Ground improvement device and ground improvement method using the same

Abstract

The present invention discloses a ground base improving apparatus capable of simply and reliably preventing the dispersion of the water pollution, and reliably improving an underwater foundation at a low cost. Meanwhile, the surrounding environment is kept at a good state during the over-water construction process. The front end of a rotary shaft (20) is provided with a stirring blade (22). A cylindrical pollution-proof frame (30) with a top (31) is mounted to cover the stirring blade, so that the rotary shaft is driven to move up and down. On one hand, solidating materials are discharged from one side. On the other hand, the underwater foundation (C) is improved through the stirring and mixing process of the stirring blade by means of the ground base improving apparatus (10). A plug-in hole (33) for the insertion of the rotary shaft is arranged at the top of the cylindrical pollution-proof frame. The sealing material (34) is arranged to seal gaps among the plug-in hole and the rotary shaft. In addition, a vent hole (36) is arranged at the top of the cylindrical pollution-proof frame. A changeover valve (37) is arranged to turn on / off the vent hole.

Description

technical field [0001] The present invention relates to a preferred ground improvement device for underwater construction for ground improvement while preventing the spread of polluted water generated when improving underwater ground, and a ground improvement method using the same. Background technique [0002] In the case of carrying out water construction on the underwater foundation, the surrounding area is polluted due to the flying of sediment caused by stirring and mixing, but as a pollution diffusion preventing device for preventing the diffusion of the polluted water, there are known Figure 12 shown device (for example, refer to Patent Document 1). [0003] Such as Figure 12 As shown, this contamination diffusion preventing device 1 includes a cylindrical body 2 whose upper surface is sealed by a top wall 3 having a truncated conical inclined surface 3 a and whose lower surface is open. In the center of the top wall 3 of the cylindrical body 2, an insertion hole 4 ...

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Problems solved by technology

[0007] However, in the conventional pollution diffusion prevention device 1, there is a gap between the insertion hole 4 of the top wall 3 and the rotation shaft 8, and the plurality of drainage holes 5 formed on the inclined surface 3a of the top wall 3 are not blocked. Closed, so when improving the underwater foundation, the external water will easily flow into the cylindrical body 2 from the lower end of the side wall 6 of the cylindrical body 2 sunk into the bottom of the water and the gap at the bottom of the water, and the external water will flow into the cylindrical body 2 In this case, the polluted water in the cylindrical body 2 leaks from the insertion hole 4 and the drain hole 5 of the top wall 3 to the outside and diffuses to the periphery, making it difficult to reliably prevent the contamination from spreading and deteriorating the surrounding environment.

[0008] In addition, Patent Document 2 discloses that a sliding bearing of a waterproof structure is provided on the top plate of a box-shaped structure with an open lower surface to prevent the spread of pollutants, and the drive shaft is passed through the sliding bearing to prevent contamination of water from passing through the drive shaft of the top plate. A device that leaks outward from the surrounding space, but because the check valve that discharges the internal water to the outside when the device for preventing the diffusion of pollutants is sunk into the bottom, and the device that prevents the diffusion of pollutants from the bottom, the external The check valve for introducing the water into the inside is indispensable, so the structure becomes complicated and the cost increases accordingly. In addition, in the structure where the water enters and exits the inside and outside of the pollutant diffusion prevention device, it is difficult to displace the water due to the water pressure. Contaminant diffusion prevention device sinks or lifts smoothly to the bottom of the water

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