JP2789991B2 - Reinforcing cage for continuous underground wall construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel cage for constructing a continuous underground wall, and more particularly, to excavating and forming a unit excavation trench in the ground while overlapping the end thereof, and adding concrete to each excavation trench. The present invention relates to a reinforcing steel cage for continuous underground wall construction used in a continuous underground wall construction method of sequentially casting and constructing an integrated wall body.

[0002]

2. Description of the Related Art For example, as a means for installing a retaining wall when digging a ground and constructing an underground structure, or as a means for building a wall body for reinforcing a soft ground in the ground. Conventionally, a continuous underground wall construction method has been adopted. This continuous underground wall construction method is to continuously form unit excavation grooves having a predetermined width and length defined by the size of the excavation machine along the extension direction of the underground wall, and to concrete To form a continuous underground wall.

In such a continuous underground wall construction method, it is necessary to continuously integrate the underground walls constructed in each unit excavation groove without forming a gap between them, so that the underground walls are joined together. It is necessary to build the part with high accuracy.

[0004] As an example of a method of accurately constructing a joint of a middle wall in each place, concrete is sequentially poured into each unit excavation groove while excavating unit excavation grooves with their ends overlapped. There has been proposed a continuous underground wall construction method for constructing a high-precision underground wall integrated with the above. In other words, in this method, a reinforcing bar cage having a pair of partition plates for partitioning an area for placing concrete and an overlap portion is inserted into a unit excavation trench formed in advance, and the overlap portion is left between the partition plates. Only the concrete is cast in the underground wall to precede it. Then, in order to construct the underground wall adjacent to this, when excavating the subsequent unit excavation groove, the overlap portion is also dug, and by excavating the subsequent unit excavation groove, Exposing the partition plate of the rebar cage in the unit excavation groove on both sides excavated and formed,
By casting concrete at the portion sandwiched by the partition plates, the concrete wall at the joint, that is, the overlap portion, can be reliably and accurately constructed.

[0005] In the continuous underground wall construction method, concrete reinforced between a pair of partition plates is inserted into the reinforcing bar inserted into the unit excavation groove between the partition plate and the side wall surface of the excavation groove. A sheet member that covers the side wall surface of the unit excavation groove from the inside of the reinforcing bar is attached between the ends of both partition plates to prevent the overflow from flowing into the overlap portion through the gap. In order to prevent the partition plate from moving due to the weight of the concrete, a filler such as crushed stone is charged into the overlap portion in parallel with the rise of the concrete.

[0006]

However, in the above-mentioned continuous underground wall construction method, it is difficult to control the filling of the filler so that the level of the filler becomes substantially the same as the top level thereof as the concrete rises. When the filling level of the filling material is higher than the top level of the concrete, the filling material goes around the surplus portion of the concrete casting area through the gap between the partition plate and the side wall surface of the excavation groove, Since the sheet member is pushed into the inside of the rebar cage, there is a problem that the wall thickness of the underground wall may not be secured due to the bite of the sheet member.

On the other hand, when the top level of the concrete is considerably higher than the filling level of the filler, the sheet member is extruded by the pressure of the concrete and is damaged by the excavation, and the poured concrete is damaged. There was a problem that there is a risk of spills.

Accordingly, the present invention has been made to solve the above-mentioned problems, and it is possible to easily secure the wall thickness of an underground wall without requiring strict top management of concrete and filler, and to provide a sheet. It is an object of the present invention to provide a steel cage for constructing a continuous underground wall that can easily prevent damage to members.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object. The gist of the present invention is to form a unit excavation groove in the ground while overlapping its end and excavate it. Reinforcing cage used in the continuous underground wall construction method in which concrete is sequentially poured into the excavation groove to construct an integrated wall body, and concrete is left without leaving both ends of the unit excavation groove to secure an overlap portion And a pair of partition plates, which are inserted into the unit excavation grooves when the concrete is cast, and partition the area where concrete is cast from the overlap portion, and are disposed between the ends of the two partition plates. A reinforcing member having a sheet member covering a side wall surface of the groove, wherein the reinforcing member cage further comprises a wire mesh member positioned inside the sheet member and spanned between the ends of both partition plates. For building underground walls In the rebar cage.

[0010]

According to the reinforcing cage for constructing a continuous underground wall of the present invention having the above construction, a wire mesh member is attached to the inside of the sheet member between the ends of both partition plates. By filling the filler before the concrete, the wire mesh member prevents the filler from pushing the sheet member inwardly into the reinforced cage even if the filler wraps around the surplus portion of the concrete casting area. . In other words, concrete can be poured while the filler is filled first,
Top management of concrete and filler can be easily performed.

When the surplus portion is large, the sheet member can be prevented from being damaged by the pressure of the concrete by allowing the filler material to wrap around the surplus portion and pressing the sheet member in advance.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, as shown in FIG. 1, a reinforcing steel cage for constructing a continuous underground wall of the present invention is used when constructing a continuous underground wall having a circular cross section to construct an underground tank or a reservoir, for example. It is. That is, in the continuous underground wall having such a circular cross section, it is difficult to adopt a method of excavating and forming an excavation groove while cutting an end of the preceding underground wall, which is known as a so-called cutting method, due to its curvature. For this reason, the concrete underground wall construction method according to the present invention is to cast concrete while leaving its end in the excavation trench, and to construct a continuous underground wall while overlappingly excavating the end as an overlap portion. It is preferable to employ it.

Then, the continuous underground wall 10 having such a circular cross section is provided.
Is constructed by dividing a circular cross section into a number of unit excavation grooves having a predetermined width and a predetermined length determined according to the size of an excavating machine for constructing an underground wall, and excavating these unit excavation grooves. For example, the digging operation of the preceding digging groove 11 is performed first by setting every other as the preceding digging groove 11 and the following digging groove 12.

When the excavation of the preceding excavation groove 11 is completed, FIG.
As shown in FIG. 5, a reinforcing rod cage 13 having a trapezoidal cross section is inserted into the preceding drilling groove 11, and both ends of the preceding drilling groove 11 partitioned by the partitioning iron plates 14 of the reinforcing rod cage 13, that is, the overlapping portions 15 are left. Concrete is poured into the inside of the inside 13, and crushed stones 16 are introduced into the overlap portion 15 as a filler so that the reinforcing bar 13 does not move due to the pressure of the concrete.

Next, a trailing excavation groove 12 located between both adjacent preceding excavation grooves 11 is excavated. That is, the crushed stone 16 filled in the overlap portion 15 of the preceding excavation groove 11 is removed, and the subsequent excavation groove 12 is formed while the overlap portion 15 is dug. Here, since the partitioning iron plate 14 of the reinforcing bar 13 is attached obliquely according to the curvature of the continuous underground wall 10 having a circular cross section, the adjacent preceding excavation groove 11
The partition plates 14 of the inner reinforcing bar 13 are located parallel to each other, so that the excavation work of the trailing excavation groove 12 can be easily performed. After the excavation is completed, a reinforcing rod cage (not shown) for the trailing excavation groove is built in the trailing excavation groove 12, and concrete is poured between the exposed partitioning iron plates 14 on both sides to be integrally formed. The new continuous underground wall 10 is constructed. The construction of the underground wall in the trailing excavation groove 12 may be performed collectively after the construction of the underground wall in all preceding excavation grooves 11 is completed.
1 can be performed immediately after the construction work of the underground wall is completed.

The reinforcing steel cage 13 for constructing the continuous underground wall of this embodiment is used by being inserted into the preceding excavation groove 11 as described above. As shown in FIG.
A number of main reinforcing bars 20 extending in the vertical direction in the inside, a distribution reinforcing bar 21 and a reinforcing frame 22 for reinforcing the main reinforcing bars 20 and fixing them at predetermined positions, and an overlapping portion 15 in which concrete is cast And a pair of partition iron plates 14 for partitioning. Further, the pair of partition iron plates 14 are fastened and fixed by screw rebars 23, and the partition iron plates 14 have various reinforcing steel materials 24.
And a hanging bracket 25 are attached.

The rebar basket 13 further has a thickness of, for example, about 0.51 mm between each end of the pair of partition iron plates 14.
About 30 sheets of civil engineering sheet 30
7 and a welding wire mesh 28 is provided on the inner side thereof via a mounting bracket 29 and the like.
6 and is fixed. Here, the civil engineering sheet 30 is
By covering the wall surface of the preceding excavation groove 11 from the inside of the reinforcing bar 13,
Concrete poured into the reinforcing bar 13 is used as the partition iron plate 14.
And flows out to the overlap portion 15 through a gap between the welding wire mesh 28 and the side wall surface of the excavation groove.
The crushed stone 16 prevents the civil engineering sheet 30 from being pushed inwardly into the reinforcing bar cage 13 even if the crushed stone 16 goes around the surplus portion of the concrete casting area.

The use of the rebar cage 13 having such a configuration makes it possible to easily manage the work of constructing the underground wall in the preceding excavation groove 11. That is, crushed stone 1
Even if 6 goes around the overburden in the concrete casting area,
Since the extruding of the civil engineering sheet 30 can be prevented by the welding wire mesh 28 and the wall thickness of the underground wall can be easily secured, the concrete can be poured while the crushed stone 16 is filled in advance, and therefore, the concrete top level It is not necessary to perform strict top management such as making the top of the crushed stone 16 substantially coincide with the top level of the crushed stone 16, and the civil engineering sheet 3 because the top level of the concrete is considerably higher than the top level of the crushed stone 16.
0 can be easily avoided. Further, in the case where the surplus portion in the concrete casting area is large, the crushed stone 16 is wrapped around the surplus portion and the civil sheet 30 is pressed in advance, thereby easily preventing the damage of the civil sheet 30 due to the pressure of the concrete. can do. Furthermore, if the mesh of the welding wire mesh 28 is set to be equal to or larger than the size of the coarse aggregate in the concrete, the concrete can extrude the crushed stones 16 in the excavated portion and sufficiently fill the concrete.

In this embodiment, the case where a continuous underground wall having a circular cross section is formed has been described. However, the present invention is not limited to such a continuous underground wall, and the unit excavation groove may be formed by overlapping the end of the unit excavation groove. In the case of the continuous underground wall method of excavating and forming in the ground and constructing an integrated wall body by sequentially casting concrete in each excavation trench, continuous underground wall extending straight, etc. It can be easily applied to the continuous underground wall.

[0020]

As described in detail above, the reinforcing cage for the construction of a continuous underground wall according to the present invention comprises a pair of partition plates for partitioning a concrete placing area from an overlap portion, and ends of both partition plates. A reinforcing member having a sheet member disposed between the portions and covering a side wall surface of the unit excavation groove, further comprising a wire mesh member provided between the ends of both partition plates inside the sheet member. Therefore, even if the filler wraps around the surplus portion of the concrete casting area, the wire mesh member prevents the sheet member from being pushed out into the reinforced cage by the filler. Strict top management of concrete and filler is not required, and breakage of the sheet member can be easily prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a continuous underground wall constructed using a reinforcing steel cage for continuous underground wall construction according to the present invention.

FIG. 2 is an explanatory view of the continuous underground wall construction method according to the present invention, showing a portion A in FIG. 1 in an enlarged manner.

FIG. 3 is a plan view showing one embodiment of a steel cage for building a continuous underground wall according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Continuous underground wall 11 Leading excavation groove (unit excavation groove) 12 Trailing excavation groove (unit excavation groove) 13 Rebar cage 14 Partition iron plate 15 Overlap part 16 Crushed stone (filling material) 28 Welded wire mesh (wire mesh member) 30 Civil engineering sheet (Seat member)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-90314 (JP, A) JP-A-54-104604 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02D 5/18-5/20

Claims (1)

(57) [Claims] 1. A continuous underground wall in which a unit excavation groove is excavated and formed in the ground while overlapping its ends, and concrete is sequentially poured into each of the excavation grooves to form an integrated wall body. A reinforced cage used in a construction method, wherein concrete is inserted into the unit excavation groove when the concrete is excavated while leaving both ends of the unit excavation groove to secure the overlap portion. A pair of partition plates for partitioning the region from the overlap portion, and a reinforcing cage having a sheet member disposed between the ends of the partition plates and covering the side wall surface of the unit excavation groove, wherein the reinforcing cage is A rebar basket for constructing a continuous underground wall, further comprising a wire mesh member positioned inside the sheet member and provided between ends of the partition plates.