JPS6375216A - Underground continuous wall construction work - Google Patents

Abstract

PURPOSE:To connect a preceding panel with a following panel under good condition without imbalance of excavation by a method in which a preceding panel is divided into segments so as to mutually cross along the curved face, and the joint is positioned on the same line. CONSTITUTION:First and second linear trenches 14 and 16 in mutually crossed state are excavated, and a reinforcing bar cage of a shape matching the crossing angle of the trenches 14 and 16 is set over the trenches 14 and 16. Concrete is placed into the trenches 14 and 16 to complete a preceding panel structure 10. The ground portion surrounded by the end of the preceding panel 10 is excavated for the following construction section. The cutting joint portion 20 can thus be excavated with uniform thickness as shown by the oblique lines, good-quality cutting joint can be obtained, and the following panel 22 can be efficiently connected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method of constructing an underground continuous wall having a curved surface shape, which is applied to a circular earth retaining wall or the like.

(Prior Art) For underground continuous walls, there are two methods of joining a trailing panel to a leading panel: the interlocking pipe method and the cutting joint method.

The former interlocking pipe construction method involves inserting locking pipes at both ends of a pair of preceding sections, excavating the section separated by the locking pipes, pouring concrete, and constructing the preceding panels, and then pulling out the locking pipes. This is a construction method in which the preceding construction section is then excavated and the following panels are constructed.

In the latter cutting joint construction method, the preceding work section is excavated in the shape of a rectangular parallelepiped, concrete is poured, and the preceding panels are constructed, and then the space between the preceding panels is excavated, and the subsequent work section is then excavated. This is a construction method in which the exposed end is cut using a hydrocutter, etc., weak parts such as defective concrete at the joint are removed, and then concrete is poured and the trailing panel is joined.

(Problems to be Solved by the Invention) Each of these construction methods has its own advantages and disadvantages, but they are effective as construction methods for linear underground continuous walls.

However, when constructing a curved diaphragm wall, such as a circular retaining structure, there are the following drawbacks.

In other words, in both of these construction methods, the polygonal shape follows the curvature of a circle to fit the curved surface, but in the interlocking pipe construction method, as shown in Fig. 3, the diameter of the rocking vibe 3 is Since the single excavation width is combined according to the width of the excavation, the length of the construction section cannot be increased and the number of joints increases. Further, since the center lines of the leading panel 1 and the trailing panel 2 intersect with each other at the joint portion, that is, at the center of the rocking vibe 3, excavation of the joint portion was difficult because it was not straight. Therefore, structural weaknesses tend to occur in this joint portion.

In addition, in the cutting joint construction method, in a simple combination of a single excavation width, as shown in Figure 4, the preceding panel 1
In order to match the end of the panel 2 to the rectangular parallelepiped shape of the trailing panel 2, the cutting joint 5 must be cut into a wedge shape as shown by diagonal lines, resulting in unbalanced cutting resistance between the inner and outer peripheries, which reduces excavation capacity and The degree of cracking at the joining part was likely to decrease, and in particular, the deep part was not cut as shown by the diagonal lines, resulting in a low opening degree.

This invention was made in view of the above problems, and in constructing this type of underground continuous wall with a curved surface, it applies the above-mentioned cutting method, and also solves the problem of unbalanced cutting, which is a drawback of the cutting method. The purpose is to eliminate this problem and to enable a good connection between the leading panel and the trailing panel.

(Means for Solving the Problems) In order to achieve the above object, the construction method of the present invention, when constructing a continuous underground wall to form a predetermined curved surface, constructs a pair of preceding panels along the curved surface. In the underground continuous wall construction method in which the joint part is then cut and the trailing panel is constructed in the shape of a rectangular parallelepiped between the leading panels, each of the leading panels is divided into multiple parts along the curved surface, and the dividing It is characterized in that the sections are constructed in a state where they intersect with each other, and the joining parts of both leading panels to the trailing panel are located on the same line as the trailing panel.

(Function) Since the splicing end of the leading panel is on the same center as the trailing panel, the excavated portion of the trailing panel is straight and there is no imbalance in the cutting of the end face of the leading panel.

(Example) A first embodiment of the present invention will be shown below.

In the figure, a pair of preceding panels 10 are bent into a dogleg shape with an appropriate length along the inner leg of a curved underground continuous wall.

In this construction method, when the forming part of the preceding panel 10 is divided into two and the curved surface is made into a polygon according to the curvature for the time being υJ, the corner of this part is made to be twice the intersection angle.

At this intersection angle, a straight line 1st. Second excavation groove 14
．． 16 in a crossed state.

After the excavation is completed, the excavated grooves 14 and 16 are continuous at the intersecting angle, so a reinforcing bar cage with a shape according to the intersecting angle is inserted into the excavated groove 14.
．． The structure of the preceding panel 10 is completed by erecting it across the panels 14 and 16, and then pouring concrete into the excavated grooves 14 and 16.

Opposing parts of each preceding panel 10 are on the same straight line,
Its end face will be exactly perpendicular to this. Therefore,
If the area surrounded by the opposing end faces is excavated as the subsequent work area, the excavation groove 18 can be excavated in the same straight line as the opposite side between the preceding panels 10, and the cutting surface becomes a plane perpendicular to this. Therefore, the concrete exposed end of this end face, that is, the cutting joint part 20, can be cut with a hydrocutter pipe to a uniform thickness as shown by diagonal lines, resulting in a high-quality cutting joint surface, which allows the trailing panel 22 to be connected well. can.

FIG. 2 shows a second embodiment of the construction method of the present invention.

In the figure, a pair of preceding panels 30 are constructed by excavating in an intersecting manner over three sections, erecting a reinforcing bar cage inside each excavated groove 32°, and pouring concrete. The adjacent ends of the panel 30 are formed in the same straight line.

Therefore, in this embodiment as well, the trailing panels 38 constructed between the leading panels 30 are on the same axis, and the cutting joint portion 40 shown by diagonal lines also has a uniform thickness on the inner and outer peripheries of the curved surface.

In addition, the crossing angle of the trapezoid for constructing the preceding panel is −
Various settings can be made depending on the length of the construction area and the curvature of the underground continuous wall to be obtained. Also, the preceding panels require extra concrete to cover the overlap of the excavated trenches, but is that an actual amount? The above is slight and the practical impediment to the obtained effect is negligible.

(High Effects of the Invention) As explained in detail in each embodiment above, in the underground continuous wall construction method according to the present invention, in the underground continuous wall having a curved shape applied to a circular earth retaining wall, etc. There is no crossing angle depending on the curvature between the leading panel and the trailing panel, and the joining can be done on the same straight line, so it can be done stably.

In addition, since defective concrete at the cutting joint can be removed with a uniform thickness, it can be removed with high accuracy and the water-stopping properties of the joint can be improved.

[Brief explanation of the drawing]

1 is an explanatory plan view showing the first embodiment of the construction method of the present invention, FIG. 2 is an explanatory plan view showing the second embodiment, FIG. 3 is an explanatory plan view showing the conventional interlocking pipe construction method, and FIG. The figure is an explanatory plan view showing the conventional cutting joint construction method.

Claims (1)

[Claims] (1) When constructing a continuous underground wall with a predetermined curved surface, after constructing a pair of leading panels along the curved surface, the joints are then cut, and the trailing panel is placed between the leading panels. In the underground continuous wall construction method, which is constructed in the shape of a rectangular parallelepiped, each of the preceding panels is divided into a plurality of parts along the curved surface, and the divided sections are constructed so that they intersect with each other, and both preceding panels are constructed with respect to the succeeding panel. An underground continuous wall construction method characterized by placing the joint part on the same line as the trailing panel.