Highway engineers have their work cut out for them. They contend with outdoor elements, carry bulky equipment and collect an enormous amount of geotechnical data each day in order to make important decisions about structural stability. But at the site of a 67-mile interstate freeway expansion in southwestern Indiana, fieldworkers are using a bundled geotechnical solution built on the Nautiz X7 rugged PDA from Handheld — and they’ve discovered how much simpler, safer and more efficient their jobs can be with rugged mobile technology.

A rocky start

Road construction sites are tough workplaces by nature. They’re exposed to a wide range of weather conditions and temperatures at all hours of the day and night. The Indiana worksite is near both low-lying marshlands and forested uplands, creating a variety of soil conditions and challenging slopes.

“There’s a 75- to 80-foot embankment going over very soft material 80 feet deep,” says Wendell Solomon, project engineer with Indianapolis-based CTL Engineering. “It’s a muddy mess out there, and you don’t get to skip the bad spots.”

In this type of environment, putting in a full and productive workday depends on having technology that’s both portable and reliable in a range of weather conditions.

Faced with these challenges, the CTL Engineering team led by Solomon began looking for a compact rugged computer that met all the necessary parameters for performing job duties, while also holding up to tough conditions and lightening the load for engineers.

Paving a better path

Solomon turned to Geokon, CTL Engineering’s trusted geotechnical instrument provider, to ask about a fully rugged, portable solution that would optimize workers’ time and provide the most accurate data possible.

Geokon manufactures high-quality geotechnical instrumentation suitable for monitoring the safety and stability of civil and mining structures, and is known for its world-class vibrating wire technology. Vibrating wire sensors can be likened to a guitar string that vibrates at a specific frequency when plucked. Instead of a finger, engineers “pluck” the wire electronically and correlate variations in the frequency of the wire vibrations to soil and water pressures.

“Geokon’s vibrating wire sensors are well-known for their excellent long-term stability and ability to transmit signals over long cables without degradation,” says Martin Gradijan, a sales associate for Geokon, “and inclinometers can provide useful information to indicate potential slope failure.”

Gradijan recommended two readouts for use at the site: The GK-405 vibrating wire readout system and the GK-604 inclinometer readout system, both of which are designed around the Nautiz X7 with performance, portability and ruggedness as top priorities.

Solomon says the decision to choose Geokon’s recommended solutions was easy.

“Over eight years of interacting with their team, it’s always been pleasant, and the equipment always works,” Solomon says. “They don’t put out products that aren’t thought through, and they have a lot of faith in Handheld’s devices.”

Handheld’s Nautiz X7 rugged field PC is built to withstand harsh outdoor environments. It’s IP67-rated, which means it’s completely dust-tight and protected against water immersion. It also meets stringent MIL-STD-810G U.S. military standards for holding up to drops, vibrations and extreme temperatures.

Despite its rugged build, the Nautiz X7 is completely portable and operable with one hand. It measures just 7 inches by 3.8 inches by 1.5 inches, includes a 3.5-inch sunlight-readable VGA touchscreen display, and weighs only 17 ounces. The Nautiz X7 offers all the performance necessary for geotechnical engineering field tasks, with a super-fast processor and plenty of storage, and its battery can last for a full 12-hour workday on a single charge.

A rugged mobile solution

Introducing the GK-405 and GK-604 systems at the construction site was a smooth process. Solomon and Jessica Lundin, a geotechnical engineer with contractor Cardno ATC, found the solutions — and the Nautiz X7 in particular — very easy to learn and employ.

At the site, engineers use the GK-405 system to read vibrating wire sensors that measure the worksite’s soil conditions. The readout box communicates information directly to the Nautiz X7 via Bluetooth, providing baseline readings the engineers can reference during continuous monitoring.

The GK-604 is used along with inclinometer probes that are lowered into special casings in the ground along the interstate. Engineers record measurements of soil movement at various depths as they survey the casings with the inclinometer probes, and the system wirelessly stores this data on the Nautiz X7. They can view inclinometer readout data directly on the Nautiz X7 or use Geokon’s SiteMaster software to graphically reproduce changes in slope profiles, or they can download the data from the handheld onto a computer, where it can be manipulated in Microsoft Excel.

Sturdier, simpler, better

Fieldworkers are currently using two GK-604 units to read 17 inclinometers along the interstate extension. They’ve found that the technology saves them time because it’s simple to operate, portable and well-suited for use in tough conditions.

“The Nautiz X7-based readouts provide a common platform for our vibrating wire sensors and our inclinometer probes,” says Gradijan. “Not only are these readouts smaller than older readouts, which were designed in the ’80s, but the memory capacity is also far greater.”

So far, these lightweight, reliable systems have worked at the site throughout a harsh winter and a hot summer.

“Being able to record data easily is a necessity because of the scale of the project,” Lundin says. “Recording my manual measurements in the handheld computer rather than writing them down saves time with data transfer and makes it possible to work in the rain.”

Being able to gather and store geotechnical data quickly and securely enables safer roadway construction and makes sure projects are done right the first time. This vastly improves engineering efficiency and saves time and money by preventing costly, time-consuming repairs.

This large interstate worksite has been a real challenge — Solomon calls it “a geotechnical engineer’s Fantasyland.” But smart solutions from Geokon and Handheld have made the task more manageable, proving once again that rugged mobile technology is an ideal solution when the rubber meets the road.

For more information about wire sensors, inclinometer probes and readouts from Geokon, please visit www.geokon.com.