Notes on the use of screw pile

　　1. The spiral ground pile ensures the height of the mud surface in the hole and strengthens the pressure on the hole wall.

　　When the ground water level of spiral pile is relatively high in soft flow plastic and loose places, the first point is to ensure the quality of mud, so that each index can meet the construction requirements, so that the mud can fully protect the wall. In order to ensure the mud surface in the hole, a cofferdam is made at the hole opening to connect with the mud in the hole. When the drilling tool is put forward, the mud in the cofferdam is added to the hole, so that the mud in the hole is always higher than the underground water level, and the higher the mud surface is, the greater the pressure on the hole wall will be, and the more stable the hole wall will be.

　　2. Screw pile controls drilling speed and prevents the effect of mud bit

　　When working in the soft flow plastic soil, in order to prevent pressing into the formation, record the depth of each hole during working, and drill from this depth during tripping; control the drilling speed and reduce the excessive disturbance to the formation.

　　3. Screw pile control footage

　　When the soft flow molds the soil, the speed of the footage is slower than usual to prevent or reduce the resistance of the piston effect when lifting the drill.

　　4. The spiral ground pile ensures the smooth surface of the drill bit to prevent or reduce the paste drilling on the soft flow plastic soil. When lifting the drill bit every time, some cohesive soil is often attached to the periphery of the drill bit. It must be cleaned as soon as possible to reduce the paste connection between the drill bit and the surrounding cohesive soil to prevent the paste drilling.

　　5. Screw ground pile reduces the joint clearance between drill bit and drill pipe

　　In order to check the link of drill bit and drill pipe frequently, it is necessary to deal with it as soon as possible when there is wear, so as to reduce the link gap.