JP2005036519A - Foam shielding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foam shielding method which is excellent in construction efficiency, construction cost, and minimization of environmental load. <P>SOLUTION: According to the foam shielding method, a foaming device generates foam by using a foaming agent as a main raw material, and excavation is carried out while the generated foam is fed to a working face 301 and a chamber 211. In the method, the foam is generated by feeding the foaming agent 101 in the form of powder or granules to the foaming device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bubble shield method.

  An air bubble shield method has been proposed which improves the mud pressure shield method that stabilizes the face by pouring mud into the face or chamber. This bubble shield method is a method in which a bubble generating device generates bubbles using a foaming agent as a main raw material, and advances the excavation work while injecting the bubbles into a face or a chamber.

As a conventional example of this bubble shield construction method, for example, in a method of digging a mechanical shield, a step of supplying bubbles generated by foaming a liquid containing a foaming agent to at least one of the face face and the earth pressure chamber; Stirring and mixing the excavation shear and air bubbles taken into the earth pressure chamber to create an excavation shear that has fluidity and water-stopper including air bubbles, and the earth pressure of the face by the excavation shear including air bubbles And a mechanical shield excavation method using a foaming agent (see Patent Document 1), which includes a step of excavating the face while resisting groundwater pressure and a step of discharging excavation shear from the earth pressure chamber. .
JP-A-5-202893

  However, since the foaming agent conventionally used in the bubble shield method is a liquid, several problems remain. For example, as a container for carrying and carrying in a foaming agent, it was necessary to use a metal-made large sealed container such as a drum can. For this reason, there has been a considerable amount of labor and cost when securing transportation means and storage locations, or when collecting and discarding containers after use. In addition, since conventional foaming agents that are liquids are mixed with antifreeze solution that prevents freezing in winter, BOD (biochemical oxygen demand) and COD of cellular soil are caused by organic components contained in antifreeze solution. (Chemical oxygen demand) was getting worse.

  Then, this invention is made | formed in view of the said subject, and it aims at providing the bubble shield construction method excellent in the surface of construction efficiency, construction cost, and a low environmental load.

  The bubble shield method of the present invention that solves the above problems is the bubble shield method in which the bubble generating device generates bubbles using a foaming agent as a main raw material, and advances the excavation work while injecting the bubbles into the face or chamber. The present invention is characterized in that bubbles are generated by supplying powder or granular foaming agent to the bubble generating device (first invention).

  The second invention is characterized in that the bubble generating device is installed on the ground, in an excavator, or in an excavation tunnel.

  In addition, the problems disclosed by the present application and the solutions thereof will be clarified by the embodiments of the present invention and the drawings.

  According to the present invention, it is possible to provide a bubble shield method excellent in construction efficiency, construction cost, and low environmental load.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a bubble shield method according to the present embodiment. The bubble shield method according to the present invention is a method in which a bubble generating device generates bubbles using a foaming agent as a main raw material, and advances the excavation work while injecting the bubbles into a face or a chamber. It is characterized in that bubbles are generated by supplying body or granular foaming agent.

  As shown in the figure, a foaming agent storage tank 102 in which a foaming agent 101 of powder or granules is stored in a building 100 in a ground portion where shield excavation is performed underground. Since the foaming agent 101 here is a powder or a granular material, it is not necessary to store it in a drum can until it is transported to the storage tank 102, and it can also be stored in a simpler container or bag. . Moreover, the size and capacity of the storage container can be arbitrarily determined according to the handling ability of the transport vehicle, the transport machine, and the manpower, and the transport cost and efficiency can be improved as compared with the conventional case. Furthermore, if the storage container or the like employs a bag or the like that can be easily reduced in volume, labor and cost after the storage can be greatly reduced.

  The foaming agent storage tank 102 includes a transport mechanism 103 that handles the foaming agent 101 in the tank, and can transport the foaming agent 101 to the dissolution tank 107. Water 104 is pumped from the water tank 105 through the pump 106 to the dissolution tank 107.

  The powder or granular foaming agent 101 and water 104 combined in the dissolution tank 107 are stirred by an agitator 108 to form a foaming material 109. For example, the mixing ratio of the foaming agent 101 and the water 104 mixed to form the foaming material 109 is 0.6: 99.4.

  Subsequently, the foaming material 109 is pumped to the foaming material storage tank 111 by the pump 110 and is appropriately stirred by the agitator 112 to maintain the properties. And it is supplied to the said shield machine 200 through the transfer path | route 115 according to the amount of bubbles used with the shield machine 200. FIG. The generation control of the foaming material 109 so far is realized by the foaming material generation control device 113 such as a computer equipped with a control program.

  In the shield machine 200, the supplied foaming material 109 is stored in the underground storage tank 201, and the foaming material 109 is pumped from the pump 202 to the foaming device 204 via the supply path 203. In addition, air is supplied to the foaming device 204 from the compressor 205 via the supply path 206. The foaming material 109 and the air supply to the foaming device 204 are executed by an injection unit 208 controlled by an injection control device 207. In addition, the injection control device 207 functions based on instruction information from the user received by the control panel 209.

  In the foaming apparatus 204, the foaming material 109 is foamed into bubbles. As the foaming mechanism provided in the foaming apparatus 204, various conventionally proposed foaming mechanisms can be arbitrarily selected. The bubbles are injected into the face 301 of the ground 300 and the chamber 211 through the hole 210. On the other hand, the shield machine 200 rotates the cutter bit 212 to cut the face 301, and proceeds with the excavation process. Foam soil (drilling shear including bubbles) generated at this time is collected from the chamber 211 by the screw conveyor 213. The collected cellular soil is conveyed to the shear steel wheel 215 by the belt conveyor 214. At this time, the antifoaming agent 216 is extracted from the antifoaming agent tank 218 by the pump 217 and sprayed onto the cellular soil on the belt conveyor 214. By spraying this antifoaming agent 216, the bubbles in the cellular soil are defoamed.

  The defoamed cellular soil returns to the excavated soil. However, this excavated soil does not contain the antifreeze component (which includes a liquid foaming agent) that has been included in the past, and does not require the above-described treatment in consideration of BOD or COD in the subsequent treatment steps. Therefore, the processing cost can be reduced as well as the material cost of the antifreeze liquid. Moreover, there is no need to worry about the deterioration of BOD and COD in the surrounding environment.

  In the above, the function of storing substances necessary for generating bubbles, such as the foaming agent 101 and the foaming material 109, the function of generating bubbles using the substances, and the function of providing the generated bubbles to the shield machine 200 In other words, an example in which a device having the above functions, that is, the bubble generating device of the present invention, is separated and arranged in the building 100 on the ground, the shield machine 200, or the tunnel where the shield machine 200 operates is shown. However, all or some of the functions may be aggregated and installed in the ground (the building 100), the shield machine 200 (digging machine), or the digging tunnel.

  Although the present embodiment has been described above, the above examples are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

It is a figure which shows the bubble shield construction method in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Building 101 Foaming agent of powder or granule 102 Foaming agent storage tank 103 Transport mechanism 104 Water 105 Water tank 106, 110 Pump 107 Dissolution tank 108, 112 Agitator 109 Foaming material 111 Foaming material storage tank 113 Foaming material Generation control device 115 Transfer route 200 Shield machine 201 Underground storage tank 202, 217 Pump 203, 206 Supply route 204 Foaming device 205 Compressor 207 Injection control device 208 Injection unit 209 Control panel 210 Hole 211 Chamber 212 Cutter bit 213 Screw conveyor 214 Belt conveyor 215 Shear steel wheel 216 Defoamer 218 Defoamer tank 300 Ground 301 Face

Claims (2)

In the bubble shield method in which a bubble generating device generates bubbles using a foaming agent as a main raw material and advances the excavation work while injecting the bubbles into the face or chamber, a powder or granular foaming agent is added to the bubble generating device. A bubble shield method characterized by supplying bubbles to generate bubbles. 2. The bubble shield method according to claim 1, wherein the bubble generating device is installed on the ground, in an excavator, or in an excavation tunnel.

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