JP4625655B2 - Groundwater purification wall construction equipment - Google Patents

Description

  The present invention relates to an apparatus and method for purifying underground polluted water, and in particular, to purify a purifying wall containing iron powder as a purifying material in the basement in order to purify groundwater containing halogen pollutants. The present invention relates to an improvement of a construction apparatus and a purification wall construction method using the construction apparatus.

A method for purifying groundwater contaminated with halogen pollutants using a metal such as iron powder has been known.
For example, according to the purification method as described in JP-T-5-501520, for the underground layer where the contaminated groundwater exists, the iron powder for purification and the sand are disposed at a position perpendicular to the flowing direction of the contaminated water. It is assumed that a main body (purification wall body) made of a mixture of the above is constructed.

In this case, the purification wall is constructed by excavating a trench (groove hole) in a necessary portion of the underground layer and filling the trench with a mixture of iron powder and sand constituting the purification wall body. And although formation of such a trench is performed using a general trench excavator, it is disclosed that it is possible also by a drill and jet method.
Here, with the drill and jet method, first, a series of test holes (bore holes) are formed at an appropriate interval with respect to the target ground. Next, pipes that reach the bottom are inserted into the respective bore holes, a mixture of iron and gravel soil and other materials is injected, and then the pipes are gradually removed.

As another known example, Japanese Patent Application Laid-Open No. 2000-263068 is known.
The invention described in this document is also a groundwater purification method in which a wall-like region composed of a metal reducing agent and fine aggregates such as dredged sand is constructed in the underground, which is a contaminated water flow area.
The groundwater purification wall according to the present invention will be described with reference to FIG.
For example, the contaminated groundwater 3 flowing down from the pollution sources 2 and 2 of a factory or the like is guided to the purification wall by the pair of water blocking walls 4 and 4 and purified by the metal reducing agent constituting the permeable groundwater purification wall 5.

Here, the permeable groundwater purification wall 5 can be filled with a purification material comprising the metal reducing agent and fine aggregate in a trench (groove hole) formed by, for example, a trench excavator. Is performed by creating the column group 6. That is, although the concrete description for constructing | cleaning a wall is not made | formed, the cylinder group 6 is comprised of each cylinder 7-7 by a permeable purification | cleaning material, and these cylinders 7-7 are intermittently arrange | positioned in line It is a thing.
Further, according to another embodiment, a wall-like region containing the above-described permeable purification material is disposed in the ground, and the wall-like region is formed from a chelate resin in a trench (groove hole) formed by trench excavation. This is filled with a permeable purification material.
Japanese Patent Publication No. 5-501520 JP 2000-263068 A

  As described above, in the construction method of a groundwater purification wall body using a conventionally known iron powder and aggregate, for example, a trench is formed using a trench excavator, and the iron powder and aggregate are formed in the trench. In order to fill the purification wall body constituting material consisting of the above, there is a limitation that the position for constructing the groundwater purification wall body, that is, the depth from the ground surface is limited, and it is difficult to construct the purification wall deep underground. there were. In addition, the width of the trench formed by the trench excavator is considerably large, the thickness of the purification wall to be constructed is increased, and there are drawbacks such as the use of a large amount of purification material in excess of the necessary amount, and purification. There was a problem that the water permeability of the wall decreased.

Furthermore, when using a group of cylinders made of a large number of cylindrical permeable materials, normal underground water channels (pulses) remain between the cylindrical purification material layers, or in the conventional soil between the cylinders. There is a drawback that a groundwater channel is formed, and contaminated groundwater flows down the existing groundwater channel (pulse) or a waterway formed in the conventional soil, which may not be purified.
Therefore, in order to eliminate these disadvantages, the inventors of the present invention have conducted experimental research on the relationship between the degree of purification of contaminated groundwater and the thickness of the purification material wall necessary for this, as a result of pure iron conversion in the mixed purification material. It was found that a thickness of the purification material layer of about 100 mm is sufficient. That is, for example, when mixing iron powder and aggregate, it has been found that the amount of iron powder alone may be about 100 mm or more in thickness.

From these results, the present invention eliminates the disadvantages of the conventionally known methods for purifying underground contaminated water, and can easily construct a purifier wall body for the underground water layer at the required depth, and can be used to purify iron powder and bone. It is an object of the present invention to provide an apparatus for efficiently constructing a purification material wall having an appropriate thickness by eliminating wasteful use of materials.
Specifically, the present invention provides a purification wall body construction apparatus and construction method that can construct a purification wall body at a high depth using a multi-axis auger having a novel configuration, and that has extremely good workability.
In addition, the purification wall body can be constructed as thin as possible to ensure sufficient purification capacity and permeability, and a special earth removal device is provided in the newly constructed multi-axis auger to improve the workability of the purification wall body construction. It is intended.

  The characteristic configuration of the present invention is an apparatus for constructing a groundwater purification wall using a multi-axis auger, and the multi-axis drilling shaft of the apparatus is provided with a spiral blade over its entire length, The multi-axis excavation shaft has a connecting device for connecting the excavating shaft bodies, and at least the lowest end of the connecting device is composed of a pair of connecting tools, and each connecting tool includes a plurality of bearing components and connecting vertical plates. A minimum thickness of the groundwater purification wall is determined by the width dimension of the auxiliary excavation member portion, and the multi-axis excavation shaft of the multi-axis auger has a horizontal plate and a substantially flat plate. An apparatus for constructing a groundwater purification wall, characterized in that it is installed on a ground surface in a state in which a soil removal device constituted by a U-shaped semi-cylindrical body is fitted and surrounded.

  According to the purification wall body building apparatus according to the present invention, since it has a multi-axis drilling shaft having spiral blades over the entire length of its shaft, a relatively thin and deep drilling groove can be easily formed, It is possible to reliably construct a depth purification wall body. Further, since the spiral blades provided on each excavation shaft body do not overlap each other, and the excavation shaft bodies are connected by a special auxiliary excavation member, the ground between the excavation shaft bodies can be reliably and Drilling holes can be opened to a certain width, and walls with as wide a width as possible can be constructed at a high depth.

The purification wall formed by the construction apparatus of the present invention or the excavation groove therefor can be constructed using a multi-axis auger with a considerably small outer diameter, and the soil between each excavation shaft can be broken and excavated by an auxiliary excavation member. Therefore, the amount of iron powder and aggregate constituting the purification wall body can be reduced, the use of useless iron powder can be prevented, the necessary minimum thickness can be secured, and water permeability can be sufficiently secured. So purification capacity is improved.
Furthermore, according to the construction method of the purification wall body of the present invention, it is possible to construct a high-depth wall body quickly and efficiently, and the processing of excavation soil is extremely easy.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is an explanatory plan view showing an operation process for constructing a purification wall body for groundwater purification according to the present invention, showing a triaxial auger 10 unique to the present invention to be described later and a generally known backhoe 40. ing. The three-axis auger 10 unique to the present invention includes a base machine 11 and a reader 12 and a three-axis drilling shaft 15 (to be referred to as an “excavation axis” hereinafter). And a soil removal device 30. In addition, the code | symbol 41 in a figure is a work groove | channel for discharging | emitting the discharge soil excavated and excavated by the triaxial auger 10 which concerns on this invention, and the excess purification wall body structural material with which it filled.

  FIG. 2 is a front view of the triaxial excavation shaft 15 for the triaxial auger 10 shown in FIG. The three excavation shaft bodies 16 to 16 are of a known type, and the respective shafts are included in the present invention over the entire length of the shaft body except for the connecting portions 17A and 17B of the respective shafts. Specific spiral blades 18 to 18 are fixed. Moreover, the discharge port which is not shown in figure with the normal excavation bits 19-19 is provided in the front-end | tip of each excavation shaft body 16-16, and the mixture of a slurry or iron powder, and an aggregate can be discharged.

  Here, in the illustrated embodiment, the spiral blades 18 to 18 are continuously provided over the entire length of each excavation shaft body 16 to 16. However, as other embodiments, the respective excavation shaft bodies 16 to 16 are provided. On the other hand, the part which has a spiral blade and the part which does not have a spiral blade can also be provided alternately. However, even in such an embodiment where the spiral blades are not continuous, the spiral blades provided in the adjacent excavation shaft bodies are provided so that the adjacent spiral blades overlap each other in the vertical direction when viewed from the side. It is important to ensure that the excavated soil that has been pushed up by the lower spiral wing is pumped up by other adjacent higher spiral wings.

FIG. 3 is a cross-sectional view of the triaxial excavation shaft 15 shown in FIG. 2 particularly at the position of the connecting portion 17B on the lower side, and shows one characteristic configuration in the purification wall body building apparatus of the present invention.
In FIG. 3, a connecting device 20 unique to the present invention is provided in a lower connecting portion 17B that integrally connects the excavation shaft bodies 16 to 16, and a pair of connecting devices 21, as will be described in detail later. 21. Each of these connectors 21 and 21 has semicircular bearing constituent members 22 to 22 that rotatably support the excavation shaft bodies 16 to 16. And each bearing structural member 22-22 is projected and extended in the horizontal direction with respect to the connection vertical plate members 23 and 23, each side surface of this connection vertical plate member, and the said semicircle bearing structural members 22-22. The auxiliary excavation members 24 and 24 are formed. Here, the structure of the other parts excluding the auxiliary excavation members 24, 24 is substantially the same as a means generally called a screw fixing band.

  4 and 5 show the structure of the above-described connecting device 20 provided in at least the lower connecting portion 17B. In the same figure, a pair of couplers 21 and 21 are each made up of three bearing constituent members 22 to 22, connecting vertical plate members 23 and 23 for connecting them, and orthogonal to the connecting vertical plate members 23 and 23. The auxiliary excavation members 24 and 24 are combined. These connecting vertical plate members and auxiliary excavation members are obtained by joining different plate members or the like by welding or the like. Further, a connecting vertical plate member similar to the connecting vertical plate member 23 is stretched further outward than the bearing constituent members 22 and 22 on both outer sides.

  The auxiliary excavation members 24 and 24 shown in FIGS. 4 and 5 are welded to the connecting vertical plate members 23 and 23 and the bearing constituent members 22 to 22 so as to be orthogonal to the connecting vertical plate members 23 and 23. Although it is comprised by the horizontal plate member couple | bonded by etc., it can be set as a vertical plate member as other embodiment. In this case, for example, a plate material similar to the connecting vertical plate member is used, and this is joined in the vertical direction to the respective side end positions of the auxiliary excavation members 24 to 24 shown in FIG. Accordingly, the auxiliary excavation members 24 to 24 using the vertical plate members are welded and fixed to the bearing members 22 to 22 only at the respective end portions. An opening is formed between each auxiliary excavation member 24, 24 and the connecting vertical plate member 23, 23. When the auxiliary excavation members 24 and 24 having such a configuration are used, the overall strength of the coupling device 20 is ensured by appropriately selecting the thickness and the vertical dimension of the plate material. In addition, it is also possible to increase the plate thickness of the members 23 and 23 to make pseudo auxiliary drilling members.

Therefore, by combining the pair of connectors 21 and 21 having such a structure and fastening each of these connecting vertical plate members 23 and 23 with bolts 25 as shown in FIGS. The excavation shaft bodies 16 to 16 can be pivotally supported at the connecting portion 17B.
The connecting tool 21 in the upper connecting part 17A may have the same structure as that of the connecting part 17B, or may be a conventionally known connecting tool, for example, a screw fixing band.

  As described above, each of the connecting vertical plate members 23, 23 is fixed to the bearing constituent members 22, 22. However, the auxiliary excavation members 24, 24 having the characteristic structure of the present invention are further connected to the connecting vertical plate members 23, 23. 23 and the bearing component members 22 and 22 are coupled to each other by welding or the like, or are coupled only to the bearing component members 22 and 22. And, as will be described later, the auxiliary action of the auxiliary excavation members 24, 24 is connected to the adjacent bearing constituent members 22, 22 or to the connecting vertical plate members 23, 23, as described later. A portion of the ground soil that has not been directly excavated and destroyed by the excavating bit is excavated and destroyed, and all of the soil can be unloaded by a spiral blade fixed over the entire length of the excavating shaft 15. Further, the minimum thickness of the excavation area is secured by the thickness of the auxiliary excavation members 24 and 24.

6 and 7 are a plan view and a side view of a soil removal apparatus used in the method for constructing a purification wall body according to the present invention.
As apparent from both drawings, the earth removing device 30 basically includes a horizontal plate 32 having a substantially U-shaped opening 31 having an opening on one end side thereof, and a U-shape of the horizontal plate 32. The opening 31 is inscribed and fixed, and is configured by a half-tubular body 33 that is substantially U-shaped in a plan view. The horizontal plate 32 and the half cylinder 33 are obtained by welding the cut or curved plate materials at the contact portion between the inside of the U-shaped opening 31 and the outer peripheral portion of the half cylinder 33, respectively. Is formed.

  As shown in FIG. 1 and FIG. 8 to be described later, such a soil removal device 30 is formed by using the substantially U-shaped half cylinder 33 of the soil removal device 30 as a drill shaft of a triaxial auger according to the present invention. 15 is used in a state of being inserted and surrounded from the side. In this case, as is apparent from FIG. 1, the horizontal plate 32 of the earth removing device 30 is placed on the ground surface across the work groove 41. Then, the excavated soil pumped up by the spiral blades 18 to 18 of the excavating shaft 15 is discharged only in one direction on the work groove 41 along the opening 31 of the earth removing device 30.

FIG. 8 explains the construction method of the purification wall body according to the present invention, and schematically shows the work of actually constructing the wall body.
In this figure, only the main part of the construction apparatus of the present invention is shown. 2 is driven by the base machine shown in FIG. 1, and the ground surface GL at the working position is grounded in the direction of the arrow in the figure. Drilling is performed. For example, the soil excavated by three excavation shafts is all unloaded by the spiral blades 18 to 18 provided over the entire length of the excavation shaft bodies 16 to 16 of the excavation shaft 15 according to one embodiment. Then, it is discharged toward the soil removal work groove 41 excavated in advance by the soil removal device 30, and this is accumulated in a dump truck or the like by the backhoe 40 and carried out.

  Here, for example, as shown in FIG. 2, the excavation shaft 15 is provided by connecting spiral blades 18 to 18, or even in other embodiments, at least the excavation shaft bodies 16 to 16 are provided. Since the spiral wings 18 to 18 are configured to overlap in the vertical direction, all excavated portions of the soil are discharged and discharged, as is apparent from the description in FIGS. The portion that could not be completely excavated by the excavation bits 19 to 19 provided on the excavation shaft bodies 16 to 16, that is, the soil of the adjacent portions of the spiral blades 18 to 18 provided on each excavation shaft, is also In particular, it is broken by the connecting vertical plate members 23 and 23 and the auxiliary excavation members 24 and 24 and is discharged by the spiral blades 18 to 18.

  The excavated soil excavated and excavated in this way is all discharged to the side of the opening 31 of the semi-cylindrical body 33 by the earth removing device 30 described with reference to FIGS. Therefore, for example, if the excavated soil guided and discharged into the work groove 41 is scraped by the backhoe 40 and loaded on a dump truck or the like, the excavation work has already been completed during the excavation work or the purification material has already been filled. It is possible to prevent the excavation soil from being mixed into the completed part (left side from the excavation shaft 15 in FIG. 8).

  That is, in FIG. 8, excavation work is sequentially performed from the left side of the drawing, and the excavation shaft is followed by the first excavation and purification material filling process in the same manner as the construction work of the underground wall by the normal triaxial earth auger. The next second excavation and purification material filling process is performed at intervals of one body. Then, the remaining intermediate portion is constructed through the excavation shafts on both sides of the third excavation shaft through the excavation holes before and after the first and second excavation and filling portions. . By repeating such an operation, a series of purification walls are formed from the left side to the right side in FIG.

Next, one embodiment of the purification wall construction apparatus according to the present invention will be described.
3 to 5 show an excavation shaft 15 which is one embodiment of the characteristic configuration of the present invention. The excavation shafts 16 to 16 are connected to each other and are not directly excavated by the excavation shaft itself. Although the portion of the soil is destroyed, the soil is unloaded, and a wall hole is formed for filling the purification material, the dimensions of each part of the excavation shaft can be set as follows.
That is, the outer diameter of each excavation shaft body 16 to 16 is set to 241.8 mm, the outer diameter of the spiral blades 18 to 18 is set to 440 mm, and the distance between the excavation shaft bodies 16 and 16 is set to 450 mm. In this embodiment, the outer diameters of the excavation bits 19 and 19 on both sides are 460 mm, and the outer diameter of the central excavation bit 19 is 450 mm.

  Accordingly, also in the connecting member 20 shown in FIGS. 4 and 5, the distance between the shafts between the bearing constituent members 22 and 22 is 450 mm. Moreover, the horizontal width of the connection vertical board member 23 which comprises the connection tools 21 and 21 can be 1343.5 mm, a vertical width can be 180 mm, and the full width of the auxiliary excavation members 24 and 24 part shown in FIG. can do. By configuring in the dimensions of such an embodiment, it is possible to secure a purification wall thickness of 300 mm, which is a minimum thickness corresponding to at least the entire width of the auxiliary excavation members 24 and 24. The connecting vertical plate member 23 is an iron plate having a thickness of about 25 mm, and the auxiliary excavation member 24 is also an iron plate having a thickness of about 32 mm.

An embodiment of the earth removing device 30 shown in FIGS. 6 and 7 is as follows.
That is, the horizontal plate 32 which is one flat plate material constituting the earth removing device 30 has an outer dimension of 1750 × 1500 mm and an inner width dimension of the U-shaped opening 31 of 500 mm. Further, the height of the half cylinder 33 is 1300 mm, and the radius of the curved portion is R = 250. And both these members are comprised with the board | plate material of thickness 20mm. In addition, since the width dimension of the horizontal board 32 is installed ranging over the said earth removal groove | channel 41, it is on condition that it is wider than the groove width at least.

  Next, the structure of the filling purification material constituting the purification wall will be described. In the construction method of the purification wall according to the present invention, the amount of iron powder as a reactant with respect to the soil of the original ground is 5 by weight. ~ 100% to be introduced. Therefore, when the purification wall construction apparatus according to the above embodiment is used, the minimum thickness of the purification wall is 300 mm (corresponding to the total width of the auxiliary excavation members 24 and 24 shown in FIG. 5 or the width between both ends). Therefore, if the pure iron equivalent thickness is 100 mm, the ratio of the iron powder and the aggregate constituting the purification wall is that the aggregate 200 mm is the minimum value with respect to the iron powder 100 mm in terms of thickness. Become.

  Thus, the purification material arbitrarily selected within the weight ratio of 5 to 100% is filled within a range in which an iron powder layer thicker than the minimum thickness of 100 mm can be secured in terms of pure iron. However, since the amount of iron powder mixed in the purification wall only needs to be 100 mm or more in terms of pure iron as described above, the minimum thickness of the purification wall, the iron powder and bone in the purification material to satisfy this condition Needless to say, the mixing ratio with the material is arbitrarily determined.

Here, the iron powder which is a reactive agent adjusts the particle size to 0.2 mm-5 mm, and uses sand or crushed stone of 0.2 mm-5 mm as an aggregate. In addition, when supplying the purification material, which is a mixture of the reactant and the aggregate, into the ground, the slurry is supplied using water.
However, in this case, a measure for preventing the breathing of the mixture is necessary. As a preventive measure, guar gum is mixed in the slurry to increase the viscosity of the slurry and prevent breathing. The mixing amount of this guar gum was suitably 0.2 to 2% by weight with respect to water.

It is plane explanatory drawing of the construction apparatus of the purification | cleaning wall body of this invention. It is a front view of the triaxial excavation axis concerning the present invention. It is sectional drawing in the connection part of the excavation shaft shown in FIG. It is a front view of the connection member of a digging shaft. It is a top view of the connection member of a digging shaft. It is a top view of a soil removal apparatus. It is a front view of a soil removal apparatus. It is explanatory drawing of the construction construction method of the purification | cleaning wall body of this invention. It is explanatory drawing of a conventionally well-known purification method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Triaxial auger 11 Base machine 15 Excavation shaft 16 Excavation shaft body 17A, 17B Connection part 18 Spiral blade 19 Excavation bit 20 Connection device 21 Connection tool 22 Bearing component member 23 Connection vertical plate member 24 Auxiliary excavation member 30 Earth removal device 31 Outline U-shaped opening 32 Horizontal plate 33 Half cylinder 40 Backhoe 41 Working groove

Claims (1)

An apparatus for constructing a groundwater purification wall using a multi-axis auger, wherein the multi-axis drilling shaft of the apparatus is provided with a spiral blade over its entire length, and the multi-axis drilling shaft is A connecting device for connecting the shafts, and at least the lowest end of the connecting device comprises a pair of connecting members, each connecting member having a plurality of bearing components, connecting vertical plate members, and auxiliary excavation members; The minimum thickness of the groundwater purification wall is determined by the width dimension of the auxiliary excavation member portion. Further, the multi-axis excavation shaft of the multi-axis auger includes a horizontal plate and a substantially U-shaped half cylinder. An apparatus for constructing a groundwater purification wall, wherein the groundwater purification wall is installed on the ground surface in a state in which the earth removal device configured by the above is fitted and surrounded.

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