JPH0971942A - Caisson and construction method of continuous wall using the caisson and support structure of retaining wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a continuous wall in a short period by constructing a caisson with a wall at an erected state on the top of two caisson boxes at the central part separately laid out and a sinking this caisson. SOLUTION: A wall 3 is integrally constructed in an erected state on the top of cylinder-shaped caisson boxes 2 at the central part separately laid out along the extending direction of a reinforced concrete-made continuous wall to be constructed. The lower end of the wall 3 forms a cutting edge which is downward tapered. The caissons 1 thus formed as described above are set up in specified locations. When the ground is excavated in a work space, the wall 3 fits in the ground from the cutting edge 3a accompanied by the settlement of the ground. When the caisson boxes 2 sink up to a specified depth, a continuous wall is constructed with the wall 3 projecting in the ground. Since it is possible to omit excavation work between the caisson boxes 2, the amount of excavation is reduced, which makes it possible to cut down construction cost and shorten a construction period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caisson suitable for constructing a continuous wall that can be used as a retaining wall, a dam, a pier, etc., and a method for constructing a continuous wall using the caisson.

The present invention also relates to a support structure for a retaining wall for supporting earth pressure from the back and maintaining the height difference of land.

[0003]

2. Description of the Related Art Conventionally, the caisson method is sometimes used to construct a continuous retaining wall, bridge pier, or the like. 8 and 9 are conceptual diagrams showing the construction method, in which caissons (21) of the same shape are installed in a line on the ground, and the ground is excavated in each working space (24) provided inside the caisson (21). Each caisson (21) is sequentially sunk in the ground G, and the wall bodies (23) projecting from the upper surface of each caisson (21) are continuous to construct a continuous wall (25).

[0004]

By the way, in the above-mentioned procedure, as shown in FIGS. 9 and 10, the excavation range of the ground covers the entire range of the upper surface of each caisson (21) to be sunk (indicated by scattered points). ), The amount of excavation and unloading of earth and sand increased, causing a rise in construction costs and a longer construction period.

Therefore, an object of the present invention is to construct a continuous wall such as a retaining wall, a dam, a bridge pier, etc. in a short period of time and at low cost.

[0006]

In order to achieve the above object,
The caisson according to the present invention is for submerging into the ground to construct a continuous wall, and a plurality of caisson boxes each having a work space whose lower surface is open are arranged in a spaced apart manner in the extension direction of the continuous wall. Along with the adjacent caisson box, a wall is integrally installed. As a result, when the caisson is sunk, the wall body fits into the ground as the caisson box subsides, so that excavation work between the caisson boxes is almost unnecessary.

[0007] If the lower end of the wall body located between the adjacent caisson boxes is provided with a downwardly tapered blade portion, the ground reaction force acting on the wall body when the caisson is subsided is reduced and the caisson is smoothly moved. It is possible to sunk.

Further, according to the present invention, a plurality of caisson boxes, each having a work space whose lower surface is open, are spaced apart from each other, and a wall is integrally installed on adjacent caisson boxes to construct a caisson, After installing this on the ground, the ground was excavated in the working space of the caisson box to sink the caisson, and a continuous wall was obtained with the wall body fitted into the ground.

A plurality of caisson boxes, each having a work space with an open lower surface, are spaced apart from each other, and a wall body is integrally installed on adjacent caisson boxes to construct a caisson. After installing them in parallel on the ground with facing each other, excavate the ground in the working space of the caisson box and sink each caisson to obtain a double row continuous wall with the wall body fitted in the ground. Is also possible.

The support structure for a retaining wall according to the present invention supports the retaining wall for supporting the earth pressure from the rear and maintaining the height difference of the land, and a caisson is laid on the highland side of the retaining wall. Then, the caisson and the retaining wall are connected by a connecting material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to FIGS. 1 to 7 and FIGS.

As shown in FIGS. 1 and 2, a caisson (1) according to the present invention is made of reinforced concrete or the like, and has two rectangular tubular shapes spaced apart along the extension direction of the continuous wall to be constructed. It is composed of a caisson box (2) and a wall body (3) integrally erected vertically upright at the center of the upper surface of the caisson box (2). Caisson box (2)
Is provided with a work space (4) whose lower surface is open. After the ground is installed, a worker or an automatic excavator for excavating the ground is accommodated in the work space (4).

At the lower end of the wall body (3) located between the caisson boxes (2), in order to facilitate the fitting of the wall body (3) into the ground, a downwardly tapered blade opening ( 3a) is formed. The shape of the blade opening (3a) is sufficient if it is tapered, and in addition to having both surfaces as tapered surfaces as shown in the figure, one surface as a vertical surface and the other surface as a tapered surface as shown in FIG. Good. Further, the wall body (3) has a solid structure in FIG. 2 (a), but it may have a hollow structure if necessary.

The caisson (1) having the above structure is installed at a predetermined location on the ground, and the ground in the working space (4) is excavated. At this time, the caisson box (2) may be sunk by the open caisson method, but depending on the construction conditions, the pneumatic caisson method for air pressure in the working space (4) may be adopted, and the caisson box may be used as a jack. A press-fitting method of press-fitting the caisson into the ground using the anchor may be adopted.

When both caisson boxes (2) sink due to excavation, the wall bodies (3) fit into the ground through the blade openings (3a). When the caisson box (2) sinks to a predetermined degree, a continuous wall (5) is constructed by the wall body (3) protruding above the ground G, as shown in FIG. The excavation area at this time is the scattered point portion shown in FIG. 5, and excavation work between the caisson boxes (2) and (2) can be omitted.
The amount of excavation is smaller than that of the conventional method shown in (1), which can reduce the construction cost and the construction period. Although only one caisson (1) is illustrated in FIG. 4, a plurality of caissons (1) may be arranged in series to construct a longer continuous wall (5).

When the caisson is sunk, the wall body (3)
In order to prevent the surrounding ground from collapsing due to the subsidence, it is desirable to drive temporary earth retaining walls (6) on both sides of the wall (3) as shown in FIG.

The wall body (3) is not limited to the central portion of the caisson box body (2) but may be arranged laterally, as shown in FIG.
As shown in (a), the outer wall (3b) of the wall body (3) and the wall surface (2b) of the caisson box (2) may be aligned.
Also, as shown in FIG. 2B, two caissons (1)
If the wall bodies (3) are arranged in parallel with each other facing each other, both wall bodies (3) can be used as a river retaining wall. Of course, the caisson (1) shown in FIG. 1 may be arranged in parallel to construct a river retaining wall.

The caisson shown in FIG.
Although it is possible to raise the wall body (3) as shown in (a) and (b), in this case, in order to secure the strength, between the caisson box body (2) and the wall body (3). It is desirable to dispose a triangular reinforcing body (9) at the boundary corner of the. Further, in order to secure the strength of the wall body (3) itself, a plurality of protrusions (10: for example, a substantially triangular cross section) may be provided over a part or the entire length of the surface of the wall body (3) in the vertical direction. This ridge (10)
If the wall is arranged on the water surface side, a wave-dissipating effect can be expected when the wall body (3) is used as a dam for a river or the like.

By the way, when widening a road or the like on a highland side on an inclined surface having a difference in height, as shown in FIG. 11, a portion (A) indicated by a broken line is removed to remove the earth and sand from the retaining wall. Need to build (15). However, in the conventional construction method, since excavation of earth and sand and construction of the retaining wall (15) are always carried out at the portion A, there are many cases where roads and the like must be closed, and the economic loss due to traffic obstruction is large. Also, although the lower part of the retaining wall (15) is cast in the ground, there is some concern about the strength. Further, when there is a risk of ground collapse, a slope (16) is provided on the lowland side of the retaining wall (15), but this is the lower end of the slope (16) and the retaining wall (15).
The space B between the and is wasted in space.

Therefore, in the present invention, as shown in FIG.
The caisson (11) is sunk on the high side of the retaining wall (15), and the caisson (11) and the retaining wall (15) are connected by a connecting material. That is, first, the caisson (11) is sunk, then the retaining wall (15) is constructed by excavating and removing the soil in the portion A, and further the retaining wall (15) and the caisson (11) are connected to each other with steel material or a steel pipe, Or connecting material consisting of reinforced concrete columns (17)
To fix it firmly. With the above structure and procedure, the upper surface C of the caisson (11) after the deposition is used as the work base,
Since a large work machine can be installed here to remove the soil in the area A, there is no need for a work space on the road side, and the road can be efficiently widened without blocking the road, etc. ) Can be built. Moreover, since the sunk caisson (11) supports the earth pressure behind it, the earth pressure applied to the retaining wall (15) can be reduced, and a structurally stable retaining wall (15) can be constructed. . Of course, since the slope (16) is not necessary, this portion can also be used as a road and the space can be effectively used.

A plurality of the above caissons (11) may be arranged adjacent to each other. Further, it is desirable that the caisson (11) is high enough to reach below the road surface, but if the ground is sufficiently hard, a lower one may be used. As the caisson (11), not only a commonly used cylindrical type or rectangular tube type box type caisson but also the caisson (1) with the wall body (3) shown in FIG. 1 can be used. In that case, the connecting member (17) may be fixed to either the caisson box (2) or the wall (3). Of course, the above-mentioned support structure is not limited to retaining walls such as roads, but is widely applicable to retaining walls in general.

[0022]

As described above, according to the present invention, since the excavation work between the caisson boxes can be omitted, the ground excavation amount can be reduced as compared with the conventional method, and the construction cost and the construction period can be reduced. Is achieved.

If a lower end of the wall body located between the adjacent caisson boxes is provided with a blade portion that tapers downward,
It becomes possible to reduce the ground reaction force acting on the wall when the caisson is subsided and to smoothly settle.

If a caisson is sunk on the high side of the retaining wall and the caisson and the retaining wall are connected by a connecting material, the upper surface of the caisson after the sunk is used as a work base, and a large work machine is installed there to provide lowland Since it is possible to excavate the earth and sand on the side and construct a retaining wall, it is possible to construct a retaining wall in a small space without blocking roads, etc., and perform road widening work while ensuring smooth traffic. be able to. In addition, since the caisson sunk supports the earth pressure behind it, a structurally stable retaining wall can be constructed, and since the slope is not required, a wide road space can be secured.

[Brief description of drawings]

FIG. 1 is a perspective view of a caisson according to the present invention.

2A is a vertical sectional view taken along line AA in FIG. 1, and FIG. 2B is a vertical sectional view taken along line BB in FIG.

FIG. 3 is a vertical cross-sectional view showing another configuration example of the blade opening portion.

FIG. 4 is a perspective view showing a caisson after ground subsidence.

FIG. 5 is a plan view of a caisson.

FIG. 6 (a) is a vertical cross-sectional view showing another configuration example of the caisson according to the present invention, and FIG. 6 (b) is a vertical cross-sectional view when a river retaining wall is constructed using the same. .

FIG. 7A is a vertical sectional view showing another configuration example of the caisson, and FIG. 7B is a plan view thereof.

FIG. 8 is a perspective view showing a conventional method.

FIG. 9 is a vertical sectional view of a caisson sunk by a conventional method.

FIG. 10 is a plan view of a caisson sunk by a conventional method.

FIG. 11 is a cross-sectional view showing a conventional road widening method.

FIG. 12 is a cross-sectional view showing a road widening method according to the present invention.

[Explanation of symbols]

 1 caisson 2 caisson box 3 wall 3a blade part 4 working space 5 continuous wall 9 reinforcement 10 ridge 11 caisson 15 retaining wall 17 connecting material

Claims (5)

[Claims] 1. A construction for constructing a continuous wall by submerging in the ground, wherein a plurality of caisson boxes each having a work space having an open lower surface are spaced apart in the extension direction of the continuous wall, A caisson characterized in that a wall is integrally installed on adjacent caisson boxes. 2. The caisson according to claim 1, wherein a blade portion having a tapered lower portion is provided at a lower end portion of a wall body located between adjacent caisson boxes. 3. A caisson is constructed by arranging a plurality of caisson boxes, each of which has a work space whose lower surface is open, and erected a wall on the adjacent caisson boxes, and constructing the caisson on the ground. A method for constructing a continuous wall, characterized in that the ground is excavated in the working space of the caisson box, the caisson is submerged, and the wall is fitted into the ground to obtain a continuous wall. 4. A plurality of caisson boxes, each having a work space with an open lower surface, are spaced apart from each other, and a wall is integrally installed on adjacent caisson boxes to construct a caisson. After installing the walls in parallel on the ground with the walls facing each other, excavate the ground in the working space of the caisson box to sink each caisson, and obtain a double row continuous wall with the walls inserted into the ground. A method of constructing a continuous wall characterized by. 5. A retaining wall for supporting earth pressure from behind to maintain the height difference of land, wherein a caisson is sunk on the highland side of the retaining wall, and the caisson and the retaining wall are A supporting structure for a retaining wall, which is characterized by being connected with a connecting material.