Power-Line corridors are seldom along the freeway right-of-way. Some locations require work to be done on the ice during sub-zero weather.

Other locations may be wet year-round and require matting in to drill at proposed structure sites or even amphibious vehicles such as this Rollagon being used to transport concrete to the hole. Special access problems are becoming the norm rather than the exception. Tri-State has built a reputation as being a problem solver.

Whatever your project and whatever the terrain—whether you are crossing river or the Rockies, a swampland, a desert, or tidewater flats—Tri-State can install the foundations in you area.

Drilled shaft foundations, as an alternate to pneumatic caisson construction, proved to be a considerable cost saving for the Interstate 80 bridge between Council Bluffs, Iowa and Omaha, Nebraska. Each of the two piers in the Missouri River has a foundation consisting of 13 drilled shafts 6' in diameter, extending 90' through alluvium, a socketted 12' - 18' into the Limestone bedrock. To facilitate construction, the general contractor dredged a sheet-piling cell full of sand to support Tri-State's crane mounted drill and related equipment.

This cantilevered lift bridge in Sheboygan, Wisconsin, is supported by 7' diameter piers with 6.5' diameter rock sockets anchored into the hard Silurian Dolomites or Lake Michigan. The shafts were constructed to within 1% of plumb to a depth of 60' below the water surface.

Unusual geology under the St. Louis River in Cloquet, MN, presented a unique challenge. A zone of shale had been metamorphosed by an igneous intrusion. Five of the eighteen 6’ diameter piers were founded directly on Gabbro making conventional drilling impossible. The 6' casing was torqued into the Gabbro and as much as possible was removed. Then a 12" diameter downhole pneumatic hammer was used to drill 4 needle shafts 12’ into the igneous rock in the shaft bottom to develop resistance to uplift from horizontal ice loading.

Tri-State has become a premier provider of foundations for Microwave and PCS towers across America because of our ability to move quickly from site to site. In today's competitive market, getting the groundwork done quickly and on schedule is a high priority for owners. Tri-State excels in the logistics that can pull a long distance project together quickly.

Caption: The MCI tower shown to the left is mounted on 7' diameter shafts, 55' deep with 13' bells. Shown above is the belling bucket attachment.

This scene shows the foundations for the Ruan Tower in Des Moines. Other projects in Des Moines were the Hilton Hotel and the Carrier Building.

Above is the Hennepin County Government Center in Minneapolis. One of the many buildings in the Twin City Area on Tri-State foundations.