JP3044589B2 - Construction method of steel underground continuous wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for constructing a steel underground continuous wall.

[0002]

2. Description of the Related Art Conventionally, a method of constructing a steel underground wall by sequentially connecting box-shaped steel sheet piles has been used.
For example, FIG. 7 shows NS-B manufactured by Nippon Steel Corporation.
This is a method of constructing a steel underground continuous wall by sequentially connecting OX sheet pile groups by using the joint 1 thereof. In such a structure, in the structure after the concrete is cast, both the inner and outer sides of the box sheet pile B are connected only by the joint 1.

[0003]

[Problems to be solved by the invention] With the rise of land prices, how to construct the underground wall thinner,
This is an important issue in reducing construction costs and effectively using space. From such a point, the method of constructing the steel underground continuous wall using the box sheet pile B as shown in FIG. 7 is an advantageous method as compared with the method of constructing the reinforced concrete wall under the ground up to that time. . However, assuming the construction of a deeper underground wall, means for making the thickness of the underground wall thinner than the above-described method have been developed. That was the two-way version of the underground wall as shown on the right of FIG.

That is, the conventional underground wall is designed as a one-way plate structure as shown in the center of FIG. This structure is based on the premise that deformation of the underground wall in the direction of the line is suppressed in advance, and deformation is allowed only in the line parallel to the abdomen. On the other hand, the structure of the two-way version is
As shown in the right side of FIG.
In addition, the structure is designed in advance so as to allow deformation in both directions, that is, a linear shape parallel to the bulge. By making such a two-way version, it is expected that a thinner and deeper underground wall can be constructed at low cost. However, in the current structure of the box sheet pile B, the joints 1 are fitted to each other with some clearance. For this reason, it has been found that there is a problem in a case where the portion of the vertical joint 1 on the side where the tensile force acts, that is, the side on which the cutting is performed is insufficiently durable against a lateral bending external force.

[0005]

The object of the present invention is to solve such a problem. Based on the design of the two-way version, it is possible to construct a thinner and deeper underground wall than conventional walls. It is an object of the present invention to provide a method for constructing a steel underground continuous wall.

[0006]

That is, according to the present invention, at least one pair of joints is formed at both ends of the outer steel plate by connecting two outer steel plates arranged in parallel with a partition steel plate in an orthogonal direction. Using a box sheet pile made of, excavating a groove in the ground, and engaging the joints of the box sheet pile with each other to sink a plurality of pieces in the groove, the joint located within the interval between the support members is The supporting members were placed at intervals and supported so that the bending moment on the ground side received from the back of the underground wall worked positively, and then one side of the trench was excavated and exposed after excavation The joints of the joints of the outer steel plates of the box sheet pile are welded to each other, and the cut side surface of the underground wall is integrated as a whole. When the underground wall receives stress, the underground wall between the support members is vertically And disperse by deforming in the horizontal direction to oppose Configured to, a method for constructing a steel diaphragm wall bidirectional version structure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for constructing a steel underground continuous wall according to the present invention will be described below with reference to the drawings. <A> Box sheet pile B to be used Box sheet pile B used in the construction method of the present invention is a sheet pile having a structure as shown in FIG. That is, the distance between the two outer steel plates 2 arranged in parallel is set to 1
One or a plurality of partition steel plates 3
Is a box sheet pile B having at least one set of joints 1 formed at both ends. When the joint 1 is cut and cut, a set of joints 1 located on the ground side is formed in a shape similar to a conventional structure. The conventional joint is, for example, a combination of a deformed C-shaped joint or a grout joint obtained by combining a C-shaped joint and a pipe-shaped joint. On the other hand, one set of the joints 1 located on the side of the open cut is configured to be weldable, for example, by projecting the welding joint 4. For this purpose, for example, as shown in FIG. 2, a groove is formed at the tip of the outer steel plate 2 and a contact plate 4 is arranged on the back side, or a structure in which a welding plate is projected from both sides. However, if the welding joint 1 is simply formed, the fitting joint 1 can be separately protruded from the welding joint 1 if there is a concern that the fitting cannot be performed at the time of assembling and the interval is separated.

<B> Deposition of Box Sheet Pile A trench is excavated in the ground by a distance that allows a plurality of the above-described box sheet piles B to be arranged and set. Excavation of this groove is performed by a conventionally known device. Next, the above-mentioned box sheet piles B are engaged with each other's joints 1 and a plurality of the box sheet piles B are sequentially sunk in the grooves.
When the subsidence is completed, concrete is poured into the space surrounded by the outer steel plate 2 and the partition steel plate 3 or the entire excavated groove.

<C> Position for arranging the joint 1 When the box sheet pile B is sunk in the groove, the position of the joint 1 is arranged at a fixed position. For this purpose, it is assumed that the underground wall will be supported at equal intervals by support members such as anchors, slivers, and columns in the future. The joint 1 of the box sheet pile B arranged within the interval between the support members is arranged at a position where the bending moment on the ground side of the underground wall is positive. In particular, in the case of general construction in which the support members are at equal intervals L, the load is evenly distributed, and the sheet piles are of equal dimensions, the joint 1 is disposed at a position 0.146 L or more away from the support member. .
With such an arrangement, the joint 1 can be positioned at a point where the bending moment is almost zero, and a thin wall with less burden can be constructed.

<D> Welding on the exposed side Next, one side of the groove is excavated. Then, one surface of the box sheet pile B is gradually exposed. The welded joint 1 appears at the end of the outer steel plate 2 exposed during excavation. The welded joints 1 are welded to each other, and the cut side of the box sheet pile B is formed as an integral structure as a whole.

[0011]

As described above, the method for constructing a steel underground continuous wall according to the present invention involves welding one of the joints as described above, so that the underground wall can be designed as a two-way version. The wall thickness can be made thinner than that of. Therefore, it is very effective especially in construction where the land price is soaring.

[Brief description of the drawings]

FIG. 1 is a perspective view of an example of a box sheet pile used in the construction method of the present invention.

FIG. 2 is a plan view of the combined state.

FIG. 3 is a plan view of another combination of sheet piles.

FIG. 4 is a plan view of another combination of sheet piles.

FIG. 5 is a conceptual diagram of a retaining structure design.

FIG. 6 is an explanatory view of a relationship between a retaining structure and a moment.

FIG. 7 is a plan view of a combination state of a conventional box sheet pile.

Claims (1)

(57) [Claims] 1. A box sheet pile formed by connecting two outer steel plates arranged in parallel with a partition steel plate in an orthogonal direction, and forming at least one set of joints at both ends of the outer steel plates. Excavate a trench in the ground, engage the joints of the box sheet pile with each other,
Joints located within the gap between the support members when submerging
The bending moment on the ground side received from the back of the basement wall is
Space the support members so that they are within the working range of the lath.
Boxed sheet piles that are separated and supported , then excavated on one side of the ditch, and exposed after excavation
The engaging portion of the joint between the outer steel plate welded to one another, basement walls
When the underground wall receives stress, the underground wall between support members is vertically
Disperse and oppose by deforming in the horizontal and horizontal directions
The construction method of the steel underground continuous wall of the bidirectional version structure that is configured as follows .