JP2812041B2 - Construction method of underground diaphragm wall and excavator used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a concrete predecessor panel in the ground by excavating a leading groove and pouring concrete, and excavating a trailing groove between the preceding panels to concrete concrete. The present invention relates to a method of constructing an underground continuous wall by casting, and an excavator used in the method.

[0002]

2. Description of the Related Art Generally, an underground continuous wall is constructed by excavating a leading groove at a predetermined interval in the ground, placing concrete in the leading groove, constructing a leading panel, and then continuously connecting the leading panel. Then, a trailing ditch is excavated, and concrete is poured into the trailing ditch to construct a trailing panel.

In this case, the excavator for excavating the leading groove or the trailing groove is roughly classified into a bucket type excavator and a drum cutter type excavator. The bucket type excavator performs excavation by grasping earth and sand by a bucket, and there are a type that is attached to a lower end of a kelly bar and a type that is suspended from a lower end of a wire. When excavating using a bucket type excavator, after excavating the leading groove for the leading panel, a locking pipe is installed on the connecting surface of the leading groove that is continuous with the following groove, and the leading panel is constructed. After the trailing ditch has been excavated, the concrete surface to which the slime is not attached is exposed by pulling out the locking pipe, thereby achieving the integrity of the concrete between the leading panel and the trailing panel, that is, waterproofness.

[0004] On the other hand, a drum cutter type excavator rotates a drum cutter suspended by a wire to perform excavation, and at the same time, pumps up excavated earth and sand with a stabilizing solution for preventing collapse of an inner wall of a groove. When the drum cutter excavates the trailing groove between the preceding panels, the connecting surface of the preceding panel is cut and the concrete surface is cut to expose the concrete surface to which the slime is not attached in a jagged manner, so that the leading panel is cut. And the following panels (water stoppage) are enhanced.

The bucket type excavator has a relatively small base machine and is constructed in a narrow place, or a relatively small underground continuous wall is constructed (for example, when the wall thickness is thin (less than 1 m)). Or when the depth is shallow (about 6
0 m). On the other hand, the drum cutter type excavator can excavate with the drum cutter lowered into the groove, which is advantageous for construction of a large-scale underground continuous wall and construction on solid ground.

[0006]

However, in the bucket excavator, not only the noise vibration occurs when pulling out the locking pipe, but also the pulling out of the locking pipe needs to be performed in accordance with the curing time after the concrete is cast. Therefore, there is a problem that the process is restricted. On the other hand, there is a problem that the integrity of the continuous wall is inferior to that of the drum cutter type excavator.

[0007] On the other hand, the drum cutter type excavator does not have a problem associated with the installation of the rocking pipe, but it has a problem in that the excavated earth and sand is mixed with a stabilizing liquid and is pumped up by a pipe to treat the muddy water mixed with the earth and sand. It was necessary to install a large-scale wastewater treatment facility, which required a vast space at the construction site.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and requires a large-scale wastewater treatment facility without using a locking pipe in the construction of a relatively small underground continuous wall. It is an object of the present invention to provide a method for constructing an underground continuous wall capable of obtaining a sufficient water stoppage without causing any trouble, and an excavator used for the method.

[0009]

In order to achieve the above object, a method for constructing an underground continuous wall according to the present invention comprises a bucket driving device suspended from a lower end of a suspension wire and a detachable mounting and dismounting device at a lower end of the bucket driving device. Opening and closing a bucket that is mounted so as to dig a leading groove, placing a reinforcing bar in the leading groove and casting concrete to form a leading panel, and opening and closing the bucket by the bucket driving device A step of excavating a trailing groove continuously to the preceding panel, a step of removing the bucket from a bucket driving device and attaching a rotatable drum cutter to the bucket driving device, and a driving force of the bucket driving device. Rotating the drum cutter to cut the connection surface of the preceding panel; removing the drum cutter from the bucket driving device; Attaching the bucket to the bucket driving device, opening and closing the bucket by the bucket driving device to make the bottom of the trailing groove rough, placing a steel cage in the trailing groove and casting concrete, and Forming a trailing panel continuously to the panel, wherein when excavating a groove by opening and closing the bucket or during cutting by rotating the drum cutter, controlling the excavation posture or the cutting posture to be in a vertical state. It is characterized by.

The excavator used in the method of constructing an underground continuous wall according to the present invention excavates a leading groove for a leading panel and suspends a bucket for drilling a trailing groove following the leading panel. A wire-suspended bucket excavator detachably attached to a bucket drive suspended from the lower end of the wire; and a bucket drive of the wire-suspended bucket excavator, which is detachable by replacing the bucket with the bucket drive. A rotatable drum cutter that is rotated by the driving force of the bucket driving device to cut the connection surface of the preceding panel, wherein the wire-suspended bucket type excavator can move forward and backward toward the inner wall of the excavation groove. And a plurality of attitude control control plates provided in the control panel.

[0011]

The leading groove and the trailing groove are excavated by opening and closing a bucket detachably attached to a lower end of the bucket driving device by a bucket driving device suspended from a lower end of the wire. After concrete is cast into the leading groove to form the leading panel, a trailing groove is excavated between the leading panels. Thereafter, the bucket is removed from the bucket driving device, and a rotatable drum cutter is attached to the lower end thereof. The driving of the bucket driving device rotates the drum cutter to cut the connection surface of the preceding panel. Next, the drum cutter is replaced with a bucket, the bottom of the trailing groove is roughened, concrete is poured, and the trailing panel is formed continuously with the preceding panel.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 9 show a preferred embodiment of the underground continuous wall construction method according to the present invention. First, the guide trench 3 is formed at a position where the underground continuous wall of the ground 1 is to be constructed (FIG. 1), and the leading groove 6 is excavated by the wire suspension bucket type excavator 5 (FIGS. 2A and 2B). . As shown in detail in FIG. 3, the wire suspension bucket type excavator 5 includes an excavator body 5 a suspended from a lower end of a wire 7 and an excavator body 5.
a pair of buckets 9 and 9 which are rotatable and detachably attached to the bucket a, and the buckets 9 and 9 are provided on the excavator body 5a and the free ends of the buckets 9 and 9 are connected with the tips of the pistons. Hydraulic cylinders (bucket drive devices) 11, 11 for opening and closing the components 9, 9, respectively. The buckets 9, 9 rotate around the rotation shafts 13, 13 by driving the hydraulic cylinders 11, 11. It grabs earth and sand and discharges it to the ground. Thus, the excavator body 5
Since a is suspended by the wire 7, the excavation directivity tends to be more unstable than in the case of using a kelly bar. Therefore, a control plate CB is provided similarly to a drum cutter type excavator in which wire suspension is generally performed. By moving the control plate CB in contact with the inner wall of the preceding groove 6 and moving it in the horizontal direction, the posture of the excavator body 5a is controlled and the excavation direction is controlled.

The leading groove 6 is filled with the stabilizing liquid 14 to prevent the inner wall of the leading groove 6 from collapsing. Thereafter, the reinforcing bar 15 assembled on the ground is placed in the preceding groove 6 (FIG. 4), and is replaced with the stabilizing liquid 14 by using the tremy tube 17 to cast concrete (FIG. 5). By doing so, the preceding panel 19 is constructed (FIG. 6). After the preceding panel 19 is constructed, the buckets 9, 9 are opened and closed by the hydraulic cylinders 11, 11, so that the trailing groove 21 is excavated in a state of being filled with the stable liquid 14 in contact with the preceding panel 19 (FIG. 7 (a),
(B)).

Next, the bucket 9 attached to the excavator body 5a and the hydraulic cylinders 11, 11 is replaced with drum cutters 23, 23 shown in FIG. That is, each bucket 9, 9 is connected to the excavator body 5a by the connecting pin 25.
Hydraulic cylinder 1
Connecting pins 2 for pistons 11a, 11a
6 and 26 are rotatably connected. And
The drum cutters 23 are rotatable about a horizontal axis with respect to the drum cutter body 23a, and the drum cutter device body 23a is fixedly connected to the excavator body 5a by connection pins 25. Therefore, the connecting pin 2
If the buckets 9 and 9 are removed by removing the buckets 5 and 26 and 26, the drum cutter 23 can be easily attached by the connecting pins 25. Thus, the excavator body 5a
The drum cutter 23 mounted on the hydraulic cylinder 11
It is structured to rotate using hydraulic pressure for driving the motor.
At this time, the hydraulic cylinders 11, 11 are not used. The diameter of each drum cutter 23 is determined by the groove width after cutting, that is, the distance (for example, 200 cm) between the preceding panels 19, 19 and the respective preceding panels 19, 1.
Although it is preferable that the gap is not formed between the drum cutters 23 to prevent the displacement thereof, it is preferable that the length is about half of the dimension (in this case, 220 cm) including the cutting thickness of 9 (for example, 10 cm). Drum cutter 23 in
Performs only cutting, so theoretically any value (e.g.,
10 cm to 110 cm). At this time, since a gap is formed between the two drum cutters 23, 23, it is possible for a person skilled in the art to appropriately add a self-evident means for preventing the axial positions of the drum cutters 23, 23 from shifting. It is. Furthermore, this drum cutter 23
Is only for cutting the concrete surface, which is the connecting surface of the preceding panel 19, and does not excavate the groove. Therefore, unlike the conventional drum cutter type excavator, the soil and dirt accompanying the excavation are sucked up together with the stabilizing liquid 14. No suction port is required.

After cutting the connection surface of the preceding panel 19 in this manner (FIGS. 9A and 9B),
In order to remove the slime accumulated at the bottom of the trailing groove 21 by cutting, the drum cutter 23 is replaced with the bucket 9 again and the bottom of the trailing groove 21 is roughened (see FIG. 7B). Then, the rebar basket 15 assembled on the ground is installed in the trailing groove 21 (see FIG. 4). Thereafter, by replacing the stabilizing liquid 14 by using a tremy tube 17, fresh concrete is poured (see FIG. 5), and the concrete is cured and hardened, so that a subsequent panel (not shown) is connected to the preceding panel 19. Is built. In this manner, the connection surface of the preceding panel 19 is cut by the drum cutter 23, and the concrete surface to which the slime is not attached is exposed in a jagged manner, so that the concrete of the preceding panel 19 and the succeeding panel are highly integrated. Thus, it is possible to construct an underground continuous wall having excellent water stopping properties.

[0017]

As described above, according to the method for constructing an underground continuous wall of the present invention and the excavator used in the method, the bucket is used for excavating the trench itself, so that the base machine is small. Since excavation using a drum cutter-type excavator does not require a wastewater treatment facility, excavation can be performed even when the construction site is narrow.

Further, by cutting the connecting surface of the preceding panel with the drum cutter, a rocking pipe is not required unlike the case of using a conventional bucket type excavator. In addition to solving the problem of the time constraint that drawing must be performed according to the hardening time of concrete, the underground continuous wall with excellent waterproofness and high integration of the leading and trailing panels is constructed can do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view when forming a guide trench, which is one step of a method of constructing an underground continuous wall according to the present invention.

FIG. 2A is a side sectional view when a trench is excavated by a bucket. FIG. 2B is a front sectional view of FIG.

FIG. 3 is a detailed view of a main part of a wire-suspended bucket type excavator as an excavator used in the method of constructing an underground continuous wall according to the present invention.

FIG. 4 is a cross-sectional view showing a step of installing a reinforcing rod cage in a preceding groove.

FIG. 5 is a cross-sectional view showing a step of placing concrete in a preceding groove.

FIG. 6 is a cross-sectional view showing a process in which concrete is hardened to form a preceding panel.

FIG. 7A is a side sectional view showing a step of excavating a trailing ditch by a bucket. FIG. 8B is a front sectional view of FIG.

FIG. 8 is a detailed view of a drum cutter replaced with a bucket.

FIG. 9A is a side sectional view showing a step of cutting a connection surface of a preceding panel using a drum cutter. (B) It is a front sectional view of FIG.9 (a).

[Explanation of symbols]

 Reference Signs List 5 wire suspension bucket type excavator 6 leading groove 7 wire 9 bucket 11 hydraulic cylinder (bucket driving device) 15 steel cage 19 leading panel 21 trailing groove 23 drum cutter 27 trailing panel

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) E02D 5/20 102-103 E02D 5/18 102 E02F 5/02 E02D 17/13

Claims (2)

(57) [Claims] A step of excavating a leading groove by opening and closing a bucket detachably attached to a lower end of the bucket driving device by a bucket driving device suspended from a lower end of a hanging wire; Installing and pouring concrete to form a leading panel, excavating a trailing groove continuously to the leading panel by opening and closing the bucket with the bucket driving device, and removing the bucket from the bucket driving device. Removing, attaching a rotatable drum cutter to the bucket driving device, rotating the drum cutter with the driving force of the bucket driving device to cut the connection surface of the preceding panel, and removing the drum cutter from the bucket driving device. Removing and attaching the bucket to the bucket driving device; A step of opening and closing the bucket to perform the roughening of the trailing groove, and a step of installing a reinforcing bar in the trailing groove, casting concrete, and forming a trailing panel continuously to the preceding panel, A method of constructing an underground continuous wall, wherein when excavating a groove by opening and closing the bucket or cutting by rotating the drum cutter, the excavation posture or the cutting posture is controlled to be vertical. 2. A bucket for excavating a preceding groove for a preceding panel and a bucket for excavating a following groove continuously from the preceding panel are detachably attached to a bucket driving device suspended from a lower end of a suspension wire. A wire-suspended bucket type excavator, and a bucket driving device of the wire-suspended bucket type excavator, which is exchangeable with the bucket and is detachable, and is driven to rotate by the driving force of the bucket driving device to change the connection surface of the preceding panel It comprises a rotatable drum cutter for cutting, wherein the wire-suspended bucket type excavator is provided with a plurality of attitude control control plates provided so as to be able to advance and retreat toward the inner wall of the excavation groove. Excavator used for the construction method of underground diaphragm wall.