Building Excavations

Dewatering your site excavation with Tri-State wells can save you money. You'll appreciate these advantages:

• Better working conditions
• Uncluttered working area
• Lower Operating Costs
• Less lost time

Tunnels

Storm water tunnels under the Minneapolis-St. Paul freeway system are often mined in St. Peter sandstone under 15’ to 70’ of artesian water pressure. Dewatering the entire length of the tunnel with Tri-State's gravel packed wells has helped to change a difficult job into a routine job.

Dams

The outlet structure of the storm water tunnel of the Northeast leg of Interstate 35 in Minneapolis was built 22’ below normal pool elevation of the Mississippi River. Five wells were required pumping approximately 8,000 gallons per minute to keep the area dry.

Four large utility shafts from 12’ to 18’ in diameter were installed as part of a 12,000 storm sewer tunnel in the St. Peter Sandstone formation 150’ below grade for the city of St. Paul. Shown here is a 17½ dia. core barrel used to cut the Platteville Limestone. Note that two Watson 5000 crane-attached drills are stacked one above the other to furnish the required drilling torque.

In Oklahoma the Arkansas River was threatening to under this river crossing tower. Tri-State was contracted to construct a 100’ diameter circle of 36” piers around the tower. Piers were constructed tightly together to form a wall. They were drilled through 20’ of drift and were socketted firmly into 3’ of limestone. If the river continues to change course the tower will be sitting on a man-made island surrounded by a castle of piers.