JP2000234332A - Connecting structure and connecting method for underground continuous wall and guide wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the construction period and construction cost. SOLUTION: This connecting structure is provided with guide walls 3a, 3b formed at both end sections 2a, 2b in the width direction of a portion where the continuous wall 2 of the ground 1 is to be formed, main reinforcements 6a provided on the guide wall 3a, a connecting recess 12, a reinforcing bar cage 4 arranged in a space 2c forming the continuous wall 2, connecting bars 7a connecting the upper section of the reinforcing bar cage 4 and the main reinforcements 6a, and concrete 16, 17 placed in the space 2c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an underground continuous wall for constructing an underground structure such as an underground tank for storing liquefied gas.

[0002]

2. Description of the Related Art A conventional method for constructing a liquefied gas storage underground tank will be described with reference to FIG. First, as shown in FIG. 1 (A), guide walls 3a, 3b made of reinforced concrete are formed in an annular shape at both ends 2a, 2b in the width direction of the portion where the continuous wall 2 of the ground 1 is to be formed. Next, a lifting machine in which an excavator (not shown) is suspended is installed on the guide wall 3, the excavator excavates between the two ends 2a and 2b, and the reinforcing bar 4 is inserted into a space from which earth and sand are removed. The concrete wall 5 is installed and the concrete wall 5 is cast near the lower ends of the guide walls 3a and 3b to form the tubular continuous wall 2. In addition, inside the outer guide wall 3a, the bending and tensioning main reinforcing bar 6a and the slip preventing bar 6a are provided.
b is provided.

Next, as shown in FIG. 1B, the inner guide wall 3b is removed and the inside of the tubular continuous wall 2 is excavated. Further, the connecting bars 7a and 7b are arranged on the upper part of the reinforcing bar 4 and the connecting bars 7a and 7b are connected to the main reinforcing bar 6a and the retaining bars 6b in the guide wall 3a, as shown in FIG. Then, concrete 9 is cast, whereby the continuous wall 2 and the guide wall 3a are integrated.

Next, as shown in FIG. 1D, an underground tank 10 is constructed inside the continuous wall 2, and an embankment 1b is constructed on the continuous wall 2 and the guide wall 3a. In this type of underground structure, the buoyancy indicated by the illustrated arrow acts on the underground tank 10 due to the groundwater, so that the continuous wall 2 and the guide wall 3a are integrated with each other in order to secure the lift resistance weight of the underground tank 10, The weight of the wall 3a and the embankment 1c on the wall 3a is considered as the resistance.

[0005]

However, in the above-mentioned conventional construction, since the construction of the joint between the continuous wall 2 and the guide wall 3a is performed in a separate step after the construction of the lower continuous wall 2, the construction period and There is a problem that the construction cost increases.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a joint structure and a joint method of an underground continuous wall and a guide wall, which can reduce the construction period and construction cost. And

[0007]

In order to achieve the above object, the underground continuous wall and the guide wall connecting structure according to the first aspect of the present invention are provided at both ends in the width direction of a portion where the continuous wall 2 of the ground 1 is to be formed. Guide walls 3a, 3b formed on 2a, 2b
A main reinforcing bar 6a and a coupling recess 12 provided on one side 3a of the guide wall, a reinforcing bar cage 4 disposed in a space 2c forming the continuous wall, and an upper portion of the reinforcing bar cage and the main reinforcing bar. The connecting streaks 7a to be connected and concretes 16 and 17 cast into the space are provided, and the invention according to claim 2 is arranged such that, in claim 1, a stabilizing streak 6b is provided in the guide wall. The underground continuous wall and the guide wall according to claim 3, wherein the end of the streak is disposed within the coupling concave portion 12 within a range not protruding from the inner wall surface of the guide wall 3a. The joining method is such that the guide walls 3a, 3b are provided at both ends 2a, 2b in the width direction of a portion where the continuous wall 2 of the ground 1 is to be formed so as to have the main reinforcing bar 6a and the coupling recess 12 on one guide wall 3a side. Form A step, wherein the guide wall 3
a step of excavating the ground between a and 3b, a step of arranging the reinforcing bar 4 in the excavated space 2c, a step of connecting the upper part of the reinforcing bar and the main reinforcing bar by a connecting bar 7a, A step of placing the muddy-water concrete 16 in the space 2c in addition to the design muddy-water-concrete top-end level WL by an extra height H, and then sucking up the extra-pile-up amount to make the design muddy-water-concrete top-end level; After curing the concrete, placing the aerial concrete 17 to the ground level GL. It should be noted that the numbers added to the above configuration are compared with the drawings to facilitate understanding of the present invention, and the present invention is not limited thereto.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. FIG. 1 (A) is a cross-sectional view showing a joint structure of reinforcing bars between an underground continuous wall and a guide wall, and FIG. 1 (B) and FIG. It is sectional drawing which shows a method.

In FIG. 1A, guide walls 3a and 3b made of reinforced concrete are formed in an annular shape at both ends 2a and 2b in the width direction of a portion where a continuous wall of the ground 1 is to be formed. Next, an excavator (not shown) is placed on the guide wall 3.
A lifting machine is installed, and both ends 2
A cylindrical excavation is made between a and 2b, and the reinforcing bar cage 4 is inserted and installed in the space 2c in which the earth and sand are removed.

On the inner periphery of the outer guide wall 3a, a connecting recess 11 is formed at the upper part, and a connecting recess 12 is formed below the connecting recess 11. A bending and tensioning main reinforcing bar 6a is provided above the inside of the outer guide wall 3a.
Is provided, and an end of the main reinforcing bar 6a protrudes into the connection concave portion 11. Then, after the reinforcing bar 4 is built, an L-shaped connecting bar 7a is fixed to the uppermost portion of the reinforcing bar 4,
The connecting bar 7a is connected to the main reinforcing bar 6a in the guide wall 3a by the nut 13. Reference numeral 15 denotes a muddy water level. In the present invention, the connection by the conventional slip stopper (6b in FIG. 2) at the muddy water level 15 or less is eliminated, and a coupling concave portion 12 is provided instead.

Next, as shown in FIG. 2B, the underwater concrete 16 is poured into the space 2c by the design top level WL of the underwater concrete and the extra height H (generally 50 cm). The slime and ready-mixed concrete will be sucked up by vacuum and the design will be at the top level of muddy water concrete. The muddy water concrete 16 may be cast to the ground level GL.

Immediately thereafter, as shown in FIG. 1C, the aerial concrete 17 is poured to the ground level GL. As a result, the aerial concrete 17 and the guide wall 3a are firmly integrated by the connection of the main reinforcing bar 6a and the connecting bar 7a and the action of the shear key by the connecting recess 11 and the connecting recess 12.

The reason why the aerial concrete 17 is constructed in this way is that the amount of the aerial concrete is smaller and less expensive than the muddy-water concrete, and the concrete strength of the continuous wall is generally larger than that of the guide wall. However, the aerial concrete can be made to have the same strength as the guide wall, because the slime does not exist, the guide wall 3a can be filled into the coupling recess 12 with high adhesion performance, and it can be easily vibrated.

FIG. 2 is a sectional view showing another embodiment of the joint structure of the underground continuous wall and the guide wall according to the present invention. Note that the same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, the stopper 6b is provided in the guide wall 3a, and the end of the stopper 6b is arranged in the coupling recess 12 within a range not protruding from the inner wall surface of the guide wall 3a. ing.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example, in the above-described embodiment, the shape of the coupling concave portion 12 is a trapezoidal cross section. However, the shape is not limited to this, and a plurality of concave and convex portions may be provided.

[0016]

As is apparent from the above description, according to the present invention, the reinforcing process and the concrete placing process for constructing the continuous wall and the joint can be integrated, so that the construction period and the cost are reduced. Can be done.

[Brief description of the drawings]

1A and 1B show an embodiment of the present invention, in which FIG. 1A is a cross-sectional view showing a connection structure of a reinforcing bar between an underground continuous wall and a guide wall, and FIG. 1B and FIG. It is sectional drawing which shows a method.

FIG. 2 is a cross-sectional view showing another embodiment of the connection structure between the underground continuous wall and the guide wall according to the present invention.

FIG. 3 is a cross-sectional view for explaining a method for constructing a conventional liquefied gas storage underground tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ground 2 ... Continuous wall 2a, 2b ... Both ends in the width direction 2c ... Space 3a, 3b ... Guide wall 4 ... Reinforcing bar 6a ... Main reinforcing bar 6b ... Slip-stopping bar 7a ... Connecting bar 12 ... Coupling concave portion 16 ... Muddy water Concrete 17… Aerial concrete

Claims (3)

[Claims] 1. A guide wall formed at both ends in the width direction of a portion of a ground where a continuous wall is to be formed, a main reinforcing bar and a coupling recess provided on one of the guide walls, and the continuous wall is formed. A reinforcing bar arranged in the space, a connecting bar connecting the upper portion of the reinforcing bar and the main reinforcing bar, and an underground continuous wall and a guide wall, which are made of concrete cast into the space. Coupling structure. 2. A slide bar is provided in the guide wall, and an end of the slide bar is disposed in the coupling recess so as not to protrude from an inner wall surface of the guide wall. The connecting structure of the underground continuous wall and the guide wall according to claim 1. 3. A step of forming guide walls at both ends in a width direction of a portion where a continuous wall of the ground is to be formed so as to have a main reinforcing bar and a coupling recess on one guide wall side;
Excavating the ground between the guide walls, arranging a reinforcing bar in the excavated space, connecting the upper portion of the reinforcing bar and the main reinforcing bar by a connecting bar, The process of placing the muddy water concrete in addition to the design muddy water concrete top end level, and then laying it up by the extra height, then sucking up the surplus amount to make the design muddy water concrete top level, and after curing the muddy water concrete, A step of casting concrete to the ground level.