Traditional foundation methods can be tricky to implement when access is limited, overhead clearance is especially low, or soil conditions call for strict weight limitations. For instance, on swampy ground or low-quality soil, the machines needed to install conventional foundations cannot always operate safely or maneuver effectively.
With residential remedial foundation repair becoming a greater concern, the CHANCE® helical pile was developed in the mid-1980s and was issued a helical underpinning methods patent in 1992. This all sounds well and good, but the question remains: Why are helical piles so effective for remedial foundation repair?
There is no equivalent for measuring torque directly in the tooling string. Using differential pressure (or pressure drop across the motor) can work if it is properly set up and calibrated, but keep in mind that pressure is being measured, not torque.
Capacity-to-torque relationships for helical piles are used frequently to determine termination criteria for helical piles. Empirical relationships between installation torque and capacity have been established for several helical pile shaft sizes, including square shaft and pipe shaft piles.
Caliche is best described as salt-cemented sand. Naturally occurring in arid and semi-arid regions, caliche is a dense, thick layer of rock-hard ground that anchor installing machines can barely scratch. CHANCE® engineers, wanting nature’s toughest test for their ROCK-IT™ helical anchor, took product to the Atacama Desert in Chile, to see if the square shaft anchor with a carbide tip welded to the shaft would live up to its name.