How to install Engineered Earth Anchors in shallow depth installations
Earth anchors are used in combination with High-Performance Turf Reinforcement Mats (HPTRM) in a number of different applications including erosion control, slope stabilization, structural support, landscaping, and ground mounting. This article will focus on the installation of engineered earth anchors in shallow depth installations (typically between 3 ft (91.44 cm) and 5 ft (152.4 cm)). In addition to installation support, this article can help with the preparation of bids and cost estimates.
Before starting an installation, it is imperative to make sure you have the following items:
Installation equipment: For most applications, it is most economical to use a hydraulic or pneumatic hammer drill or a gas-powered post driver. It is best to have an internal adaptor (such as a reducer sleeve or SDS max drive adaptor) that will fit snugly around the diameter of the chosen drive steel. It is possible to use a fence post driver or hammer on very small projects. Pro tip - make sure you have a generator or extra gas on hand and that you have sized the equipment by the force needed to drive the anchors to the proper depth in your site-specific soils.
Drive steel: The head of each engineered earth anchor has a hollow cavity to insert the tapered end of a drive steel. Select the drive rod according to the size and make of the earth anchor. Most drive steel is 1/2 in (1.27 cm), 3/4 in (1.91 cm), or 1 in (2.54 cm) in diameter and comes in various lengths. For deeper applications, a threaded drive steel with couplers can be used in combinations to reach the proper design depth. Pro tip: use cold rolled hardened steel and always have extra drive steel on site. You don't want to shut down a project while waiting on replacement drive rods.
Drive steel removal devices: For most shallow depth installations, a Jack Jaw can be used to grab the drive rod and pull it straight out of the soil. A Jack Jaw can also be used to set the anchor by pulling up on the flexible tendon once the load-bearing top plate is flush with the surface. For deeper applications, you may consider welding a loop on the shank of the top portion of the drive rod to pull with an excavator or large piece of equipment. Pro tip: it usually takes about 2 cranks on the Jack Jaw handle to load lock the anchor. Stop once you feel resistance substantially increasing.
Cable cutters: To complete the anchor installation, on most applications, it is critical to cut the cable below the top of the load-bearing top plate so high-quality wire cutters come in handy. Pro tip: most cable tendons range from 1/8 inch (0.32 cm) to 1/4 inch (0.64 cm) in diameter, select the size of your cutters accordingly.
There are many different tools that can be used to drive and properly set engineered earth anchors, but partnering with the manufacturer and distribution before installation can help ensure a stress-free installation and save money and headaches.
