METHOD FOR CAST-IN-PLACE PILE FORMING Russian patent published in 2005 - IPC

FIELD: building, particularly foundation building, namely for erecting pile foundations in seasonally freezing ground.

SUBSTANCE: method involves forming well extending for the full thickness of seasonally freezing ground layer, wherein well diameter increases pile diameter; installing heater in the well; transferring heat; driving casing pipe with detachable tip in ground through heater cavity; concreting well bore along with simultaneous lifting casing pipe and removing heater. Heat is supplied to concrete mixture within the limits of seasonally freezing ground after casing pipe removal. Inductor made as copper wire coil covered with heat-protective layer and located outside metal pipe is used as the heater. Heating is performed within 10-12 hours along with maintaining 75-80°C temperature of concrete mix by regulating inductor power up to obtaining concrete strength equal to 80% of design strength. After inductor removal from the well gap formed between well wall and pile body is filled with non-heaving ground.

EFFECT: reduced power inputs along with maintaining high productivity and increased load-bearing pile capacity.

2 cl, 3 dwg