GB965372A - Improvements relating to the production of subterranean piles or like structures - Google Patents

Abstract

965,372. Piles; excavating by jetting. CEMENTATION CO. Ltd. July 22, 1963 [Aug. 3, 1962], No. 30063/62. Headings E1F and E1H. A method of producing subterranean piles by impregnation of soil in situ with a consolidating medium, e.g., a suspension of cement, sand cement, clay in water or chemicals causing a gel reaction, or bituminous emulsions, comprises forming a hole 8 of smaller diameter than the pile and enlarging it progressively by erosion from the bottom of the hole by the upward progression of a rotating single stream of grouting medium from the jet 6a, the grouting consolidating medium being added to the hole in two successive upward passages of the jet. The pump 1 supplies liquid, e.g., water, to the rotating jet 6a from the pit 13 and during the first drilling excess liquid together with entrained soil particles pass through the pipe 9 and channel 10 to the settling tank 11 and liquid passes further over the weir 12 to the pit 13. When the drill has reached the required depth at which it is required to start consolidating the soil, grout is fed to the pit 13 from the tanks 15, the pump pressure is increased and the drill reversed up the hole to enlarge it and erode particles to form a suspension in the top it is again reversed to a downwards direction, with the eroding power of the jet made less by reducing the jet velocity or jet size, to be raised again after it has reached the bottom of the hole. The particles may be separated by a mechanical separator or hydraulic classifier to be rejected or returned directly to the hole while the remaining liquid is recirculated through the jet. Specification 796,959 is referred to.