JPS6358976B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is an effective construction method for constructing underground continuous walls, particularly cylindrical continuous walls used as earth retaining and water-stop walls for cylindrical underground tanks. It is about the method.

<Problems to be Solved by the Invention> Figures 1 and 2 show an outline of the construction of an underground tank.
The continuous walls must be joined in the circumferential direction to form a single cylindrical shell structure, and therefore the joint must have bending rigidity.

Therefore, as shown in FIG. 3, a reinforcing bar overlap joint method is adopted in which the end transverse reinforcements of the leading panel reinforcing bar cage 3A and the trailing panel reinforcing bar cage 4A are lapped together.

In the case of such a method, as shown in Figures 4 and 5, after constructing the leading panels 3 on both sides, the trailing excavation groove 5 is excavated in the center and the trailing panel 4 is constructed. , after excavation of the trench 5, there is a problem that the excavated debris accumulates in the location P where it is impossible to excavate, making it impossible to replace it with concrete.

<Purpose of the invention> This invention was proposed in view of the above circumstances, and its purpose is to provide a construction method that can efficiently and economically construct an underground continuous wall using reinforcing bar lap joints. be.

<Structure of the Invention> The method for constructing an underground continuous wall according to the present invention is to provide a previously excavated trench with a partition plate at the longitudinal end of the trench, and to extend a transverse line from the partition plate with a predetermined length. A preceding panel reinforcing bar cage configured to protrude is erected and concrete is poured, and a protective plate having a substantially U-shaped cross section is extended from both sides of the substrate to cover the protruding horizontal reinforcement of the preceding panel reinforcing bar cage. Attach a locking tube to the outer surface of the plate, erect the protective plate along the partition plate, then, after excavating an adjacent trailing excavation groove, pull out the protective plate, and then into the trailing excavation groove, Concrete is placed by erecting the trailing panel reinforcing bar cage so that the horizontal reinforcement at the longitudinal end of the groove overlaps with the protruding horizontal reinforcement of the preceding panel reinforcing bar cage.

<Example> The present invention will be described below based on an illustrative example. This embodiment is a case of a cylindrical underground continuous wall of an underground tank, and leading panels 10 and trailing panels 11 curved at a predetermined curvature are alternately arranged as shown in FIGS. 6 and 7. established and configured.

The reinforcing bar cage 10A of the leading panel and the reinforcing bar cage 11A of the trailing panel each have vertical reinforcements 12 and horizontal reinforcements 13, and are further configured to resist with lattice reinforcements 14 and the like so as to maintain a predetermined curvature.

Further, the preceding panel reinforcing bar cage 10A is configured such that partition steel plates 15 are provided at both ends thereof, and horizontal reinforcements 13A protrude from the partition steel plates 15 by a predetermined length. The horizontal reinforcement 13 and the vertical reinforcement 12 are screw bars, and the horizontal reinforcement 13 is fixed to the partition steel plate 15 with a nut 16.

The partition steel plate 15 has water-stop steel plates 17, 17' on both sides.
Concrete wrap prevention sheet 18 on both ends
A rubber plate 19 for preventing concrete spillage is attached, and guide portions 20 having a semicircular shape and curving toward the trailing panel are formed at both ends, and are used as guides when installing a protection plate to be described later. ing.

Horizontal reinforcement 13B at the end of trailing panel reinforcing bar cage 11A
is bent inward to wrap with the horizontal reinforcement 13A of the preceding panel reinforcing bar cage 10A at a predetermined distance. Furthermore, the vertical bars 12 of the horizontal bars 13B are arranged on the inside, and a flat bar 21 is arranged on the inside of the horizontal bars 13A, and this flat bar 21 serves as a guide when inserting the trailing panel reinforcing bar cage 11A.

Next, as shown in FIG. 9, the protection plate 22 is attached to the end of the preceding panel 10 to protect this end during excavation of the trailing excavation trench, and has a U-shaped cross section. This protection plate 22 consists of a base plate 22A having a concave portion in the center, and an extension plate 22B that extends from the base plate 22A toward the partition steel plate 15 without contacting the side wall of the preceding excavation groove. A locking tube 23 is attached to the outer surface. After the construction of the protection plate 22 is completed, if muddy water is injected into the locking tube 23 and the rocking tube 23 is inflated, the gap between the protection plate 22 and the side wall of the preceding excavation trench is closed, thereby preventing excavation debris from entering. .

Furthermore, the protection plate 22
In the same way, it is divided into a plurality of lots and added to them one after another, but as shown in FIG. It is protruded at the tip.
This is to make it possible to easily follow the vertical deflection of the preceding panel end, that is, the partition steel plate 15, during erection. Further, on the lowermost protection plate 22, a partition steel plate cleaning brush 25, a protruding horizontal strip 13A cleaning brush 26, a water stop steel plate 17 cleaning brush 27 are attached to the respective members 15,
It is attached to 13A and 16 in a pressed state. Since the ends of the leading panels are left in muddy water for a long period of time, slime is attached to them, so it is necessary to remove the slime and excavated debris just before constructing the reinforcing bar cages of the trailing panels. If,
Cleaning can be performed simultaneously with pulling out the protection plate 22.

Next, an example of joining the protective plates 22 to each other is shown in FIGS. 11 and 12. In this case, a joint plate 29 having bolt holes 28 is made to protrude from the upper end of the protection plate 22 and is attached to the protection plate 22 via a reinforcing plate 30.
A reinforcing plate 32 having a diameter is attached to the reinforcing plate 32 and joined with bolts and nuts. Note that the locking tube 23 is connected to the lower end by a thin rubber plate 33.

Next, FIG. 13 and FIG. 14 show the preceding panel guide 34, which includes a pipe 36 to be inserted into the end of the preceding excavation groove 35, and a pipe 36 arranged at intervals in the vertical direction. positioning member 37
Consisting of This positioning member 37 has a semicircular cylindrical portion 38 located in a semicircular groove at the end of the preceding excavation groove 35.
and a water-stop steel plate 17 protruding toward the partition steel plate 15.
It is provided with a pair of protrusions 39 sandwiching the two.

In the above configuration, construction is performed in the following process order.

As shown in FIG. 15, a leading groove 35 is excavated.

As shown in FIG. 16, the preceding panel guide 3
4 are built into both ends of the leading groove 35.

As shown in Fig. 17, the preceding panel reinforcing bar cage 1
Set up 0A.

As shown in Fig. 18, if concrete is poured, as shown in Fig. 19, the preceding panel 1
0 is obtained.

As shown in FIG. 20, a protection plate 22 is installed at the end of the preceding panel 10.

As shown in FIG. 21, a trailing groove 40 is excavated.

As shown in FIG. 22, slime processing is performed.

As shown in FIG. 23, the end portion of the preceding panel 10 is cleaned while the protective plate 22 is being pulled out.

As shown in Fig. 24, trailing panel reinforcing bar cage 1
Construction of 1A will be carried out.

As shown in FIG. 25, concrete is poured to obtain trailing panels.

By sequentially repeating these steps in the circumferential direction, a cylindrical underground continuous wall is constructed.

Although the above description has been made regarding a cylindrical underground continuous wall, the construction method according to the present invention can also be effectively applied to a linear continuous wall.

<Effects of the Invention> As described above, according to the present invention, a protective plate with a relatively simple structure is used, and the locking tube allows the end of the leading excavated groove to be completely secured from the trailing excavated groove when excavating the trailing groove. This makes it possible to block and prevent the intrusion of excavation debris, and to make it easier to clean the horizontal stripes of the leading panel when the horizontal strips protruding from the partition steel plate of the preceding panel are overlapped with the horizontal strips of the trailing panel.
It is possible to efficiently and economically construct an underground continuous wall using the reinforcing bar lap joint method.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views showing the outline of underground tank construction, Figure 3 is a schematic plan view showing reinforcing bar lap joints for underground walls, and Figures 4 and 5 are underground tank construction diagrams. FIG. 6 is a plan view showing a leading panel, FIG. 7 is a plan view showing a trailing panel, and FIG. FIG. 9 is a plan view showing the protection plate of the preceding panel; FIG. 10 is a perspective view showing the lower end thereof; FIG. 11 is a perspective view showing the joint portion of the protection plate; FIG. 12 is a perspective view showing how the protection plates are joined; FIGS. 13 and 14 are plan views and front views showing the preceding panel guide; and FIGS. 15 to 25 are construction methods according to the present invention. FIG. 1... Underground tank, 2... Underground continuous wall, 3...
Leading panel, 4... Trailing panel, 5... Trailing excavation groove, 10... Leading panel, 11... Trailing panel,
10A, 11A...Reinforcement cage, 12...Vertical reinforcement, 1
3, 13A, 13B...Horizontal bar, 14...Lattice bar, 15...Partition steel plate, 16...Nut, 17,
17'...Waterstop steel plate, 18...Sheet for preventing concrete from running around, 19...Rubber plate for preventing concrete outflow, 20...Guide portion, 21...Flat bar, 22...Protection plate, 22A...Substrate, 22
B... Extension plate, 23... Locking tube, 2
4... Engaging protrusion, 25, 26, 27... Cleaning brush, 28... Bolt hole, 29... Joint plate, 30
... Reinforcement plate, 31 ... Bolt hole, 32 ... Reinforcement plate, 33 ... Rubber plate, 34 ... Leading panel guide, 35 ... Leading excavation groove, 36 ... Pipe, 37
... Positioning member, 38 ... Cylindrical portion, 39 ... Projection part, 40 ... Trailing excavation groove.

Claims (1)

[Claims] 1. A preceding panel reinforcing bar cage, which has a partition plate at the longitudinal end of the groove and is configured such that horizontal reinforcements protrude at a predetermined length from the partition plate, is erected in the previously excavated trench, and then concrete is poured. Pour the concrete,
A locking tube is attached to the outer surface of the extended plate extending from both sides of the base plate of the protective plate having a substantially U-shaped cross section capable of covering the protruding horizontal reinforcement of the preceding panel reinforcing bar cage, and the protective plate is constructed along the partition plate. Then, after excavating an adjacent trailing excavation groove, the protection plate is pulled out, and then a trailing panel reinforcing bar cage is placed in the trailing excavation groove so that the transverse reinforcement at the longitudinal end of the groove is aligned with the preceding panel reinforcing bar. A method of constructing an underground continuous wall, which is characterized by placing concrete so as to overlap the protruding horizontal bars of a cage.