JPH0639784B2 - Pile driving and drawing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a method for performing effective pile driving and pulling out work by allowing a chemical to be present on the surface of the pile or in the vicinity thereof to reduce the resistance during pile driving and pulling out. Regarding

(Conventional technology and its problems) Conventionally, in order to reduce the resistance when driving or pulling steel pipe piles into the ground, water is sprayed on the surface of the piles, or a jet pipe is attached to the tip of the piles There was a construction method in which water was ejected while being ejected.

This method has drawbacks that it may be difficult to secure a large amount of water, or that a large amount of water may be poured into the ground to weaken the ground.

In addition, when the piles were pulled out, the soil adhered to the belly part of the piles, which could cause secondary pollution such that the soil had holes after the piles were pulled out.

Further, in the shield construction method, there is a construction method in which a chemical is used to reduce the frictional resistance on the peripheral surface of the propulsion pipe. As the liquid chemical, for example, the one disclosed in Japanese Patent Laid-Open No. 58-27774 uses a sphere-dried water-absorbing polymer, and it takes time and labor to inject the chemical during construction. . Further, there is a problem that the reaction time for the chemical to absorb water and become a gel is long.

(Means for Solving the Problems) The present invention has been invented based on the conventional drawbacks described above, and a water-in-oil type water-swellable polymer particle emulsion or the same is provided on or near the surface of a pile. It is characterized in that an aqueous dispersion is present, and then the pile is driven into the ground by a pile driver, such as reducing the peripheral frictional resistance of the pile and improving the water blocking effect. The purpose is to improve the efficiency of drawing work.

(Operation) A pile having a water-in-water type water-swellable polymer particle emulsion or its water dispersion formed on the surface is mounted on a pile driver and driven into the ground. The above-mentioned chemicals formed on the surface of the pile reduce the frictional resistance on the peripheral surface when the pile is driven into the ground, and the pile can be driven smoothly with a small force even when the driving depth of the pile becomes deep.

Further, even when the pile is pulled out, the frictional resistance on the peripheral surface is reduced, the pile is quickly pulled out with a small force, and the amount of soil attached to the pile is small, and secondary pollution is avoided.

It is considered that the absorbed particles are in the form of fine spheres, so that the particles are likely to be displaced from each other, and fine oil droplets are also generated, which synergistically increases the lubricity.

In addition, the chemical formed on the grip portion of the pile absorbs water and quickly becomes a gel to exhibit a water blocking effect. When the chemical of the present invention comes into contact with water, it absorbs and swells in a short time, has a water retention property, and the absorbed water is hardly released even if a slight pressure is applied. In addition, it can be smoothly transferred by a pump and injected into the soil, etc., and impregnating processing on unclothed cloth and paper is easy.

(Structure) Water-in-water type water-swellable polymer particle emulsion is a radical polymerization reaction in which an aqueous solution of a water-soluble vinyl monomer and a crosslinkable monomer is dispersed in an organic dispersion medium with a hydrophobic surfactant. It is an emulsion containing particles.

In addition, a water-in-oil emulsion obtained by a reverse phase suspension polymerization method or an emulsion polymerization method may be used. Further, it may be a dispersion obtained by finely pulverizing powder and dispersing it in an organic dispersion medium in the presence of a surfactant and / or a stabilizer. In short, a water-in-oil emulsion or emulsion-like substance may be used.

As the water-soluble vinyl monomer, (1) nonionic vinyl monomer, (2) anionic vinyl monomer and (3) cationic vinyl monomer are used.

(1) Nonionic vinyl monomers include (meth) acrylamide, vinyl methyl ether, vinyl ethyl ether, and vinylpyrrolidone, and (2) anionic vinyl monomers include (meth) acrylic acid and 2 -Acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, itaconic acid, maleic acid,
Examples include fumaric acid and arylsulfonic acid. (3) Cationic vinyl monomers include dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth)
Neutralized salts or quaternary salts of dialkylaminoalkyl (meth) acrylates such as acrylates, dialkylaminoalkyl (meth) acrylamides such as dimethylaminomethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide, etc. .

The crosslinkable monomer is a monomer that can be copolymerized with a water-soluble vinyl monomer, and includes, for example, N, N′-methylenebis (meth) acrylamide, divinylbenzene, (meth).
Examples thereof include divinyl compounds such as vinyl acrylate, vinyl methylol compounds such as methylol (meth) acrylamide, vinyl aldehyde compounds such as acrolein, methyl acrylamide and glycolate methyl ether.

The emulsion thus obtained is as follows. The water solubility of one or more water-soluble vinyl monomers and a crosslinkable monomer is dispersed in an organic dispersion medium with a hydrophobic surfactant, and radical polymerization reaction is carried out. 25-75% by weight, organic dispersion medium 20-50% by weight,
Hydrophobic surfactant 0.5 to 5% by weight (preferably HLB
3 to 6) and 0 to 5% by weight of hydrophilic surfactant (preferably HLB of 10 or more).

The polymer particles of the emulsion thus produced have an average particle size of 10 μm or less, and particularly have particles having an average particle size of 2 to 6 μm. The emulsion viscosity is 3
While it is about 00 to 800 cps, it can be used as an emulsion as it is or as an aqueous dispersion thereof. In this case, the amount of dispersion is 0.5 to 2% by weight.
It is a degree.

Next, the emulsion prepared as described above is formed on the surface of the pile. Examples of the forming method include brush coating, spray coating, dipping, and the like, and the forming portion is part or all of the pile.

Alternatively, a nonwoven fabric or paper may be impregnated to form the nonwoven fabric or the like on the surface of the pile. Further, the emulsion can be made to exist on the surface of the pile when the pile is driven, by injecting the emulsion into the ground together with the pile or in advance.

(Example) First, a synthesis example of the water-in-oil type water-swellable polymer particle emulsion of the present invention will be given.

(1) N, N'-methylenebisacrylamide 0.15 g
HLB 4.3 to 683 g of 100 mol% ammonia-neutralized acrylic acid 54% aqueous solution and 240 g of organic dispersion medium weight.
18 g of sorbitan monooleate was added and emulsified with a homogenizer. After emulsification, the mixture was transferred to a 4-necked flask, and degassed with N ₂ gas purging while stirring. The radical polymerization catalyst was added dropwise while purging with N ₂ gas, and polymerization was carried out at a temperature of 60 ° C. After completion of the polymerization, 27 g of polyoxyethylene lauryl ether of HLB 12.1 was added and stirred. The viscosity of the obtained emulsion was 330 cps / 25 ° C (B type viscometer,
NO.2 rotor, measured at 12 rpm), average particle size 3.
It was 8 μm.

(2) In the synthesis example (1), the crosslinkable monomer was changed to 0.07 g of vinyl acrylate, the water-soluble vinyl monomer was changed to 537 g of a 41.6% acrylamide aqueous solution, and the amount of other organic dispersion medium was changed. 196g, HLB with hydrophobic surfactant
4.3 g of 4.3, hydrophilic surfactant HLB12.
An emulsion was prepared in place of 23 g of No. 1 The viscosity of the obtained emulsion was 310 cps / 25 ° C. (measured by B-type viscometer, NO.2 rotor, 12 rpm), and the average particle size was 3.3 μm.

(3) In the above Synthesis Example (1), the crosslinkable monomer was changed to 0.09 g of vinyl methacrylate, and the water-soluble vinyl monomer was changed to 619 g of a 51% aqueous solution of dimethyl quaternary methyl chloride quaternary compound. In addition, 224 g of other organic dispersion medium, 14 g of HLB 4.3 for hydrophobic surfactant and HLB 12.1 for hydrophilic surfactant 2
An emulsion was prepared in place of 5 g. The viscosity of the obtained emulsion is 530 cps to 25 ° C. (B type viscometer, N
O.2 rotor, measured at 12 rpm), average particle size 5.1
was μm.

(4) A dispersion was prepared using the emulsion 1 of Synthesis Example (1) and 100 of water.

The underground driving of a pile using the emulsion of the present invention obtained as described above will be described with reference to the accompanying drawings.

FIG. 1 is a front view showing a state in which a pile is driven by a pile driving and drawing machine.

The pile driving / pulling machine 1 of the present embodiment is a known static load type pile driving / pulling machine provided with a chuck portion 3 for holding a pile in front thereof. This pile driving and pulling machine 1 is a clamp 2 provided below,
By holding the existing pile P1, the main body is fixed on the existing pile P1 and the reaction force when driving the press-fitted pile P into the ground is obtained from the existing pile P1.

The surface of the press-fitting pile P is previously coated with the emulsion of the present invention by an appropriate method such as brush coating, spray coating or dipping. As the application mode of this emulsion, as shown in FIG. 2, (a) the entire belly part of the press-fitting pile P, (b) only the bottom part of the press-fitting pile P's belly part, or
(c) The press-fitted pile P can be appropriately selected depending on the working conditions such as the entire circumference of the press-fitted pile P, the length of the press-fitted pile P, the soil quality, etc.

When driving the press-fitting pile P having the emulsion layered on the surface as described above, the press-fitting pile P is held by the chuck portion 3 of the pile driving and extracting machine 1 and the grip portion of the most advanced existing pile P1 is held. The grip portion 7 of the press-fitting pile P is engaged (see FIG. 3), and the chuck portion 3 is lowered to drive the press-fitting pile P into the ground.

At this time, since the emulsion is layered on the surface of the press-fitting pile P, the circumferential frictional resistance of the press-fitting pile P is reduced, and the press-fitting pile P is reduced.
Is pressed vertically and quickly.

The emulsion formed on the surface of the press-fitting pile P absorbs moisture in the ground during the driving into the ground and quickly becomes a gel state, further reducing the frictional resistance between the press-fitting pile P and the soil. Water may be applied in advance to the surface of the press-fitting pile P depending on the soil condition. Further, water can be injected into the pile and the ground near the pile with a pipe or the like.

Even when the press-fitting pile P is pulled out, the emulsion on the surface of the press-fitting pile P reduces the frictional resistance generated at the time of pulling out, but in particular, it is possible to prevent a large amount of soil from attaching to the belly part of the conventional pile.
It is possible to prevent holes from being formed around the pile when the pile is pulled out.

The emulsion formed in the grip portion 7 of the press-fitting pile P is in a gel state, so that the water stopping property is improved. That is, pile P
When the soil retaining wall or the like is constructed by continuously driving in, the wall may be expected to have a water blocking effect, but according to the construction method of the present invention, this effect is also completely effective. Therefore, in some cases, the object of the present invention can be achieved by layering the emulsion only on the grip portion 7.

The type of pile used in the method of the present invention is not limited, and various types of sheet piles such as a U-shaped steel sheet pile, a Z-shaped steel sheet pile, an H-shaped steel sheet pile, a deformed steel sheet pile, a concrete sheet pile, a steel pipe, and the like, as well as steel pipes, It is applicable to steel pipe piles, and the pile driving method is most preferably the static load press-fitting method of this embodiment, but is not limited to this, and any driving or pulling-out method such as vibration type or impact type can be selected. And

Experimental Example Next, an experimental example of the pile driving method of the present invention will be described.

(1) Test content Comparison of the press-fit ton number between the case where the emulsion of the present invention is applied to a U-shaped steel sheet pile and press-fitted, and the normal press-fitting.

Performance of used pile punching and drawing machine Press-fitting speed 2.7 to 7.5 m / min Drawing speed 2.2 to 21.8 m / min Used steel sheet pile U-shaped steel sheet pile, 10 m 1st pile-normal press-fitting 2nd pile-steel sheet pile Emulsion coating only on the bottom of the 3rd pile-water from the tip of the steel sheet pile to 3m. Emulsion coating only on the bottom of the 4th pile-water from the tip of the steel sheet pile to 3m. (2) Test result The emulsion used in the above experiment was the one in the above Synthesis Example (1), but the same results were obtained when the same experiment was performed in Synthesis Examples (2), (3) and (4).

As described above, the steel sheet pile having the emulsion of the present invention applied to the surface thereof was smoothly press-fitted because the frictional resistance on the peripheral surface at the time of underground driving was reduced, and the extraction was also smoothly performed. Further, when water was sprayed on the surface simultaneously with press-fitting of the steel sheet pile, the same effect as described above was produced, and further, when the emulsion of each of the above Synthesis Examples was injected into the ground, a further friction reducing effect was obtained.

(Effects of the Invention) As described above, according to the present invention, when piles are driven into the ground, it is possible to reduce the frictional resistance between the surface of the pile and the ground and to have a water blocking effect at the grip portion. It is possible to carry out the withdrawal operation and to smoothly transfer the emulsion by the pump and inject it into the soil.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a front view showing a pile driving state, FIG. 2 is a plan view showing a state in which an emulsion is applied to a U-shaped steel sheet pile, and FIG. The top view which shows the grip meshing state of the shaped steel sheet pile, FIGS. 4-7 is a graph which shows the relationship between the press-fitting pressure of each steel sheet pile used in the experiment example for demonstrating the effect of this invention, and press-fitting depth. Is. 1 ... Pile driving and pulling machine, 3 ... Chuck part P ... Pile

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Claims (5)

[Claims] 1. To reduce the frictional resistance on the peripheral surface during pile driving or pulling out by allowing water-in-oil type water-swellable polymer particle emulsion or its water dispersion liquid to exist on or near the surface of the pile. Pile driving and pulling method. 2. A water-in-oil type water-swellable polymer particle emulsion, wherein an aqueous solution of one or more water-soluble vinyl monomers and a crosslinkable monomer is organically dispersed with a hydrophobic surfactant. Average particle size of 10 μm dispersed in a medium and subjected to radical polymerization reaction
The pile driving and drawing method according to claim 1, which is an emulsion containing the following particles. 3. The pile driving and drawing method according to claim 2, wherein the water-in-oil type water-swellable polymer particle emulsion contains a hydrophilic surfactant. 4. The pile driving and drawing method according to claim 1, wherein the water-in-oil type water-swellable polymer particle emulsion is layered on the surface of the pile. 5. A water-in-oil-type water-swellable polymer particle emulsion or an aqueous dispersion thereof is present on or near the surface of a pile, and water is present near the pile to provide a peripheral surface when the pile is struck or pulled out. A pile driving and pulling method characterized by reducing frictional resistance.