Horizontal Auger Boring (HAB)
Horizontal Auger Boring is truly an innovative alternative to trenching when it comes to utility installation. The trenchless HAB method, sometimes also referred to as “Boring and Jacking,” is preferable in many casing to pipe ramming or pipe jacking methods.
Advantages of HAB are that it eliminates damage to previously existing road or railroad embankments and requires limited traffic disruptions; therefore it is the preferred method for installing utility pipelines under roads, highways, or railroads. The HAB method is a very economical choice as well. HAB trenchless techniques can be used to install pipelines up to 72 inches in diameter in a cost-effective manner.
Machines used to perform horizontal borings can be equipped with cutting heads to drill holes ranging from 8 to 80 inches in diameter. The first step in performing a HAB installation is to acquire a geotechnical site survey. This geotechnical site survey will provide necessary information about soil and groundwater conditions as well as expected obstructions and will allow the drilling company to effectively plan the HAB operation in cooperation with project engineers.
Before installation begins, the site should also be cleared for underground utilities, something that is readily accomplished in most states by calling a “one-call” hotline. Next, the crew will prepare a drive pit at one end of the planned pipeline. This is where the crew will operate from during the boring. Then, a drilling machine is brought on site that includes lengths of auger, casing, and a cutting bit suited to the soil conditions at the site.
During pipeline installation, drill cuttings exit the casing in the drive pit and can be excavated from there. Once the casing pipe is in place, the carrier pipe, or the pipeline being installed, can be pushed or pulled through the casing as it is assembled. Final steps of the installation include preparing as-built drawings, grouting voids created during drilling, and hook-up of the installed pipeline. Overall, HAB methods provide a great chance of success for difficult installation projects.