Colorado’s expansive soils represent a unique challenge for builders. Heaving caused by expanding clay soils can cause serious structural damage to buildings.
Helical piers are one way that builders have addressed this challenge. These steel piers are installed “to a specified pressure and torque that will be able to support a certain amount of weight,” according to Cody Rushing, sales and marketing manager at Techno Metal Post in Colorado Springs.
Helical piers can be used on new construction or existing homes. Rushing noted that the application for helical piers include everything from foundations and decks to mailboxes, flagpoles or solar panels.
“There’s really a ton that you can do with it,” Rushing said. “Pretty much anything that goes into the ground and needs a foundation, we can support it.”
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The size of the pier used depends on the amount of weight it needs to support, as well as lateral loads that will be applied to it, according to Rushing. For example, “a ground-mounted solar panel is going to need a lot more support laterally,” he said.
Rushing said that installation starts with a soil test to determine how much pressure will be put on the piers once they’re in the ground.
One of the biggest benefits to builders is that helical piers don’t need an inspection because there’s no excavation, he said.
“For caissons, they’re going to have to inspect the hole to make sure it’s deep enough. They’re going to have to inspect the concrete to make sure it cures,” Rushing said.
With helical piers, the engineer will sign off on the installation showing the depth of each pier and the pressure applied to each one. Builders can file that report with the building department which will suffice for inspection, Rushing said.
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Colleen Merrill, senior project manager for Anchor Engineering in Denver, noted that typically, a geotechnical engineer or field tech will be present during installation of helical piers to make sure that the bearing material, torque and depth are correct.
“The geotechnical engineer and/or contractor should provide installation records of each screw pile, which lists the torque, depth, pile size, etc., to the EOR for review and approval,” Merrill said by email. “We often provide a report of the installation based on this information, without having observed the installation ourselves.”
However, she noted that “while a representative from the structural engineer’s office might not be present, a qualified third-party inspector should be present during the helical pile installations.”