JP7123782B2 - Joint structure of diaphragm wall - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm wall joint structure that secures the integrity of a leading continuous wall and a trailing continuous wall constructed in the ground.

A diaphragm wall constructed through the process of forming an excavated trench in the ground, installing a reinforcing bar cage in the excavated trench, and pouring concrete is a section divided in the continuous direction of the diaphragm wall. Work from the formation of excavated trenches to the placement of concrete is carried out in units. In this relationship, the adjacent section is divided into a leading section and a trailing section, and after finishing the work up to placing concrete in the leading section, the work up to placing concrete in the trailing section is performed. A leading section is a section skipping an adjacent section, and the skipped section may become a trailing section.

At the interface between the leading section and the trailing section, a partition plate that acts as a barrier for the concrete of the leading section is placed. In addition, the horizontal bars of the reinforcing bar cage installed in the preceding section pass through the partition plate and are also arranged in the following section. In order to ensure the integrity of the continuous wall in the leading section (preceding continuous wall) and the continuous wall in the trailing section (trailing continuous wall), both continuous walls should be sheared in the out-of-plane direction in addition to the in-plane direction of the continuous wall. It may not be sufficient for the transverse ribs to straddle between the two continuous walls, as the forces must be connected in a transmissible manner.

In the method of using a partition plate to transmit the shear force in the in-plane direction and the out-of-plane direction between the leading continuous wall and the trailing continuous wall, plates are provided on both sides of the partition plate and projections are formed on the plate. (see Patent Document 1), or a method in which plates are arranged side by side and a steel bar is installed between openings formed in the opposing plates (see Patent Document 2). In addition, there is also a method of forming a large number of concave portions on both sides of the partition plate (see Patent Document 3).

Japanese Patent Application Laid-Open No. 59-217829 (Claim 1, page 2, upper left column, line 7 to lower left column, line 10, Figs. 1 to 4) Japanese Patent Application Laid-Open No. 61-31522 (Claim 1, Gazette page 2, upper right column, line 6 to page 3, upper left column, line 11, Figs. 3 to 6) Japanese Patent No. 2631600 (claim 1, paragraphs 0013 to 0017, FIGS. 1 and 2)

In the method of Patent Document 1, it is necessary to weld a large number of steel materials such as round bars to the plate in order to form the projections on the plate. In both cases, it takes time and effort to manufacture the partition plate because it requires the erection of steel bars.

In the method of Patent Document 3, concave portions (recesses) arranged in two directions are formed from one side of the partition plate, and a large number of convex portions are formed on the other side surface, so that convex portions adjacent to the other side surface are formed. Although a recess is formed between them, the amount of protrusion of the projection from the surface of the partition plate is small, so the shear force transmission effect of the recess on both sides of the partition plate is not high.

In view of the background described above, the present invention proposes a joint structure for a diaphragm wall that has a simple structure and a high shear force transmission effect as compared with Patent Document 3.

The joint structure of the diaphragm wall according to claim 1 is provided with a partition plate in the preceding excavated groove excavated in the ground in advance and on the succeeding excavated groove side adjacent to the preceding excavated groove. After placing concrete in the preceding excavated groove, excavate the succeeding excavated groove to the position of the adjacent excavated groove on that side, install a reinforcing bar cage in the succeeding excavated groove, and concrete is a joint structure of a diaphragm wall that connects a preceding continuous wall constructed in the preceding excavated groove by placing and a succeeding continuous wall constructed in the succeeding excavated groove,
An attachment having a projecting portion facing a direction intersecting the surface of the partition plate, and having a plurality of holes formed at intervals in the height direction in the projecting portion or a projecting portion connected to the projecting portion. A material is joined to at least one side of the partition plate continuously or intermittently in the height direction, and is placed in at least one of the preceding excavated groove and the succeeding excavated groove. is buried in
The additional material is joined to both sides of the partition plate, and through-bars are inserted into the holes formed in the projecting portions of the additional material. A structural requirement is that the reinforcement is arranged in at least one of the preceding excavated trench and the succeeding excavated trench .
The diaphragm wall joint structure according to claim 2 is the diaphragm wall joint structure according to claim 1, wherein both ends of the penetrating bar are vertically engaged with the horizontal bars forming the reinforcing bar cage. The configuration requirement is to be in a state where it can be stopped.

``Reinforcing bar cage with a partition plate on the trailing excavation groove side'' means that the partition plate is attached to the trailing excavation groove 9 side of the reinforcing bar cage 1A installed in the preceding excavation groove 8 as shown in FIG. 2-(a). 4 is integrally attached, and means that the partition plate 4 is connected to the reinforcing bar cage 1A by some means when the reinforcing bar cage 1A is installed (before concrete is placed). For example, as shown in FIG. 1 and the like, the partition plate 4 is supported by the horizontal reinforcement 3 by passing the horizontal reinforcement 3 of the reinforcing bar cage 1A through the partition plate 4, and the horizontal reinforcement 3 supports the partition plate 4 as shown in FIG. In the case where it does not penetrate, it includes being supported by the vertical reinforcement 2 or the horizontal reinforcement 3 or the like via a binding wire or the like. A steel material or the like that is sandwiched between the reinforcing bar cage 1A and the reinforcing bar cage 1B in the trailing excavated ditch 9 via a spacer or the like without being supported by the vertical reinforcement 2 or the horizontal reinforcement 3, or that is temporarily fixed. It may be held by an auxiliary material or the like. The partition plate 4 is formed on the interface between the leading continuous wall 10 constructed by placing concrete in the leading excavated groove 8 and the trailing continuous wall 11 constructed by placing concrete in the trailing excavated groove 9. Become.

"Having an overhang facing the direction intersecting the surface of the partition plate" means that when the additional material 6 is joined (fixed) to the surface of the partition plate 4 as shown in FIG. The center line or surface of the partition plate 4 faces in a crossing direction such as perpendicular to the center line or surface of the partition plate 4 . Further, it is sufficient that the additional member 6 has a projecting portion 61 as a plate element or the like, and the cross-sectional shape of the additional member 6 itself does not matter. When the additional member 6 consists of only the projecting portion 61, the additional member 6 is formed to have an I-shaped cross section from a plate, a flat bar, or the like. A steel material is mainly used for the additional material 6, but the steel material is not necessarily required.

The “protruding portion 62 continuous with the protruding portion 61 ” means that the protruding portion 62 as a plate element or the like continues from the tip end side of the protruding portion 61 when viewed from the partition plate 4 and is perpendicular to the protruding portion 61 . etc., it means that they are formed facing the intersecting directions. More specifically, it means that the additional member 6 is L-shaped, T-shaped, or the like from the projecting portion 61 and the projecting portion 62, except for the joint portion to the partition plate 4, for example. A plurality of holes 6 a are formed in at least one of the projecting portion 61 and the protruding portion 62 . The partition plate 4 has a width spanning the opposing groove walls of the excavated groove and is basically made of a steel plate in order to bear the casting pressure as a concrete barrier plate placed in the preceding excavated groove 8 .

A plurality of holes 6a formed in the additional material 6 exhibit shear resistance force due to the concrete placed in at least one of the preceding excavated groove 8 and the succeeding excavated groove 9 entering into the holes 6a. spaced at least in the height direction (vertical direction) so that "At least in the height direction" means that a plurality of holes 6a may also be arranged in the width direction of the projecting portion 61 or the projecting portion 62 as shown in FIG. The shear resistance force due to the concrete entering the hole 6a functions mainly against shear forces in the in-plane direction and the out-of-plane direction between the adjacent leading continuous wall 10 and trailing continuous wall 11 .

By entering the concrete into the hole 6a of the additional material 6, in addition to the adhesive force with the concrete on both sides in the thickness direction of the overhang 61 etc., the outer peripheral surface of the columnar concrete existing in the hole 6a and the inside of the hole 6a The bearing force acting between the peripheral surface and the shear resistance force on both axial end surfaces of the concrete in the hole 6a are summed up as the resistance force against the shear force acting between the overhanging portion 61 and the like and the concrete. Hereinafter, the resistance generated within the hole 6a will be referred to as "the resistance within the hole 6a". The hole 6a is formed in a circular shape, a polygonal shape, or the like, and any shape is acceptable.

The resistance force in the holes 6a generated in the plurality of holes 6a formed at intervals in the height direction of the additional material 6 mainly acts in the direction orthogonal to the axis of the columnar concrete existing in the holes 6a. Therefore, if the hole 6a is formed in the protruding portion 61, the resistance force in the hole 6a functions effectively against the in-plane shear force mainly generated between the leading continuous wall 10 and the trailing continuous wall 11. . As shown in FIG. 11, if a hole 6a is formed in the protruding portion 62 facing in a direction intersecting the overhanging portion 61, the resistance in the hole 6a is mainly generated between the leading continuous wall 10 and the trailing continuous wall 11. Effective against out-of-plane shear forces. The shear force in the in-plane direction is the shear force acting in the vertical direction (horizontal direction for the continuous walls 10 and 11 as a whole) on the partition plate 4 between the leading continuous wall 10 and the trailing continuous wall 11, and the shear force acting in the out-of-plane direction. is a shear force acting horizontally in the wall thickness direction between the leading continuous wall 10 and the trailing continuous wall 11 .

The resistance force in the hole 6a exerts an effect against the shear force between the leading continuous wall 10 and the trailing continuous wall 11, mainly in the in-plane direction and the out-of-plane direction, so that one (one) additional Only by joining the material 6 to the partition plate 4, a high shear force transmission effect can be obtained between the partition plate 4 integrated with the additional material 6 and the concrete. Further, if the hole 6a is formed in the additional material 6 in advance, the partition plate 4 with the additional material 6 can be manufactured only by joining the additional material 6 to the partition plate 4 by welding or bolting. The manufacture of plate 4 is simplified. "Mainly against shear force" means that the effect can be exhibited also against vertical and horizontal bending moments.

In claim 1, "(additional material) is continuously joined" means that the single piece of additional material 6 has a continuous length in a certain section in the axial direction, or the case where the single piece of additional material 6 is continuous in the axial direction. It means that there are cases where a plurality of additional members 6 are butted against each other in the axial direction and joined to the partition plate 4 although they do not have the same length. "Intermittently joined" means joining to the partition plate 4 while securing a space between the additional members 6, 6 adjacent in the axial direction. Regardless of whether it is continuous or intermittent, the additional material 6 has a certain length or more in the axial direction, unlike a bar material such as a stud bolt, so that when it is joined to the partition plate 4, the above-mentioned In addition to exhibiting resistance to the applied shear force, it also exerts a function of imparting bending rigidity to the partition plate 4, and functions to prevent bending deformation of the partition plate 4 due to the placing pressure received from the concrete.

Since the additional material 6 is joined to both sides of the partition plate 4 (claim 1 ), the resistance force in the hole 6a forms a couple with the partition plate 4 interposed therebetween. It also acts as a resistance against horizontal and vertical bending moments acting between the continuous walls 11 . When the additional members 6, 6 are joined to both sides of the partition plate 4, the additional members 6, 6 are arranged at symmetrical positions with respect to the in-plane centerline of the partition plate 4, as indicated by solid lines in FIG. They do not necessarily have to be aligned, and they may be arranged in a staggered manner in the direction of the center line of the partition plate 4 as indicated by the dashed line in FIG.

When the additional members 6, 6 are joined to both sides of the partition plate 4, if the hole 6a is formed in the overhanging portion 61, the couple of resistance forces in the hole 6a is mainly directed vertically (at the center of the partition plate 4). It also resists bending moments about the horizontal axis, including the line. If the hole 6a is formed in the protruding portion 62, the couple of the resistance force in the hole 6a mainly acts as a resistance force against the bending moment in the horizontal direction (around the vertical axis). In particular, when the hole 6a is formed in the protruding portion 62 or also in the protruding portion 62, the position where the resistance force is generated in the hole 6a of the protruding portion 62 is higher than in the case where the hole 6a is formed in the protruding portion 61. , the distance from the surface of the partition plate 4 increases, the resistance to the horizontal bending moment increases.

Since the additional members 6 are joined to both sides of the partition plate 4 (claim 1 ), the penetrating bars 7 are inserted into the holes 6a formed in the projecting portions 61 of the additional members 6 as shown in FIG. It is also possible to make it (claim 1 ). 1 to 5 show an example in which the horizontal reinforcement 3 penetrates the partition plate 4 in the thickness direction, but as shown in FIG. Reinforcement may be arranged in internal units. In this case, the joining state of the leading continuous wall 10 and the trailing continuous wall 11 is mainly maintained by the resistance exerted by the partition plate 4 and the additional members 6, 6 joined to both surfaces thereof.

When inserting the penetrating bar 7 into the additional member 6, the penetrating bar 7 is arranged in at least one of the preceding excavated groove 8 and the succeeding excavated groove 9 of the reinforcing bar cage 1A installed in the preceding excavated groove 8. It is streaked (claim 1 ). In this case, when the resistance force in the hole 6a is exerted, the penetrating muscle 7 exerts the resistance force while bearing the bending moment, so the shear force in the in-plane direction and the resistance force against the bending moment are increased. Although the penetrating bar 7 does not need to straddle between the horizontal bars 3, 3 of the reinforcing bar cage 1A, for example, both ends of the penetrating bar 7 can engage the horizontal bars 3, 3 forming the reinforcing bar cage 1A (1B) in the vertical direction. (Claim 2) , the bending moment borne by the penetrating bar 7 is transmitted to the transverse bars 3, 3 of the reinforcing bar cage 1A, so that the leading continuous wall 10 and the trailing continuous wall 11 as a whole bear the bending moment. become a state.

In addition , since the additional material 6 is joined to both sides of the partition plate 4 (claim 1) , the resistance exerted by the penetrating bar 7 is generated on both sides of the partition plate 4, and this resistance force is generated. can act in balance on both sides of the partition plate 4 or form a couple.

A tension member (tie rod) 5 is connected to the partition plate 4 on the side of the leading continuous wall 10 as shown in FIG. There is something . In addition, as shown in FIG. 5, in the reinforcing bar cage 1A, the horizontal reinforcement 3 bears the tensile force acting between the leading continuous wall 10 and the trailing continuous wall 11 while transmitting it to the concrete via adhesive force. By penetrating the partition plate 4 and arranging the bar straddling the leading continuous wall 10 and the trailing continuous wall 11, it can be said that it is a reinforcing material in the sense that it reinforces the concrete against the tensile force acting on the concrete.

In these cases, since the tensile force of the reinforcing material tends to concentrate near the connection position of the reinforcing material (tension material) to the partition plate 4 or near the position where the reinforcing material (horizontal reinforcement 3) penetrates the partition plate 4, the partition plate 4, if the additional member 6 is joined to the vicinity of the reinforcing member, the effect of preventing the bending deformation of the partition plate 4 by the additional member 6 is more likely to be exhibited effectively. The stiffeners include tensile members 5 and crossbars 3, but also other tensile force resisting members. The reinforcement is placed in the pre-drilled trench 8 .

When the additional material 6 is joined to the trailing excavated groove 9 side of the partition plate 4 as shown in FIG. It can serve as a guide for guiding up and down of a cleaning device for cleaning the horizontal reinforcement 3 before placing concrete for the trailing continuous wall 11 . In this case, since the additional material 6 also serves as a guide for installing the cleaning device, there is no need to separately join a guide for the cleaning device to the partition plate 4 .

An additional material in which a plurality of holes are formed at intervals in the height direction in the projecting portion facing the direction intersecting the surface of the partition plate or the projecting portion continuous to the projecting portion is joined to at least one side of the partition plate. In this way, the shear force and bending moment between the leading continuous wall and the trailing continuous wall can be resisted, so the production of the partition plate with additional material can be simplified, and the resistance force in the multiple holes can be effectively exhibited. be able to.

(a) is a plan view (horizontal sectional view) showing a state in which a reinforcing bar cage with a partition plate for the preceding continuous wall is installed in the preceding excavation groove, and one additional member is joined to each side of the partition plate. In this case, (b) is an elevational view of (a) showing the state of arrangement of the reinforcing bar cage, and (c) is a view taken along line xx of (a). (a) shows how a reinforcing bar cage with a partition plate for the preceding continuous wall is installed in the preceding excavated groove, and a reinforcing bar cage for the following continuous wall is installed in the following excavated groove. A plan view showing an example in which additional members are arranged in parallel and joined, (b) is an elevation view of (a) showing a reinforcing bar cage, (c) is an xx arrow view of (a) FIG. (d) is a yy line view of (a). (a) is a plan view showing an example in which a through-reinforcement is inserted into the hole of the additional material, (b) is an elevation view of (a), and (c) is an xx line arrow of (a). It is a perspective view. FIG. 4 is a plan view showing an example of a case in which an additional member holds a tensile member as a reinforcing member for reinforcing the concrete of the preceding continuous wall. FIG. 10 is a plan view showing an example of a case in which additional members hold horizontal bars forming a reinforcing bar cage in the preceding continuous wall. (a) is a plan view showing an example in which the horizontal bars of the reinforcing bar cage in the preceding excavated groove do not penetrate the partition plate, and the reinforcing bar cage in the preceding excavated groove and the reinforcing bar cage in the succeeding excavated groove are separated. , (b) is an xx line cross-sectional view, (b) is an elevation view of (a), (c) is a yy line cross-sectional view of (a), (d) is a z of (a) -z line sectional view. (a) is a plan view showing a state in which an additional member, which is a steel plate (plate) consisting only of an overhang portion, is joined to a partition plate, and (b) is an elevation view of (a). (a) is a plan view showing a state in which an L-shaped cross-sectional additional member having an overhang and a base as a joint portion to the partition plate is joined to the partition plate, and (b) is an elevation view of (a). It is a diagram. Fig. 11 is a plan view showing an example of a case in which an additional material has a role of a guide for guiding up and down of a cleaning device for cleaning horizontal bars protruding to the trailing trench side of a reinforcing bar cage in the preceding trench. be. (a) is a plan view showing a state in which an additional member having an H-shaped cross-section having an overhang and a protrusion and having a hole formed in the overhang is joined to a partition plate; ) is an elevation view. (a) is a plan view showing a state in which an additional member having an H-shaped cross-section having an overhang and a protrusion and a hole formed in the protrusion is joined to a partition plate; (b) is a plan view of (a); and (c) is a side view taken along the line xx of (a). Fig. 1 is a graph showing the relationship between displacement of concrete (continuous walls) on both sides of the partition plate and shear stress acting on both sides of the partition plate, with and without the additional material shown in Fig. 1. be.

1-(a) to (c) show a reinforcing bar cage 1A having a partition plate 4 in a preceding excavated groove 8 excavated in the ground in advance and on the side of the succeeding excavated groove 9 adjacent to the preceding excavated groove 8. After placing concrete in the preceding excavated groove 8, a reinforcing bar cage 1B is installed in the following excavated groove 9, concrete is poured, and the preceding continuous wall 10 constructed in the preceding excavated groove 8 and an example (reference example) of a joint structure of a diaphragm wall that connects the trailing wall 11 constructed in the trailing excavated trench 9. FIG. The excavated trenches (preceding excavated trench 8 and trailing excavated trench 9) are formed by, for example, a bucket type excavator, a horizontal multi-axis excavator, or the like, but the formation method is not limited.

At least one side of the partition plate 4 has a protruding portion 61 facing in a direction that intersects the surface of the partition plate 4, such as perpendicular to the surface of the partition plate 4. An additional member 6 made of, for example, steel having a plurality of holes 6a formed at intervals in the height direction is joined (fixed) continuously or intermittently in the height direction. The additional material 6 may be pre-joined before the reinforcing bar cage 1A with the partition plate 4 is brought into the site, or may be pre-joined at the site. 1 to 3 show an example in which the additional material 6 has a flat plate shape consisting of only the projecting portion 61, but if the additional material 6 has the projecting portion 61 and the projecting portion 62, the additional material 6 is formed in any cross-sectional shape.

The reinforcing bar cages 1A and 1B are basically two plane reinforcing bar units assembled by combining vertical bars 2 and horizontal bars 3 in a grid shape, facing each other, as shown in FIG. 2-(a). The partition plate 4 is configured to hold both reinforcing bar units at the portion of the horizontal reinforcement 3 penetrating the partition plate 4 . The end of the horizontal reinforcement 3 on the side of the partition plate 4 penetrates the partition plate 4 and stretches to the side of the trailing excavated trench 9 for the transmission of the tensile force to the concrete placed in the trailing trench 9. put out. The vertical reinforcement 2 is also connected to the portion of the horizontal reinforcement 3 that protrudes toward the trailing excavated groove 9 side.

As shown in FIG. Due to the lap joint of the cage 1A with the horizontal reinforcement 3 overhanging from the partition plate 4 via the adhesive force with the concrete, the distance between the parallel horizontal reinforcements 3, 3 of the reinforcing bar cage 1A in the preceding excavation groove 8 is smaller than the distance. It's becoming

FIG. 1 shows a fabrication example of a reinforcing bar cage 1A in which the additional members 6 are joined to both sides of the partition plate 4 when the additional members 6 have a flat cross-sectional shape. Here, when the additional material 6 consists only of the projecting portion 61, one additional material 6 is attached to one side of the partition plate 4 near the center of the partition plate 4 in the width direction. 1 and subsequent drawings show an example in which the additional material 6 is continuous in the height direction.

Between the holes 6a, 6a adjacent to each other in the height direction, a distance is ensured that does not cause deformation around the hole 6a as a result of bearing the shear force in the direction perpendicular to the axis of the columnar concrete entering the hole 6a. be done. Although the shape of the hole 6a is mainly circular as shown in FIG. 1-(b), it is not necessarily limited to circular. 1 to 3 show an example in which the holes 6a are arranged in one row in the width direction of the projecting portion 61 as shown in (b) of each figure. Depending on the size of 6a, they may be arranged in a plurality of rows in the width direction of projecting portion 61 or in the width direction of projecting portion 62, or may be arranged in a zigzag pattern.

When a (vertical) shear force acts in the in-plane direction between the continuous walls 10 and 11 (concrete) on both sides of the partition plate 4, the shear displacement between the continuous walls 10 and 11 and the partition plate 4 FIG. 12 shows the relationship between shear stresses acting on both surfaces. The dashed line indicates the history when the horizontal reinforcement 3 only penetrates the partition plate 4, and the solid line indicates the history when the additional members 6, 6 are joined to both sides of the partition plate 4 as shown in FIG. From FIG. 12, when the additional members 6, 6 are joined to the partition plate 4, compared with the case where only the horizontal ribs 3 pass through the partition plate 4, the same shear force stress is applied between both sides of the partition plate 4. It can be seen that the deviation displacement when acting is reduced to about a fraction of that.

FIG. 2 is an example of a case where two or more additional materials 6, 6 having the shape shown in FIG. (reference example) is shown. As described above, in the trailing excavated groove 9, the distance between the horizontal bars 3, 3 of the reinforcing bar cage 1B near the partition plate 4 is smaller than the distance between the horizontal bars 3, 3 of the reinforcing bar cage 1A. 9, it is arranged at a position that does not contact the horizontal reinforcement 3 of the reinforcing bar cage 1B. In particular, on the elevation of the trailing excavated groove 9, as shown in FIG. 2-(a), the additional material 6 in the trailing excavated groove 9 has a width such that the horizontal reinforcement 3 of the reinforcing bar cage 1B and the additional material 6 overlap. or when the horizontal reinforcement 3 has a length that overlaps the additional member 6, the tensile force in the axial direction of the horizontal reinforcement 3 is transmitted between the additional member 6 and the horizontal reinforcement 3 via the adhesion force of the concrete. become a state.

FIG. 3 shows an example (embodiment) in which the penetrating bar 7 is inserted into the hole 6a formed in the projecting portion 61 of the additional member 6. As shown in FIG. In FIG. 3, the penetrating bars 7 are arranged so as to straddle between the transverse bars 3, 3 facing each other in at least one of the preceding excavated groove 8 and the trailing excavated groove 9 of the reinforcing bar cage 1A. However, both ends of the penetrating muscle 7 in the axial direction may not intersect the horizontal muscles 3, 3 on a plane. As shown in FIG. 3-(c), when both ends of the penetrating rebar 7 are placed in a state where they can be locked to the horizontal rebars 3, 3 in the vertical direction, the bending moment borne by the penetrating rebar 7 is It is transmitted to the transverse bars 3, 3 of 1A. When the additional material 6 is joined to both sides of the partition plate 4, the bending moment generated in the leading continuous wall 10 is transmitted to the trailing continuous wall 11, and the bending moment generated in the trailing continuous wall 11 is transferred to the leading wall. It becomes a state of being transmitted to the continuous wall 10 .

FIG. 4 shows the tension member 5 placed in the pre-excavated trench 8 and used as a reinforcing member for reinforcing the concrete placed in the excavated trenches 8 and 9, when the tension member 5 is connected to the partition plate 4. An example in which the additional material 6 is joined to the partition plate 4 so as to suppress the bending deformation of the partition plate 4 due to the tensile force acting on the partition plate 4 is shown. The additional material 6 is joined by welding or the like such that the projecting portion 61 faces the direction intersecting the surface of the partition plate 4 . Since reinforcing bars and steel bars are mainly used for the tension member 5, in FIG. The tensile member 5 is connected to the partition plate 4 by, for example, screwing a fastener 51 such as a nut to the portion of .

The tensile member 5 resists the tensile force from the partition plate 4 when the pressure of the concrete when poured into the preceding excavated groove 8 acts on the partition plate 4, and the partition plate 4 moves toward the following excavated groove 9 side. It works to prevent movement. For this reason, the tension member 5 is mainly arranged (reinforced) on the side of the pre-excavated groove 8 of the partition plate 4, and in FIG. Although it is joined only to the surface of the partition plate 4 on the preceding excavated groove 8 side, it may also be joined to the surface on the following excavated groove 9 side.

In the example shown in FIG. 4, the extension 61 of the additional member 6 is arranged along the axial direction of the tension member 5, and the center line (surface) of the extension 61 is aligned with the center line (surface) of the partition plate 4. The axis of the hole 6 a is oriented parallel to the center line of the partition plate 4 . The additional material 6 has the role of stiffening the vicinity of the connection point of the tension member 5 (reinforcement material) to the partition plate 4, so it is arranged along the tension member 5 (reinforcement material). Due to their different behavior, they are separated from the tensile members 5 .

FIG. 5 shows a partition in the case where the reinforcing material for reinforcing the concrete placed in at least one of the preceding excavated groove 8 and the following excavated groove 9 and reinforcing the concrete placed in the excavated grooves 8 and 9 is the horizontal reinforcement 3. An example of joining the additional material 6 to the plate 4 is shown. The horizontal reinforcement 3 arranged in the preceding excavated groove 8 penetrates the partition plate 4 and protrudes toward the following excavated groove 9 side. The additional material 6 having only the projecting portion 61 on the surface is joined. In this example as well, the center line of the projecting portion 61 faces the direction intersecting the center line of the partition plate 4, and the axis of the hole 6a faces the direction of the center line of the partition plate 4. FIG. In this case too, the additional members 6 are arranged along the transverse bars 3 (reinforcers), but separated from the tensile members 5 .

FIG. 6 shows that the horizontal bars 3 of the reinforcing bar cage 1A in the preceding excavated groove 8 do not penetrate the partition plate 4, and the reinforcing bar cage 1A in the preceding excavated groove 8 and the reinforcing bar cage 1B in the following excavated groove 9 sandwich the partition plate 4. Shown are examples of bar arrangement in each of the excavated trenches 8 and 9 when they are separated by . As shown in FIGS. 6(b) to 6(d), vertical reinforcements 2 are arranged so as to surround at least multiple stages of horizontal reinforcements 3 in excavated trenches 8 and 9, and serve also as shear reinforcing reinforcements. But also. In this example, since the horizontal bars 3 of the reinforcing bar cage 1A and the reinforcing bar cage 1B do not pass through the partition plate 4, the partition plate 4 is attached to the horizontal bars 3 or the vertical bars 2 via binding wires or auxiliary materials fixed as temporary materials. indirectly supported by In this example, the leading continuous wall 10 and the trailing continuous wall 11 resist the respective out-of-plane shearing forces by the adhesive force on both sides of the partition plate 4 and the resistance generated in the additional material 6. 6 are joined to both sides of the partition plate 4, and a plurality of them are arranged in the width direction of the partition plate 4. - 特許庁

7 and 8 show a specific example of the additional material 6 of the joining example shown in FIGS. 1 to 5. FIG. In FIG. 7, when the additional material 6 consists of only the flat plate-like projecting portion 61 and is butt-welded to one side of the partition plate 4, FIG. This is the case where the L-shaped cross section is formed from the base 63 and joined to the partition plate 4 at the base 63 by welding or bolts. In either example, the holes 6a are formed in the projecting portion 61 at intervals in the height direction. 7 and 8, the holes 6a are arranged in one row in the width direction of the projecting portion 61, but they may be arranged in a plurality of rows or in a zigzag pattern.

FIG. 9 shows an example in which the additional material 6 is joined to the surface of the partition plate 4 on the trailing excavated groove 9 side. In this example, the dirt adhering to the horizontal bars 3 that penetrate the partition plate 4 and protrude toward the trailing excavated groove 9 side until the concrete is poured into the preceding excavated groove 8 is removed. It is envisioned that the additional material 6 will have the function of supporting a cleaning device for cleaning before pouring concrete inside. In this case, the additional material 6 functions as a guide material (guide) for moving up and down while being gripped by the cleaning device. The additional material 6 used in this example is formed in a cross-sectional shape having at least two portions, an overhanging portion 61 and a protruding portion 62, so that the cleaning device grips the additional material 6 and does not separate from the additional material 6 when moving up or down. be.

10 and 11 show specific examples of the additional material 6 in the joining example shown in FIG. In these examples, the additional material 6 has a protruding portion 61, a protruding portion 62 continuous from the tip side of the protruding portion 61 to both sides in the thickness direction of the protruding portion 61 when viewed from the partition plate 4, and a protruding portion On the side of the partition plate 4 of 61, there are three portions of a base portion 63 that are continuous on both sides of the projecting portion 61 in the thickness direction. When the additional material 6 has the protruding portion 61 and the protruding portion 62, the base portion 63 may not be present, or the protruding portion 62 and the base portion 63 may be formed only on one side of the protruding portion 61 in the thickness direction. The additional material 6 may have a T-shaped cross section, a C-shaped cross section, or the like.

FIG. 10 shows an example in which the holes 6a are formed in one row only in the projection 61, and FIG. 11 shows an example in which two rows of holes 6a are formed in the width direction of the projection 62 only in the projection 62. In the example shown in FIG. 11, the hole 6a is formed in the projecting portion 62 farthest from the center line of the partition plate 4, so that the shear resistance generated in the columnar concrete filled in the hole 6a is reduced by the partition plate. Since the distance from the center line 4 increases, it is expected that the resistance force in the hole 6a also functions as a resistance force against the bending moment acting in the thickness direction of the partition plate 4. FIG.

1A...Reinforcing bar cage (within preceding excavation trench), 1B...Reinforcing bar cage (within trailing excavation trench),
2...vertical bar, 3...horizontal bar, 4...partition plate, 5...tension member, 51...fastener,
6...additional material, 61...protruding portion, 62...protruding portion, 63...base portion, 6a...hole,
7 ... penetrating muscles,
8 ... preceding excavation groove, 9 ... trailing excavation groove,
10 -- leading continuous wall, 11 -- trailing continuous wall.

Claims (2)

In the preceding excavated trench that was excavated first in the ground, a reinforcing bar cage with a partition plate was installed on the trailing excavated trench side adjacent to the preceding excavated trench, and concrete was placed in the preceding excavated trench. After that, the succeeding excavated groove is excavated to the position of the excavated groove adjacent to that side, a reinforcing bar cage is installed in the succeeding excavated groove, and concrete is poured to form the preceding excavated groove in the preceding excavated groove. A joint structure of a continuous wall and a continuous underground wall connecting the trailing continuous wall constructed in the trailing excavated trench,
An attachment having a projecting portion facing a direction intersecting the surface of the partition plate, and having a plurality of holes formed at intervals in the height direction in the projecting portion or a projecting portion connected to the projecting portion. A material is joined to at least one side of the partition plate continuously or intermittently in the height direction, and is placed in at least one of the preceding excavated groove and the succeeding excavated groove. is buried in
The additional material is joined to both surfaces of the partition plate,
Penetrating bars are inserted into the holes formed in the projecting portions of the additional members, and at least in the preceding excavated groove and the following excavated groove of the reinforcing bar cage installed in at least the preceding excavated groove. A joint structure for a diaphragm wall, characterized in that reinforcing bars are arranged on either one of the walls. 2. The joint structure of a diaphragm wall according to claim 1 , wherein both ends of said penetrating bar are in a state of being able to engage with the horizontal bar forming said reinforcing bar cage in the vertical direction .

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