JP6915186B1 - Soil removal jig, soil removal device, and soil removal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of drawing in earth and sand from the outside of a reinforcing steel plate, to improve the workability of the earth and sand removal work at the final stage, and to cleanly discharge the earth and sand at a corner and the bottom of the reinforcing steel sheet. Provided are a soil removal jig for a soil removal device, a soil removal device, and a soil removal method. SOLUTION: When a reinforcing steel plate is press-fitted around a columnar existing structure, the upper and lower ends are opened in an earth removal jig of an earth removal device that discharges earth and sand in a gap between the reinforcing steel plate and the existing structure. It is provided with a cylindrical soil removal jig main body, and an injection port for injecting compressed gas is formed on the side plate of the soil removal jig main body, and the positive soil discharge jig main body is on the side of the existing structure. A suction notch for sucking earth and sand is formed in the face plate in the vertical direction, and a notch is not formed in the back plate on the opposite side as a straight shape in which the lower end is lowered below the upper end of the suction notch. [Selection diagram] Fig. 2

Description

The present invention relates to a soil removal device utilizing the air lift effect, a soil removal jig thereof, and a soil removal method using them.

Conventionally, as a reinforcement method for reinforcing columnar existing structures such as piers and their foundations, a temporary cut-off body is installed around the existing structure in advance to construct a dry area, and then earth and sand are excavated to provide reinforcement. The RC winding method and the steel plate winding method were used. However, there is a problem that it takes time and cost for the temporary construction work to install the temporary deadline body which is not directly related to the reinforcement work.

Therefore, in order to reinforce columnar existing structures such as existing piers and foundations, a reinforcing steel plate press-fitting method has been developed in which a reinforcing steel plate is press-fitted into the ground to reinforce it. This reinforced steel plate press-fitting method is superior in workability and economic efficiency to the conventional RC winding method and steel plate winding method in which a temporary cut-off body is installed and excavated. Therefore, in recent years, columnar RC structures have been constructed. It has become the mainstream of reinforcement construction methods.

As a method of discharging earth and sand in the reinforced steel sheet in this reinforced steel sheet press-fitting method, compressed air or gas is blown into the water mixed with earth and sand in the steel pipe to make the apparent specific gravity of the bubble mixture in the pipe smaller than that of the external liquid. There is known an air lift method that generates relative lift and discharges soil. However, simply applying the air lift method limits the diameter of the soil removal pipe in the narrow gap between the structure such as the pier and the reinforcing steel plate, resulting in poor soil removal efficiency and workability. There was a problem that it was bad.

For example, in Patent Document 1, in a soil discharge device using an air lift effect from an annular space on the outer periphery of a columnar structure, a water supply means for keeping the water level of the annular space at a predetermined water level and the annular space below the annular space are communicated with each other. A detachable partition member that forms a discharge flow path extending in the vertical direction, and a fluid supply pipe that injects air or a mixed fluid of air and water downward toward the bottom of the discharge flow path. Disclosed is an earth removal device using an air lift effect in which a high-pressure air supply pipe that injects high-pressure air horizontally or diagonally upward at a position above the lowermost end of the partition member is arranged in the discharge flow path. Claim 1, claims of patent document 1, paragraphs [0011] to [0021] of the specification, FIGS. 2, 3 and the like in the drawing).

However, although the soil removal device using the air lift effect described in Patent Document 1 has improved soil removal efficiency, it draws in the earth and sand outside the reinforcing steel sheet from the lower end of the reinforcing steel sheet that has been press-fitted, and is in the final stage. There was a problem that the workability of excavation of excavated soil was not good.

Japanese Unexamined Patent Publication No. 2003-328385

Therefore, the present invention has been devised in view of the above-mentioned problems, and the purpose of the present invention is to solve the problem of drawing in the earth and sand outside the reinforcing steel sheet, and to remove the earth and sand at the final stage. It is an object of the present invention to provide an earth removal device, an earth removal jig, and an earth removal method which have good workability and can cleanly discharge earth and sand at corners and the bottom of a reinforcing steel plate.

The earth removal jig of the earth removal device according to claim 1 is an earth removal device that discharges earth and sand in the gap between the reinforcing steel plate and the existing structure when the reinforcing steel plate is press-fitted around the columnar existing structure. A tubular earth removal jig body with open upper and lower ends is provided, and an injection port for injecting compressed gas is formed on the side plate of the earth removal jig body. At the same time, a suction notch for sucking earth and sand opened in the vertical direction is formed on the front plate on the side of the existing structure of the earth removal jig main body, and the lower end of the back plate on the opposite side has the suction notch. It is characterized by having a linear shape that descends downward from the upper end of the jig and no notch is formed.

The soil removal jig of the soil removal device according to claim 2 is the soil removal jig of the soil removal device according to claim 1, and the side plate of the soil removal jig main body is from the position where the injection port is formed. It is characterized in that the lower part is bent outward and widened.

The soil removal jig of the soil removal device according to claim 3 is the soil removal jig of the soil removal device according to claim 1 or 2, and the soil removal jig main body discharges the earth and sand in the reinforcing steel plate to the outside. It is characterized in that the upper part to which the earth and sand fluid discharge means to be connected is connected is divided into a plurality of parts.

The soil removal jig of the soil removal device according to claim 4 is the soil removal jig of the soil removal device according to any one of claims 1 to 3, and the suction notch is formed from the front plate to the side plate. It is characterized by being.

The earth removal device according to claim 5 is an earth removal device that discharges earth and sand in the gap between the reinforcing steel plate and the existing structure when the reinforcing steel plate is press-fitted around the columnar existing structure. The soil removal jig of the soil removal device according to any one of 1 to 4, the compressed gas supply means for supplying the compressed gas connected to the injection port, and the earth and sand connected to the upper end of the soil removal jig main body. It is characterized by comprising a fluid discharge means.

The earth removal method according to claim 6 is an earth removal method in which when a reinforcing steel plate is press-fitted around a columnar existing structure, the earth and sand in the gap between the reinforcing steel plate and the existing structure is discharged. It is characterized in that the earth and sand at the lowermost part of the reinforcing steel plate on the side of the existing structure is sucked from the suction notch and discharged by using the earth removal jig of the earth removal device according to 5.

According to the inventions according to claims 1 to 6, a suction notch for sucking earth and sand is formed on the existing structure side of the earth removal jig main body, and the lower end is extended downward and is notched on the opposite side. Is not formed, so that the problem of drawing in the earth and sand outside the reinforcing steel plate can be solved. Therefore, the workability of the soil removal work at the final stage at the bottom of the steel sheet is good. Further, according to the inventions of claims 1 to 6, since the area where the ascending current is generated is covered with the soil removal jig, the air lift effect can be applied locally, and a stronger lift is generated. Suction can be done from the lower end of the soil removal jig body or the suction notch. Therefore, gravel having a heavy specific density can be discharged, and the earth and sand at the corners and the bottom of the reinforcing steel plate can be discharged cleanly.

In particular, according to the invention of claim 2, since the side surface of the soil removal jig main body is widened, the jig connected to the injection port does not get in the way, and even when the reinforcing material of the reinforcing steel plate is used. The main body of the earth removal jig can be moved. Therefore, the earth and sand accumulated in the inner corner of the reinforcing steel plate can be discharged cleanly.

In particular, according to the invention of claim 3, since the upper part to which the earth and sand fluid discharge means is connected is divided into a plurality of parts, the entire earth and sand fluid discharge means such as the suction hose and the sunny hose that affect the amount of earth and sand is discharged is cut off. The diameter can be reduced without changing the area. Therefore, a desired amount of soil can be discharged by using a commercially available suction hose, sunny hose, or the like, which can be obtained in a required quantity at a low cost without custom ordering.

In particular, according to the invention of claim 4, since the suction notch is formed from the front plate to the side plate, suction is directly performed from the vicinity of the stiffener of the reinforcing steel plate which is the inside corner of the reinforcing steel plate. In addition, it is possible to cleanly remove the earth and sand at the corners and the bottom of the reinforcing steel plate.

FIG. 1 is a perspective view schematically showing an outline of seismic retrofitting work for soil removal using the soil removal device according to the embodiment of the present invention. FIG. 2 is a front view of a state in which soil is discharged using the soil removal device according to the present embodiment as viewed from the existing structure in the direction of the reinforced steel plate. FIG. 3 is a plan view showing a state in which soil is discharged using the same soil removal device. FIG. 4 is a vertical cross-sectional view showing a state in which soil is discharged using the same soil removal device.

Hereinafter, embodiments of the soil removal device, the soil removal jig, and the soil removal method according to the present invention will be described in detail with reference to the drawings.

First, with reference to FIGS. 1 to 4, the soil removal device according to the embodiment of the present invention, the soil removal jig thereof, and the soil removal method using these will be described. FIG. 1 is a perspective view schematically showing an outline of seismic retrofitting work for soil removal using the soil removal device 1 according to the embodiment of the present invention. Further, FIG. 2 is a front view of a state in which soil is being discharged using the soil removal device 1 according to the present embodiment as viewed from the existing structure in the direction of the reinforced steel plate, and FIG. 3 is a front view of the soil removal device of FIG. It is a top view which shows the state which the soil is discharged using 1. FIG. 4 is a vertical cross-sectional view showing a state in which soil is discharged using the soil discharge device 1 of FIG.

As shown in FIG. 1, in the soil removal device 1 according to the present embodiment, a reinforcing steel plate S1 is wound around a pier P1 which is a columnar existing RC structure (existing structure), press-fitted, and a non-shrink mortar or the like is used over time. It is suitably used for soil removal work in the reinforced steel plate press-fitting method, which performs seismic reinforcement by integrating with a hardened material.

In this reinforced steel plate press-fitting method, the pressure ring PR is applied by a plurality of press-fitting jacks PJ fixed to the side surface of the pier P1 by taking a reaction force from the existing RC structure to be reinforced. The reinforcing steel plate S1 is press-fitted into the ground through the structure. After that, the reinforcing steel plate S1 is welded or mechanically assembled to add lots (stages), and the reinforcing steel plate S1 is sequentially assembled and press-fitted to be press-fitted into the ground. Then, the soil removal device 1 is used in combination with the water jet to locally exert the air lift effect in a limited range in the soil removal jig 2, and the gap between the reinforcing steel plate S1 and the pier P1 is mixed with earth and sand. It creates a violent updraft in the running water (fluid) of the water, and discharges earth and sand containing gravel.

<Soil removal device>
As shown in FIGS. 2 to 4, the soil removal device 1 according to the present embodiment is a soil removal jig 2 having the soil removal jig main body 20 as a base, and a compressed gas in the soil removal jig 2. The compressed air supply means 3 for supplying the compressed air and the earth and sand fluid discharge means 4 connected to the upper end of the soil discharge jig main body 20 are provided.

(Soil removal jig)
The soil removal jig 2 is a jig that uses the soil removal jig main body 20 having an open upper and lower ends as a base and causes an air lift action locally in the soil removal jig main body 20. .. However, as shown in FIGS. 2 and 3, the soil removal jig main body 20 according to the present embodiment has a rectangular shape in which the horizontal cross-sectional shape of the intermediate portion 2b is elongated in the width direction. The depth is about 90 mm and the width is about W1 = 235 mm, which is less than the gap D1 (D1 = 94 mm in the figure) between the pier P1 and the reinforcing steel plate S1. Further, the upper portion 2a of the soil removal jig main body 20 is composed of three cylindrical bodies 21 divided into three forks along the width direction, and the opening at the upper end is divided into three circular openings 22 (see FIG. 3). ). Then, in the lower portion 2c of the soil removal jig main body 20, the side plate is bent outward in the middle and gradually widened in a tapered shape to the left and right in front view, and the width W2 of the lower end opening 23 becomes wider than the width W1 of the intermediate portion 2b. In the illustrated form, W2 = 342 mm.

Further, as shown in FIG. 2, the pair of left and right side plates of the soil removal jig main body 20 are formed with injection ports 24 for injecting compressed air from the compressed air supply means 3.

Then, as shown in FIG. 2, the inlet 24 is equipped with a connection fitting 32 and an air supply pipe 31 of the compressed air supply means 3, which will be described later. The difference in width between the width W2 of the lower end opening and the width W1 of the central portion is larger than the protrusion of the connection fitting 32 and the air supply pipe 31 attached to the injection ports 24 on both sides. Therefore, the earth removal jig main body 20 is moved to the stiffener St of the reinforcing steel plate S1 shown in FIG. 3 without the protruding connection fitting 32 and the air supply pipe 31 becoming an obstacle. be able to. Therefore, the earth and sand accumulated in the inner corner of the reinforcing steel plate S1 can be discharged cleanly.

Further, as shown in FIG. 2, a suction notch 25 for sucking earth and sand opened in the vertical direction is formed on the front plate on the bridge pier P1 side (existing structure side) of the soil removal jig main body 20. .. Therefore, as shown in FIG. 4, due to the rising flow of the air lift effect generated in the soil removal jig main body 20, the earth and sand mixed with gravel is pushed from the existing RC structure side through the suction notch 25 formed in the front plate. It can be sucked well and discharged.

On the other hand, the suction notch 25 is not formed on the back plate of the soil removal jig main body 20 on the opposite side. Therefore, the possibility of pulling in the earth and sand Sd from the back plate side, that is, the outside of the reinforcing steel plate S1 is reduced (see FIG. 4). Therefore, it is possible to solve the problem that the workability of excavation of excavated soil at the final stage is not good because the earth and sand Sd outside the reinforcing steel plate S1 is drawn in from the lower end of the reinforcing steel plate S1 that has been press-fitted as described in the prior art. ..

Although the case where the suction notch 25 is formed only on the front plate has been described as an example, the suction notch 25 may be provided over a part of the side plate from the pier P1 side. In this way, since the suction notch 25 extends to a part of the side plate, it is possible to directly suck from the vicinity of the stiffener St of the reinforcing steel plate S1 which is the inside corner of the reinforcing steel plate S1. This is because the earth and sand at the corners deposited at the lowermost part of the reinforcing steel plate S1 on the footing F1 of the pier P1 shown in 4 can be discharged cleanly.

Further, in the illustrated embodiment, the soil removal jig main body 20 is considerably small and compact with a height H1 = 750 mm. For this reason, lifting and the like is easy even under a bridge with short head restrictions (sky restrictions). Moreover, by reducing the size of the soil removal jig main body 20, the weight of the soil removal jig 2 as a whole can be reduced, lateral movement by human power becomes easy, and workability is improved.

(Compressed air supply means: Compressed gas supply means)
The compressed air supply means 3 includes a compressor 30 that compresses and sends out air by applying a high pressure, and an air supply pipe 31 that connects the compressor 30 and the above-mentioned injection port 24 formed on the side plate of the soil removal jig main body 20. , The connection fitting 32 for connecting the air supply pipe 31 and the injection port 24, and the like.

Of course, the compressed gas supply means according to the present invention is not limited to the one that supplies compressed air, and may be one that supplies other compressed gas. Further, as the compressed air supply means 3, a receiver tank may be provided in addition to the above. This is because workability is improved when the sediment fluid is continuously discharged by the air lift.

(Sediment fluid discharge means)
As shown in FIGS. 2 to 4, the earth and sand fluid discharge means 4 is mainly from three suction hoses 40 attached to the above-mentioned three cylindrical bodies 21 divided into three forks of the soil discharge jig main body 20. It is configured. The suction hose 40 has a cylindrical shape with a smooth inner peripheral surface whose pressure resistance is strengthened by a spiral reinforcing material, and the outer peripheral surface is reinforced with the reinforcing material to form irregularities to make it flexible. A rich hose. Further, the earth and sand fluid discharging means 4 has a function of discharging the earth and sand fluid mixed with gravel to the outside of the reinforcing steel plate S1.

Here, as described above, the upper portion 2a of the soil removal jig main body 20 is a small-diameter cylindrical body 21 divided into a plurality of parts along the width direction of the soil removal jig main body 20, so that the amount of soil discharged can be increased. The diameter of the suction hose can be reduced without changing the total cross-sectional area of the affected suction hose. Therefore, it is possible to achieve a desired amount of soil discharged by using a commercially available suction hose that can be obtained in a required quantity at a low cost without custom-ordering.

Although the suction hose 40 has been described as an example of the earth and sand fluid discharge means 4, it goes without saying that the earth and sand fluid discharge means made of another flexible and flexible pipe body such as a sunny hose may be used. do not have.

Further, as shown in FIGS. 3 and 4, the outer diameter of the suction hose 40 is smaller than the gap D1 between the pier P1 and the reinforcing steel plate S1. However, since the soil removal device 1 exerts the air lift effect within a limited range in the soil removal jig main body 20, a strong updraft can be generated, and any gravel that can pass through the suction hose 40 can be generated. It is possible to discharge.

In addition, the lower part 2c of the soil removal jig main body 20 has a wide shape along the lateral direction of the reinforcing steel plate S1. Therefore, gravel having a size that cannot pass through the suction hose 40 can be accumulated in the soil removal jig main body 20 to a certain extent. For this reason, the number of times the jig is pulled up to the water is less than when the gravel stuck in the pipe is pulled up to the water and removed by the conventional air lift method using a pipe and the pipe is lowered again. Work efficiency is improved accordingly.

According to the soil removal device according to the embodiment of the present invention described above, the soil removal jig thereof, and the soil removal method using these, the suction notch 25 is formed on the structure side opposite to the reinforcing steel plate S1. Therefore, it is possible to solve the problem of drawing in the earth and sand Sd outside the reinforcing steel plate S1. Therefore, the earth and sand Sd deposited at the lowermost part of the reinforcing steel plate S1 on the footing F1 of the pier P1 shown in FIG. 4 can be discharged cleanly, and the workability of the earth removal work at the final stage is improved. ..

Moreover, according to the soil removal device, the soil removal jig, and the soil removal method according to the present embodiment, since the area where the air lift is generated is covered with the soil removal jig 2, the air lift effect can be exerted locally. It is possible to generate a stronger ascending flow and suck the earth and sand mixed with gravel in the gap D1 between the reinforcing steel plate S1 and the pier P1 from the lower end opening 23 and the suction notch 25 of the earth removal jig main body 20. Therefore, gravel having a heavy specific density can be discharged, and the earth and sand at the corners can be discharged cleanly, and the final stage of soil removal work can be efficiently performed.

Although the soil removal device 1, the soil removal jig 2, and the soil removal method using them according to the embodiment of the present invention have been described in detail above, all of the above-mentioned or illustrated embodiments carry out the present invention. It merely shows one embodiment that has been embodied in the above. Therefore, the technical scope of the present invention should not be construed in a limited manner by these.

In particular, the earth removal jig 2 has been described by taking as an example a roughly square tubular shape having a rectangular horizontal cross section, but as shown in FIG. 1, the existing columnar structure is a columnar or oval type. In the case of the above, it is preferable to form a cylindrical body having an arcuate horizontal cross section according to the wall surface shape of the columnar existing structure. The shape of the inside corner between the reinforcing steel plate S1 and the stiffener St is not rectangular but arcuate, and the arcuate cylinder has a gap D1 between the reinforcing steel plate S1 and the pier P1 (existing structure). This is because the earth and sand inside can be efficiently discharged.

1: Soil removal device 2: Soil removal jig 2a: Upper part 2b: Intermediate part 2c: Lower part 20: Soil removal jig main body 21: Cylindrical body 22: Circular opening 23: Lower end opening 24: Injection port 25: Suction notch 3 : Compressed air supply means (compressed gas supply means)
30: Compressor 31: Air supply pipe 32: Connection fitting 4: Sediment fluid discharge means 40: Suction hose (sediment fluid discharge means)
P1: Bridge pier (existing structure)
F1: Footing G1: Ground Sd: Earth and sand (outside the steel plate) GA: Ground anchor PJ: Press-fit jack PM: Press-fit stand PR: Pressurized ring S1: Reinforcing steel plate St: Stiffener D1: Gap

Claims (6)

It is a soil removal jig of a soil removal device that discharges earth and sand in the gap between the reinforcing steel plate and the existing structure when the reinforcing steel plate is press-fitted around the columnar existing structure.
Equipped with a tubular soil removal jig body with open upper and lower ends
An injection port for injecting compressed gas is formed on the side plate of the main body of the soil removal jig, and the injection port is formed.
A suction notch for sucking earth and sand opened in the vertical direction is formed on the front plate on the side of the existing structure of the earth removal jig main body, and the lower end of the back plate on the opposite side has the suction notch. A soil removal jig for a soil removal device, which is characterized by having a straight line that descends from the upper end and no notch is formed. The soil removal jig for the soil removal device according to claim 1, wherein the side plate of the soil removal jig main body is bent outward and widened below the position where the injection port is formed. The soil removal device according to claim 1 or 2, wherein the soil discharge jig main body is divided into a plurality of upper portions to which a soil fluid discharge means for discharging the soil in the reinforcing steel plate is connected. Soil removal jig. The earth removal jig of the earth removal device according to any one of claims 1 to 3, wherein the suction notch is formed from a front plate to a side plate. It is a soil removal device that discharges the earth and sand in the gap between the reinforcing steel plate and the existing structure when the reinforcing steel plate is press-fitted around the columnar existing structure.
The soil removal jig of the soil removal device according to any one of claims 1 to 4, the compressed gas supply means for supplying the compressed gas connected to the injection port, and the upper end of the soil removal jig main body are connected to each other. A soil discharge device characterized by being provided with a sediment fluid discharge means. This is a soil removal method that removes the earth and sand in the gap between the reinforcing steel plate and the existing structure when the reinforcing steel plate is press-fitted around the columnar existing structure.
The soil removal jig of the soil removal device according to claim 5 is used to suck the soil at the lowermost part of the reinforcing steel plate on the side of the existing structure from the suction notch and discharge the soil. Soil removal method.

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