METHOD FOR CAST-IN-PLACE PILE BUILDING IN COLLAPSIBLE GROUND Russian patent published in 2005 - IPC

FIELD: building, particularly to erect cast-in-place pile having large diameter in collapsible ground layer of large thickness.

SUBSTANCE: method involves drilling pilot hole; installing casing pipe connected to puncher; punching the well ground by dropping load on the puncher through casing pipe to reach design point and enlarging the casing pipe; arranging reinforcement case in the pipe; filling the well with concrete mix as casing pipe moves upward; compacting the concrete mix. In the case of pile with 300-1500 mm diameter forming and in the case of collapsible ground layer thickness up to 18 m or 18-50 m ratio between pilot hole depth and collapsible ground thickness is 1:(4.5-6) and 1:(1.5-5). The puncher has reinforced concrete tip and head made of tube with outer diameter equal to inner diameter of pilot hole. Welded to the head are centering rings. The tip has ring to engage thereof with technological control rod provided with thread, washer with retainers and nut on opposite end thereof. Ratio of height H of upper head part provided with centering rings to length of casing pipe to be installed in the head is 1:(20-30). Ratio between outer puncher diameter D and outer diameter d at tapered part ℓ thereof is equal to 1:0.8. Length ratio between cylindrical head part L and cylindrical tapered part ℓ is equal to 1:0.6. Angles γ of head and head transition area leading to tapered part ℓ are equal to 30°. Difference between outer puncher diameter D to outer casing pipe T diameter is 90-100 mm.

EFFECT: reduced labor inputs and decreased material consumption.

2 dwg