JPH02285106A - Constructing underground continuous wall - Google Patents

Abstract

PURPOSE:To construct a thick-bodied underground continuous wall by forming adjoining column bodies with a plurality of excavating shafts equipped with churning blades rotating respectively in the opposite directions, and by burying stressing materials into each of overlapping column bodies that are formed spanning spaces between each of the adjoining column bodies formed continuously in a row. CONSTITUTION:Excavation is made into the earth with two excavating shafts rotating respectively in the opposite directions, and two column bodies 26a and 27a are adjoiningly made thereby in series being formed of consolidating agent injected thereto, and forming operations I1, I2... continue therewith. Then the forming operations II1, II2... proceed with making of the column bodies 26b and 27b so that they fill spaces provided between each pair of the column bodies 26a and 27a. The forming operations III1, III2... are further made to make the column bodies 26c and 27c that equally span spaces between the adjoining column bodies 26a nd 27a, and between 27a and 26b, and after making these overlapping column bodies 26c and 27c, stressing materials 19 and 20 are buried into the center of the column bodies 26c and 27c and an underground continuous wall is constructed therewith. Thereby improvement is made available for work efficiency as well as for balancing at the execution, and the degree of overlaps in each of the column bodies can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a construction method for an underground continuous wall used as an earth retaining wall or the like.

BACKGROUND OF THE INVENTION Conventionally, as methods for constructing underground continuous walls, there are two known methods: a method in which columns are formed one by one, and a method in which a plurality of columns are formed.

To explain the former construction method, first, a solidification agent is spouted out while rotating an excavation shaft with stirring blades, and this solidification agent is stirred and mixed with earth and sand to form a column. Bury stress material made of H-shaped steel. Next, a column is formed in the same manner as above so as to partially overlap the existing column, and the same stress material as above is embedded in this column. Thereafter, by repeating the same operations as above, an underground continuous wall can be constructed. Note that the stress material may be buried for each column depending on the required strength, or it may be buried for each desired number of columns.

To explain the latter construction method, this construction method uses a multi-shaft excavator, for example, by spouting a consolidation agent while rotating three excavation shafts with stirring blades.
This solidifying agent is stirred and mixed with earth and sand to form pillars that partially overlap each other, and the stress material is buried in the desired pillars. below,
The operation can be performed continuously to create an underground continuous wall, or the above operation can be performed at desired intervals, and then the above operation can be performed to fill in the spaces between the existing multiple consecutive columns to create an underground continuous wall. can be created.

Problems to be Solved by the Invention However, among the above-mentioned conventional methods, the construction method in which columns are formed one by one is inferior in work efficiency, and since one excavation shaft rotates only in one direction, it is difficult to excavate. The balance during excavation is poor, the core is easily misaligned during excavation, and it is difficult to create a straight underground continuous wall. In addition, adjacent columns need to be overlapped with each other while avoiding stressed materials, and since the amount of overlap is small and the wall thickness of the overlapped part of the underground continuous wall is thin,
There may be cases where a reliable water supply effect cannot be obtained. Furthermore, since a stress material made of H-shaped steel is used alone, it is necessary to use a thick and large material in order to obtain the specified strength.
Not only is it expensive, but the thickness of the underground continuous wall becomes large.

On the other hand, the construction method of forming multiple columns at a time has the advantage of improving work efficiency, but since an odd number of excavation shafts are used, the number of excavation shafts with different rotation directions is different. Poor balance during excavation, the core tends to shift during excavation, making it difficult to create a straight underground continuous wall.

In addition, since the stirring blades on each excavation shaft need to avoid adjacent excavation shafts, the amount of overlap between the columns formed at the same time is small, and the overlap of subsequent columns with respect to the existing column is small. The amount is also small to avoid stressed materials, and the thickness of the overlapping part of the diaphragm wall is narrow, so a reliable water-stopping effect may not be obtained. Furthermore, as in the conventional example above, since a stress material made of H-shaped steel is used alone, it is necessary to use a large material in order to obtain the specified strength, which is not only expensive, but also requires continuous underground construction. The wall becomes thicker.

The present invention solves the problems of the prior art as described above, and not only improves work efficiency, but also improves the balance during excavation and creates a straight underground continuous wall. In addition, by increasing the amount of overlap between the pillars, it is possible to create a continuous underground wall with an almost uniform thickness throughout, and it is possible to obtain a reliable water-stopping effect. Provides a method for constructing a medium continuous wall, and also improves the strength of stress materials, as well as improving stress and obtaining a specified strength by using small and thin stress materials, thereby reducing costs. The purpose of the present invention is to provide a construction method for an underground continuous wall that allows the wall thickness of the underground continuous wall to be reduced.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to eject a solidifying agent while rotating an even number of excavation shafts having stirring blades in mutually opposite directions. Stir the binder with earth and sand to form columns adjacent to each other, repeat this operation to install adjacent columns in a row, and then repeat the above operation approximately equally between each two adjacent columns. This process is performed sequentially to form overlapping columns to make the columns continuous, and to embed the stress material in the desired column.

Further, the above-mentioned stress material is configured in a unit shape consisting of a plurality of stress material bodies and a connecting plate connecting these stress material bodies, and this unit-shaped stress material is formed into each set of overlapping columns. It was designed to be buried astride.

The stress material main body connects the central portions in the longitudinal direction of the opposing elongated plates with a perpendicular elongate plate, and the continuous plate has a length in the perpendicular direction to the opposing elongate plates in the stress material main body. Connect the connection part with the shaku plate in a diagonal direction,
It is preferable to bury the connecting plate so that the intersecting part of the connecting plate is located approximately at the center of the line connecting the central axes of the overlapping columns.

Further, it is preferable that the connecting plate connects the stress material bodies at a plurality of locations in the longitudinal direction.

action The effects of the above technical means are as follows.

Since the solidifying agent is ejected while rotating an even number of excavation shafts having stirring blades in opposite directions, the balance during excavation can be improved. Moreover, after arranging the adjacent columns, overlapping columns are formed in the same manner as above to almost evenly straddle between each two adjacent columns, and the columns are continuous. Since the overlapping columns do not overlap each other, there is no risk of being affected by buried stressed materials, and the overlapping amount of the columns is increased and the wall thickness of the overlapping part is thickened (so that the entire wall is almost uniform). It is possible to create thick underground continuous walls.

In addition, the strength of stressed materials can be improved by connecting multiple stressed material bodies with a connecting plate and using them as a unit. It is possible to use one that is smaller and thinner than wood.

Example The present embodiment will be described below with reference to the drawings.

First, the construction equipment used in the construction method of the present invention will be explained. Figure 1A is a schematic side view of the creation device, Figure 1B is a schematic front view of its main parts, Figure 2A is an enlarged view of the main parts of Figure 1B, Figure 2B is its bottom view, Figure C is l1c of Figure 2 A.
-IIc is a sectional view taken along the arrow.

As shown in FIGS. 1A and B and FIGS. 2A to C, a rotating body 2 is mounted on a traveling body 1 so as to be able to rotate. A vertical leader 3 is attached to the front side of the revolving structure 2, and the leader 3 is supported by a backstay 4. A guide 5 is provided along the vertical direction on the front side of the leader 3, and a drive device 6 is supported on the guide 5 so as to be movable up and down.
is suspended by a wire 7. A multi-axis device 8 linked to the drive device 6 is supported on the lower side of the drive device 6 so as to be movable up and down on the guide 5, and the multi-axis device 8 has an even number (two in the illustrated example) of hollow excavation shafts. The excavating shafts 9 are suspended and supported in parallel so that they can rotate in opposite directions, and each excavating shaft 9 has a spout 10 formed at its lower end for solidifying agent or the like. Each drilling axis 9
A spiral rocking blade 11 is used to excavate and stir the ground.
and plate-shaped stirrers X12 are installed alternately in the vertical direction. That is, the adjacent spiral rocking blades 11 rotate in opposite directions, the adjacent stirring blades 12 tilt in opposite directions, and the adjacent spiral rocking blades 11 alternately rotate the number of turns, In other words, the lengths of the stirring blades 12 are slightly different, and adjacent stirring blades 12 are installed so as to be slightly offset from each other in the vertical direction. An O-head 13 is attached to the tip of each excavation shaft 9. Adjacent rocking blades 11, stirring blades 12, and auger heads 13 are set so that the rotation loci of their outer edges do not overlap in a plane and are slightly separated from each other.

Adjacent excavation shafts 9 are rotatably inserted into the bearing portions 15 of the connecting member 14 at multiple locations in the vertical direction, and the excavation shafts 9
The spacing is kept constant. Bearing part 1
5 are connected by a plate-shaped portion 16 so as not to get in the way when excavating the ground as described later. Bearing part 1
The plate-shaped protrusion 17 is formed on the outside of the auger head 13 to fit within the rotation locus of the outer edge of the auger head 13, etc. Used for prevention.

A steadying device 18 is attached to the lower end of the leader 3, and each excavation shaft 9 is supported by this steadying device 18 so as to be rotatable and movable up and down.

Next, the stress material (core material) will be explained.

3 and 4 show an example of the stress material, with FIG. 3 being a perspective view and FIG. 4 being an enlarged plan view.

As shown in FIGS. 3 and 4, the stress material 19 is made of steel, and includes a plurality of (two in the illustrated example) stress material bodies 20 and a connecting plate 21 that connects these stress material bodies 20. It is constructed in a unit form. The stress material main body 20 has opposing elongated plates 22 whose central portions in the longitudinal direction are connected by an elongated plate 23 in a perpendicular direction! or H-shape, and the connecting portions between the opposing elongated plates 22 and the elongated plates 23 in the perpendicular direction in the stress material main body 20 are connected at multiple points in the longitudinal direction.
1, they are connected by welding so as to intersect in a diagonal direction. This connecting plate 21 may be welded to the stress material main body 20 in advance and transported to the construction site, or may be welded at the construction site.

FIG. 5 is an enlarged plan view showing another example of the stress material. In this example, the bent portion 21a at the end of each connecting plate 21 is a connecting portion of the long plate 23 closer to the long plate 22, and the bolt 24,
They are connected by a nut 25, and the other structure is the same as that of the above embodiment.

Note that the stress material 1 shown in FIG. 3, FIG. 4, or FIG. 5 above
9 is not limited to the above shape, for example, one connecting plate may be connected linearly between the long plates 22 and 23, or two connecting plates may be connected in parallel between the long plates 22 and 23. Various design changes can be made, such as by connecting them.

Next, a method for constructing an underground continuous wall according to the present invention using the above-mentioned construction device and stress material 19 will be explained.

FIGS. 6A to 6C are explanatory plan views showing a construction method for an underground continuous wall in the first embodiment of the present invention.

1 and 2, while operating the drive device 6 and lowering the multi-axis device e8 along the guide 5,
The two excavation shafts 9, the movement 'x11, the stirring X12, and the auger head 13 are rotated in opposite directions to excavate the ground.

At this time, in hard ground, excavation can be easily performed by spouting bentonite or the like from the spout 10 of the excavation shaft 9. Then, along with the excavation, the excavated soil is moved upward by the spiral moving blades 11, and here, the stirring blades 12
The excavated earth and sand can be stirred uniformly. During this excavation, as mentioned above, the two excavation shafts 9, the movable blades 11,
Since the stirring blades 12 and the auger head 13 are rotated in opposite directions, balance can be improved and misalignment can be prevented. When excavating to a predetermined depth, a solidifying agent instead of bentonite or the like is ejected from the spout 10 of the excavation shaft 9, and the excavation shaft 9 is pulled up while rotating and moving up and down. During this time, the excavated earth and sand are moved upward together with the solidifying agent by the spiral moving blades 11, and are stirred and mixed by the stirring blades 12. In this way, as shown in FIG. 6A, two columns 26a and 27a are formed adjacent to each other, in which the solidifying agent is stirred and mixed with the excavated earth and sand. Next, the above operation is repeated at predetermined intervals to form two columns 26a and 27a.

After completing the first forming steps 1, 2, 3, etc. of the column bodies 26a and 27a in this way, the same operation as above is performed as shown in FIG. 6B. A second column 26b is installed to fill the space between the existing columns 26a and 27a.
, 27b are formed by forming operations Ill, II2, ■3, . In this way, the adjacent columns 26a, 27a, 2
6b, 27b1... are arranged in a row. Next, as shown in FIG. 6C, between the two adjacent columns 26a and 27a,
72. Perform the above operation almost evenly across the space between 26b to form the overlapping columns 26c and 27c. After forming the overlapping columns 26c and 27c, the stresses shown in FIGS. 3 and 4 are applied to the overlapping columns 26c and 27c. Bury material 19. At this time, the duplication column 26c,
The stress material main body 2o is buried in the center of the connecting plate 27c, and the connecting plate 21 has a pillar body 26c whose intersection part at the center almost overlaps.
27c so that it is located in the center on the line connecting the central axes of the 27c. In the central part on the line connecting the central axes of the overlapping columns 26c and 27c, the distance between the columns 26c and 27c is the narrowest, and because they are brought close to each other, they are easy to collapse during excavation. It can be buried in The formation of the overlapping columns 26c, 27c and the embedding of the stress material 19 are performed sequentially at predetermined intervals like (1), (2), (3), etc. in the same way as above, and then these Existing duplication column 26c,
IVt between 27c.

Fill it in with IVz,... Therefore, it is possible to increase the amount of overlap by overlapping the columns 26 and 27 almost to the vicinity of the central axis, and increase the thickness of this overlapping part, thereby creating an underground continuous wall with approximately the same thickness. The water stopping effect can be improved. Then, as described above, the stress material body 2
0 connected by a connecting plate 21
By using this method, it is possible to maintain a stable buried condition without being affected by the soil ridges etc. during the formation of adjacent pillars. It also has excellent strength, so in order to obtain the desired strength, thinner materials can be used compared to conventional examples.
Alternatively, it is possible to achieve miniaturization, and the thickness of the underground continuous wall can be formed thin.

Next, a second embodiment of the construction method of the present invention will be described.

FIG. 7 is an explanatory plan view showing a second embodiment of the construction method of the present invention.

In this embodiment, stress material 28 made of a single I-type W4 (or H-type W4) is buried in every other column 26c127c for duplication, that is, in each column 26c, as in the conventional example. The other aspects are the same as those of the first embodiment.

Next, a third embodiment of the construction method of the present invention will be described.

FIG. 8 is an explanatory plan view showing a third embodiment of the construction method of the present invention.

In this embodiment, every other 26c and 27C is used for duplication, and 2 pieces are used in the same way as in the conventional example! Type steel (or H type'i
In this embodiment, the stress material 28 consisting of a single element of A) is buried, and the other features are the same as in the first embodiment.

In addition, in the creation apparatus used in the above embodiment, a case has been described in which a combination of spiral rocking blades 11 and plate-shaped stirring blades 112 are used as stirring blades, but the invention is not limited to this. Depending on the target ground, only the spiral swing blades 11 may be continuously provided, or only the plate-shaped stirring blades X12 may be provided. Further, in the above embodiment, the case where the columns 26 and 27 are formed every two columns has been explained, but an even number of columns 26 and 27 may be formed. It is sufficient to provide them symmetrically on both sides to improve balance during excavation, etc. At this time, when using the stress materials 19 shown in FIGS. 3 and 4, the number of stress material bodies 2o may be increased in accordance with the number of stress materials 19 and the stress materials 2o may be connected by the connection plate 21. Further, in the above embodiment, two pillars 26 and 27 are formed at predetermined intervals, and then the pillars are formed to fill in the spaces between the existing pillars, and the two pillars 26 and 27 that are being formed are Although consideration has been given to making the hardness on both sides approximately equal, in both the work of arranging adjacent pillars and the work of forming overlapping pillars, the columns in that work do not overlap each other, so the above order is correct. The formation order is not limited to, and various formation orders can be selected, such as sequentially.

Effects of the Invention As described above, according to the present invention, since an even number of columns are formed, work efficiency can be improved. In addition, since the solidifying agent is jetted out while rotating an even number of excavation shafts having stirring blades in mutually opposite directions, the balance during excavation can be improved. Moreover, after arranging the adjacent columns, overlapping columns are formed in the same manner as above, spanning almost evenly between each two adjacent columns in order, so that the columns are continuous. , Since the overlapping columns do not overlap each other, there is no risk of being influenced by the buried stress material. It is possible to create a thick underground continuous wall and obtain a reliable water-stopping effect.

In addition, the strength of stressed materials can be improved by connecting multiple stressed material bodies with a connecting plate and using them as a unit. It is possible to use a smaller size and thinner wall compared to other materials, so it is possible to reduce costs and reduce the thickness of the underground continuous wall.

[Brief explanation of drawings]

Figures 1A and B and Figures 2A to C show the construction equipment used in the construction method of the present invention, Figure 1A is a schematic side view of the construction equipment, Figure 1B is a schematic front view of the main parts, Figure 2A is an enlarged view of the main part of Figure 1B, Figure 2B is its bottom flash, Figure 2C
is a sectional view taken along the line l1c-IIc in Fig. 2A, Figs. 3B and 4 show examples of stress materials used in the construction method of the present invention, Fig. 3 is a perspective view, and Fig. 4 is an enlarged plan view. Figures 5 and 5 are enlarged plan views showing other examples of stress materials used in the construction method of the present invention, and Figures 6A to C show the construction method of underground continuous walls in the first embodiment of the present invention. An explanatory plan view shown in FIG. 7,
FIG. 8 is an explanatory plan view showing the construction method of the underground continuous wall in the second and third embodiments of the present invention, respectively. 9... Excavation shaft, 11... Moving tool, 12... Stirring blade, 13... Auger head, 14... Connecting member, 19
... Stressed material, 20... Stressed material body, 21... Connecting plate, 26.27... Column body, 28... Stressed material. Figure 1A Figure 1B Figure 3

Claims (5)

[Claims] (1) An even number of excavation shafts with stirring blades are rotated in opposite directions to eject a consolidation agent, and the consolidation agent is stirred and mixed with earth and sand to form adjacent pillars. Repeat the operation to arrange adjacent columns in a row, and then perform the above operation sequentially across each two adjacent columns almost evenly to form an overlapping column and connect the columns. With,
A construction method for underground continuous walls that is characterized by burying stressed materials in desired columns. (2) The stress material is constructed in a unit shape consisting of a plurality of stress material bodies and a connecting plate connecting these stress material bodies, and this unit-shaped stress material is formed into each set of overlapping columns. 2. The method for constructing an underground continuous wall according to claim 1, wherein the underground continuous wall is buried across the wall. (3) The method for constructing an underground continuous wall according to claim 2, wherein the central portions in the longitudinal direction of the long plates facing each other with the stressed material bodies are connected by a long plate in a perpendicular direction. (4) A column in which the connecting plate connects the opposing long plates in the stress material main body so as to diagonally intersect between the connecting parts of the opposing long plates and the long plates in the perpendicular direction, and the intersecting parts of the connecting plates almost overlap each other. Claim 2: The burial site is located at the center of the line connecting the central axes of the
Or the method for constructing an underground continuous wall as described in 3. (5) The method for constructing an underground continuous wall according to any one of claims 2 to 4, wherein the connecting plate connects the stressed material bodies at a plurality of locations in the longitudinal direction.