HORIZONTAL DIRECTIONAL DRILLING
Horizontal Directional Drilling (HDD) is a construction technique whereby a tunnel is drilled under a waterway or other designated area, and a pipeline or other utility is pulled through the drilled underground tunnel.
The underground tunnel follows an arc line from the entry point, down under the special crossing area, and then resurfaces on the opposite side. Using advanced technology and highly trained technicians, a drill head guides the drilling pipe electronically to ensure the angle, depth, and exit point adhere to carefully designed engineering plans.
- Long-distance underground pipelines are built across open areas, such as rural farmlands and urban utility corridors.
- Typically, construction crews clear an approved route, dig a specially prepared trench, lower welded sections of pipeline into the trench, and carefully replace removed soil for the restoration process.
- Usually, this method is preferred for open area installation and can be completed in a way that minimizes environmental and stakeholder impact, even in sensitive areas.
- Although land around the drill entry and exit locations is disturbed during HDD activities, it will be restored to its pre-drill state.