JPH0437202B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> The present invention relates to a method of constructing a continuous underground wall, and particularly relates to a method of connecting and constructing a continuous underground wall along a predetermined curved surface.

<<Prior Art>> As is well known, the locking pipe method is a type of construction method for continuous underground walls constructed underground.

In this construction method, after drilling a hole for the preceding panel to a predetermined depth, a locking pipe is inserted into the end of the hole and concrete is poured.While the concrete is completely hardening, the locking pipe is inserted. A leading panel is formed by removing the panel, and the same operation is repeated thereafter to sequentially connect and form trailing panels on the sides of the leading panel.

According to this construction method, continuous underground walls can be constructed not only in straight lines but also in curved forms, but the following problems arise especially when constructing continuous underground walls with curved forms. Ta.

<<Problem to be solved by the invention>> In other words, when constructing a continuous underground wall with a curved surface shape, such as an earth retaining wall with a circular cross section, using the locking pipe method, it is necessary to construct the leading and trailing panels with a circular curvature. By forming it along the curve and making it into a polygonal shape, it can be adapted to curved surfaces, but as the curvature increases, the intersection angle of the leading and trailing panels becomes smaller, causing overlap between the leading and trailing panels. There was a problem that it became difficult to excavate the trailing panel.

Furthermore, when excavating the overlapping portion between the leading and trailing panels, the ends of the leading panels tend to come off, which could impair the watertightness between the panels.

This invention was made in view of these conventional problems, and its purpose is to:
To provide a method for constructing a continuous underground wall that can easily form a continuous underground wall with a curved surface shape and ensure water-tightness at joints.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a method for constructing a continuous underground wall along a predetermined curved surface, in which preceding panels are placed at predetermined intervals on the curved surface. After construction, when forming an excavation hole for a trailing panel between the leading panels, the end of the leading panel is cut into a substantially triangular shape, and this cut part is used as a joint surface. .

<Operation> According to the construction method with the above configuration, the joint surface is formed by cutting the end of the preceding panel into a substantially triangular shape, so it is easy to create a continuous underground wall that follows the curved shape regardless of the size of the curvature. can be constructed.

Furthermore, since the joint surface is formed by cutting, sufficient water-stopping properties are ensured.

<<Example>> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 show an embodiment of the method for constructing a continuous underground wall according to the present invention.

The construction method shown in the figure is applied when constructing a continuous underground wall with a circular cross section. It is composed of S1 to S7.

In the underground wall construction method, first, preceding panels P1 to P7 are constructed along a circular curved surface at intervals approximately equal to the length of the panels.

In constructing the preceding panels P1 to P7, a rectangular excavation groove is formed using the excavator 10 shown in FIG. 3, a reinforcing bar cage is erected in the excavation groove, and then concrete is poured.

The excavator 10 includes a guide frame 12 assembled in a rectangular shape and suspended by a crane or the like, a suspension cylinder 14 installed inside the guide frame 12,
A plurality of cutters 16 are pivotally attached to the lower end of the guide frame 12, a mud pump 18 is connected to a discharge port of the mud pump 18, and a mud pump 18 is configured to send upward the earth, sand, concrete, etc. cut by the cutters 16. The pipe 20 and four retractable first correction plates 22 are disposed oppositely at the upper and lower ends of the guide frame 12 and abut against the short side of the excavated groove h, and abut against the long side of the excavated groove h. 4 hauntable 2nd
A correction plate 24 is provided.

Then, when the construction of the preceding panels P1 to P7 is completed, the following panel S1 is inserted between the preceding panels P1 to P7.
An excavated groove h for constructing ~S7 is formed.

In this case, the ends of the preceding panels P1 to P7 are cut into a substantially triangular shape, as shown by the diagonal lines in FIGS.
P7, the joint surface between S1 and S7, but at this time, the inner and outer cross-sectional areas of the cut part C are unbalanced with respect to the longitudinal axis X of the cut surface,
The inner cross-sectional area becomes larger than the outer cross-sectional area.

For this reason, the cutting resistance of the cutter 16 is greater on the inside than on the outside, and in particular, as the depth of the underground wall increases, the excavator 10 tends to be eccentric toward the outside where the cutting resistance is smaller.

Therefore, in this embodiment, the swingable cutter 1
6, as shown in FIG. 4, is excavated by making it eccentric by a predetermined angle θ toward the side with larger cutting resistance, that is, inwardly.

In addition, the second correction plate 24 extends the one on the opposite side to the direction in which the cutter 16 is eccentric, so that the excavation groove h
to prevent the cutter 16 from eccentrically moving outward.

In order to prevent the eccentricity of the cutter 16, since the excavator 10 is suspended, the center of gravity of the entire excavator 10 should be in the vicinity of the cutter 16, and the horizontal force due to the excavator's own weight should be used. It is also possible.

As for the shape of the cross-sectional area of the cut portion C, as shown in FIG. 2, it is desirable that the ratio of the lengths l ₁ and l ₂ be approximately 1:3.

When the excavation groove h for the trailing panels S1 to S7 is excavated as described above, the trailing panels S1 to S7 are constructed by the same process as the preceding panels P1 to P7, and a continuous polygonal shape along a circular cross section is formed. The underground wall is completed.

Now, when constructing a continuous underground wall using the method described above, the joint surface between the leading and trailing panels P and S becomes a roughly triangular cut section C, which is difficult to construct using the conventional rocking pipe method. It is possible to easily construct an underground wall that follows the shape of a curved surface, regardless of the size of the curvature.

Further, since the joint surface between the panels P and S is a surface obtained by cutting the end of the preceding panel P, sufficient water-stopping properties can be obtained.

FIG. 5 shows a second embodiment of the invention,
In this embodiment, the cutting portion C of the preceding panel P is formed into a right triangle having a height approximately half the thickness of the panel P, and the above-mentioned eccentricity prevention means are taken during cutting.

In this embodiment, the thickness of the succeeding panel S may be half that of the preceding panel P as long as the connection strength is satisfied.

FIG. 6 shows a third embodiment of the invention,
Only the characteristic points will be explained below.

In this embodiment, when cutting the cutting portion C, the end of the leading panel P is placed on the side where the cutting resistance of the cutter 16 is small, that is, on the outside of the trailing panel S to be constructed. Cut while leaving it in contact with the

This prevents the cutter 16 from eccentrically moving outward due to the unbalance of the cutting resistance at the end of the preceding panel P.

Therefore, if the cutting portion C is set to have the cross-sectional shape as in this embodiment, the cutter 16 shown in the first embodiment
It is not necessarily necessary to take measures to prevent eccentricity.

Further, as a configuration that does not require eccentricity prevention means, the cross-sectional area may be set so that the cut surfaces of the preceding panel P are approximately equal on the inside and outside of the longitudinal axis X.

In the embodiment shown in FIG. 6, the portion of the leading panel P that remains at the end may be inside the trailing panel S.

FIG. 7 shows a fourth embodiment of the invention,
Only the characteristic points will be explained below.

That is, in this embodiment, a projection A projecting in a U-shape is provided on the outside of a substantially triangular cut portion C of the preceding panel P.

In order to form the protrusion A, small-diameter auxiliary cutters 16a, 16a are provided on the frame 12 of the excavator 10, as shown by imaginary lines in FIG.
It can be formed simultaneously with the excavation of the excavation groove h.

Also in this embodiment, the auxiliary cutters 16a, 16a that cut the protrusion A can prevent eccentricity of the cutter 16 due to unbalance of cutting resistance.

<<Effects of the Invention>> As described above in detail in the examples, according to the method for constructing a continuous underground wall according to the present invention, a continuous underground wall with a curved surface can secure water-tightness at the joints and Easy to build.

[Brief explanation of drawings]

Fig. 1 is an overall plan view showing the first embodiment of the method of the present invention, Fig. 2 is an enlarged view of the main part of Fig. 1, Fig. 3 is a side view of the excavation equipment used to carry out the method, and Fig. 4 5 is an explanatory diagram showing the usage state of the drilling equipment, FIG. 5 is an explanatory diagram showing the second embodiment of the method of the present invention, FIG. 6 is an explanatory diagram showing the third embodiment of the method, and FIG. 7 is an explanatory diagram showing the same method. It is an explanatory view showing a 4th example of this. P, P1-P7...preceding panel, S, S1-S
7... Trailing panel, C... Cutting section, h... Excavation groove, 16... Cutter.

Claims (1)

[Claims] 1. In a method for constructing a continuous underground wall along a predetermined curved surface, after constructing preceding panels at predetermined intervals on the curved surface, a trailing panel is constructed between the preceding panels. A method for constructing a continuous underground wall, characterized in that when forming an excavation hole, the end of the preceding panel is cut into a substantially triangular shape, and the cut portion is used as a joint surface. 2. The method for constructing a continuous underground wall according to claim 1, wherein the cutting section is cut while biasing a cutting cutter from a side with a smaller cutting resistance to an area with a larger cutting resistance. 3. The continuous area according to claim 1, wherein the cutting part is cut while leaving the edge of the preceding panel in contact with the side surface of the cutter on the side where the cutting resistance of the cutting cutter is smaller. How to build a middle wall. 4. Construction of a continuous underground wall according to claim 1, wherein the cutting section is set so that the cutting area of the preceding panel that the cutting cutter comes into contact with is approximately equal before and after the cutting axis. Method.