JPS60242218A - Treatment for drawing out pile - Google Patents

Abstract

PURPOSE:To easily draw out a pile by a method in which a mixture of a water- soluble urethane polymer and a gel accelerating catalyst and an aqueous solution of an alkali metal salt of aluminic acid or silicic acid are concurrently sprayed from separate nozzles onto a pile to form a hydrated gel film. CONSTITUTION:A mixture A of a water-soluble urethane polymer and a gel accelerating catalyst is prepared and housed in a tank 22. An aqueous solution B of an alkali metal salt of aluminic acid or silicic acid is prepared and stored in a tank 30. The mixture A and the solution B are concurrently sprayed in an atomized state onto a pile 10 from the ports 16a, 18a of nozzles 16, 18 to form a hydrated urethane polymer gelled film 12 on the surface of the pile 10. Since the film 12 is turned into a grease form when drawing out the pile 10, the pile 10 can be easily drawn out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Prior Art) The present invention relates to a treatment method for pulling out piles buried underground.

Piles buried underground, for example, piles used for constructing earth retaining walls, are pulled out and removed after construction of the underground structure is completed.

In order to facilitate the pulling out of such piles, the applicant of the present application proposed in Japanese Patent Application No. 57-228597 that a water-soluble urethane prepolymer and water were added to the surface of the piles before installing the piles underground. proposed to form a hydrogel membrane obtained by the reaction of When the pile is installed in the ground, the hydrous gel film formed on the pile is absorbed by the alkaline components around the pile (the alkaline components of the ground or the grooves formed in the i1!! board for burying the pile). (for example, alkaline fillers such as soil cement, solidified mud, mortar, concrete, etc.), and after several injuries from the installation of the pile to its removal, almost all of the hydrogel membrane becomes grease-like. becomes.

Therefore, when the pile is removed, the grease-like substance completely separates the pile from the ground or the filling around the pile, and also acts as a lubricant when the pile is pulled out. , the pull-out resistance of the pile is significantly reduced. As a result, the work of pulling out the pile becomes easier.

By the way, in order to form a film of hydrous gel obtained by a reaction between a water-soluble urethane prepolymer and water on the surface of the pile before installing the pile underground, a mixture of a water-soluble urethane prepolymer and water is used. It is possible to apply it to the surface of the pile with a brush. However, when using a brush, it is not easy to obtain a hydrous gel layer with a uniform layer thickness, and moreover, the application process requires a lot of time due to the shape and irregularities of the piles. On the other hand, if spraying using a nozzle can be used to form the hydrogel layer, the formation work of the hydrogel layer can be done quickly.

Therefore, in order to efficiently form a hydrogel film obtained by reacting a water-soluble urethane prepolymer with water, it is necessary to
It is conceivable to mix the water-soluble urethane prepolymer and water in advance in a container such as a tank, guide this mixture to a nozzle with a hose, and spray it onto the pile from the nozzle. However, the mixture of water-soluble urethane prepolymer and water in the tank may cause clogging due to progress of keling in the tank, hose, or nozzle. Therefore, it is not practical to mix the water-soluble urethane prepolymer and water in advance in a container such as a tank and then spray the mixture with a nozzle.

In order to prevent the mixture of water-soluble urethane prepolymer and water from gelling in the tank, the water-soluble urethane prepolymer and water are stored in separate containers, and both are connected by a hose extending from each container. separately guided to a common nozzle,
It is conceivable to mix both in the nozzle and spray it onto the pile. According to this, the clogging described above due to gelation in the tank and hose can be prevented, but if the mixture mixed in the nozzle remains in the nozzle,
This residual mixture may clog the nozzle as gelation progresses.

In order to solve the above-mentioned clogging problem, that is, the clogging problem, the water-soluble urethane prepolymer and water are stored in separate containers, and hoses extending from each container guide the two to separate nozzles. It is conceivable that a water-containing gel film is formed on the surface of the pile by the reaction between the water-soluble urethane prepolymer and water by simultaneously spraying both from each nozzle onto the pile. However, in this case, the water-soluble urethane prepolyboot spouted from each nozzle,
The time it takes for the mixture to adhere to the pile surface after being mixed with water is extremely short, and as a result, the mixture adheres to the pile surface without being sufficiently gelled, causing dripping from the pile surface and preventing spraying. There was a large loss of the water-soluble urethane prepolymer material.

(Objective) Therefore, an object of the present invention is to reduce the amount of sagging of the hydrogel film of water-soluble urethane prepolymer from the surface of the pile, and to efficiently and quickly form the hydrogel film on the surface of the pile. An object of the present invention is to provide a method for extracting piles that can be carried out easily and quickly.

(Structure and Effects) The present invention provides a method of preparing a mixture of a water-soluble urethane prepolymer and a gelation promoting catalyst, and an aqueous solution of an alkali metal salt of aluminate or an aqueous alkali metal salt of silicic acid before installing a pile underground. are simultaneously sprayed onto the pile using separate nozzles to form a hydrogel film.

According to the present invention, the mixture of water-soluble urethane prepolymer and gelation promoting catalyst does not gel by itself, and the aqueous alkali metal salt solution of aluminium or silicic acid does not gel by itself. Therefore, it is possible to use a nozzle that forms a hydrous gel film at a desired location on a pile without causing any clogging problem in the nozzle, etc., and thereby, regardless of the presence or absence of irregularities or shape of the pile. Since the mixture and aqueous solution can be quickly and easily sprayed onto desired locations on the pile, a hydrogel film can be efficiently formed.

Further, the gelation promoting catalyst promotes gelation of the water-soluble urethane prepolymer when the water-soluble urethane prepolymer reacts with water in the alkali metal salt aqueous solution, and the alkali metal salt aqueous solution This is because spraying containing a hydrogel of the water-soluble urethane prepolymer reduces the fluidity of the entire material by reacting with carbon dioxide generated during gelation of the water-soluble urethane prepolymer and gelling it. , a water-containing gel film of a water-soluble urethane prepolymer can be formed on the surface of the pile to a substantially uniform thickness by reducing dripping from the surface of the pile.

Furthermore, since the Kel substance of the aqueous solution of the alkali metal salt of aluminic acid or the aqueous solution of the alkali metal salt of silicic acid itself exhibits alkalinity, it acts to turn the water-containing gel of the water-soluble urethane prepolymer into a grease state. Therefore, by adjusting the concentration of the aqueous solution, the time when the water-containing gel film of the water-soluble urethane prepolymer becomes grease-like can be adjusted to coincide with the time when the pile is pulled out.

Furthermore, the present invention provides a method for forming a hydrogel film by spraying a mixture of a water-soluble urethane prepolymer, a gelling accelerator catalyst, and a gel desiccant onto the pile at the same time using separate nozzles before installing the pile underground. It is characterized by the formation of

According to the present invention, the mixture of water-soluble urethane prepolymer, gelation promoting catalyst and gel drying agent does not gel by itself and therefore does not cause blockage problems in said nozzles etc. A nozzle can be used to form a hydrogel film at the location, thereby
Regardless of the presence or absence of irregularities or the shape of the pile, the mixture and aqueous solution can be quickly and easily sprayed onto a desired location on the pile, so that a hydrogel film can be efficiently formed.

Further, the gelation promoting catalyst promotes gelation of the water-soluble urethane prepolymer when the water-soluble urethane prepolymer reacts with the water, and the gel drying agent promotes gelation of the water-soluble urethane prepolymer when the water-soluble urethane prepolymer reacts with the water. Since spraying containing hydrogel reduces the fluidity of the entire material, it is possible to reduce dripping from the surface of the pile and form a hydrogel film of water-soluble urethane prepolymer on the surface of the pile.

Furthermore, the present invention provides a method for preparing a mixture of a water-soluble urethane prepolymer, a gelling-promoting catalyst, and a gel drying agent, and an aqueous alkali metal salt solution of aluminate or an aqueous alkali metal salt silicic acid solution, respectively, prior to installing the pile underground. The method is characterized in that a hydrogel film is formed by simultaneously spraying onto the pile using another nozzle.

According to the present invention, the mixture of water-soluble urethane prepolymer, gelation promoting catalyst and gel drying agent does not gel by itself, and the aqueous alkali metal salt solution of aluminic acid or silicic acid gels by itself. There's nothing to do,
Therefore, the nozzle can be used to form a hydrogel film at a desired location on the pile without causing a clogging problem in the nozzle, etc., and thereby, regardless of the presence or absence of irregularities or the shape of the pile, the nozzle can be used quickly and easily. Since the mixture and the aqueous solution can be easily sprayed onto desired locations on the pile, a hydrogel film can be efficiently formed.

Further, the gelation-promoting catalyst promotes gelation of the water-soluble urethane prepolymer when the water-soluble urethane prepolymer reacts with water in the aqueous solution, and the alkali metal salt aqueous solution itself By reacting with carbon dioxide generated during gelation of the water-soluble urethane prepolymer to form a gel, spraying containing a water-containing gel of the water-soluble urethane prepolymer reduces the fluidity of the entire material, and furthermore, the gel dries. Since the spraying of the agent reduces the fluidity of the entire material, it is possible to further reduce dripping from the surface of the pile and form a hydrogel film of the water-soluble urethane prepolymer on the surface of the pile.

(Embodiments) The features of the present invention will become clearer from the following description of the illustrated embodiments.

As an example, a treatment method for piles used in constructing an earth retaining wall will be described with reference to FIG. It is formed. Pile ■0 may be made of steel, concrete, or wood, and its shape does not matter.

Device 14 for forming hydrous gel By t 2 on this pile 10
comprises a first nozzle 16 and a pair of second nozzles (18) arranged close to and parallel to both sides of the first nozzle and fixed to the first nozzle. The first nozzle 16 is connected to a first tank 22 via a pipe 20, and a pump 24 is connected to the pipe 20 for pumping liquid A in the first tank 22 to the first nozzle 16. and a valve 26 for adjusting the flow rate. The second nozzle 18 is connected to the second tank 3 via a pipe 28 provided with a branch 28a connected to each nozzle 18.
0, and the pipe 28 is connected to a second tank 30.
A pump 32 for pumping the liquid B inside to the second nozzle 18 and a valve 34 for adjusting the flow rate are provided, respectively.

Liquid A in the first tank 22 is a mixed liquid of a water-soluble urethane prepolymer and a gelation promoting catalyst that promotes gelation when the water-soluble urethane prepolymer reacts with water and becomes a gel. be.

The water-soluble urethane prepolymer can be obtained, for example, by urethane bonding a hydrophilic polyoxyalkylene polyol and an organic polyincyanate to leave an incyanate group at the end, or by modifying it with a dimer acid. can get. The water-containing gel obtained by reacting the water-soluble urethane prepolymer thus obtained with water is easily attacked by alkali and also easily attacked by ursium ions.

The gelation promoting catalyst is, for example, a tin octoate such as stanna octoate, a tin carboxylate such as dibutyltin dilaurate, or a higher amine such as triethylenediamine, and is a combination of a water-soluble urethane prepolymer and monohydrochloride. A catalyst that rapidly promotes gelation by reaction can be appropriately selected.

This is an aqueous alkali metal salt solution or an aqueous alkali metal salt solution of silicic acid. The water in this aqueous solution B causes the water-soluble urethane prepolymer to gel, and the alkaline component of the aqueous solution B itself reacts with carbon dioxide generated when the water-soluble urethane prepolymer gels. Gel.

The general component weight ratio of the liquid A and the liquid B is such that when the water weight of the liquid B is 100, the water-soluble urethane prepolymer of the liquid A is 3 to 50.

The alkaline component of liquid B is 10 to 200. In addition, the gelation promoting catalyst contains water-soluble urethane prepolymer with 10%
If it is set to 0, then 0.
2 to 1, and 0.5 to 1 when dibutyltin dilaurate is used.

The A is a mixture of the water-soluble urethane prepolymer and the gelling-promoting catalyst contained in the first tank 22.
The liquids do not gel by themselves, and because the aqueous alkali metal salt solution of aluminic acid or silicic acid is contained in the second tank 30, the liquids A and B are
It does not gel in each tank 22 and 30, and by the operation of each pump 24 and 32, it is guided through the container tubes 20 and 28 to each nozzle 16 and 18, and gels until it is ejected from the nozzle. There's nothing to do. Accordingly, said tubes 20 and 28 and each nozzle 16 and 1
8 is not blocked by the gel material, and the liquid A and liquid B flow through the nozzle hole 16 of each nozzle 16 and 18.
A mist is ejected from a and 18b toward the pile 10.

When the A liquid and the B liquid are simultaneously ejected in a mist form from the respective nozzles 16 and 18, the two liquids are mixed until they reach the pile 10, and adhere to the surface of the pile io in a mixed state. When the liquids A and B are mixed, the water-soluble tumble polymer of the liquid A reacts with the moisture of the liquid B, that is, the aqueous alkali metal salt solution, and begins to gel. The gelation of this water-soluble urethane prepolymer is rapidly accelerated by the gelation accelerator of the A solution. Furthermore, since the aqueous alkali metal salt solution itself gels by reacting with carbon dioxide generated during gelation of the water-soluble urethane prepolymer, spraying containing a hydrous gel of the water-soluble urethane prepolymer is preferred. decreases the fluidity of the entire material.

As a result, the water-soluble urethane prepolymer sprayed onto the surface of the pile 1O rapidly gels on the attached surface of the pile 1O and its fluidity decreases, so it does not cause avalanche as in the conventional case. Regardless of the presence or absence of irregularities on the adhesion surface, a hydrogel film 12 having a substantially uniform thickness is formed.

When spraying with the above-described nozzle, it is preferable that the distance between the nozzle hole and the spraying surface of the stake is 20 to 100 cm, and the thickness of the hydrogel film 12 is 0.
．． It is preferable to set it as 1-5II11. Each nozzle 16
The number of nozzles 16 and 18 can be increased or decreased as appropriate, and each nozzle 16 and 18 can be separated without being fixed to each other.

A gel drying agent can be further added to the mixed solution of the water-soluble urethane prepolymer and the gelling-promoting catalyst, that is, the liquid A. Metal soap can be used as this gel drying agent.

Among these metal soaps, it is preferable to use a zinc compound such as zinc naphthenate or a cobalt compound such as cobalt naphthenate. When using the gel drying agent, water can be used as the B liquid. The component weight ratio of the water-soluble urethane prepolymer and the gelation promoting catalyst of the liquid A is the same as described above, and the weight ratio of the gel drying agent is the same as that of the water-soluble urethane prepolymer when cobalt naphthenate is used. When the polymer is taken as 100, it is generally 3 to 15.

The gelling-promoting catalyst in the mixed liquid sprayed in a mist form from the nozzle 16 is activated when the water-soluble urethane prepolymer in the mixed liquid A reacts with the water sprayed in a mist form from the nozzle 18. Promotes gelation of water-soluble urethane prepolymers. Furthermore, the gel desiccant in the mixed solution A removes water from the hydrogel of the water-soluble urethane prepolymer, so that spraying containing the hydrogel reduces the fluidity of the entire material.

Therefore, as in the above example, the water-soluble urethane prepolymer sprayed onto the surface of the pile 10
Because the fluidity of the entire material decreases during spraying as it rapidly gels on the surface to which it is applied, it does not cause avalanches like in the past, and the thickness is almost uniform regardless of the presence or absence of irregularities on the surface to which it is applied. A hydrogel film 12 of the same size can be formed.

As the liquid A, a mixed solution of the water-soluble urethane prepolymer, the gelation promoting catalyst, and the gel drying agent can be used, and as the liquid B, the aqueous alkali metal salt solution of aluminic acid or silicic acid can be used. In this case, as is clear from the above, the gelation promoting catalyst promotes gelation of the water-soluble urethane prepolymer when the water-soluble urethane prepolymer reacts with water in the aqueous solution, and The aqueous alkali metal salt solution itself gels by reacting with the carbon dioxide generated during gelation of the water-soluble urethane prepolymer, so that the spraying containing the hydrous gel of the water-soluble urethane prepolymer covers the entire material. Furthermore, since the gel drying agent reduces the fluidity of the entire material,
A hydrogel film of water-soluble urethane prepolymer can be formed on the surface of the pile by further reducing dripping from the surface of the pile.

For example, in the muddy water solidification method, the pile 10 on which the hydrogel film 12 is formed is placed in a trench filled with a stabilizing liquid such as bentonite slurry, and is then filled with water glass or cement in order to solidify the stabilizing liquid. A solidifying agent consisting of, etc. is put into the groove, and an earth retaining wall is constructed by solidifying the stabilizing liquid. Since this solidifying agent exhibits alkalinity, the hydrous gel film 12 formed on the surface of the pile 1O gradually becomes grease-like due to the alkaline components around it. It has been found that calcium ions contained in the cement also act to turn the hydrogel film 12 into a grease state.

Since the pile is generally pulled out at the earliest after several injuries after the pile is installed, almost all of the hydrogel film 12 becomes grease-like when the pile is pulled out. From this, when the pile is pulled out, the pile and the solidified layer around the pile are almost completely separated, and the gel film 1 is turned into a grease.
2 acts as a lubricant. Therefore, the resistance to pulling out the pile is reduced, and the pile can be easily pulled out.

When the above-mentioned aqueous alkali metal salt solution of aluminic acid or aqueous alkali metal salt solution of silicic acid is used as the B solution, as mentioned above, the aqueous solution itself is generated during gelation of the water-soluble urethane prepolymer. It reacts with carbon dioxide and turns into a gel. Since this gel material exhibits alkalinity, it functions to make the water-containing gel layer of the water-soluble urethane prepolymer into a grease state. Therefore, by adjusting the concentration of the aqueous solution, the time when the hydrogel film of the water-soluble urethane prepolymer becomes almost completely grease-like can be made to coincide with the time when the pile is pulled out.

Further, the spraying of the liquid mixture to form the hydrous gel M12 on the pile 10 is carried out in such a way as to improve workability and work efficiency, such as when temporarily placing, erecting, or constructing the pile. can be selected as appropriate.

In the above, an example was explained in which the pile 10 on which the hydrogel film 12 was formed was used in the mud solidification method, but the pile 10 on which the hydrogel film 12 was formed was A solidifying agent such as cement paste or mortar is injected into the drilled hole, and after stirring and mixing this with the earth and sand remaining in the hole, piles are inserted into the hole to construct an earth retaining wall. Soil cement column pile method,
It can be used in the joist construction method, in which a pile is inserted into a hole formed by pre-boring, and then the hole is backfilled with earth and sand to construct an earth retaining wall.This joist construction method ensures that the ground around the pile is alkaline. In order to achieve this, it is preferable to mix an alkaline substance such as cement or lime into the backfill earth and sand. Further, when the ground is alkaline soil, the pile IO on which the hydrous gel film 12 is formed can be directly driven into the ground.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the apparatus used to practice the invention. 10: Pile, 12: Hydrogel layer, 16, 18: Nozzle. Agent Patent Attorney Nobuyuki Matsunaga

Claims (8)

[Claims] (1) Prior to installing the pile underground, a mixture of a water-soluble urethane prepolymer and a gelation promoting catalyst and an aqueous alkali metal salt solution of alumina or an aqueous alkali metal salt solution of silicic acid are simultaneously applied through separate nozzles. A method for treating piles, which comprises spraying onto the piles to form a hydrous gel film. (2) The treatment method according to claim 1, wherein the gelation promoting catalyst is a tin carboxylate. (3) The treatment method according to claim 1, wherein the kelization promoting catalyst is a higher amine. (4) Prior to installing the pile underground, a mixture of a water-soluble urethane prepolymer, a gelation promoting catalyst, and a gel drying agent, and water are simultaneously sprayed onto the pile using separate nozzles to form a hydrogel film. A pile processing method characterized by: (5) The treatment method according to claim 4, wherein the gel desiccant is a metal soap. (6) The treatment method according to claim (5), wherein the metal soap is a cobalt compound. (7) The treatment method according to claim 5, wherein the metal soap is a zinc compound. (8) Prior to installing the pile underground, separate the mixture of water-soluble urethane prepolymer, gelation promoting catalyst, and gel desiccant with an aqueous alkali metal salt solution of aluminate or an aqueous alkali metal salt solution of silicic acid. A method for treating piles, comprising simultaneously spraying onto the piles with a nozzle to form a hydrous gel film.