CommScope ConQuest Conduit Construction - Manual (Page 26)

The Drilling Square*
The factors that make a successful bore are too interrelated to be able to point a finger at any one of them as being the
cause of a problem in all cases. Therefore these factors are best placed in the form of a square.
The drilling square is a simple and useful tool to remembering the four factors affecting fluid flow, which is the key to
successful horizontal directional drilling.
FLOW Fluid Volume
Bits/Reamers
Soil Identification
Soil
Soil is classified in two general conditions: coarse soils and fine soils.
Coarse soils are classified by material weight, not material size, as:
• Sand
• Gravel
• Rock
Coarse soils create ground conditions with high porosity and permeability. They are non-reactive, do not swell, and do
not get sticky.
Fine soils are classified by moisture content:
• Clay
• Shale
Fine soils are reactive and can change with moisture content. They swell and get sticky.
4.8 Underground Installation Methods
The Drilling Square