JP5635804B2 - Method for removing earth retaining member and method for installing slope reinforcing block using the same - Google Patents

Description

The present invention relates to a method of removing a soil retaining member after construction of soil retaining work using a soil retaining member such as a sheet pile (steel sheet pile).

When constructing underground pipes such as water pipes, gas pipes, culvert boxes, sewer pipes, gutters, etc., first install earth retaining members such as simple sheet piles, iron plates, and sheet piles at the positions where both walls of the groove should be constructed. After preventing the groove wall from collapsing, the ground is excavated to form a groove, and laying work such as a water pipe in the groove is performed. When the laying operation is completed, the earth retaining member is pulled out. The earth retaining member collected in this way is reused in the next construction. However, when sand or soil is piled up in the groove and the retaining member is pulled out, a void corresponding to the volume of the retaining member is generated in the ground. The inventors of the present application point out in Patent Documents 1 to 3 that the surrounding earth and sand move to fill this gap, and various problems such as ground subsidence may occur, and a soil retaining method for preventing this is disclosed. did. In addition, Patent Document 4 describes that earth and sand are dropped to fill a gap when a steel sheet pile is pulled out. Patent Literature 5 and Patent Literature 6 describe that “ground compaction agent” is poured to fill a cavity, and Patent Literature 7 describes that “filler” is injected. Furthermore, Patent Document 8 describes an invention for preventing ground subsidence when a soil retaining member is built.

Patent No. 3940735 JP 2008-101373 A JP 2006-291701 A JP-A 64-58713 JP 57-108311 A JP 57-108312 A JP 49-49404 JP 2009-185494 A

Patent Documents 1 to 8 describe a soil retaining method related to preventing adverse effects such as ground subsidence caused by voids in the trace of the retaining member. However, in Patent Documents 4 to 7, no specific explanation is given, and some technically contradictory descriptions are included, and the invention cannot be implemented based on these documents. . It seems that the inventions described in Patent Documents 4 to 7 were not implemented.

It is considered that the earth retaining member drawing method that does not generate a void due to the drawing of the earth retaining member was first implemented by the inventors of this application based on the invention described in Patent Documents 1 to 3 or Patent Document 8. As a result, it is possible to prevent ground subsidence caused by pulling out the retaining member and metal contamination caused by leaving the retaining member.

However, it has been found that there is a case where it is desired to quickly realize a stable state in which ground subsidence does not occur when trying to widely carry out this retaining member pulling method under various environments. For example, when installing a slope reinforcement block such as a decorative block on the riverbank or coastal slope, the construction period can be shortened by reaching a stable state as soon as possible so that the ground does not sink due to the load of this slope reinforcement block. it can. Also, since sand subsidence is likely to cause land subsidence, it is desirable that a stable state be established quickly.

An object of the present invention is to provide a method for removing a soil retaining member so that the soil retaining member removal location can quickly be stabilized in order to prevent ground subsidence when the soil retaining member is removed or immediately after the soil removal.

In order to solve the above-mentioned problem, the method of removing a retaining member according to the present invention is to install an injection pipe along the retaining member, and to pull up the retaining member while injecting the injection material from the injection tube, and to inject the trace of the retaining member. This is a method of removing the retaining member that is filled with the material. The injection tube is installed at a rate of one for the three retaining members, and the injection tube is installed at the position where the injection material is injected from the injection tube. The earth retaining member adjacent to the earth retaining member is pulled up, and then the earth retaining member adjacent to the soil retaining member at the position where the injection tube is installed is poured while injecting the injection material from the injection tube.

In addition, there is a method of removing the earth retaining member by installing an injection pipe along the earth retaining member, pulling up the earth retaining member while injecting the injection material from the injection pipe, and filling the extraction trace of the earth retaining member with the injection material. The injection pipe is installed at a ratio of one to the earth retaining member, and the injection pipe is installed without being fixed to the earth retaining member. While injecting the injection material from the injection pipe, the earth retaining member next to the earth retaining member at the position where the injection pipe is installed is pulled up, and then the earth retaining member at the position where the injection pipe is installed while injecting the injection material from the injection pipe. The next earth retaining member can be pulled up. Alternatively, in the earth retaining member group composed of the earth retaining member at the position where the injection pipe is installed and the both neighboring soil retaining members, it is a method of lifting one of the two adjacent soil retaining members last, and injecting in this last lifting An injection pipe lifting member having an arm directed toward the upper part of the pipe is mounted on the earth retaining member, the arm of the injection pipe lifting member is connected to the injection pipe, and the earth retaining member is pulled up while lifting the injection pipe by lifting the injection pipe.

Alternatively, the earth retaining member removing method according to the present invention is configured such that an injection pipe is installed along the earth retaining member, the earth retaining member is pulled up while injecting the injection material from the injection pipe, and the withdrawal mark of the earth retaining member is filled with the injection material. This is a method of removing the earth retaining member, characterized in that a two-component injection material having a uniaxial compressive strength of 0.20 N / mm ² or more and 0.40 N / mm ² or less after one week has elapsed after injection.

It is preferable to use a two-component injection material having a gel time of 30 seconds to 40 seconds.

Furthermore, the slope reinforcing block installation method of the present invention is a method using the above-mentioned soil retaining member removing method, in which the soil retaining member is installed along the length direction of the slope, and the slope reinforcing block is disposed on the slope below the soil retaining member. Installed, and then injecting the injection material from the injection tube, the earth retaining member is pulled up and removed, and a slope reinforcement block is installed on the slope above the position where the earth retaining member was located after the period when the injection material reaches the specified strength. To do.

The retaining member removing method of the present invention can pull out the retaining member without leaving a void in the ground. In addition, it is possible to realize a stable state in which ground subsidence does not occur in a short time. Therefore, it can be widely applied to various soils, topography, and uses.

It is a conceptual diagram which shows the raising operation | work of a earth retaining member. It is a front view which shows the earth retaining member pressure drawing machine. It is the same top view. It is a conceptual diagram which shows the example of an injection tube. It is a perspective view which shows a soil retaining member. It is a conceptual diagram which shows the slope reinforcement | strengthening block installation method. It is a top view which shows the 2nd example of the earth retaining member removal method. It is the same front view. It is a conceptual diagram which shows another example of an injection tube. It is a front view which shows an injection material hose protection member. FIG. It is a top view which shows the 3rd example of the earth retaining member removal method. It is the same front view. It is a top view which shows the 4th example of the earth retaining member removal method. It is the same front view. It is a top view which shows the 5th example of the earth retaining member removal method. It is the same front view. It is a front view which shows an injection pipe lifting member. It is the same top view. FIG. It is a conceptual diagram which shows the example of a single injection pipe. It is a conceptual diagram which shows the installation method of a single injection pipe.

EMBODIMENT OF THE INVENTION The form for implementing this invention is demonstrated based on drawing. FIG. 1 is a conceptual diagram showing the work of pulling up the earth retaining member, FIG. 2 is a front view showing an example of the earth retaining member pressure drawing machine, and FIG. 3 is a plan view thereof. The earth retaining member drawing machine 1 is a well-known device that is widely used as a noise-free and vibration-free pile material drawing machine, and performs pressure drawing and drawing of the earth retaining member by hydraulic pressure.

The earth retaining member drawing machine 1 has a chuck 2 for gripping the earth retaining member x which is an object of drawing or drawing, and an elevating device 3 for moving the chuck 2 up and down. In the upper part of the chuck 2, there is a small circular opening 4 that allows the earth retaining member x to pass therethrough. In addition, a plurality of grip portions 5 for gripping the existing earth retaining members are provided. By grasping the existing pile by the grip portion 5, a reaction force is taken from the existing pile, and the earth retaining member x is press-fitted or pulled out from the ground by the chuck 2. Moreover, the earth retaining member extracting machine 1 can move along the existing earth retaining member.

First, prior to drawing the earth retaining member, the injection pipe 6 is installed in the ground. Although the earth retaining member to which the injection pipe is attached in advance may be built, here, an example in which the injection pipe is installed along the already built earth retaining member will be described.

FIG. 4 is a conceptual diagram schematically showing an example of an injection tube. The injection tube 6 can be disassembled into a plurality of parts, and is a swivel 7, an intermediate rod 8, a discharge part 9, and a tip part 10 from the top.

The swivel 7 has a rectangular parallelepiped outer shape, and a first hose attachment port 13 and a second hose attachment port 14 are provided on the side surface. The inside of the swivel 7 has a double tube structure, and two independent fluid passages are formed. And the 1st hose attachment port 13 and the 2nd hose attachment port 14 are connected with the fluid passage of the main-body part 12, respectively. The swivel 7 can be directly mounted on the surface of the earth retaining member by welding.

A plurality of intermediate rods 8 are provided. Like the swivel 7, the inside has a double tube structure and two independent fluid passages are formed.

A discharge port 15 is formed on the side surface of the discharge unit 9. In the vicinity of the discharge port 15, there is a ball 16 that acts as a stopper. Further, a spring 17 is provided under the ball 16 to apply a force that pushes the ball 16 upward. When there is no weight on the ball 16, the ball 16 is in a position to close the flow path leading to the discharge port 15. When a strong pressing force is applied from above the ball 16, the ball 16 descends while pushing down the spring 17, and a flow path leading to the discharge port 15 is opened.

A bit 18 made of a hard material is attached to the lower end of the distal end portion 10. Even if the ground is hard, the bit 18 can cut and advance the soil and reduce the burden on the entire injection pipe 6 at the time of driving.

The swivel 7, the intermediate rod 8, the discharge part 9, and the tip part 10 are formed with screw parts so that they can be easily connected and separated from each other. The intermediate rods 8 can also be connected and separated.

The injection tube 6 is driven into the ground while drilling using a boring machine or the like. A number of intermediate rods 8 that can cover the lengths of the tip portion 10, the discharge portion 19, and the earth retaining member x are connected. Instead of the swivel 7, a plug that closes the upper end is attached to the uppermost intermediate rod 8 so that earth and sand do not enter the injection pipe 6 during installation. The injection pipes 6 may be installed for all the earth retaining members x. However, when the injection material reaches far, it may be installed every two or every three. Even when installing in such a manner, it is preferable to install the injection pipe 6 for the earth retaining member to be pulled out first.

The upper end of the injection tube 6 is set to a position lower by about 60 cm than the upper end of the earth retaining member x. When the earth retaining member x protrudes from the ground by about 50 cm, the upper end of the injection pipe 6 and the upper end of the uppermost intermediate rod 8 are buried about 10 cm below the ground surface.

Thereafter, the ground near the retaining member x is dug until the upper end of the injection pipe 6 appears. When the upper end of the injection pipe 6 is dug, the stopper is removed and the swivel 7 is connected. A short injection material hose 44 is attached to the hose attachment ports 13 and 14 with respect to about 10 injection pipes 6. The injecting material hose 44 is a flexible hose that is easily bent, and has a height below the upper end of the earth retaining member x. By doing so, it is possible to prevent interference with the chuck 2 of the earth retaining member pressure drawing machine 1, and it becomes extremely easy to perform drawing work and pouring work. Next, the earth retaining member pressure drawing machine 1 is installed on the existing earth retaining member, and is adjusted to the position of the earth retaining member x to be extracted. Here, as shown in FIG. 1, it is assumed that the injection pipe 6 is attached to the earth retaining member x (No. 3). A long injection material hose 44 is added to the injection pipe 6 and connected to a pump (not shown) for supplying the injection material.

FIG. 5 is a perspective view showing the earth retaining member. The earth retaining member x used in this example is called a sheet pile and is a commonly used earth retaining member. It has a rectangular plate-shaped central portion 21 and rectangular plate-shaped side portions 22 formed at both end portions of the central portion 21. The side portion 22 has a slightly larger angle than the right angle with respect to the central portion 21. Therefore, the earth retaining member x has a substantially U-shaped cross section. An end portion of the side portion 22 is formed with a bowl-shaped curl, and a portion called a section is provided. This section 23 serves as a joint for connecting adjacent earth retaining members. A suspension hole 24 is provided at the upper end of the earth retaining member x. The suspension hole 24 has an appropriate size to which a suspension hook or shackle can be attached. In addition to the sheet pile, the earth retaining member may be one having an H-shaped cross section or a cylindrical one.

The retaining member x is gripped by the chuck 2. The chuck 2 presses two thin members against the left and right sides of the surface of the central portion 21 of the earth retaining member x and does not contact the vicinity of the center of the central portion 21. Therefore, the injection tube 6 attached near the center of the central portion 21 does not hit. The opening 4 provided on the chuck 2 has only a minimum size necessary for the earth retaining member x to pass through, but the injection tube 6 is within the circle of the opening 4. A hose attached to the first hose attachment port 13 and the second hose attachment port 14 of the swivel 7 is passed through the earth retaining member pressure drawing machine. Here, a two-component type curing agent that mixes two types of liquids, liquid A and liquid B, is used. The hose passes through the opening 4 and is connected to a source of hardener (not shown).

When the retaining member 1 is grasped by the chuck 2, the retaining member 1 starts to be pulled up. While pulling up, the injection material is introduced through the hose, swivel 11 and injection pipe 10 and discharged into the ground. The earth retaining member 1 is pulled up so as to be pulled up by 50 cm in one step.

Here, an example of the injection material to be used will be described. In order to quickly fill the trace of the earth retaining member x, a curing agent having a short gel time for mixing two liquids is preferable. Therefore, an example of the instantaneous setting material will be described. Here, the product name YMS60tai (Sanko Colloid Chemical Co., Ltd.) of a non-aqueous glass type inorganic suspension type is used as an accelerator and a curing agent. This is a combination of a curing agent and an accelerator, the curing agent is mainly composed of sodium carbonate and sodium aluminate, and the accelerator is mainly composed of calcium hydroxide. Table 1 shows examples of the injection material, and Table 2 shows the physical properties of the injection material. The example of four types from which the mixing | blending of A liquid differs is shown. According to the formulation shown in Table 1, 200 liters of A liquid and B liquid can be prepared, respectively. This A liquid and B liquid are used on a one-to-one basis.

As the cement, blast furnace cement type B, which has a low risk of heavy metals such as hexavalent chromium, is used. Further, the curing agent and the accelerator are also safe and non-polluting drugs that do not contain heavy metals and do not contain poisonous substances or deleterious substances. Therefore, all of these injection materials are safe and have no adverse effects on the environment.

When the earth retaining member x is pulled up and 50 cm remains in the ground, the introduction of the injection material is finished. Washing water is supplied to the swivel using a hose with an injection material introduced on the spot. Thus, the inside of the injection tube 10 is cleaned. Then, the earth retaining member x is completely pulled out and lifted by a tow truck and moved to a safe place.

Since the trace where the earth retaining member x is pulled out is filled with the injection material, no void remains in the ground. Therefore, there are no adverse effects such as land subsidence or groundwater fluctuation in the surroundings during and after construction.

A first embodiment of the present invention will be described. In this example, uniaxial compressive strength of 1 week after a lapse after injection is characterized by the use of 0.20 N / mm ² or more 0.40 N / mm ² or less and comprising 2-component injection material. Here, as the uniaxial compressive strength, for example, a value measured by a method defined by JIS can be used.

In the four types of injection materials shown in Table 1, the injection material 2 and the injection material 3 correspond to this embodiment. In slope reinforcement block installation work, which will be described later, the ground where the block is installed is required to be in a stable state so as not to sink due to the load of the block. Here, when installing the slope reinforcement block on the riverbank, the load by the block is often about 2 t / m ² . That is, if it becomes a state which can endure the load of ² t / m <2>, the accumulation operation | work of a slope reinforcement block can be started.

Of the four types of injection materials shown in Table 1, the injection material 1 and the injection material 4 are also used in the soil retaining member removal method according to Japanese Patent Application No. 2009-100673 previously filed by the inventors of this application. . The injection material 1 is also an injection material with a relatively short gel time, but the strength after 7 days is 0.17 N / mm ² and does not reach the strength to withstand a load of ² t / m ² . In order to withstand a load of ² t / m ² , a strength of 0.20 N / mm ² is required, but it takes two weeks or more for the injection material 1 to reach its strength. Therefore, after injecting the injection material 1 and removing the earth retaining member, the slope reinforcing blocks cannot be stacked until two weeks or more elapses. Such a waiting time delays the construction period and increases the construction cost. In riverbank construction, part of the river flow may be stopped, but such construction is not always possible, and is limited to periods when the amount of water is low, so a shorter construction period is advantageous.

On the other hand, the injection material 4 has a strength of 0.30 N / mm ² after 7 days, and has reached the strength to pile up the slope reinforcing blocks. However, since the injection material 4 that hardens too quickly uses a large amount of blast furnace cement, there is a problem that the cost increases. In addition, the gel time is as short as 20 seconds or less, but the injection material with such a short gel time is difficult to handle, and if the work stagnates even during the injection, hardening starts near the tip of the injection tube and seems to be clogged. Trouble can occur. Therefore, the inventors have repeatedly studied and developed the injection material 2 and the injection material 3 shown in Table 1.

The mixing | blending of the injection material 2 is demonstrated. Liquid A is a mixture of 168.8 liters of water, 90 kg of blast furnace cement type B, and 4 kg of accelerator of YMS 60 tai. On the other hand, a mixture of 198 liters of water and 10 kg of a curing agent of YMS60tai is designated as B liquid. By using this A liquid and B liquid on a one-to-one basis, an injection material having a gel time at 20 ° C. of 40 seconds and an intensity of 0.20 N / mm ² per week can be obtained.

Next, the composition of the injection material 3 will be described. A mixture of 166.3 liters of water, 97.5 kg of blast furnace cement type B 97.5 kg, and 4 kg of promoter of YMS 60 tai is designated as liquid A. On the other hand, a mixture of 198 liters of water and 10 kg of a curing agent of YMS60tai is designated as B liquid. By using the A liquid and the B liquid in a one-to-one relationship, an injection material having a gel time at 20 ° C. of 30 seconds and a week strength of 0.27 N / mm ² can be obtained.

It may be blended so as to be between the injection material 2 and the injection material 3. Depending on the formulation, gel time and 1 week strength can be adjusted as appropriate.

The slope reinforcement block installation method based on this Example is demonstrated. FIG. 6 is a conceptual diagram showing a slope reinforcing block installation method. The present invention relates to a method of installing slope reinforcement blocks on slopes such as river dikes and coasts. Here, in order to expand the road width on the bank of a river, an example in which a slope reinforcement block is installed on the slope of the bank will be described.

FIG. 6 is a cross-sectional view of part of a river and a dike. In this figure, the right side of the embankment 31 is inside the river. A side surface of the dike 31 facing inward is a slope 32. A road is made above the embankment 31 and an inward end is a sidewalk 33. In order to extend this sidewalk 33, a construction is performed in which a soil 34 is placed on the inner side surface 32 of the embankment 31 and a decorative panel is attached. The bank 31 continues for a long time in a direction perpendicular to the paper surface. The direction perpendicular to the paper surface is the length direction of the levee 31 and the side surface 32.

Place soil near the embankment to restrict the flow of water so that it does not flow near the embankment. Moreover, the earth retaining members are built in two rows in parallel along the length direction of the slope. The first row of retaining members x1 is driven under the slope 32 into the riverbed. The second row of retaining members x2 is built on top of the slope 32 (FIG. 6a). Of the previously accumulated soil, the soil 34a between the first row of retaining members x1 and the slope 32 of the bank is removed.

Next, soil is piled up from the lower side of the slope, and a slope reinforcing block is attached thereon (FIG. 6b). When the slope reinforcement block is installed close to the second row of retaining members x2, the soil is returned between the first row of retaining members x1 and the levee slope 32, and the first row of retaining members x1 is pulled up (FIG. 6c). At this time, even if the injection material is not particularly injected, the sediment at the bottom of the river moves smoothly and fills the trace of the earth retaining member x1, and does not affect the surrounding ground condition.

Further, the second row of retaining members x2 is pulled out. At this time, such as implantation material 2 and injecting material 3 in Table 1, the uniaxial compressive strength of 1 week after a lapse after injection of 0.20 N / mm ² or more 0.27N / mm ² or less and comprising 2-component injection material injection While raising the earth retaining member x2. In this way, the space of the trace from which the earth retaining member x2 is pulled out is filled with the injection material, so that no void is generated in the ground (FIG. 6d). This injecting material uses less blast furnace cement than the injecting material 4, and the cost is reduced. Moreover, since the gel time is 30 seconds or more, it is easy to handle.

In the construction of this example, the load due to the accumulation of the slope reinforcing blocks is about 2 t / m ² , but the injected material has a strength of 0.20 N / mm ² or more when one week has elapsed after the injection. Therefore, the stacking of the slope reinforcing blocks can be started one week after the removal of the second row of retaining members x2. Since a preparation period of about one week is required for stacking the slope reinforcing blocks, the stacking can be started as it is when the preparation is completed, and there is almost no wasteful waiting time.

The soil is piled up above the position where the second row of retaining members x2 was located, and the slope reinforcing block is attached thereon. A slope reinforcement block is attached to the upper end of the slope 32. Thus, the width of the embankment 31 is expanded toward the inside of the river, and the width of the sidewalk 33 above the embankment 31 is also expanded (FIG. 6e). Remove the accumulated soil 34 and restore the water flow.

The example of construction on the river bank has been described above, but it can also be applied to slopes such as the coast. Especially in rivers and coasts, if the retaining members are left without being removed, the corrosion proceeds rapidly, and metal components flow out to the surroundings. However, according to the retaining member removing method and the slope reinforcing block installing method, the retaining member is removed after the construction is completed, so that environmental pollution can be prevented.

A second embodiment of the present invention will be described. FIG. 7 is a plan view showing a second example of the retaining member removing method, and FIG. 8 is a front view thereof. The earth retaining members are continuously built, but are identified by numbering sequentially from the left end. An injection pipe 6 is installed on the leftmost earth retaining member (number 1). The injection pipe 6 is not installed in the two subsequent soil retaining members (Nos. 2 and 3), and the injection tube 6 is installed in the fourth soil retaining member (No. 4). Thus, the injection pipe 6 is intermittently installed by skipping two.

Although it is possible to install the injection pipe 6 in all the earth retaining members, the materials and labor to be used increase and the cost increases. Therefore, it has been found that the cost for removing the retaining members exceeds the value of the collected retaining members. If the soil retaining member is left unattended and the surroundings are contaminated, it will be very expensive to recover, but such costs are difficult to consider. However, in this embodiment, the number of injection pipes to be installed is one-third, and the merit that the retaining member can be recycled exceeds the cost. By adopting this retaining member removing method, the cost can be reduced in the short term.

Here, a sheet pile as shown in FIG. 5 is used as the earth retaining member. The injection pipe 6 is attached along the center line inside the U-shaped groove of the earth retaining member. Although the injection pipe 6 may be installed by using a boring machine after the earth retaining member is installed, here, the earth retaining member is installed by attaching the injection pipe 6 in advance.

FIG. 9 is a conceptual diagram showing an example of an injection tube used here. The intermediate rod is two cylindrical pipes 8a and 8b provided in parallel. Each pipe 8a, 8b forms an independent hardener flow path. An anti-blur member 19 is attached in the middle of the intermediate rod. The anti-blur member 19 has a substantially rectangular parallelepiped outer shape, and two holes 19a and 19b for receiving the pipes 8a and 8b pass therethrough. The positional relationship between the pipes 8a and 8b is fixed by the anti-blur member 19, thereby preventing the pipes 8a and 8b from blurring when the earth retaining member is installed.

The front end portion 10 has a substantially rectangular parallelepiped shape, and the surface of the most distal end portion is formed in a shape that is cut off obliquely, and is easy to travel through the soil when built. In the discharge part 9 attached on the front-end | tip part 10, two flow paths merge and the liquid which passed through each pipe 8a, 8b is mixed. There are three outlets in the lateral direction on the side.

As mentioned above, since the front-end | tip part 10, the discharge part 9, and the blurring prevention member 19 have a substantially rectangular parallelepiped external shape, surface contact is made with the earth retaining member in each member. Therefore, it is firmly fixed to the earth retaining member only by lightly welding. Although the injection pipe 6 is attached to the earth retaining member at the construction site, it is difficult to roll due to the substantially rectangular parallelepiped member, and the attaching operation to the earth retaining member is easy even when the construction site is inclined. The injection tube 6 is attached so that the discharge part 9 is positioned slightly above the lower end of the earth retaining member.

The extraction of the earth retaining member will be described. As a large flow, the earth retaining member is pulled out in order from the end. However, since the earth retaining member with the injection pipe 6 is pulled out after the earth retaining member without the injection pipe adjacent thereto, the drawing order is partially changed. A short injection material hose 44 is attached to a hose attachment port in advance for about 10 injection pipes 6. A flexible hose that is easily bent is used so that the height is lower than the upper end of the earth retaining member x. By doing so, it is possible to prevent interference with the chuck 2 of the earth retaining member pressure drawing machine 1, and it becomes extremely easy to perform drawing work and pouring work.

In the example of FIGS. 7 and 8, the second earth retaining member is pulled out while stepping up prior to the first earth retaining member. At this time, a long hose is added to the injection pipe 6-1 of the first earth retaining member and connected to the pump. Since the pouring material hose 44 crawls below the end of the earth retaining member, it does not hinder the movement of the earth retaining member pressure drawing machine or the operation of the chuck. An injection material is injected from the injection tube 6-1. For example, the injection material shown in Table 1 can be used. This injection material is filled in the place where the second earth retaining member was present. In the state as shown in FIG. 2, injection material injection and earth retaining member extraction are performed. Thus, no gap is generated in the ground even when the second earth retaining member having no injection pipe is being pulled up. Next, the first earth retaining member is stepped up and pulled out while injecting the injection material from the injection pipe 6 into the ground.

Next, the third and subsequent retaining members are pulled out. In the third and subsequent sections, a description will be given in units of a group of three retaining members including a retaining member having an injection pipe 6 (for example, fourth) and a retaining member having no injection pipes on both sides thereof (for example, third and fifth). To do. First, one (for example, the third) of the earth retaining members that do not have the injection pipes on both sides is pulled out. At this time, the injection material is injected from the injection pipe 6-2 of the center earth retaining member of the earth retaining member group. Next, the soil retaining member (fifth) not having the other injection pipe is similarly pulled out. Finally, the center retaining member of the retaining member group is pulled out while injecting the injection material from the injection pipe 6. The sixth and subsequent earth retaining members are pulled out by the above procedure.

In the injection pipe used here, the positions of the first hose attachment port 13 and the first hose attachment port 14 for introducing the injection material are about 60 mm lower than the upper end of the earth retaining member. A pump or the like (not shown) for supplying the injection material is placed near the ground. Therefore, the hose into which the injection material is introduced is brought into contact with the upper end of the earth retaining member and turned back. However, since the corner of the upper end of the earth retaining member is pointed, there is a possibility that the injecting material hose may be damaged if it comes into contact with it. Therefore, it is preferable to attach an injection material hose protection member to the upper end of the earth retaining member. FIG. 10 is a front view showing the injection material hose protection member, and FIG. 11 is a side view thereof.

The injection material hose protection member 40 has a groove 41 for attaching to the upper end of the earth retaining member x. Two pulleys 42 are provided in the upper part. Moreover, the notch part 43 is formed in the center part.

The groove 41 is fitted into the center of the upper end of the earth retaining member x, and the injection material hose protection member 40 is attached to the earth retaining member x. In order to prevent the fall, it is preferable to fix the hatched portion of FIG. 10 by welding or the like. The injection material hose 44 is placed on the pulley 42. The pulley 42 prevents the injection material hose 44 from contacting the upper end of the earth retaining member x, and reduces the resistance. There is a hole 24 for attaching a hook or the like in the center of the top of the earth retaining member x. However, since there is a notch 43, this hole is not blocked. Therefore, a large-sized shackle or hook with high strength can be attached and lifted safely. Since the injection tube does not pass through the hole 24, the lifting operation is easy.

According to the earth retaining member removing method of this embodiment, a state where there is a void in the ground does not occur even during construction. Therefore, even on unstable ground such as sand, the retaining member can be removed without causing adverse effects such as land subsidence. Since one injection pipe is used for three earth retaining members, the construction cost is low and the construction period is short.

Although the case where the earth retaining member to which the injection pipe having a rectangular cross-sectional shape is attached has been described above, the case where the injection pipe having the cylindrical outer shape shown in FIG. 4 is used will be described. Using the boring machine, the injection pipe 6 is installed along the center line of the retaining member inside the U-shaped groove of the retaining member.

A third embodiment of the present invention will be described. FIG. 12 is a plan view showing a third example of the retaining member removing method, and FIG. 13 is a front view thereof. The arrangement is similar to that of the second embodiment, and the injection pipe 6 is intermittently installed by skipping two. The left end of the retaining member (number 1) is provided with an injection pipe 6, and the two following retaining members (numbers 2 and 3) are not provided with an injection pipe 6, and the fourth retaining member (number) In 4), an injection tube 6 is installed.

In this embodiment, an injection tube having a cylindrical outer shape as shown in FIG. 4 is used. The injection pipe 6 is installed along the center line inside the U-shaped groove of the earth retaining member. Although the injection pipe 6 is installed using a boring machine after the earth retaining member is installed, it is not fixed to the earth retaining member. It is preferable to install the tip of the injection tube 6 so as to protrude about 50 to 500 mm below the lower end of the earth retaining member x.

Prior to the first retaining member, the second retaining member is pulled out while stepping up. At this time, the injection material is injected from the injection pipe 6 of the first earth retaining member. Next, the first earth retaining member is stepped up and pulled out while injecting the injection material from the injection pipe 6 into the ground. Since the injection pipe 6 is not fixed to the earth retaining member, only the earth retaining member rises and the injection pipe 6 remains in the ground.

Next, the third and subsequent retaining members are pulled out. When a group of three retaining members including a retaining member with the injection pipe 6 and a retaining member without the adjacent injection pipes is used as a unit, a retaining structure without the adjacent injection pipes as in the second embodiment. Pull out the member. At this time, the injection material is injected from the injection pipe 6 of the center retaining member of the retaining member group. Thereafter, the central retaining member of the retaining member group is pulled out while injecting the injection material from the injection tube 6, but the injection tube 6 still remains in the ground. All the retaining members are pulled out by repeating the above procedure. Finally, the injection tube 6 is pulled out with a wrecker while injecting the injection material into the ground. Thus, the drawing trace of the injection tube 6 is also filled with the injection material.

In the second embodiment, the injection pipe 6 is also raised at the same time when the central retaining member is pulled out. Therefore, the earth retaining member has to be pulled up while removing the intermediate pipe of the injection pipe 6 from above, which is disadvantageous in that the work becomes complicated. In this embodiment, since the earth retaining member and the injection pipe 6 are pulled up separately, the operation is simplified.

A fourth embodiment of the present invention will be described. FIG. 14 is a plan view showing a third example of the retaining member removing method, and FIG. 15 is a front view thereof. The arrangement is similar to that of the third embodiment, and two injection pipes 6 are intermittently installed by skipping two. Also in this embodiment, an injection tube having a cylindrical outer shape is used and not fixed to the earth retaining member. By not fixing the injection pipe to the earth retaining member in this way, the earth retaining member provided with the injection pipe does not necessarily have to be pulled out last.

In this example, the retaining members are removed in order from the end. The first earth retaining member is pulled up while injecting the injection material from the injection pipe provided along the first earth retaining member, and then the second earth retaining member is pulled up while injecting the injection material from the same injection pipe. Further, the third to fifth earth retaining members are pulled up while injecting the injection material from the injection pipe provided along the fourth earth retaining member. All the retaining members are pulled out by repeating the above procedure. The injection tube 6 still remains in the ground. Finally, the injection tube 6 is pulled out with a wrecker while injecting the injection material into the ground. Thus, the drawing trace of the injection tube 6 is also filled with the injection material.

According to this embodiment, since the earth retaining members are removed in order from the end, the earth retaining member press-removing machine proceeds in one direction without returning in the middle. Therefore, the work is easy to understand and simple.

A fifth embodiment of the present invention will be described. 16 is a plan view showing a fifth example of the retaining member removing method, and FIG. 17 is a front view thereof. The fact that the injection pipe is not fixed to the earth retaining member is the same as in the fourth embodiment. The first injection pipe is installed in the second retaining member from the end, and every two injection pipes are arranged from there.

While injecting the injection material from the injection pipe provided along the second earth retaining member, the first earth retaining member is pulled up. While injecting the injection material from the same injection pipe, the second earth retaining member is also pulled up. Here, the injection tube still remains. Next, the third earth retaining member is pulled up while injecting the injection material from the injection tube. At this time, the injection tube lifting member is attached to the upper portion of the third earth retaining member, the injection tube is connected to the injection tube lifting member, and the earth retaining member is pulled up while the injection tube is lifted by the injection tube lifting member. Similarly, when pulling up the sixth earth retaining member, an injection pipe lifting member is attached, and the injection pipe provided along the fifth earth retaining member is pulled up.

18 is a front view showing the injection pipe lifting member, FIG. 19 is a plan view thereof, and FIG. 20 is a sectional view thereof. The injection pipe lifting member 60 has a groove 61 for attaching to the upper end of the earth retaining member x. A notch 62 is formed at the center. Further, an arm 63 is provided, and a wire 64 is attached near the tip of the arm 63.

The groove 61 is fitted into the center of the upper end of the earth retaining member x at the position next to the earth retaining member provided with the injection pipe, and the injection pipe lifting member 60 is attached to the earth retaining member x. In order to prevent dropping, fixing by spot welding or the like is preferable. There is a hole for attaching a hook or the like at the center of the top of the earth retaining member x. However, since the notch 62 is present, this hole is not blocked.

When the injection pipe lifting member 60 is attached to the earth retaining member x, the wire 64 is positioned near the upper part of the injection pipe. The lower end of this wire 64 is connected to the swivel 7 at the top of the injection tube 6.

Thus, the injection pipe 6 is also raised simultaneously with the raising of the earth retaining member x. Since the injection pipe 6 is located at a position shifted from the earth retaining member x to be pulled up, it can be easily pulled out without interfering with the earth retaining member pressure drawing machine. The process of pulling out the injection pipe 6 with a crane or the like after the earth retaining member x is pulled up can be omitted, and the construction period can be shortened.

A sixth embodiment of the present invention will be described. The arrangement of the earth retaining member and the injection pipe and the order of raising the earth retaining member are the same as those shown in FIGS. 14 and 15 regarding the fourth embodiment. FIG. 21 is a cross-sectional view showing a single injection tube used in this embodiment, and FIG. 22 is a conceptual diagram showing a method for installing a single injection tube.

An injection pipe is installed along the center line of the retaining member inside the U-shaped groove of the retaining member. The injection tube is inserted into the ground by a procedure similar to the double packer method. That is, a hole is first drilled to a predetermined depth by a boring machine, a cylindrical casing 71 is inserted into the hole (FIG. 22A), and then the injection tube 6 is inserted into the casing 71 (FIG. 22). (B)). After inserting the injection tube 6, the casing 71 is pulled out from the ground. By repeating the above procedure, one injection pipe 6 is installed in the ground for the three retaining members. So-called non-chemical liquids such as cement milk and cement bentonite, solution type gel time of about 5 minutes, gel time of about 1 minute, etc. can be used as the injection material, and these materials can be combined. Sequential injection can also be performed. As the injection pipe 6, for example, a PVC pipe having a diameter of 2.54 cm called an inch PVC pipe is used. A cap is put on the tip, and a discharge port for discharging the injection material is provided on the side surface slightly above. When the injection pipe 6 is installed in the ground, a cap is put on the upper end and the injection material hose 44 is connected.

A discharge port is provided near the tip of the injection tube 6. Further, a substantially cylindrical plug 16 is provided in the vicinity of the tip of the PVC pipe. The injection tube 6 and the stopper 11 are located at the position shown in FIG. 21A and block the discharge port. Although there is a slight gap between the stopper 16 and the cap, the stopper 16 is prevented from dropping downward by an O-ring provided at the lower part of the stopper 16 when only atmospheric pressure is applied. Therefore, when the injection pipe 6 is inserted into the ground, the discharge port is closed by the stopper 16 so that earth and sand do not enter the injection pipe 6. When the injection material is fed into the injection tube 6, the stopper 16 is pushed down by the injection material and moves down to the position shown in FIG. Thus, the discharge port previously blocked by the plug 16 is opened, and the injection material is discharged into the ground (FIG. 22 (c)). A small hole is made in the cap of this example so that air under the stopper 16 can escape and the lowering of the stopper 16 is not prevented. In addition, a conical recess is provided on the upper surface of the stopper so that the stopper effectively receives the pressure of the injection material, and the injection material released into the ground is sent upward.

The first earth retaining member is pulled up while injecting the injection material from the injection pipe 6a provided along the first earth retaining member, and then the second earth retaining member is pulled up while injecting the injection material from the same injection pipe 6a. Furthermore, the 3rd-5th earth retaining member is pulled up, inject | pouring an injection material from the injection pipe 6b provided along the 4th earth retaining member. All the retaining members are pulled out by repeating the above procedure. Finally, the injection tube 6 is pulled out with a wrecker while injecting the injection material into the ground. Thus, the drawing trace of the injection tube 6 is also filled with the injection material.

After removing all the retaining members, the injection tube 6 still remains in the ground. The injection tube 6 may be left in the ground without being removed. Unlike the double pipes used up to the fifth embodiment, the injection pipe 6 is inexpensive and can be shortened in construction period and cost by not being removed. Since it is made of a PVC pipe, there is no risk of the metal component flowing out, and it will not adversely affect the environment if left as it is. If the ground is found to be unstable after construction, the remaining injection tube 6 can be used to reinject the injection material.

In addition, you may comprise the injection pipe of the same structure with the material of natural decomposability instead of vinyl chloride. As such a naturally decomposable material, materials that are already mainly composed of paper components can be selected. The injection pipe left in the ground is disassembled and returned to the soil, so there is less space for the environment.

x. Earth retaining member Earth retaining member pressure drawing machine2. Chuck 6. 6. Injection tube Swivel 8 Intermediate rod 22. Central part 24. Suspension hole 40. Injection material hose protection member 42. Pulley 44. Injection material hose 60. Injection pipe lifting member 63. Arm 64. wire

Claims (4)

It is a method of removing the earth retaining member by a chuck for grabbing the earth retaining member, an elevating device for moving the chuck up and down, and an earth retaining member extracting machine having a grip portion for grasping the existing earth retaining member.
An injection pipe having two independent fluid passages is installed along the earth retaining member, and the earth retaining member is pulled up while injecting an injection material, which is a two-liquid type curing agent, from the injection pipe, and an extraction trace of the earth retaining member is injected. This is a method of removing the earth retaining member that is filled with a material, and the ratio of one injection pipe to three earth retaining members is such that the upper end of the injection pipe is lower than the upper end of the earth retaining member and the chuck does not interfere with the upper end of the injection pipe. placed in position, by attaching a flexible grout hose injection tube, the next earth retaining member position earth retaining member injection tube while injecting the injection material from the injection tube is installed pulling while stepping up, followed A method of removing a soil retaining member , wherein the soil retaining member at a position where the injection tube is installed is pulled up while stepping up while injecting an injection material from the injection tube. The soil retaining member removing method according to claim 1, wherein a two-component injection material having a gel time of 30 seconds or more and 40 seconds or less is used. This is a method of removing the earth retaining member by installing an injection pipe along the earth retaining member, pulling up the earth retaining member while injecting the injection material from the injection tube, and filling the extraction trace of the earth retaining member with the injection material. Uniaxial compressive strength at the time of 0.20 N / mm ² 0.27 N / mm or more ² It is a slope reinforcement block installation method using a soil retaining member removal method characterized by using the following two-component injection material. The soil retention member is installed along the length direction of the slope and below the soil retention member. A slope reinforcement block is installed on the side slope, and then the earth retaining member is pulled up and removed while injecting the injecting material from the injection pipe. The slope reinforcement block installation method which installs the slope reinforcement block on the slope. The slope reinforcement block installation method according to claim 3, wherein a two-component injection material having a gel time of 30 seconds to 40 seconds is used.

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