GB1074688A - A method and apparatus for forming columns of material in soil - Google Patents

Abstract

1,074,688. Boring earth etc.; piles. R. E. LANDAU. Dec. 17, 1963 [Dec. 21, 1962; July 5, 1963 (2); Nov. 21, 1963], No. 49805/63. Headings E1F and E1H. Apparatus for forming columns of material in the ground comprises an auger 10 having a flight 12 and carrying a hopper 16 at its upper end. The auger and' hopper are rotated by a shaft 26 driven by motor 30 and reduction gearing 28. The motor and gearing are mounted on a carriage 32 slidable on uprights 44, 46, the weight of the motor, gearing, carriage, hopper and auger providing the force driving the auger into' the ground. During normal boring the lower end of the auger is closed by a cap (58, Figs. 4, 7) which may be replaced by a drill head to penetrate obstructions or bedrock, or by a bit (292) to sample the ground, or by a probe to test the earth. The auger is prevented from falling rapidly through voids or soft ground during drilling by a pivoted spring urged member (254, Fig. 4) fixed to the uprights and engaging the underside of the flight. The hopper is loaded with coarse sand M for forming a sand drain by a bucket 176 pivotally mounted on a carriage and having a slide 192 which opens on contact with the coaming 132 of a pivoted, pneumatically controlled door giving access to the hopper. As the auger which is not rotating is withdrawn from the hole sand is fed into the hole, the falling of the sand being ensured by air supplied from nozzles 108, 116 and by a vibrator 166. Apparatus (Fig. 6 not shown) suitable for forming a concrete pile, has extending within the auger a shaft (270) carrying a flight (286). The shaft (270) is driven in either direction by gearing (278), or permitted to rotate with the hopper by the disengagement of a clutch (29), and may be fed vertically by a feed-nut (272). The flight (286) serves to eliminate segregation of the aggregate of pre-mixed concrete, and to feed the concrete into the cavity formed by the auger. A vibrator may be inserted into the freshly deposited concrete through the shaft (270) apparatus may be lowered through the shaft to sample and bearing test the ground, a weight may be added to the shaft (270) during drilling through obstructions or when depositing the concrete, and a drill may be fixed to the shaft (270) to drill bedrock to form a seat for the pile. A pile having a smaller diameter upper portion may be formed by reverse rotation of the auger as it is withdrawn from the upper portion.