. New York-based Villager Construction handled the milling, using a Wirtgen milling machine.

The milling operation began on the inside lanes, generating some 40,000 cubic yards of material. The milled material was immediately used as fill along portions of the outside lanes where fill was required.

Other stretches of the outside lanes, however, did not need fill but required milling instead. Milling of those sections of shoulder and roadway generated an additional 100,000 cubic yards of material. That material, too, was transported to other parts of the site, providing the 4 to 5 feet of fill needed to lengthen some of the outside slopes. Along some parts of the project the milled material only had to be placed to the side; in other areas, it had to be transported by truck to the locations where it was needed.

In addition to this milling, Howard notes, plans call for the existing roadway to be milled to a depth of 2 inches, then repaved with 2 inches of new material.

"But to do that it is necessary to one-lane the project," he says, adding that one-laning is limited to the hours between 7 p.m. and 7 a.m.

Paving on this I-95 project involves construction of some complex grades. The 6-foot-wide portion of new roadway in each direction is at a 2-percent grade, Howard notes, while the 12-foot-wide portion is at a 4-percent grade. To construct that paving, Seaboard is using multiple paving machines, including pavers from Blaw-Knox, Cedarapids and Ingersoll Rand. A Roadtec SB2500 shuttle buggy is also being used. Other machines utilized during paving include Cat and Ingersoll Rand rollers, a Cat 140H motor grader, a Cat 924G loader, and a Rosco Challenger II broom.

Overall, construction of the new roadway and shoulder will require some 195,000 square yards of graded aggregate base, plus about 146,000 tons of asphalt. The asphalt mixes being used on the project are being produced at Seaboard's Brunswick, Ga., plant.

One major element of the project is intersection reconstruction at Exit 29. At that interchange, five ramps are being completely rebuilt. This ramp work includes four straight ramps and one loop ramp. Existing asphalt ramp paving is being removed and then replaced with concrete, a change made necessary to eliminate problems with rutting caused by the large number of heavy trucks that use the interchange. Subcontractor J.A. Long Construction is handling the concrete ramp paving.

Other project challenges come in the form of widening four sets of bridges. Starting near the south end of the job, as part of the Exit 29 interchange upgrade portion of the project, Rogers Bridge is widening the bridges over U.S. 520/U.S. 17 (Exit 29).

Moving north, the next bridge work (also being handled by Rogers Bridge) involves widening of the bridges that carry I-95 over the Colonels Island rail lines serving the Georgia Port Authority. Those tracks are busy all the time — something which the Rogers Bridge crews must keep constantly in mind as they work to widen the existing structures.

About a mile north of the project's southern end, a major part of the project's bridge work is focusing on the widening of the 28-span, 1,825-foot-long bridges carrying the Interstate across the South Brunswick River. The work on this bridge is being handled by TIC.

The main span bents on the South Brunswick River Bridge are being constructed atop 24-inch square piles with lengths of up to 77 feet 6 inches. To place those main-span piles, it was necessary to drill through about 8 feet of rock. A number of cranes — including a 150-ton Manitowoc 4000, a 100-ton Manitowoc 3900 and an 85-ton American 5299 — have stayed busy on the South Brunswick River widening.

About 4,300 feet north of the South Brunswick River spans is the northernmost set of bridges on the job. These spans, which cross SR 303 and Hillary Slough, have a length of about 1,300 feet. Scott Bridge Co. is handling this portion of the bridge work.

Members of the project team agree that, for the most part, the project is going smoothly. There have been some utility conflicts, Howard notes, but the biggest challenge has come from the high-speed traffic that flashes by just feet from the work area.

"The worst part about a project like this is the traffic," Howard says. "I love Interstate work, but the high-speed traffic can make it terribly unsafe and dangerous."

The project should be completed in January 2009.