Method and apparatus of forming sand piles for improving a soft ground
AssigneeFudo Construction Co., Ltd.
InventorsMasaru Shono, Takahiro Kawakami, Toshiyuki Matsumoto, Thoru Tamura, Hideki Matsumoto
Life of this patent
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Abstract
A method for uniformly improving a soft ground is proposed. It includes the steps of driving a pipe into the ground, putting sand thereinto and pulling up the pipe gradually while discharging and compacting the sand. In forming the sand piles, the diameter and/or strength of the sand piles are changed according to the soil nature of the ground to be improved to improve the ground uniformly.
Claims6
An apparatus of forming sand piles for improving a soft ground in a controlled manner, comprising:
- a pipe driven into the ground and through which sand is supplied into the ground,
- sand discharging/compacting means disposed at the lower end of said pipe for discharging the sand out of said pipe and compacting it,
- a hydraulic cylinder having a piston for moving said sand discharging/compacting means vertically,
- detecting means for detecting the working distance of said piston by detecting the flow rate of fluid supplied to said hydraulic cylinder,
- sensor means for sensing the pressure of said fluid when the downward stroke of said piston has reached to a predetermined value,
- comparing means for comparing the pushing force applied by said sand discharging/compacting means, computed based on said fluid pressure with a predetermined value, and
- means for changing the diameter and/or strength of the sand piles according to the result of the comparison.
A method of forming sand piles for improving soft ground, comprising the steps of:
- driving a pipe into the ground;
- putting sand into said pipe;
- and
- pulling up said pipe gradually while discharging and compacting the sand with a piston disposed within a hydraulic cylinder including,
- detecting the working distance of said piston by detecting the flow rate of fluid supplied to said hydraulic cylinder,
- sensing the pressure of said fluid when the downward stroke of said piston has reached a predetermined value,
- comparing the pushing force, applied during the discharging and compacting step, which is based on said fluid pressure, with a predetermined value, and
- changing the diameter and/or strength of the said piles during the formation thereof according to the result of the comparison, thereby creating sand piles resulting in uniformly improved ground.
Dependencies are inferred from the claim text.