JPH0473488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method and apparatus for forming a soil pile retaining wall underground.

[Background Art] Grout is injected into an underground excavation hole and solidified together with the earth and sand in the excavation hole to form an underground wall, thereby forming a retaining wall.

Generally, the construction of this retaining wall involves forming multiple parallel drilling holes using a drilling rod, overlapping some of these drilling holes, and connecting the grout to be filled into the drilling holes to form a continuous mountain. A retaining wall is formed underground.

However, due to changes in soil conditions, the direction of rotation of the auger head, etc., when the drilling holes reach a deep depth of 20 m or more, they may not be drilled in parallel accurately, and there is no overlap between adjacent drilling holes, creating a continuous underground wall. cannot be formed, causing water leakage. For this reason, a conventional method has been proposed in which a plurality of drilling rods are arranged in parallel and the end drilling rod is inserted into the already drilled hole as a guide while performing the drilling work (Japanese Patent Application Laid-Open No. 133119-1982).
issue). In this drilling method, the drilled holes are overlapped with the drilled rods at the ends, so the parallelism of the multiple drilled holes is maintained, overlapping is ensured, and the drilled holes are accurately connected. It turns out.

However, with this excavation method, it is necessary to always insert the end drilling rod into an already excavated borehole, and therefore, when a long underground wall is to be formed, rapid excavation work cannot be performed. In addition, grout is injected into the excavated part at the same time as the excavation, but the excavation work is carried out using another drilling rod while inserting the drilling rod using the excavated part already filled with grout as a guide.
This excavated hole that has already been filled with grout has to be filled with grout again, which causes an increase in the amount of grout used.

In consideration of the above facts, the present invention provides a method and apparatus for forming a soil pile retaining wall, which eliminates the need to excavate the excavated part again, allows quick excavation work, and reduces the amount of grout used. is the purpose.

[Summary and operation of the invention] A method for forming a soil heap retaining wall according to the first invention of the present application includes filling grout into a trailing excavation part excavated adjacent to a preceding excavation part filled with grout after excavation. At the same time, the method is characterized in that grout is continuously spouted only in a portion adjacent to the preceding excavation part and the following excavation part, thereby communicating the preceding excavation part and the following excavation part.

In other words, when a trailing excavation section is excavated and filled with grout adjacent to a preceding excavation section that has already been excavated and filled with grout, continuous excavation is performed only in the adjacent section between the preceding excavation section and the following excavation section. The grout is now gushing out. This eliminates the need to excavate the preceding excavation twice.

Further, if the preceding excavated part and the succeeding excavated part are not excavated in parallel, the preceding excavated part and the succeeding excavated part may not overlap or the amount of overlap may be small. However, even in such a case, the grout injected from the trailing excavation part collapses the hole wall between the excavation parts and connects the preceding excavation part and the trailing excavation part. This creates a soil pile retaining wall that does not leak water. Further, since the hole wall is a thin portion caused by a slight misalignment of the axis, it can be broken down by injection of grout.

A soil pile retaining wall forming apparatus according to a second aspect of the present invention is a soil retaining wall forming apparatus that fills grout into a plurality of adjacent excavated portions to form a continuous retaining wall underground. an excavation rod that is inserted into the ground while rotating to form an excavation section; and a excavation rod that is disposed around the outer circumference of the excavation rod and that penetrates into the excavation section together with the excavation rod without rotating with the excavation rod. An injection nozzle support member, an injection nozzle that is attached to the injection nozzle support member and that continuously sprays grout only in areas adjacent to the preceding excavation section and the following excavation section, and a grout that supplies grout to the injection nozzle. It is characterized by having a supply means.

As a result, the injection nozzle is inserted into the ground together with the excavation rod, so there is no need to separately insert the injection nozzle into the ground. Further, since the injection nozzle does not rotate together with the excavation rod, grout can be continuously ejected only to the adjacent portions of the preceding excavation section and the following excavation section.

Further, by changing the injection direction of the injection nozzle using the injection direction changing means, it is possible to secure a large amount of overlap between the preceding excavation section and the following excavation section as necessary. Further, since this injection direction changing means is driven by the rotational force of the excavating rod or the change in the injection reaction force of the injection nozzle, there is no need to provide a separate driving means.

[Embodiments of the Invention] FIG. 1 shows an excavator 10 to which the present invention is applied. This excavator 10 is provided with a multi-shaft auger machine 12 at the upper end, and a plurality of (four in this embodiment) drilling rods 14 that protrude vertically downward from the multi-shaft auger machine 12 are inserted into the ground. It has become a department. Each of these excavating rods 14 has an excavating bit 16 attached to its tip and is rotatably driven by a multi-shaft auger machine 12, so as to break up earth and sand underground.
These excavation bits 16 form an excavation portion 20 that partially overlaps each other, as shown in FIG.

A plurality of drilling blades 22 are fixed to the drilling rods 14 above these drilling bits 16, and further above, four drilling rods 14 are connected and supported to each other by rod connecting plates 24 and 26. .

As shown in FIGS. 2 and 3, the rod connecting plate 24 is constructed by overlapping two plates 24A and 24B, and the outer periphery of the excavating rod 14 is connected between these plates 24A and 24B via a bearing metal 28. It is pivoted.

Each drilling rod 14 has a hollow shape, and the drilling bit 16 is filled with grout (cement milk) at the shaft center.
A grouting tube 30 has been passed through for guidance.

A steel pipe 32 is stretched between the rod connecting plate 24 and the multi-axis auger machine 12 in parallel with the excavating rod 14, and an inclinometer (not shown) for adjusting the excavating angle is disposed inside.

Attachment plates 34 are fixed to the top surfaces of both ends of the rod connecting plate 24 in the longitudinal direction (left and right directions in FIGS. 2 and 3), and injection nozzles 36 are attached thereto. This injection nozzle 36 is rotatably attached to the mounting plate 34 about a vertical axis 37, and the injection direction of the injection port 38 can be changed within a horizontal plane. A high-pressure hose 40 is connected to the end of the injection nozzle 36 opposite to the injection port 38 . This high-pressure hose 40 is led to the multi-shaft auger machine 12 through a steel pipe 32 and connected to a high-pressure grout supply device.

Further, a tension coil spring 42 is interposed between the injection nozzle 36 and the mounting plate 34, and the tension coil spring 42 is connected to the drilling rod 1.
The injection nozzle 36 is attached to the outer periphery of the cam 44 fixed to the cam 44.
The middle part of the is pressed. This cam 44 is designed to rotate the injection nozzle 36 about the shaft 37 against the biasing force of the tension coil spring 42 when the excavating rod 14 rotates.

It is preferable that a cover 46 is attached to the injection nozzle 36, the tension coil spring 42, and the cam 44 except for the injection port 38 to prevent dirt and the like from entering inside.

Next, the operation of this embodiment will be explained.

FIG. 4 shows the order in which the retaining walls are constructed in a step-by-step manner in this embodiment.

That is, as shown in FIG. 4A, the preceding excavation parts 20A and 20B are formed at an interval Q separated by 5/3 times the excavation pitch P. These advance excavation parts 20
Grout is filled in A and 20B, and this grout is mixed with the excavated earth and sand.

Next, as shown in FIG. 4B, the trailing excavation section 20C
A portion thereof overlaps (dimension O) with the preceding excavated portions 20A and 20B. When grout G is injected laterally from the injection nozzle 36 during this excavation and grout filling, this grout G is injected into the excavated portions at the ends of the preceding excavated portions 20A and 20B that have already been filled. For this reason, the advance excavation section 2
The grouts of 0A and 20B and the grout of the trailing excavation section 20C are mixed. In addition, the advance excavation part 20A,
Even if the axes 20B and the trailing excavation section 20C are not excavated accurately in parallel with each other and the amount of overlap (dimension O) is small, it is possible to remove the earth and sand between the preceding excavation section and the trailing excavation section. Since the grout injected from the injection port 38 is scraped off, the preceding excavation part 20A,
20B and the trailing excavation part 20C are communicated over a sufficiently large area, and an underground wall with no gaps is formed.

FIG. 5 shows the construction procedure when forming an underground wall by bending it. That is, the advance excavation section 20
After continuously forming A and 20B, the preceding excavation part 2
A trailing excavation portion 20C is formed at right angles to the end of 0B. In this case, grout G is filled from the end of the trailing excavation section 20C to the rear end of the preceding excavation section 20B using the injection nozzle, so that the trailing excavation section 2
0C and the preceding excavation part 20B are reliably communicated.
The connecting portion between the preceding excavated portions 20A and 20B is also filled with grout.

Further, the present invention is not limited to the intersection angle between the preceding excavation part and the following excavation part being at right angles, but can also be applied to the case where they are connected at an angle other than this. Further, the injection nozzles 36 are not limited to being provided at both ends of the plurality of excavating rods 14, but may be provided only on one side.

Furthermore, in the above embodiment, the injection nozzle 36 is connected to the cam 44.
Although we have shown a configuration in which the injection angle is changed by
If the injection nozzle can secure a wide range of injection angles, there is no need to rotate it. Further, the driving force of the excavating rod 14 may be transmitted to the injection nozzle 36 by a driving force transmitting structure other than the cam. Furthermore, the injection nozzle 36
Alternatively, the injection angle may be automatically changed by the injection reaction force of the grout.

[Effects of the Invention] As explained above, the present invention eliminates the need to excavate the preceding excavated portion again when forming the soil pile retaining wall, and prevents the preceding excavated portion and the subsequent excavated portion from overlapping or overlapping. Even if the amount is small, at the same time as filling the trailing excavation with grout,
The preceding excavation part and the following excavation part are reliably communicated with grout, and a soil pile retaining wall without water leakage can be constructed. Furthermore, since grout is injected only to the necessary areas, the amount of grout used can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a front view of an excavator to which the present invention is applied in an excavating state, Fig. 2 is an enlarged view showing the vicinity of the injection nozzle attachment part, Fig. 3 is a plan view of Fig. 2, Fig. 4, and FIG. 5 is a plan view showing the excavation procedure. 10...Excavator, 14...Drilling rod, 20
A, 20B... Leading excavation part, 20C... Trailing excavation part, 36... Injection nozzle, 38... Injection port, 44
……cam.

Claims (1)

[Scope of Claims] 1. Filling grout into a trailing excavation section that is excavated adjacent to a preceding excavation section filled with grout after excavation, and at the same time filling a portion adjacent to the preceding excavation section and the trailing excavation section with grout. A method for forming a soil heap retaining wall, characterized in that grout is spouted continuously in a limited manner to connect the preceding excavation section and the following excavation section. 2. A soil pile retaining wall forming device that fills grout into a plurality of adjacent excavated parts to form a continuous retaining wall underground, and is inserted into the ground while rotating to form the excavated parts. a drilling rod, an injection nozzle support member disposed on the outer periphery of the drilling rod and inserted into the excavation portion together with the drilling rod without rotating; and a jet nozzle support member attached to the injection nozzle support member. A soil heap stopper characterized by having an injection nozzle that continuously sprays grout only in an area adjacent to a preceding excavation section and a following excavation section, and a grout supply means that supplies grout to the injection nozzle. Wall forming equipment. 3. The soil pile retaining wall forming apparatus according to claim 2, further comprising a jetting direction changing means for changing the jetting direction of the jetting nozzle. 4. The soil mound retaining wall forming apparatus according to claim 3, wherein the jetting direction changing means is driven by a rotational force of an excavating rod or a change in jetting reaction force of a jetting nozzle. .