JP3028053B2 - Joining method between building and diaphragm wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining a skeleton and an underground continuous wall in a large underground structure such as an LNG underground tank or an underground warehouse.

[0002]

2. Description of the Related Art Conventionally, as a method of constructing a large underground structure, there has been a method of constructing a retaining wall (also used as a water stop wall in some cases) with a continuous underground wall, excavating the inside thereof, and then constructing a skeleton. Used.

[0003] The dimensions of underground structures such as underground tanks, which are constructed below the groundwater level and act on buoyancy, are determined in terms of safety against buoyancy and safety in terms of strength. With the ability to be used at a low cost, and with the increase in size and depth of structures, the dimensions of members have come to be determined from the viewpoint of safety against buoyancy rather than strength.

For this reason, it has been found that it is advantageous in terms of cost and construction period to make the weight of the underground continuous wall not only the weight of the underground continuous wall, but also the weight of the underground continuous wall, and it is advantageous to join the frame to the underground continuous wall. Proposed.

In order to transmit the insufficient weight of the skeleton against the buoyancy to the underground continuous wall, it is sufficient to restrain at least the upward force from the skeleton by the underground continuous wall. In the case of an LNG underground tank, for example, Since the content liquid (LNG) is at an extremely low temperature of -162 °, and the temperature of the frame shrinks, the structure for joining is not restricted by the temperature shrinkage of the frame, and the frame and the underground continuous wall are joined together. In order not to generate stress (temperature stress) due to temperature change in the radial direction of the frame,
It is necessary that the contraction in the vertical direction is free.

In order to satisfy such demands,
The applicant has previously filed a Japanese Patent Application No. Hei 3-135743 (Japanese Patent Application Laid-Open No. 4-337200, Japanese Patent Publication No. Hei 6-30080) and applied a method for joining underground structures receiving buoyancy as shown in FIG. Patent No.
1975773).

In the underground continuous wall 1, a steel plate 2 is buried in the middle part in the vertical direction on the basis of an iron plate 2, and the inside of the continuous underground wall 1 is excavated. Then, a short steel pipe 3 as a support member is removed from the iron plate 2. It protruded horizontally. Further, the side wall 6 is raised upward from the outer periphery of the bottom plate.

The side wall 6 is formed close to the underground continuous wall 1, and is buried on the outer peripheral surface of the side wall 6 based on the iron plate 2, and a short steel pipe 7 as a support member is formed from the iron plate 2. It was projected in the horizontal direction, and was loosely fitted into the steel pipe 3.

The steel pipe 3 has a larger diameter than the steel pipe 7, and the loose fitting secures a gap that allows the steel pipe 7 to descend when the side wall 6 sinks. The steel pipe 7 is filled with concrete 8. Further, in the vicinity of the outer peripheral portion of the steel pipe 7, the grout hose 9 opening between the steel pipes 7 is embedded in the side wall 6 side.

When the side walls 6 are sequentially raised and a bottom slab is constructed to construct a skeleton, the ground sinks due to the weight of the skeleton, and when the side walls 6 descend with respect to the underground continuous wall 1, a steel pipe 7 is formed.
Also moves from above to below within the steel pipe 3.

After completion of the frame, the steel pipe 3 is poured out of the grout hose 9 between the steel pipes 7 and the grout 4 is poured out.
To fix the steel pipe 3 and the steel pipe 7.

As described above, the steel pipe 3 protruding from the underground continuous wall 1 and the steel pipe 7 protruding from the side wall 6 form a bearing for transmitting a vertical force. Weight is available as resistance.

[0013]

The joining method shown in FIG. 3 is effective when the downward force is greater than the upward force from the side wall and the supporting ground of the frame is weak. However, since the grout 4 is later filled with the grout 4 via the grout hose 9, the structure and the construction are complicated, and it takes time and cost.

Further, as an example of the experimental results, as shown in FIG. 4, the toughness (stickiness) is small, and the displacement follow-up performance from the start of applying buoyancy to breaking is small. For this reason, it is necessary to set the structure and number of the large shear force transmitting members in consideration of the unbalance of the resistance force due to the construction error and the like, which is wasteful.

An object of the present invention is to solve the disadvantages of the prior art and to reduce the cost of the buoyancy by using the weight of the underground continuous wall to make up for the shortage of the skeleton weight. It can be a large joint structure,
Moreover, it is an object of the present invention to provide a joining method of a skeleton and an underground continuous wall which can be joined with a simple and inexpensive structure.

[0016]

According to the present invention, in order to achieve the above object, firstly, an embedded anchor for connecting a connecting reinforcing bar is previously attached to an underground continuous wall to be constructed, and a front surface of the underground continuous wall is installed. After excavating, a connecting rebar is attached to the embedded anchor, and further, a cage rebar is attached to the connecting rebar, and concrete is cast, and a joint made of reinforced concrete is integrally protruded from the continuous underground wall surface. Secondly, the joint is provided with a cushioning material on the upper surface, and the joint is constructed so as to incorporate the joint with the cushioning material. Third, the joining is performed. The gist of the section is to be continuous in the lateral direction.

When supported by solid ground, the subsidence due to the tank's own weight + the liquid weight is about 2 to 3 cm. When an upward force due to buoyancy acts, it is lifted up by the amount of subsidence and then transmitted to the shear force. The mechanism will work and resist buoyancy. With this degree of movement, there is no problem in function as a tank.

According to the first aspect of the present invention, as shown in FIG. 2 as an example of an experimental result, a joint formed by casting concrete has a tough reinforced concrete structure. Since the force acts on the structure almost equally to the shear force transmitting structure with respect to the upward force, it is not necessary to design the upward force extra. further,
It has a simple structure and is inexpensive because no hardware is used.

According to the second aspect of the present invention, in addition to the above-mentioned action, the downward force that the skeleton sinks does not act on the shear force transmission structure, but is absorbed by the compression displacement of the cushioning material at the joint. Therefore, only the upward force needs to be considered for the shear force transmission mechanism, which is economical.

According to the third aspect of the present invention, in addition to the above-described operation, the joining portion is made continuous in the lateral direction, so that a bar or fitting metal is buried at appropriate intervals and joined. The same coupling effect can be obtained as when many of them are densely arranged.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional side view of an essential part showing one embodiment of a jointing method of a skeleton and an underground continuous wall of the present invention,
In the figure, 1 is an underground continuous wall, and 10 is a frame of a large underground structure such as an underground tank.

The underground continuous wall 1 is to be constructed in advance prior to the construction of the skeleton 10. The continuous underground wall 1 is to be used for water stoppage and soil retention, and the lower end is extended to an impermeable layer.

When the underground continuous wall 1 is constructed, an embedded anchor 11 for connecting a connecting reinforcing bar 12 described later is attached in advance.

In this embodiment, the embedded anchor 11 is formed by screwing a threaded reinforcing bar 14 to a threaded joint 13 and fixing a fixing plate 15 to an end of the threaded reinforcing bar 14 with a fixing nut 16. In the figure 17
Is a reinforcing bar forming the underground continuous wall 1.

The underground continuous wall 1 is constructed in this way, and after excavating the front surface thereof, the embedded anchor 11 is detected and the connecting reinforcing bar 18 is attached thereto. The connecting rebar 18 was also screwed to the screw joint 13 using a screw rebar, and a fixing plate 15 was fixed to an end with a fixing nut 16.

Further, after the cage bar 21 is attached to the connecting bar 18, the cage bar 21 is bent around by a formwork, and concrete is cast to form a reinforced concrete joint 19 integrally with the surface of the underground continuous wall 1. It is formed so that On the upper surface of the joint 19, a cushioning material 20 having a small rigidity (easy to deform) such as styrene foam is provided.

The reinforcing bar on the side of the skeleton 10 is assembled so as to take in such a joint 19 with the cushioning material 20, and concrete is cast to construct the skeleton 10.

The connecting portion 19 may be intermittent, but it is long and continuous in the horizontal direction, for example, in the case of an underground tank, in the circumferential direction.

Further, as another embodiment, when the supporting ground is very good and the amount of settlement due to the weight on the skeleton side is extremely small, the skeleton 10 can be constructed without attaching the cushioning material 20.

As described above, the joint 19 projecting from the underground continuous wall 1 forms a bearing for transmitting a vertical force, and the weight of the underground continuous wall 1 can be used as resistance against the buoyancy of the frame 10. .

[0031]

As described above, the method for joining a skeleton and a diaphragm wall according to the present invention can reduce costs by utilizing the weight of the diaphragm wall for the shortage of the skeleton weight with respect to buoyancy. In this case, it is possible to obtain a joining structure having a large toughness, and to join with a simple and inexpensive structure.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a main part showing one embodiment of a joining method of a skeleton and an underground continuous wall of the present invention.

FIG. 2 is a graph showing a relationship between a shear force and a displacement in the present invention.

FIG. 3 is a vertical sectional side view of a main part showing a conventional example.

FIG. 4 is a graph showing a relationship between a shearing force and a displacement in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Underground continuous wall 2 ... Iron plate 3 ... Steel pipe 4 ... Grout 6 ... Side wall 7 ... Steel pipe 8 ... Concrete 9 ... Grout hose 10 ... Building body 11 ... Embedded anchor 13 ... Screw joint 14 ... Screw reinforcement 15 ... Fixing plate 16 ... Fixation Nut 17 ... Reinforcing bar 18 ... Connected reinforcing bar 19 ... Junction 20 ... Cushioning material 21 ... Cage bar

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Katsunori Taguchi 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (56) References JP-A-7-62647 (JP, A) 4-337200 (JP, A) JP-A-6-108460 (JP, A) JP-A-5-321245 (JP, A) Jiko 48-14883 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 29/00-29/04 E02D 5/00-5/20

Claims (3)

(57) [Claims] 1. An embedded anchor for connecting a reinforcing bar is previously attached to an underground continuous wall to be constructed first, and after excavating the front surface of the underground continuous wall, a connecting reinforcing bar is attached to the embedded anchor. After installing the cage bar, concrete is cast and a reinforced concrete joint is protruded integrally with the continuous underground wall, and the skeleton is constructed so as to incorporate this joint. Continuous wall joining method. 2. The method according to claim 1, wherein a cushioning material is provided on an upper surface of the joint, and the frame is constructed so as to take in the joint with the cushioning material. 3. The method according to claim 1, wherein the joint is continuous in a lateral direction.