JP2020165212A - Underground continuous wall and construction method for underground continuous wall - Google Patents

Abstract

To provide an underground continuous wall and a construction method for underground continuous walls that can easily be constructed, and that can efficiently transmit in-plane shear forces between a first element (preceding element) and a second element (following element).SOLUTION: In an underground continuous wall 1A, a preceding element 2 (first element) and a following element 3 (second element) that are constructed next to a ground 11 are connected via a joint 4. The joint 4 is provided, in a height direction, across the end surfaces of the preceding element 2 and the following element 3 on the side in which they are connected. The joint 4 has a partition 41 for which concrete 21 of the preceding element 2 is set on one surface, and concrete 31 of the following element 3 is set on the other surface. A diamond plate, the surface of which is provided with a plurality of protrusions 411, is used for the partition 41.SELECTED DRAWING: Figure 1

Description

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

An underground continuous wall made of RC may be constructed by providing leading elements in the ground at intervals and providing trailing elements between leading elements provided in advance. The leading element and the trailing element may be integrally connected so that the load (shear force) can be transmitted to each other, or may be connected to each other but not to transmit the load to each other.
It is said that it is desirable that the leading element and the trailing element are integrally connected so that the load can be transmitted to each other as a structural performance as compared with the case where the load is not transmitted to each other.

Patent Documents 1 and 2 disclose an underground continuous wall that transmits a vertical shear force (in-plane shear force) between a leading element and a trailing element via a connecting member such as a corrugated steel plate. ..
In these underground continuous walls, the convex portion of the trailing element is configured to fit into the concave portion of the leading element, and a connecting member that is embedded in the concrete of the leading element and projects into the recess is driven into the recess. The leading element and the trailing element are connected by being buried in the concrete of the trailing element.

Japanese Patent No. 39823227 JP-A-2010-242318

In the underground continuous wall disclosed in Patent Documents 1 and 2, when the leading element is constructed, the connecting member is embedded in the concrete of the leading element and a recess is formed by using a joint jig in which the connecting member is set. are doing. Then, after the concrete of the preceding element is hardened, the jointing jig is peeled off to expose the portion embedded in the following element of the connecting member. Therefore, in the underground continuous wall disclosed in Patent Documents 1 and 2, there is a problem that the peeling step of the jointing jig takes time and effort.
Further, when the preceding excavation part where the preceding element is constructed is excavated and the jointing jig is installed, if there is a gap between the jointing jig and the side surface of the preceding excavation part, the concrete of the preceding element is cast. When installed, this concrete may flow out to the trailing element side, and there is a problem that construction is troublesome.

The present invention has been made in view of the above-mentioned problems, and can be easily constructed, and an in-plane shear force is applied between the first element (leading element) and the second element (successor element). An object of the present invention is to provide a method for constructing an underground continuous wall and an underground continuous wall that can be efficiently transmitted.

In order to achieve the above object, the underground continuous wall according to the present invention is the underground continuous wall in which the first element and the second element constructed adjacent to the ground are connected via a joint portion. The joint portion is provided on the end faces of the first element and the second element on the side connected to each other over the entire height direction, and the concrete of the first element is fixed on one surface and the first element is fixed on the other surface. It has a partition plate on which two elements of concrete are fixed, and the partition plate is characterized by using a striped steel plate having a plurality of protrusions formed on its surface.

In the present invention, since a striped steel plate is used as the partition plate provided on the end faces of the first element and the second element on the side connected to each other over the entire height direction, the first element and the second element are via a plurality of protrusions of the striped steel plate. The in-plane shear force can be efficiently transmitted between the first element and the second element. The plurality of protrusions of the striped steel plate serve as shear transfer elements for efficiently transmitting the in-plane shear force between the first element and the second element.
A shear transmission element (a plurality of protrusions of a striped steel plate) for efficiently transmitting an in-plane shear force between the first element and the second element is provided by installing a partition plate, and further. Since a jig that temporarily supports the shear transmission element and needs to be removed afterwards is not required, a continuous underground wall can be easily constructed.

Further, the underground continuous wall according to the present invention is an underground continuous wall in which the first element and the second element constructed adjacent to the ground are connected via a joint portion, and the joint portion is the said. The first element and the end faces of the second element on the side connected to each other are provided over the entire height direction, the concrete of the first element is fixed on one surface, and the concrete of the second element is fixed on the other surface. It is characterized by having a partition plate to be fixed and a perforated steel plate gibber joined to both sides of the partition plate.

In the present invention, since the perforated steel plate shears are joined to both sides of the partition plate provided over the entire height direction on the end faces of the first element and the second element on the side connected to each other, the perforated steel plate shears In-plane shear force can be efficiently transmitted between the first element and the second element through the concrete of the first element and the concrete of the second element filled in the round hole. The perforated steel plate gibber serves as a shear transfer element for efficiently transmitting an in-plane shear force between the first element and the second element.
A shear transmission element (perforated steel plate jig) for efficiently transmitting a shear force between the first element and the second element is joined to the partition plate and is provided by installing the partition plate. Further, since a jig that temporarily supports the shear transmission element and needs to be removed afterwards is not required, the underground continuous wall can be easily constructed.

Further, the underground continuous wall according to the present invention is an underground continuous wall in which the first element and the second element constructed adjacent to the ground are connected via a joint portion, and the joint portion is the said. The first element and the end faces of the second element on the side connected to each other are provided over the entire height direction, the concrete of the first element is fixed on one surface, and the concrete of the second element is fixed on the other surface. The partition plate has a partition plate to be fixed, and the partition plate has a triangular pyramid-shaped concavo-convex steel plate having a triangular pyramid-shaped convex portion formed on one surface side and a triangular pyramid-shaped concave portion formed on the other surface. It is characterized by being used.

In the present invention, the partition plate provided on the end faces of the first element and the second element on the side connected to each other over the entire height direction has a triangular pyramid-shaped convex portion formed on one surface side and the other. A triangular pyramid-shaped uneven steel plate having a triangular pyramid-shaped recess is used for the surface. Therefore, the in-plane shear force is efficiently transmitted between the first element and the second element through the concrete filled in the convex portion of the triangular pyramid-shaped uneven steel plate and the concave portion of the triangular pyramid-shaped concave-convex steel plate. Can be done. The convex portions and concave portions of the triangular pyramid-shaped concavo-convex steel sheet serve as shear transfer elements for efficiently transmitting in-plane shear force between the first element and the second element.
Then, a shear transmission element (concave and convex portions of a triangular pyramidal concave-convex steel plate) for efficiently transmitting an in-plane shear force between the first element and the second element is provided by installing a partition plate. Further, since a jig that temporarily supports the shear transmission element and needs to be removed afterwards is not required, the underground continuous wall can be easily constructed.

Further, the method for constructing an underground continuous wall according to the present invention is the method for constructing an underground continuous wall in which the first element and the second element constructed adjacent to the ground are connected via a joint portion. The joint portion is provided over the entire height direction on the end faces of the first element and the second element on the side connected to each other, the concrete of the first element is fixed on one surface, and the joint portion is formed on the other surface. A first excavation step in which the concrete of the second element is fixed and an area of the ground where the first element is constructed is excavated to form a first excavation portion, and the second element in the first excavation portion. The first element concrete placing step of placing the concrete of the first element in the first excavation part, and the first element concrete placing step of installing the joint part at the end portion on the side where the concrete is constructed. It has a second excavation step of excavating an area where two elements are constructed to form a second excavation portion, and a second element concrete placing step of placing concrete of the second element in the second excavation portion. Then, between the joint portion installation step and the first element concrete placing step, a gap closing means for installing a gap closing means for closing the gap in the gap between the joint portion and the side surface of the first excavation portion is installed. An installation step is performed, and after the first element concrete placing step, a gap closing means removing step of removing the gap closing means is performed, and the gap closing means is a tube that expands and contracts by supplying and discharging liquid or gas. It is characterized by being a body.

In the present invention, the concrete of the first element is the second element because the gap between the joint portion and the side surface of the first excavation portion can be closed by the gap closing means of the tube body that expands and contracts by supplying and discharging the liquid or gas. It is possible to surely prevent the outflow to the element side, and it is possible to facilitate the construction of the underground continuous wall.

According to the present invention, a continuous underground wall can be easily constructed, and an in-plane shear force can be efficiently transmitted between the first element and the second element.

It is a horizontal sectional view of the underground continuous wall by 1st Embodiment of this invention. It is a horizontal sectional view explaining the joint part which attached the shutter. It is a figure explaining the advance excavation process of the construction method of the underground continuous wall. It is a figure explaining the preceding element concrete placing process of the construction method of the underground continuous wall. It is a figure explaining the follow-up excavation process of the construction method of the underground continuous wall. It is a figure explaining the follow-up element concrete placing process of the construction method of the underground continuous wall. It is a horizontal cross-sectional view corresponding to the AA line cross section of FIG. 8 which shows an example of the joint part of the underground continuous wall by 2nd Embodiment of this invention. It is a vertical cross-sectional view corresponding to the BB line cross section of FIG. 7 which shows an example of the joint part of the underground continuous wall by 2nd Embodiment of this invention. It is a horizontal sectional view of the joint part of the underground continuous wall according to the 3rd Embodiment of this invention. It is a horizontal sectional view explaining the construction method of the underground continuous wall and the underground continuous wall according to the 4th embodiment of the present invention.

(First Embodiment)
Hereinafter, the underground continuous wall 1A according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6.
As shown in FIG. 1, in the underground continuous wall 1A according to the first embodiment, a plurality of wall-shaped elements 2 and 3 are connected via a joint portion 4. The horizontal direction orthogonal to the wall surface of the continuous underground wall 1A is the wall thickness direction, the horizontal direction orthogonal to the wall thickness direction along the wall surface is the wall length direction, and the wall thickness direction and the wall length direction. The direction orthogonal to is the vertical direction or the height direction.
The plurality of elements 2 and 3 constituting the underground continuous wall 1A are a leading element 2 (first element) 2 constructed in advance and a trailing element 3 (second element) constructed after the leading element 2. The leading element 2 and the trailing element 3 are arranged in the wall length direction via the joint portion 4.
Both the leading element 2 and the trailing element 3 are constructed by excavating the ground 11.
The space formed by excavating the ground 11 to construct the leading element 2 is referred to as the leading excavation section 12, and the space formed by excavating the ground 11 to construct the trailing element 3 is referred to as the trailing excavation section 13. .. The leading excavation section 12 and the trailing excavation section 13 are adjacent to each other in the wall length direction.

The leading element 2 and the trailing element 3 are RC wall bodies in which vertical bars 22, 32 and horizontal bars 23, 33 are embedded in concrete 21, 31, respectively. The leading element 2 and the trailing element 3 are set to have the same dimensions in the wall thickness direction and the height direction, and are arranged so that their respective wall cores match. The leading element 2 and the trailing element 3 are arranged so that their respective end portions 2a and 3a in the wall length direction abut each other via the joint portion 4.
In the following, in the description of the connecting portion between the leading element 2 and the trailing element 3 and the joint portion 4, the side in the wall length direction in which the trailing element 3 is arranged with respect to the leading element 2 is referred to as the front side. The side where the preceding element 2 is arranged is the rear side with respect to the row element 3, and the wall length direction may be described as the front-rear direction.

The joint portion 4 has a partition plate 41 and a T-shaped T-shaped guide 49 joined to the partition plate 41.
The partition plate 41 is formed at a height that covers the entire height of the leading element 2 and the trailing element 3.
The partition plate 41 has a first partition plate portion 42 having a vertical surface whose plate surface faces in the wall length direction, and a gradual wall thickness toward the front side from one end in the wall thickness direction of the first partition plate portion 42. The second partition plate portion 43 extending diagonally to one side in the vertical direction and the first partition plate portion 42 gradually extending diagonally from the other end in the wall thickness direction toward the front side toward the other side in the wall thickness direction. It has a third partition plate portion 44.
The partition plate 41 is formed in a C shape that opens to the front side when viewed from the vertical direction. The recess surrounded by the first partition plate portion 42, the second partition plate portion 43, and the third partition plate portion 44 of the partition plate 41 is referred to as the partition plate recess 45.
The partition plate 41 is formed line-symmetrically with respect to the axis of each element 2 and 3 in the wall thickness direction. The second partition plate portion 43 and the third partition plate portion 44 are formed line-symmetrically with respect to the axial cores of the elements 2 and 3 in the wall thickness direction.

In the partition plate 41, one end in the wall thickness direction (one end in the wall thickness direction of the second partition plate 43) is one side surface of the preceding excavation portion 12 in the wall thickness direction. The other end in the wall thickness direction (the other end in the wall thickness direction of the third partition plate 44), which is in contact with or in close proximity to 122, is the other end in the wall thickness direction of the preceding excavation part 12. It is arranged so as to abut or approach the side surface 123 on the side.
As the partition plate 41, a striped steel plate having a plurality of protrusions 411 formed on one surface thereof is used. In the present embodiment, the surface where the protrusion 411 is located is the front side (the trailing element 3 side).

The T-shaped guide 49 is a member that guides the movement of the jet cleaning machine when the joint portion 4 is water jet-cleaned by using a jet cleaning machine before placing the concrete 31 of the trailing element 3.
The T-shaped guide 49 is joined to substantially the center of the front surface of the first partition plate portion 42 in the wall thickness direction over the entire height of the first partition plate portion 42. The T-shaped guide 49 is joined to the tip of the first T-shaped guide plate 491 extending from the front surface of the first partition plate 42 to the front side of the first T-shaped guide plate 491, and is joined to the tip of the first T-shaped guide plate 491. It has a second T-shaped guide plate portion 492 protruding from the portion on both sides in the wall thickness direction. In the T-shaped guide 49, the first T-shaped guide plate portion 491 and the second T-shaped guide plate portion 492 are connected so as to form a T-shape.
The second T-shaped guide plate portion 492 is arranged on the rear side of the front end portions of the second partition plate portion 43 and the third partition plate portion 44.
The T-shaped guide 49 is inserted into a groove portion formed in the jet washer that extends in the vertical direction, and is configured to guide the vertical movement of the jet washer.

The rear surface of the partition plate 41 is fixed to the concrete 21 of the leading element 2, and the front surface of the partition plate 41 is fixed to the concrete 31 of the trailing element 3. The T-shaped guide 49 is embedded in the concrete 31 of the trailing element 3.

As shown in FIG. 2, the front end portions of the second partition plate portion 43 and the third partition plate portion 44 are configured to have a detachable shutter 5 that closes the partition plate recess 45 from the front side. The shutter 5 is formed of a flat steel plate, and when attached to the second partition plate portion 43 and the third partition plate portion 44, the plate surface is arranged in a direction orthogonal to the axis of each element 2 or 3. ..
Guide portions 431 and 441 that slidably support the shutter 5 in the vertical direction are provided at the front end portions of the second partition plate portion 43 and the third partition plate portion 44, respectively. The guide portions 431 and 441 have a groove portion into which the edge portion of the shutter 5 is inserted.

Next, the construction method of the underground continuous wall 1A according to the first embodiment will be described.
First, as shown in FIG. 3, the leading excavation section 12 is excavated in the region where the leading element 2 of the ground 11 is constructed (first excavation step). Note that FIG. 3 also shows the installation of the joint portion 4 later.
In the present embodiment, only the area where the leading element 2 is constructed is excavated, and the trailing element 3 side is not excavated.

Subsequently, the joint portion 4 is installed at the end portion (front end portion) 121 of the preceding excavation portion 12 in the wall length direction (joint portion installation step).
At this time, the shutter 5 is attached to the partition plate 41 of the joint portion 4, and the front surface of the shutter 5 is brought into contact with the front end surface 121 of the preceding excavation portion 12.
By doing so, when the leading element 2 in which the trailing excavation portion 13 is not excavated is constructed, the front surface of the partition plate 41 does not abut on the ground 11 and the front surface of the shutter 5 abuts on the ground 11. It is possible to prevent soil from adhering to the partition plate 41 and prevent excavated soil from flowing into the partition plate recess 45.

Subsequently, as shown in FIG. 4, the vertical bars 22 and the horizontal bars 23 of the preceding element 2 are arranged. Note that FIG. 4 also shows the placement of the concrete 21 of the preceding element 2 later.
Subsequently, the concrete 21 of the preceding element 2 is placed (first element concrete placing step).
The concrete 21 of the leading element 2 is placed in the leading excavation portion 12, the vertical bars 22 and the horizontal bars 23 of the leading element 2 are embedded in the concrete 21, and the concrete 21 is fixed to the rear surface of the partition plate 41 of the joint portion 4.

Subsequently, as shown in FIG. 5, the trailing excavation section 13 is excavated in the region where the trailing element 3 of the ground 11 is constructed (second excavation step).
After the trailing excavation portion 13 is excavated, the shutter 5 is removed from the partition plate 41, and the partition plate recess 45 of the joint portion 4 is opened toward the trailing excavation portion 13.

Subsequently, as shown in FIG. 6, the vertical bars 32 and the horizontal bars 33 of the trailing element 3 are arranged. Note that FIG. 6 also shows the placement of the concrete 31 of the trailing element 3 later.
Subsequently, the concrete 31 of the trailing element 3 is placed (second element concrete placing step).
The concrete 31 of the trailing element 3 is placed in the trailing excavation portion 13, the vertical bars 32 and the horizontal bars 33 of the trailing element 3 are embedded in the concrete 31, and the concrete 31 is placed on the front surface of the partition plate 41 of the joint portion 4. After fixing, the protrusion 411 on the front surface of the partition plate 41 is embedded in the concrete 31.
After placing the concrete 31 of the trailing element 3, a curing period is provided to harden the concrete 31.
In this way, the underground continuous wall 1A is constructed.

Next, the action / effect of the underground continuous wall 1A according to the first embodiment described above will be described with reference to the drawings.
In the underground continuous wall 1A according to the first embodiment described above, since a striped steel plate is used for the partition plate 41 provided on the end faces of the leading element 2 and the trailing element 3 on the side connected to each other over the entire height direction, the striped steel plate is used. The in-plane shear force can be efficiently transmitted between the leading element 2 and the trailing element 3 through the plurality of protrusions 411.
A shear transmission element (a plurality of protrusions 411 of a striped steel plate) for efficiently transmitting an in-plane shear force between the leading element 2 and the trailing element 3 is provided by installing a partition plate 41. Further, since a jig that temporarily supports the shear transmission element and needs to be removed afterwards is not required, the underground continuous wall 1A can be easily constructed.

(Other embodiments)
Next, other embodiments will be described with reference to the accompanying drawings, but the same or similar members and parts as those in the above-described first embodiment will be described by using the same reference numerals, and the description will be omitted with reference to the first embodiment. Different configurations will be described.
(Second Embodiment)
As shown in FIGS. 7 and 8, in the underground continuous wall 1B according to the second embodiment, a steel plate having a flat surface is used for the partition plate 41B of the joint portion 4B instead of the striped steel plate as in the first embodiment. , The perforated steel plate gibber 46 is joined to the front side and the rear side of the first partition plate portion 42B of the partition plate 41B.

Similar to the partition plate 41 of the first embodiment, the partition plate 41B has a first partition plate portion 42B having a vertical surface whose plate surface faces the wall length direction and a first partition plate portion 42B in the wall thickness direction. The second partition plate portion 43B extending diagonally from one end to the front side in one side in the wall thickness direction and the first partition plate portion 42B from the other end in the wall thickness direction toward the front side. A partition plate having a third partition plate portion 44B that gradually extends to the other side in the wall thickness direction, and is surrounded by a first partition plate portion 42B, a second partition plate portion 43B, and a third partition plate portion 44B. It has a recess 45B.
Further, similarly to the first embodiment, the front end portions of the second partition plate portion 43B and the third partition plate portion 44B of the partition plate 41B support the shutter 5 that closes the partition plate recess 45B from the front side so as to be slidable in the vertical direction. Guide portions 431 and 441 are provided.

The perforated steel plate gibber 46 is formed in the shape of a long flat plate, and a plurality of round holes 461 penetrating the plate surface are provided at regular intervals in the longitudinal direction. The perforated steel plate gibber 46 is joined to the front surface and the rear surface of the partition plate 41B in a direction in which the plate surface faces the vertical surface facing the wall thickness direction, and protrudes from the partition plate 41B to the front side or the rear side.
A plurality of perforated steel plate gibber 46s are provided on the front surface and the rear surface of the first partition plate portion 42 at regular intervals in the wall thickness direction. The perforated steel plate gibber 46 joined to the front surface of the first partition plate portion 42 and the perforated steel plate gibber 46 joined to the rear surface are arranged in the wall length direction via the first partition plate portion 42.

In the underground continuous wall 1B according to the second embodiment described above, the perforated steel plate shears 46 are provided on both sides of the partition plate 41B provided on the end faces of the leading element 2 and the trailing element 3 on the side connected to each other over the entire height direction. Since they are joined, a surface is formed between the leading element 2 and the trailing element 3 via the concrete 21 of the leading element 2 and the concrete 31 of the trailing element 3 filled in the round hole 461 of the perforated steel plate shear 46. The internal shear force can be transmitted efficiently.
The shear transmission element (perforated steel plate jigbell 46) for efficiently transmitting the in-plane shear force between the leading element 2 and the trailing element 3 is joined to the partition plate 41B, and the partition plate 41B is joined. Further, since a jig that temporarily supports the shear transmission element and needs to be removed after being temporarily supported is not required, the underground continuous wall 1B can be easily constructed.

(Third Embodiment)
As shown in FIG. 9, the underground continuous wall 1C according to the third embodiment has a triangular pyramid-shaped uneven steel plate having a large number of triangular pyramid concave portions 412 and convex portions 413 formed on the surface of the partition plate 41C of the joint portion 4C. It is used. The triangular pyramid-shaped concavo-convex steel sheet is a steel sheet in which a triangular pyramid-shaped concave portion (convex portion) is press-formed, and a triangular pyramid-shaped concave portion 412 is formed on one surface and a triangular pyramid-shaped convex portion 413 is formed on the other surface. It is called the tiger score panel. In the concave portion 412 and the convex portion 413, the convex portion 413 is arranged on the opposite side of the concave portion 412. The sizes of the concave portion 412 and the convex portion 413 with respect to the partition plate 41C are not limited to the form shown in FIG.

The partition plate 41C extends linearly in the height direction and the wall thickness direction, and one end in the wall thickness direction is in contact with or close to one side surface 122 in the wall thickness direction of the preceding excavation portion 12. The other end portion in the wall thickness direction is arranged at a position where it abuts or is close to the other side surface 123 in the wall thickness direction of the preceding excavation portion 12.
In the present embodiment, the side of the partition plate 41C where the recess 412 is formed is the rear side (leading element 2 side), and the side where the convex portion 413 is formed is the front side (following element 3 side). ing. Therefore, the concrete 21 of the leading element 2 is filled inside the concave portion 412 of the partition plate 41C, and the convex portion 413 of the partition plate 41C is embedded in the concrete 31 of the trailing element 3.

In the third embodiment, shutter support plates 47 and 48 are provided at both ends of the partition plate 41C in the wall thickness direction so as to project forward and the shutter 5 is attached to and detached from the tip (front end).
Guide portions 471 and 481 that slidably support the shutter 5 in the vertical direction are provided at the front end portions of the shutter support plates 47 and 48. The guide portions 471 and 481 have a groove portion into which the edge portion of the shutter 5 is inserted.
In the third embodiment, a partition plate recess 45C that is surrounded by the partition plate 41C and the shutter support plates 47 and 48 and opens forward is formed.

In the underground continuous wall 1C according to the third embodiment described above, a triangular pyramid-shaped uneven steel plate is used for the partition plate 41C provided on the end faces of the leading element 2 and the trailing element 3 on the side connected to each other over the entire height direction. Therefore, the in-plane shear force is efficiently generated between the leading element 2 and the trailing element 3 via the concrete 21 filled in the convex portion 413 of the triangular pyramid-shaped uneven steel plate and the concave portion 412 of the triangular pyramid-shaped concave-convex steel plate. Can be transmitted.
A partition plate 41C is installed as a shear transmission element (recessed portion 412 and convex portion 413 of triangular pyramidal concave-convex steel plate) for efficiently transmitting an in-plane shear force between the leading element 2 and the trailing element 3. Further, since a jig that temporarily supports the shear transmission element and needs to be removed after being temporarily supported is not required, the underground continuous wall 1C can be easily constructed.

(Fourth Embodiment)
As shown in FIG. 10, in the underground continuous wall 1D according to the fourth embodiment, the joint portion 4D is attached to the partition plate 41D and the first side member of the partition plate 41D on one end in the wall thickness direction. It has 61 and a second side member 62 attached to the other end of the partition plate 41D in the wall thickness direction.
For the partition plate 41D, a corrugated steel plate in which convex portions 63 and concave portions 64 are alternately arranged on both sides and processed so that the cross-sectional shape has a corrugated shape is used.
The first side member 61 and the second side member 62 are provided so as to be line-symmetric with respect to the axial cores of the elements 2 and 3.
The first side member 61 and the second side member 62 are long mold members having an L-shaped cross section, and are arranged in a direction extending in the height direction. The first side member 61 and the second side member 62 are set to have the same length dimension as the length dimension of the partition plate 41D in the height direction.
The two pieces connected at right angles forming an L-shape of the cross-sectional shape of the first side member 61 and the second side member 62 are referred to as a front plate portion 611, 621 and a side plate portion 612, 622.

In the first side member 61, the plate surface of the front plate portion 611 is a vertical surface facing the wall length direction, and the side plate portion 612 is the other end portion of the front plate portion 611 in the wall thickness direction (on the partition plate 41D side). It is arranged so that it protrudes rearward from the end).
In the second side member 62, the plate surface of the front plate portion 621 is a vertical surface facing the wall length direction, and the side plate portion 622 is one end of the front plate portion 621 in the wall thickness direction (on the partition plate 41D side). It is arranged so that it protrudes rearward from the end).

The front surface of each of the front plate portions 611 and 621 of the first side member 61 and the second side member 62 is at the same position as the front end portion 41a of the partition plate 41D, or slightly in front of the front end portion 41a of the partition plate 41D (for example, 1 to 1). It is arranged on the front side of 2 mm).
The side plate portions 612 and 622 of each of the first side member 61 and the second side member 62 have a surface on the partition plate 41D side in contact with the side portion of the partition plate 41D and are joined to the partition plate 41D.
The side plate portions 612 and 622 are formed longer than the dimensions of the partition plate 41D in the front-rear direction (wall length direction), and the rear end portion is arranged on the rear side of the rear end portion of the partition plate 41D.
Both ends of the recessed portion 64 of the partition plate 41D in the wall thickness direction are closed by the first side member 61 and the second side member 62.
The first side member 61 and the second side member 62 are arranged so that the front surfaces of the front plate portions 611 and 621 are in contact with or close to the side surfaces 122 and 123 of the preceding excavation portion (first excavation portion) 12.

In the method of constructing the underground continuous wall 1D according to the fourth embodiment, the preceding excavation portion 12 is excavated (first excavation step) and the joint portion 4D is installed (joint portion installation step) as in the first embodiment. Then, before placing the concrete 31 of the preceding element 3 (first concrete placing step), a gap closing means 7 for closing the gap between the joint portion 4D and the side surfaces 122 and 123 of the preceding excavation portion 12 is provided. Install (gap closing means installation process).
The gap closing means 7 is, for example, a gap guard or the like, and is composed of a tube body that expands and contracts by supplying and discharging a liquid or gas. Both liquid and gas may be supplied to or discharged from the gap closing means 7.
In the gap closing means installation step, the gap closing means 7 is placed between the side plate portion 612 of the first side member 61 and the side surface 122 on one side in the wall thickness direction of the preceding excavation portion 12 over the entire height direction of the joint portion 4D. In addition to arranging, the gap closing means 7 is arranged between the side plate portion 622 of the second side member 62 and the side surface 123 on the other side in the wall thickness direction of the preceding excavation portion 12 over the entire height direction of the joint portion 4D.
The gap closing means 7 is provided between the side plate portion 612 of the first side member 61 and the side surface 122 of the preceding excavation portion 12, and between the side plate portion 622 of the second side member 62 and the side surface 123 of the preceding excavation portion 12. One or more are provided so as to close the gap between the side plate portions 612 and 622 of the first side member 61 and the second side member 62 and the side surfaces 122 and 123 of the preceding excavation portion 12.

After placing the concrete 31 of the preceding element 3, the gap closing means 7 is removed (gap closing means removing step).
After removing the gap closing means 7, the trailing excavation section 13 is excavated (second excavation step), and the trailing element 3 is constructed in the same manner as in the first embodiment.

In the method of constructing the underground continuous wall 1D according to the fourth embodiment described above, since the gap closing means 7 can close the gap between the joint portion 4D and the side surfaces 122 and 123 of the preceding excavation portion 12, the concrete of the preceding element 2 It is possible to surely prevent the 21 from flowing out to the trailing element 3 side, and it is possible to facilitate the construction of the underground continuous wall 1D.

Although the embodiment of the underground continuous wall according to the present invention has been described above, the present invention is not limited to the above embodiment and can be appropriately modified without departing from the spirit thereof.
For example, in the first to fourth embodiments described above, the joint portions 4, 4B and 4C are provided with a T-shaped guide 49 that is joined to the partition plates 41, 41B and 41C and projects toward the trailing element 3. However, the T-shaped guide 49 may not be provided.
Further, in the first and second embodiments described above, the partition plates 41 and 41B have a first partition plate portion 42, a second partition plate portion 43, and a third partition plate portion 44, and have a partition plate recess 45. Although it is formed so that the cross-sectional shape is C-shaped as described above, it may be formed in a flat plate shape. In such a case, as in the third embodiment, a shutter support plate extending from both sides in the wall thickness direction of the partition plate to the front side and attaching and detaching the shutter may be provided at the front end portion.

1A-1D Underground continuous wall 2 Leading element (first element)
3 Trailing element (second element)
4,4B-4D Joint part 7 Gap closing means 11 Ground 12 Pre-excavation part (1st excavation part)
13 Trailing excavation part 21,31 Concrete 41,41B-41D Partition plate 46 Perforated steel plate Jibel 49 T-shaped guide 122,123 Side surface 411 Projection part 412 Concave part 413 Convex part

Claims (4)

In the underground continuous wall where the first element and the second element constructed adjacent to the ground are connected via a joint portion,
The joint portion
The first element and the end faces of the second element on the side connected to each other are provided over the entire height direction, the concrete of the first element is fixed on one surface, and the concrete of the second element is fixed on the other surface. Has a partition plate to which concrete is fixed,
The partition plate is a continuous underground wall characterized by using a striped steel plate having a plurality of protrusions formed on its surface. In the underground continuous wall where the first element and the second element constructed adjacent to the ground are connected via a joint portion,
The joint portion
The first element and the end faces of the second element on the side connected to each other are provided over the entire height direction, the concrete of the first element is fixed on one surface, and the concrete of the second element is fixed on the other surface. With the partition plate where
An underground continuous wall having a perforated steel plate gibber joined to both sides of the partition plate. In the underground continuous wall where the first element and the second element constructed adjacent to the ground are connected via a joint portion,
The joint portion
The first element and the end faces of the second element on the side connected to each other are provided over the entire height direction, the concrete of the first element is fixed on one surface, and the concrete of the second element is fixed on the other surface. Has a partition plate to which concrete is fixed,
The partition plate is characterized in that a triangular pyramid-shaped uneven steel plate having a triangular pyramid-shaped convex portion formed on one surface side and a triangular pyramid-shaped concave portion formed on the other surface is used. Continuous wall. In the construction method of an underground continuous wall in which the first element and the second element constructed adjacent to the ground are connected via a joint portion,
The joint portion is provided on the end faces of the first element and the second element on the side connected to each other over the entire height direction, and the concrete of the first element is fixed on one surface and the joint portion is fixed on the other surface. The concrete of the second element is configured to settle,
The first excavation process of excavating the area where the first element of the ground is constructed to form the first excavation part, and
The joint portion installation step of installing the joint portion at the end of the first excavation portion on the side where the second element is constructed, and
The first element concrete placing step of placing the concrete of the first element in the first excavation part, and
A second excavation process of excavating the area where the second element of the ground is constructed to form a second excavation part, and
It has a second element concrete placing step of placing the concrete of the second element in the second excavation portion.
Gap closing means installation step of installing a gap closing means for closing the gap in the gap between the joint portion and the side surface of the first excavation portion between the joint portion installation step and the first element concrete placing step. And
After the first element concrete placing step, a gap closing means removing step for removing the gap closing means is performed.
A method for constructing an underground continuous wall, wherein the gap closing means is a tube body that expands and contracts by supplying and discharging a liquid or gas.

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