It was a complex design with an incredibly tight schedule. But Keller pulled out all the stops to complete foundations for a liquid natural gas (LNG) tank in Utah, impressing the client and securing work across the entire Magna energy facility.
Once construction is finished later this year, Dominion Energy’s LNG facility in Magna, Utah, will provide a reliable source of cleaner energy for hundreds of thousands of people living in Salt Lake City and the surrounding counties.
LNG will be produced during the warmer months and stored in a 15-million-gallon tank ready for use in the winter. Building such a large, heavy structure – 120ft high and 180ft in diameter – on highly variable soft soil layers in an area prone to earthquakes is no easy feat, particularly when the project is already behind schedule.
“Before coming to Keller, the client, Matrix Services, had approached other contractors, with little success,” explains Christopher Rogers, Senior Project Manager, who’s based in New Orleans. “They basically said, if you can get the design done and be here in two weeks, the job’s yours. We’ve wanted to work more with Matrix, and this was a high-value project, so we went at it full force. In fact, I was setting up the batch plant while the design was still being finalised and approved!
“Why were we able to deliver where others couldn’t? We have a lot of academic horsepower in this company, including seismic experts who helped us generate the complex design to meet the strict criteria. At any time, we could have three PhDs on the phone with the client – that’s reassuring.
“We also have the tremendous capacity to quickly mobilise two crews to work double shifts. We really had our very best people on this, including a superintendent from Miami who’s an expert in deep soil mixing.
“It’s not just people either. We brought in a grout batch plant and drill rig from 1,600 miles away, the latter of which required permits to travel across states.”
A high-quality, cost-effective solution
Keller opted for deep soil mixing as it was a more technically viable, cost-effective technique than more conventional foundation methods, such as driven piles. The design called for more than 300 overlapping deep soil mixed columns (with 8ft diameters constructed to 37ft) to mitigate the liquefaction-induced settlement and ensure the overall settlement was within the stringent limits.
Throughout the project, daily samples of the mixed material were taken and tested for compressive strengths, with selected columns cored to their full depth for further analysis.
“Although we had some hurdles to overcome, including ensuring we could source the vast quantities of cement we needed, the stars aligned, everything ran smoothly, and we finished in around four weeks,” says Christopher.
Delivering on our promises
The client was so impressed with Keller pulling out all the stops to get this project back on track; they subsequently awarded the team the foundation works for the rest of the entire LNG facility – a contract worth around $13 million.
“There was a big gravel parking lot when we first arrived, and now everything sitting there is on foundations built by Keller,” he adds. “We made a lot of promises and thanks to the great people we have, we delivered on them and built a strong relationship with a major client.”