Shear Wall Helical Anchors at Edwards AFB

Friday, July 12th, 2019 by George Stez

Challenge

Saber was called in to anchor a new shear wall at the Edwards Air Force Base Combined Test Force Compound in Kern County. The USAF needed to anchor footings that would be able to support a wall that could easily withstand extremely strong lateral forces resulting from the heavy winds of the high desert.

Solution

For the anchoring project, Saber marked the pier locations in the trench per the engineered plan, which was 18 inches off the existing wall on each side of the shear wall footing. We drove the first HA 150 helical pile down to 9 feet @ 6,072 foot pounds of torque,
using the torque correlation method and a K factor of 10 for an ultimate capacity of 60.7 kips. The second helical was installed to a depth of 8 feet @ 5566 foot pounds of torque, using the torque correlation method and a K factor of 10 for an ultimate capacity of 55.7 kips. We installed the caps 6 inches from top of grade. The finished spacing between the two piers was 67 inches.