JPS62164912A - Method and apparatus for improving ground under water - Google Patents

Abstract

PURPOSE:To prevent the pollution (or mudding) of water as well as raise the stirring efficiency of a ground improving agent by pressurizing the inside of a casing. CONSTITUTION:A screw driver 17 is attached in a vertically movable manner to a leader 14 erected on a working machine 10. A screw 18 having an injecting hole 22 for a ground improving agent is turned, and while excavating the ground, a groove improving agent is injected. The lower end of a casing 19 covering the periphery of the screw 18 is contacted with with ground under water, compressed air is charged into the casing 19, and while discharging water in the casing 19, the improving agent is injected. The stirring efficiency of the improving agent can thus be raised, the hardening of the improving agent can also be accelerated, and the intermixture of the improving agent into water can be avoided. The pollution (or muddling) of water can be prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an underwater ground improvement method and apparatus.

[Conventional technology]

In the conventional underwater ground improvement method, a screw drive device is attached to a leader installed on a pontoon floating on the water surface or a self-propelled super wetland work device so that it can be raised and lowered, and this screw drive device As shown in Fig. 4, a screw having a hole for injecting a ground improvement material such as cement milk is rotated, and while excavating the ground G below the water surface with the screw 1, cement milk, etc. is injected from the tip of the screw 1. The ground is improved by injecting and stirring the soil improving material and letting it harden.

(Problems to be Solved by the Invention) However, in the above case, there is a problem in that the ground improvement material mixes into the water, reduces the stirring efficiency, pollutes the water quality, and causes pollution.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an underwater soil improvement method and apparatus that improves the stirring efficiency of soil improvement material and prevents water pollution.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention has a first invention that rotates a screw having a hole for injecting a soil improvement material by a screw drive device that is movably provided on a leader installed on a working machine,
In an underwater ground improvement method that excavates underwater ground and injects a ground improvement material, the lower end of the casing that covers the outer periphery of the screw is grounded on the underwater ground, and the inside of the casing is pressurized with air to drain the water inside the casing. The second invention is an underwater ground improvement method characterized by excavating the underwater ground and injecting a soil improvement material, and the second invention is an underwater ground improvement device for carrying out the above method, in which a screw is attached to a leader installed upright on a work machine. In an underwater ground improvement device that includes a drive device and a screw that is rotated by the screw drive device and has a hole for injecting a soil improvement material so as to be movable up and down, a casing that covers the outer periphery of the screw is provided at a lower part of the screw drive device. The casing is characterized in that it is provided with an air compressor that pressurizes the inside of the casing.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 3.

The ultra-wetland working machine 10 is a self-propelled type that can travel on muddy terrain, shallow water channels, etc. with a lower traveling body 11.
A bracket 15 of a leader 14 is pivotally connected to a front bracket 13 at the front of an upper revolving body 12 provided on the upper part of the revolving structure 1, and a backstay 16 supports the leader 14 so as to be able to rise and fall.

A screw drive device 17 is provided on the leader 14 so as to be movable up and down, and a screw 18 that rotates by the drive of the screw drive device 17 and a casing 19 that covers the outer periphery of the screw 18 are provided below the screw drive device 17. ing.

The screw 18 is in the shape of a vibrator with a ground improvement material injection port formed in the center, has a slurry swivel 20 at the top for injecting a ground improvement material such as cement milk, and has an excavation tool 21 at the bottom tip. An injection port 22 is formed for injecting the ground improvement material into the hole excavated by.

The casing 19 is slightly longer than the entire length of the screw 18, and its upper part is hermetically opened by the screw driving device 17, and inside the casing 19, the piping 24 of the air conditioner breech nut 23 disposed on the upper revolving body 12 is connected to the control valve 25. connected via.

Air compressor unit 23 is air compressor unit 2
6, a water trap 27, a relief valve 28, and a pressure regulator 29.

To explain the underwater ground improvement method using the ultra-wetland working machine 10 configured in this way, first, the screw drive device 1
7 and lower the casing 1 as shown in FIG.
While grounding the casing 1 to the ground IG under the water surface, air sent from the air converter 1 unit 23
The inside of the casing 19 is pressurized, the water inside the casing 19 is discharged, and as shown in FIG. , improve the ground by stirring and hardening the ground improvement material.

Since the underwater ground is improved in this way, the agitation efficiency of the soil improvement material is improved, and since the soil improvement material does not come into contact with water, hardening is accelerated, and water pollution caused by the soil improvement material is prevented. .

〔Effect of the invention〕

As described above, the present invention provides an underwater ground improvement device in which a casing that covers the outer periphery of the screw is provided at the bottom of the screw drive device, and the inside of the casing is pressurized with air supplied from an air compressor to discharge water inside the casing. Since the work is carried out while the work is being carried out, it is possible to improve the stirring efficiency of the ground improvement material and to accelerate the hardening of the ground improvement material, and since the ground improvement material does not mix into the water, it is possible to prevent water pollution.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a front view of a working machine for super wetlands, and FIGS. 2 and 3 are front views showing an underwater ground improvement method according to the present invention, respectively. , FIG. 4 is a front view showing a conventional ground improvement method.

Claims (1)

[Scope of Claims] 1. A screw drive device that is movable up and down on a leader installed on a working machine rotates a screw having an injection hole for the ground improvement material, excavates the underwater ground, and injects the ground improvement material. In the underwater ground improvement method, the lower end of the casing that covers the outer periphery of the screw is grounded on the underwater ground, and the inside of the casing is pressurized with air to drain the water inside the casing while excavating the underwater ground to obtain the ground improvement material. An underwater ground improvement method characterized by injecting. 2. A screw drive device is attached to the leader installed on the work machine,
In the underwater ground improvement device, the screw is rotated by the screw drive device and has a hole for injecting a soil improvement material, and the screw is movable up and down. An underwater ground improvement device that is equipped with an air compressor that pressurizes the inside.