Profile:
The Foundations Lab at the South Dakota Department of Transportation (SDDOT)provides recommendations for the design of bridge and retaining wall foundations. Its lab tests are conducted in accordance with AASHTO and SDDOT standards.

Challenge:
South Dakota is growing. Faced with an increasing number of transportation projects and the increasing quality and complexity of state projects, SDDOT needed to upgrade its efficiency and technical capabilities.

“The state is doing more work and its jobs are getting more high-tech, so there is more testing involved with each project,” said Nena Nelson, Senior Transportation Technician at the Foundations Lab. For example, new bridges are designed with retaining walls, which require special testing. “With just a simple two-span bridge, you’d only run some unconfined tests. If you’re putting up a retaining wall, you have to do direct shear tests,” Nelson said. “Now we need more accurate data.”

“We have more than doubled our output.”

Nena Nelson Senior Transportation Technician Foundations Lab South Dakota Department of Transportation (SDDOT)

To supply SDDOT’s Foundations Engineer with timely and accurate geotechnical lab tests and test reports, the Foundations Lab began a search for new and more reliable testing equipment. Managers wanted a solution that would provide consistently accurate results while offering a user-friendly interface. And they needed to comply with state guidelines mandating comparative shopping based on quality, price and user-friendliness.

“My boss is extremely picky about state expenditures,” Nelson said.

Solution:
The SDDOT Foundations Lab selected three geotechnical testing units from Geocomp Lab Products, including two LoadTrac II machines and one ShearTrac unit. The Lab uses one LoadTrac II to conduct one-dimensional consolidation tests on undisturbed samples, a second Load Trac II to test the unconfined strength of soils, and the ShearTrac for direct shear testing to determine the shear parameters of soils.

Geocomp’s offerings compared favorably with other vendors’ products based on user-friendliness, price and technical support, Nelson said. And, unlike some vendors, Geocomp offered easy upgrade capabilities.

Benefits:
The SDDOT’s Geocomp equipment improves the lab’s soil testing efficiency tremendously.

“The time to run the tests has been cut in half,” Nelson said.

The result is a significant increase in the number of samples that the lab is able to test. “It shows in our year-end progress reports. We have more than doubled our output,” Nelson said.

Having up-to-date soil testing equipment has made it easier for the Foundation Lab to meet increasing demand. For the amount of money that the lab once spent to run one soil sample, it can now run two to three. “The cost-effectiveness is a lot better,” Nelson said.

Automation and reliability are key improvements. “Instead of having to constantly monitor my testing equipment, I have more time to go ahead and draft up other projects,” Nelson said.

The lab’s direct shear unit has been up for a full year without shutting down. “It runs 24/7,” Nelson said. “I don’t know if we ever expected that. It’s extremely reliable.”

The new equipment is also easy to use, the Lab reports.

“If you have any computer skills whatsoever, it is extremely user-friendly,” Nelson said.

Help from Geocomp got SSDOT up and running quickly, and the lab’s rapport with Geocomp’s technical support team has been excellent. “Any time I need anything, I just go ahead and call Rachid [Hankour]. He knows me on a first name basis,” Nelson said. “If he doesn’t get back to me personally, he will have someone do it,” she said.

Other state labs are interested in Geocomp products because of the Foundation Lab’s positive experience with the equipment. “There’s no reason to look at anyone else. When I have looked out there, it seems that Geocomp has the top of the line as far as I can see,” Nelson said.

The Foundations Lab has updated both its direct shear and consolidation testing capabilities since it purchased its units four years ago, and will likely purchase additional geotechnical testing units and upgrades as demand for soil testing continues to increase, Nelson said.