What is the umbrella value of pile foundation hole formation?

the value. The umbrella value of pile foundation pore-forming is the value situation, which is umbrella-shaped distribution. "Umbrella-shaped measuring instrument for hole-forming aperture of bored pile" This is a new patent, manual digging cast-in-place pile: it is a method of digging holes manually and pouring concrete into piles. This kind of pile is a main construction method of large-diameter cast-in-place pile because of its reliable mechanical performance, no need of large machinery and equipment and simple construction operation technology.