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TRENCHING is one of the most common methods of hydro excavation ( Non Destructive Digging). There are various forms of trenching (slot, perimeter, box, linear, cross and exploratory trenching) each of which offers a strategic variation that specifically suits the scope of work. From a definitional standpoint, hydro excavation trenching uses pressurized water and an ever-present vacuum excavation system to cut a circuitous or straight-line ditch of various dimensions in the ground.

The process starts with a simple pot hole. With the mechanical or manual vacuum system hovering the designated surface area, the operator excavates straight down in the ground. The depth of the initial pot hole is usually determined by the scope of work and will generally set grade for the trench to follow.

Some of the more common applications for trenching include

  • straight-line exploratory cutting prior to auguring foundation pier shafts for an above-ground pipeline or electrical conduit rack
  • exploratory trenches prior to excavating with a track hoe for the subsurface installation of pipeline, electrical or fiber optic utilities
  • predesign perimeter trenching to provide structural engineers empirical data about subsurface utilities
  • narrow trenching around the perimeter of a foundation for the installation of grounding wires or electrical lines
  • cross trenching ( X ) to verify subsurface clearances prior to the installation of foundation structures for transmission and cellphone towers
  • slot trenches to determine clearances above, below or between subsurface utilities
  • slot trenches to locate and expose wayward directional drill heads or drill heads that may have encountered underground utilities or structures
  • box trenching around buried pipeline valves or sections of buried pipeline for point repair operations
  • slot trenching to provide clearance for the installation of sheet pile shoring around pipeline utilities