JP2012026216A - Injection mechanism of hardening material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an effective and appropriate injection mechanism for injecting a hardening material underground when pulling out an earth-retaining member such as a steel sheet pile.SOLUTION: The injection mechanism includes: an injection tool 11 which is fixed to the distal end part of the earth-retaining member such as the steel sheet pile 1 and jets the hardening material underground; and an injection pipe 21 for pressurizing and supplying the hardening material to the injection tool. The injection tool comprises: a protective pipe 12 fixed to the distal end part of the earth-retaining member; and an inner pipe 15 disposed inside the protective pipe. For the protective pipe, nozzle holes 14 are formed on the peripheral surface and the distal end part is turned to a sharp angle point part 13. For the inner pipe, the distal end is closed, a jetting port of a hardening material is formed on the peripheral surface, and a valve body 20 for opening and closing the jetting port is mounted. The valve body comprises a rubber tube which opens the jetting port by being elastically expanded to the outer side by the supply pressure when the hardening material is pressurized and supplied.

Description

  The present invention relates to earth retaining work carried out during ground excavation, and more particularly to an injection mechanism for injecting a hardened material such as cement bentonite into a void after extraction when the earth retaining member such as a steel sheet pile is pulled out after being backfilled. .

  As is well known, a temporary earth retaining wall (mountain wall) installed to hold the ground surrounding the excavation part during ground excavation is usually removed after the excavation part is backfilled. If you simply pull out and remove the earth retaining member, etc., there are concerns about various adverse effects such as leaving a gap and loosening the ground, so attach the injection pipe to the earth retaining member in advance, from the injection pipe There has been proposed a method of filling a void by drawing while injecting a hardener such as cement bentonite (see, for example, Patent Documents 1 to 3).

In the case of the above construction method, in order to reliably inject the hardening material when the earth retaining member is pulled out, it is necessary to reliably prevent the injection pipe from being clogged with the earth and sand when it is driven.
Therefore, in Patent Documents 1 and 2, a pipe having a valve shoe or a slide valve provided at the lower end with a valve shoe or a slide valve that is closed by the resistance to the ground and opened by the resistance of the ground when pulled out is attached to the steel sheet pile. I have to.
In Patent Document 3, a cylindrical stopper is provided at the tip of an injection pipe attached to a steel sheet pile, and when the steel sheet pile is driven, the stopper is urged by a spring to close the injection port, and when it is pulled out, a curing agent is used. The curing agent is sprayed by pushing down the plug by the pressure of the pressure and opening the spray port.

JP-A-57-108311 JP-A-57-108312 JP 2005-290963 A

  However, in the construction methods shown in Patent Documents 1 to 3, the injection pipe is configured with a movable member such as a valve shoe, a slide valve, or a stopper. Therefore, the injection pipe is blocked and the injection pipe is blocked, It may become impossible to inject by biting into a movable member, and therefore it is not always sufficient in terms of reliability, and both have dislikes that the structure is too complicated and expensive, so it is widely spread widely It has not reached.

  In view of the above circumstances, an object of the present invention is to provide an effective and appropriate injection mechanism capable of reliably injecting a curing material while having a sufficiently simple structure.

  The invention described in claim 1 is attached to a retaining member such as a steel sheet pile that is pressed into the ground during ground excavation and pulled out after the excavation portion is backfilled. When the retaining member is pulled out, a liquid such as cement bentonite is attached. An injection mechanism for injecting the hardened material into the cavity after being pulled out, the injection tool being fixed to the tip of the earth retaining member, and ejecting the hardened material into the ground, and hardening with respect to the injection tool An injection tube for pressurizing and supplying the material, and the injection tool is disposed in the protective tube and is pressurized and supplied from the injection tube. The protective tube comprises an inner tube for injecting the hardener into the protective tube, and the protective tube is formed with a nozzle hole for injecting the hardener into the ground on the peripheral surface, and the tip is a sharp pointed head. The end is an open end, and the protective tube has its tip The inner tube is fixed to the retaining member in a state of being directed downward, and the inner tube can be inserted into the inside from its rear end. The inner tube is closed at the tip and is added to the peripheral surface from the injection tube. A spout for ejecting the pressure-cured hardener is formed, and a valve body for opening and closing the spout is attached to the inner pipe, and the valve body is attached in close contact with the outer peripheral surface of the inner pipe A rubber tube that closes the jet port in a liquid-tight manner, and the valve body elastically expands outward by the supply pressure when the hardened material is supplied under pressure to open the jet port. It is characterized by being configured to eject the hardener from the outlet.

  The invention according to claim 2 is the hardening material injection mechanism according to claim 1, wherein the injection pipe and the injection tool are formed on the surface of the excavation side of the steel sheet pile as the earth retaining member. It is attached to the joint part currently formed in the side edge part.

  A third aspect of the present invention is the hardening material injection mechanism according to the first or second aspect, wherein the injection pipe is provided at a root portion of the tip of the earth retaining member and the ground is excavated. The length of the injection pipe is set so that the upper end of the injection pipe is exposed on the bottom surface of the excavation, and a flexible hose as another injection pipe can be connected to the upper end of the injection pipe. Is placed along the earth retaining member and the excavation portion is backfilled with the upper end thereof reaching the surface portion, and then the hardening material is added to the injection tool from the surface portion through the hose and the injection pipe. The hose can be pulled out together with the earth retaining member while supplying pressure.

  The injection mechanism of the present invention is attached in advance to a retaining member such as a steel sheet pile, and is press-fitted into the ground together with the retaining member, and when the retaining member is pulled out, the retaining member is injected while injecting a hardener into the ground from the injection mechanism. By pulling out, it is possible to immediately fill the cavities after the drawing with a hardener and close the gaps, and it is possible to prevent various adverse effects caused by the gaps remaining after the drawing.

In particular, the injection mechanism of the present invention employs an injection tool having a configuration in which an inner tube is arranged in a protective tube, and injects a hardening material from the inner tube into the protective tube, and further through a nozzle hole formed on the peripheral surface of the protective tube. In addition, the inner pipe is provided with a valve body made of a rubber tube that naturally expands slightly due to the supply pressure of the hardener and opens and closes the jet outlet. There is no possibility that earth and sand enter the inner pipe and block it, so that the hardener can be reliably injected at the time of drawing. Moreover, since the groundwater does not enter the inner pipe before the earth retaining member is pulled out, the inner pipe can be prevented from being rusted.
In addition, the injection mechanism of the present invention has a very simple and simple configuration with no moving parts except for a slight expansion of the valve body, and only with inexpensive general-purpose materials and parts such as steel pipes, steel materials, and rubber tubes. It can be manufactured at low cost, and it does not require any troublesome work or operation other than the need to install this injection mechanism to the steel sheet pile. It is very reasonable and effective.

The embodiment of the injection mechanism of the present invention is shown, and is a schematic configuration diagram showing a state in which the injection mechanism of the present embodiment is attached to a steel sheet pile. It is a figure which shows the structural example of an injection tool. It is a figure which shows the structural example of an injection tool. It is a figure which shows the structural example of a protective tube. It is a figure which shows the structural example of an inner pipe | tube similarly. It is a figure which shows an example of the earth retaining work by the steel sheet pile to which the injection | pouring mechanism was attached, and is a figure which shows the process until excavation. It is a figure which shows the process until it pulls out a steel sheet pile. It is a figure which shows the other example of the earth retaining work by the steel sheet pile to which the injection | pouring mechanism was attached, and is a figure which shows the process until excavation. It is a figure which shows the process until it pulls out a steel sheet pile.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, an injection mechanism 10 according to the present embodiment is used by being attached to a surface on the excavation side of a steel sheet pile 1 as a retaining member, and is near the tip of the steel sheet pile 1 (for example, An injection tool 11 fixed at a position of about 50 cm from the tip) and an injection pipe 21 for supplying a liquid hardener (for example, cement bentonite) to the injection tool 11 from the ground surface under pressure. It is.
In this embodiment, as shown in FIG. 1 (b), the steel sheet pile 1 is press-fitted while being excavated by the auger 2, so that the injection mechanism 10 is made of steel as in the conventional method shown in Patent Documents 1 and 2. Since it will contact with the auger 2 when attached in the recessed part of the sheet pile 1, in this embodiment, either one of the joint parts 1a formed in the both-sides edge part of the steel sheet pile 1 (in the example of illustration, excavation side) The injection mechanism 10 is attached to the joint portion on the right side when viewed from the side to avoid interference with the auger 2.

As the injection pipe 21 in the injection mechanism 10 of the present embodiment, a general-purpose steel pipe (for example, SGP 15A) frequently used as a construction / civil engineering material can be suitably employed, as shown in FIG. The injection pipe 21 may be piped from the injection tool 11 to the top, and the important point may be firmly fixed to the steel sheet pile 1 by welding or by appropriate means to prevent the injection pipe 21 from dropping off during press-fitting or withdrawal. .
In addition, in the case where the injection pipe 21 is piped over almost the entire height of the steel sheet pile 1 as in the illustrated example, when the steel sheet pile 1 is long, a plurality of steel pipes may be connected by a socket joint. In that case, the socket joint may be welded to the steel sheet pile 1.
Further, as will be described later, the hose 31 as another injection pipe is connected to the upper end of the injection pipe 21 at the time of starting the pressure supply of the curing material (see FIG. 7B). The upper end of the injection tube 21 may be sealed with a plug 22 to prevent earth and sand from entering.

  On the other hand, the injection tool 11 fixed to the front end portion of the steel sheet pile 1 is welded and fixed to the joint portion 1a at the front end portion of the steel sheet pile 1 as shown in detail in FIGS. The tube 12 and an inner tube 15 disposed in the protective tube 12 are configured. The distal end of the injection tube 21 is connected to the base end (upper end) of the inner tube 15.

The protective tube 12 is a member obtained by processing a steel material into a cylindrical shape. In this embodiment, the rear end (upper end) has a substantially pentagonal cross section as shown in FIG. 4 and the front end (lower end). ) Is formed as an acute pointed head 13 and is welded to the steel sheet pile 1 with the flat bottom face closely attached to the joint 1a with the pointed head 13 facing downward. It is firmly and securely fixed so that it does not become a large resistance when being pulled out or pulled out and does not fall off the steel sheet pile 1.
A plurality of nozzle holes 14 are formed on the peripheral surface of the protective tube 12 (four surfaces excluding the bottom surface in the illustrated example) (three in each illustrated example are three on each surface). As shown in FIG. 2 (b), the hardened material ejected from 15 into the protective tube 12 is ejected from the nozzle holes 14 toward the surrounding ground.

As shown in detail in FIG. 5, the inner tube 15 disposed in the protective tube 21 is a tube body in which a short tube 16 is a main body and sockets 17 are connected to both ends thereof, and a socket on the distal end side. The tip of the inner tube 15 is closed by attaching the plug 18 to the member 17. A plurality of jets 19 for ejecting the hardened material pressurized and supplied from the injection pipe 21 are formed on the circumferential surface of the short tube 16 in a spiral arrangement, and the outer circumferential surface of the short tube 16. Is fitted with a rubber tube as a valve body 20 for opening and closing the spout 19.
The rubber tube as the valve body 20 is reinforced by a bias reinforcing material and has sufficient strength and elasticity. The rubber tube is attached in close contact with the outer peripheral surface of the short tube 16 and normally closes the jet port 19 in a liquid-tight manner. However, when the hardened material is supplied under pressure, it is elastically slightly expanded outwardly as shown in FIG. 5 (d) by the supply pressure, and the ejection port 19 is opened, whereby the hardened material is ejected. It is like that. Of course, when the pressure supply of the hardener is stopped, the valve body 20 naturally contracts due to its own elasticity, thereby closing the ejection port 19.

  As shown in FIG. 2, the inner tube 15 is inserted into the inside from the rear end (upper end) of the protective tube 12 which is an open end, and the entire inner tube 15 is almost entirely inside the protective tube 12 except for the rear end portion. In this state, the injection tube 21 connected to the inner tube 15 is fixed to the steel sheet pile 1 by welding or the like, so that the inner tube 15 comes out of the protective tube 12. There is no room for it to be held stably in the protective tube 12.

The inner diameter (minimum inner dimension) of the protective tube 12 is set to be slightly larger than the outer diameter (maximum diameter) of the inner tube 15, and the inner tube 15 is inserted into the protective tube 12 without any trouble. It is sufficient that the valve body 20 can be allowed to slightly expand in the protective tube 12. However, in this embodiment, since the inner tube 15 having a circular cross section is disposed in the protective tube 12 having a substantially pentagonal cross section, the inner surface of the protective tube 12 and the outer surface of the inner tube 15 are in close contact with each other. Since a gap for allowing expansion of the valve body 20 (that is, opening of the ejection port 19) is naturally secured between them, the inner tube 15 can be inserted into the protective tube 12 within a range. If so, their dimensions may be approximately the same.
Moreover, since the annular clearance formed between the rear end of the protective tube 12 and the peripheral surface of the inner tube 15 also functions as a spout for blowing the hardened material upward, leave the clearance as it is. However, there is an advantage that when the steel sheet pile 1 is pulled out, there is an advantage that the pulling resistance can be reduced by ejecting the hardened material upward from the gap. Therefore, it is preferable to leave the gap.
However, since there is room for dirt to enter the protective tube 12 from the gap, if there is a concern that the sand will enter the protective tube 12 and blockage occurs when the gap is particularly large, the protective tube 12 The gap may be closed by welding the end to the peripheral surface of the inner tube 15 (the peripheral surface of the socket 17 on the rear end side).

FIGS. 6 to 7 are work procedures when constructing and removing a retaining wall using the steel sheet pile 1 to which the injection mechanism 10 is attached as a retaining work when constructing the box culvert 3 in the ground. Is shown.
The steel sheet pile 1 to which the above injection mechanism 10 (injection tool 11 and injection pipe 21) is attached as shown in FIG. 6 (a) is press-fitted into the construction position of the retaining wall, and the tip portion thereof as shown in FIG. 6 (b). To the bottom of the excavation bottom. In this manner, the steel sheet piles 1 are sequentially press-fitted to construct the retaining wall, and then the inside of the retaining wall is excavated as shown in (c).
Therefore, the box culvert 3 is constructed on the bottom of the excavation as shown in FIG. 7 (a), and after completion, the entire excavation part is backfilled as shown in (b).
After that, the steel sheet pile 1 is pulled out and the earth retaining wall is removed. At that time, a pressurized supply device 30 for supplying a hardening material such as cement bentonite to the injection mechanism 10 is installed on the ground surface and injected. The plug 22 (see FIG. 1) that closed the upper end of the tube 21 is removed, and the injection tube 21 and the pressurized supply source device 30 are connected via a flexible hose 31.
Then, as shown in (c), the hardening material is pressurized and supplied to the injection tool 11 from the pressure supply source device 30 through the hose 31 and the injection tube 21, and the hardening material is added to the surrounding ground by the injection tool 11. The steel sheet pile 1 is pulled out while pressure injection.
Thereby, a hardening material is immediately filled with the space | gap after pulling out the steel sheet pile 1, and a space | gap does not remain, but a stable ground can be recovered.
The drawn steel sheet pile 1 can be reused, and the injection mechanism 10 attached to it can be quickly cleaned before the hardened material adhering to or remaining in the injection tube 21 or the injection tool 11 is cured. Once cleaned, it can be reused as it is.

As explained above, by attaching the injection mechanism 10 of the present invention to the steel sheet pile 1 in advance and pulling out the steel sheet pile 1 while injecting the hardened material into the ground by the injection mechanism 10 when the steel sheet pile 1 is pulled out. The voids after being pulled out are immediately closed by the curing material, and various adverse effects due to the remaining voids can be prevented in advance.
In particular, the injection tool 11 of the present invention has a valve body 20 made of a rubber tube attached to the inner tube 15 for ejecting the hardened material, and the injection port 19 is sealed by the valve body 20 when the steel sheet pile 1 is press-fitted. Since the inner tube 15 is disposed in the protective tube 12 so that the hardener is ejected through the nozzle hole 14, earth and sand will not enter the protective tube 12 and the inner tube 15 during press-fitting. Even if some earth and sand enter 12, it can be blown off by the ejection pressure of the hardener, and therefore it is possible to reliably prevent the injection from becoming impossible as in this type of conventional injection mechanism.
The injection mechanism 10 of the present invention has a very simple and simple configuration in which there are no mechanical moving parts and there is no moving part except that the valve body 20 is elastically slightly expanded. It can be manufactured at low cost only with general-purpose inexpensive materials and parts such as rubber tubes, and it is troublesome and complicated at the time of press-fitting and injection except that this injection mechanism 10 is attached to the steel sheet pile 1 in advance. Therefore, the cost increase of the entire earth retaining work by using it is insignificant, and it is extremely reasonable and effective.

  Although the basic embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various design changes and applications such as those listed below are possible.

The injection tube 21 may be a double tube or a multiple tube instead of a single tube as in the above embodiment.
Moreover, in the said embodiment, although the steel pipe as the injection pipe 21 was piped to the top so that it might cover almost the full height of the steel sheet pile 1, there is no fear of a damage at the time of press-fit or pull-out, and it crushes by earth pressure. If there is no concern about this, another material such as a PVC pipe or a pressure-resistant hose can be employed instead of a part or the whole of the pipe.
In particular, instead of previously piping the injection pipe 21 made of a steel pipe to the top of the steel sheet pile 1 as in the above-described embodiment, the steel pipe as the injection pipe 21 is simply piped to the base of the tip portion. In this case, it is also preferable that a hose is connected as another injection tube, and the operation is performed according to the procedure shown in FIGS.
That is, as shown in FIGS. 8A to 8C, the length of the injection pipe 21 is shortened so that the upper end portion of the injection pipe 21 is exposed on the excavated bottom surface after excavation. When the retaining wall is constructed as shown in b), the entire injection tube 21 is buried in the ground, and when the excavation is completed as shown in (c), the upper end of the injection tube 21 is on the bottom of the excavation. Leave it exposed.
Then, as shown in FIG. 9 (a), the box culvert 3 is constructed on the bottom of the excavation, and at this time, a flexible hose 31 as another injection pipe is connected to the upper end of the injection pipe 21 to the steel sheet pile 1. Arrange along the top and lead the upper end to the surface.
In this state, as shown in (b), the excavation part is backfilled and the hose 31 is also buried as it is, and when the steel sheet pile 1 is pulled out, the hardening material supply source device 30 is installed on the ground surface part and the hose 31 is attached thereto. If the steel sheet pile 1 is pulled out together with the hose 31 while being pressurized and supplied to the injection tool 11 via the hose 31 and the injection tube 21, the hose 31 is wound up on the ground surface. good.
In this way, not only can the cost be reduced by substituting the steel pipe as the injection pipe 21 with the necessary minimum but the other cheaper hose, as in the case of the process shown in FIGS. Since the hose 31 does not need to be pulled up to a high place when the steel sheet pile 1 is pulled out, there is an effect that the workability can be improved.
In addition, since the hose 31 used in this case is buried in the backfilling soil and receives the earth pressure, the hose 31 is not damaged at the time of pulling out and is crushed by the earth pressure, so that the supply of the hardened material becomes impossible. It is practical to use a pressure-resistant hose having such a strength that it does not become.

In addition, the configuration of the injection device 11 in the above embodiment is merely a preferred example, and the shape and dimensions of the protective tube 12 and the inner tube 15 that configure the injection device 11 and the specific configuration of each part thereof are described in the present invention. Various modifications can be made without departing from the scope of the present invention.
For example, the protective tube 12 has a pointed head 13 and is capable of being firmly fixed so as not to cause a large resistance during press-fitting and not to fall off the steel sheet pile 1. Any material can be used as long as the hardened material ejected from the inner tube 51 can be ejected from the nozzle hole 14 to the surrounding ground while the tube 15 is stably held. The shape is not limited to a pentagonal cross-sectional shape, and a simple circular steel pipe or square steel pipe can be formed by machining, and the number, position, interval, and the like of the nozzle holes 14 may be arbitrarily set. .
Although it is realistic that the protective tube 12 is fixed to the steel sheet pile 1 by welding as in the above embodiment, if there is no concern that the protective tube 12 may be accidentally dropped, for example, other bolt fastening or the like may be used. It does not preclude fixing in a removable state by the technique.

The inner tube 15 may be configured to open and close the jet port 19 formed on the peripheral surface by a valve body 20 made of a rubber tube that expands due to the supply pressure of the curing material. For example, it is conceivable that the inner tube 15 is formed integrally with the distal end portion of the injection tube 21 so that the distal end portion of the injection tube 21 also serves as the inner tube 15 as it is.
Specifically, the tip of the injection tube 21 is sealed with a plug 18, a jet 19 is formed on the peripheral surface of the tip, and a valve body 20 made of a rubber tube is attached thereto, and the tip is protected as it is. By inserting it into the tube 12, it is possible to configure an injection tool that is substantially the same as that of the above-described embodiment, and it is possible to reduce the number of parts and further simplify the configuration.

  Since the above embodiment is an application example when the steel sheet pile 1 is press-fitted while excavating with the auger 2, the injection mechanism 10 of the present invention is attached to the joint portion 1 a at the side edge of the steel sheet pile 1. The invention is not limited to this, and it is natural that the invention can be similarly applied to steel pipe sheet piles, H-shaped steels and other piles in general as long as they are pressed into the ground as a temporary earth retaining member and finally pulled out. And the attachment position and attachment form to such a retaining member may be appropriately set in consideration of the cross-sectional shape of the retaining member and its press-fitting / pulling-out process.

The injection mechanism of the present invention is preferably attached to all of the many retaining members constituting the retaining wall, but is not limited thereto, and a single injection mechanism 10 can inject a hardened material over a wide range. In some cases, it may be installed every other, or at an appropriate interval, and may be attached only to a specific retaining member. Conversely, if necessary, a plurality of injection mechanisms 10 are arranged in parallel for one retaining member. It is conceivable that the injection mechanism 10 is attached to both the joint portions 1a on both sides of the steel sheet pile 1, for example.
Moreover, it is realistic to attach the injection | pouring mechanism 10 to the surface of the excavation side of a retaining member like the said embodiment, Although the work procedure shown in FIGS. 8-9 is employable only in that case. However, the present invention is not limited to this, and the same effect can be obtained by attaching the injection mechanism 10 to the natural ground side (surface opposite to the excavation side).
Of course, if necessary, the injection mechanisms 10 may be attached to both sides of the earth retaining member, or the injection mechanisms 10 attached to the earth retaining members may be alternately attached to both the excavation side and the ground side.

Further, the hardener is not limited to cement bentonite, and may be any liquid material having appropriate fluidity that can be injected into the ground through the injection mechanism 10 of the present invention. Or chemicals can be used as they are.
However, in any case, the arrangement plan of the injection mechanism 10, the selection of the hardening material, the supply pressure, the supply amount, etc. are the ground conditions so that the hardening material can be surely injected into the entire gap after the removal of the entire retaining wall. Needless to say, the optimum setting should be taken into consideration.

1 Steel sheet pile (earth retaining member)
DESCRIPTION OF SYMBOLS 1a Joint part 2 Auger 3 Box culvert 10 Injection mechanism 11 Injection tool 12 Protective tube 13 Pointed head 14 Nozzle hole 15 Inner tube 16 Short tube 17 Socket 18 Plug 19 Jet port 20 Valve body (rubber tube)
21 Injection pipe 22 Plug 30 Pressurized supply device 31 Hose (injection pipe)

Claims (3)

Cavity after being pulled out of a liquid hardening material such as cement bentonite when it is attached to a steel sheet pile or other earth retaining member that is pressed into the ground during ground excavation and pulled out after the excavated part is backfilled An injection mechanism for injecting into,
It consists of an injection tool that is fixed to the tip of the earth retaining member and ejects the curing material into the ground, and an injection tube for supplying the curing material to the injection tool under pressure.
The injection tool comprises a protective tube fixed to the tip of the earth retaining member, and an inner tube that is disposed in the protective tube and jets a hardened material that is pressurized and supplied from the injection tube into the protective tube,
The protective tube is formed with a nozzle hole for ejecting a hardener into the ground on the peripheral surface, the tip is a sharp pointed head and the rear end is an open end. It is fixed to the earth retaining member in a state where the front end portion is directed downward, and the inner tube can be inserted into the inside from the rear end,
The inner pipe has a tip that is closed and a jet outlet through which a hardened material pressurized and supplied from the injection pipe is jetted is formed on the peripheral surface, and the inner pipe is a valve body that opens and closes the jet outlet. Is installed,
The valve body is a rubber tube that is attached in close contact with the outer peripheral surface of the inner pipe and closes the jet port in a liquid-tight manner, and the valve body is externally exposed by the supply pressure when the hardened material is supplied under pressure. And a hardener injection mechanism, wherein the hardener is ejected from the spout by opening the spout. A curing material injection mechanism according to claim 1,
The said injection pipe and the said injection tool are attached to the joint part currently formed in the side edge part of this steel sheet pile in the excavation side surface of the steel sheet pile as said earth retaining member, Injection mechanism. An injection mechanism for a hardener according to claim 1 or 2,
The injection pipe is provided at the base of the tip of the earth retaining member, and its length is set so that the upper end of the injection pipe is exposed on the bottom of the excavation when the ground is excavated. , A flexible hose as another injection pipe can be connected to the upper end of the injection pipe,
After the hose is arranged along the earth retaining member and the excavation portion is backfilled in a state where the upper end portion reaches the ground surface portion, the hardening material is passed through the hose and the injection pipe from the ground surface to the injection tool. An injection mechanism for a hardener, wherein the hose can be pulled out together with the earth retaining member while pressure is supplied.

Images