JPH07133611A - Water stopping method for joint section in steel pipe pile construction - Google Patents

Abstract

PURPOSE:To insure the water stopping, and enhance the efficiency of works by filling two kinds A and B of liquids in a joint space when a water-proofing wall is constructed with steel piles connected together, and thereby producing hardened copolymer by means of the reaction, which is heavier than the specific weight of water, and is elastic. CONSTITUTION:Liquid A containing metallic salt and liquid B containing uretaneprepolymer are filled in a joint space 6 or 9 formed between steel pipe piles 1, and hardened hardened copolymer heavier in specific weight and elastic is thereby produced by the reaction of the above two liquids. In this case, the liquids are loaded with hardening accelerator, surface active agent, diluent solvent, aging preventing agent and the like as required, so that a charging efficiency is enhanced, and even repeated impact by waves can concurrently be absorbed by the joint space. By this constitution, a water-proofing wall excellent in durability can thereby be obtained with ease.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water stop method for a joint portion in a steel pipe sheet pile construction method.

[0002]

2. Description of the Related Art In civil engineering works under water or at the water's edge, usually, a cut-off structure is temporarily installed by a steel pipe sheet pile method. Here, the steel pipe sheet pile construction method refers to a joint (3) having a slit (2) extending in the longitudinal direction on the side surface of the steel pipe sheet pile 1, as shown in the schematic sectional view and side view in FIGS. 1 (a) and 1 (b). ) Is provided, and the sheet pile is driven while the joint is engaged like a hook.

There are several types of joint structures in the steel pipe sheet pile method, as shown in FIGS. 2 to 4, but in any case, the slit portions (4, 7, 10) and the joints (5, 5) are used.
Since there is a gap between (8, 11), it is necessary to stop the water between them. This water stopping has been conventionally performed by injecting clay mortar into a space (6, 9, 12; referred to as "joint space" in this specification) formed by the joint and the joint. However, clay mortar is hard to solidify, and its resistance to recurrent water level changes such as tides and running water such as waves is not sufficient. Therefore, a method of inserting a bag or a tube with a bottom into the joint part and filling it with clay mortar, a method of using cement mortar as a part (see Japanese Examined Patent Publication No. 62-45922), super absorbent fiber instead of mortar An improved method using a material (Japanese Patent Laid-Open No. 4-179725) has been proposed.

However, in the improved method using a mortar bag or the like, the problem that the solidification rate is slow has not been solved at all, and it is difficult to stop the joint space reliably and quickly. On the other hand, in the method using cement mortar,
The water resistance to solidification is still insufficient and the impact absorption capacity after solidification is poor, so various impacts that may occur during construction, such as impacts due to waves and the connection with caisson, cannot be absorbed and partial destruction occurs. Can happen. The method using a super absorbent fiber is difficult in terms of strength when used in a place where the water depth reaches several tens of meters. In addition, there is a possibility that the absorbent fiber may flow out when the dead-end structure is disassembled, which may adversely affect the environment.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention has an effect on the environment that realizes quick and reliable water stoppage which has sufficient resistance to running water and is excellent in shock absorption. The purpose is to provide a water-stopping method with less water consumption.

[0006]

Means for Solving the Problems That is, according to the present invention, 1) a joint of steel pipe sheet piles is connected to construct a closed structure, and a filler is injected into a joint space formed by the connected joints. In a method of stopping water leakage of a joint portion in a steel pipe sheet pile construction method for preventing water leakage, a curing weight that produces a liquid A containing a metal salt and water and a liquid B containing a urethane prepolymer as a filler by the reaction of both liquids. A water-stopping method, characterized in that the specific gravity of the united body is used at a ratio not less than the specific gravity of environmental water, 2) A flexible bag is inserted into the joint space up to the bottom thereof, and a pipe is inserted into the bag. 2. The water stopping method according to 1 above, wherein the filler is injected. 3) The urethane prepolymer in the liquid B is

[0007]

Embedded image A urethane prepolymer obtained by reacting a diisocyanate represented by OCN-Ar-NCO (wherein Ar represents an optionally substituted benzene nucleus) with a bifunctional polyoxyalkylene glycol. The water stopping method according to 1 above,

4) The water-stopping method as described in 3 above, wherein the bifunctional polyoxyalkylene glycol comprises an addition compound of ethylene oxide and propylene oxide.

In the present invention, as the water blocking filler,
Two liquids, a liquid A containing a specific gravity increasing agent composed of a metal salt and water, and a liquid B containing a urethane prepolymer, which produces an elastic non-foaming type curable urethane resin having a higher specific gravity than environmental water at the time of reaction. It is essentially important to use.

Of the above two liquids, liquid A is used to cure the urethane prepolymer which is the main component of liquid B. The metal salt of the specific gravity increasing agent is not particularly limited as long as it does not inhibit the reaction between the urethane prepolymer and water, and the specific gravity of the urethane resin produced can be made larger than that of water. Is preferred. Of these, alkaline earth metal salts such as magnesium chloride are components of seawater themselves and are suitable for imparting an appropriate specific gravity, and thus are particularly preferably used. The amount of the specific gravity increasing agent added is preferably 20 to 60% by weight of the solution A. 20% by weight
If it is less than 50%, it is difficult to make the specific gravity of the urethane produced larger than that of water. If it exceeds 60% by weight, magnesium chloride may precipitate as crystals in winter.

Here, the specific gravity of the generated urethane and the specific gravity of water to be compared refer to the specific gravity of water in the environment where the dead-end structure is installed. It is about 1 in fresh water, and varies in the range of 1.02 to 1.03 in seawater or near the coast, although it varies depending on salinity and temperature.
Therefore, in using the method of the present invention, the specific gravity
As long as the composition produces urethane of 1.03 or more, it can usually be used without problems.

A curing accelerator for accelerating the reaction may be added to the liquid A. Examples of such curing accelerators include:
Aliphatic monoamines such as dimethyloctylamine, dimethyllaurylamine, triethylamine, ethanolamine, diethylethanolamine, diethanolamine, and triethanolamine, aliphatic diamines such as ethylenediamine, triethylenediamine, 1,6-hexanediamine, tetramethylenediamine, and morpholine. Cyclic amines such as and piperazine, imidazole-substituted compounds and imidazolines, 2,4,6-tris (dimethylaminomethyl) phenol-N, N, N ', N'-tetramethylmethanediamine, 4,4'-diamino Examples thereof include aromatic amines such as diphenylamine, and organometallic catalysts such as dibutyltin dilaurate, tin octylate, stannic chloride, lead octenoate and lead naphthenate. The amount of the curing accelerator used is B
0.1 to 20% by weight, preferably 0.5 to 1 relative to the components
It is 5% by weight.

Surfactants may be used to disperse the curing accelerator in the infusion fluid. Examples of such surfactants include sodium salts such as alkyl sulphates, alkyl benzene sulphonates, ethoxy alkyl sulphates, ethoxy alkyl benzene sulphates, amine salts or ammonium salts, anionic surfactants such as alkyl phosphates, polyethylene glycol alkyls. Examples include nonionic surfactants such as ether.
In addition, a cationic or amphoteric surfactant may be used depending on the curing accelerator used.
The amount of these surfactants is 1 to 100% by weight, preferably 10 to 20% by weight of the curing accelerator.

In the present invention, the solution B used in combination with the solution A has an isocyanate group (-NCO) at the terminal.
Is a urethane prepolymer having typically:

[0015]

[Chemical 3]

(Wherein Ar represents an optionally substituted benzene nucleus, and Gl is a bifunctional polyoxyalkylene glycol from which the terminal hydrogen has been removed). Include those in which a plurality of are bonded via one or more polyoxyalkylene glycols.

As shown in the above formula, the isocyanate component contained in the prepolymer is preferably a diisocyanate having an isocyanate group directly bonded to the benzene nucleus. By using such an isocyanate, excellent strength can be obtained upon curing. The benzene nucleus may be substituted by an alkyl group such as a methyl group. A relatively inexpensive tolylene diisocyanate is preferably used.

The above diisocyanate is combined with a bifunctional polyoxyalkylene glycol to give a urethane prepolymer represented by the above formula. Examples of polyoxyalkylene glycols used for such purposes include polyether polyols such as copolymers of ethylene oxide and propylene oxide. By selecting the type of polyoxyalkylene glycol, B
It is possible to adjust the hydrophilicity and viscosity of the liquid, the hardness of the urethane resin resulting from the reaction with the liquid A, and the like. Generally, hydrophilicity can be imparted by introducing an oxyalkylene chain, and it is effective that the addition molar ratio of ethylene oxide and propylene oxide is such that the addition of ethylene oxide is large. The preferred mixing ratio of ethylene oxide and propylene oxide is in the range of 90-60: 10-40. When the addition of ethylene oxide is more than the above range, it cannot be used because it dissolves when added to a large amount of water. On the other hand, when the addition of propylene oxide is excessive, the compatibility with the liquid A decreases.

The liquid B may contain a diluent in addition to the above components. Examples of diluents include dioctyl phthalate
, Dibutyl phthalate, dioctyl adipate, alkylene carbonate (eg propylene carbonate), ethylene diglycidyl acetate (EDGA) and the like. These may be used alone or in combination. The upper limit is determined by considering the strength of the target ground and the like, but is usually 30% by weight or less of the B liquid.

If desired, stabilizers such as anti-aging agents, heat resistance imparting agents and antioxidants may be used. The water blocking filler is a combination of the above liquids A and B in such a ratio that the specific gravity of the cured polymer produced by the reaction of both liquids is equal to or higher than the specific gravity of the construction environment water. Mixed. For example, a tank for each liquid is provided at the work site, and a flexible pipe is used to introduce the liquid from each tank into the joint space. A liquid mixing means is provided at the discharge end of the pipe to mix the liquids at the time of discharge. The mixing ratio is usually 1:10 to 1
Within the range of 0: 1, preferably within the range of 1: 3 to 3: 1. Outside of the above range, one of the reaction solutions becomes excessive, so that a good effect cannot be achieved.

The joint space may be directly filled with water, but a flexible bag is inserted into the space in advance and both AB liquids are injected by using a pipe as in the above. You may do it. The bag has a length that is substantially equal to or greater than the depth of the joint space and is flexible enough to close the joint space without any gap when the water blocking filler is injected. Need to be For these materials,
For example, there is a grout jacket in which a polyester yarn having high strength and little stretchability is used in the longitudinal direction and a nylon yarn having excellent stretchability is used in the circumferential direction. The diameter and length of the bag may be appropriately selected depending on the size of the joint space.

Regardless of whether a bag is used or not, the discharge end of the pipe is at the bottom of the space at the beginning of introduction of the liquid so that the liquid is completely filled up to the bottom of the joint space. It is preferable to use a suitable hoisting means so that it can be gradually lifted. The structure of the steel pipe sheet pile and the joint portion for connecting the same are the same as in the conventional method, and the construction of the closed structure by connecting the steel pipe sheet piles may be performed in accordance with the conventional method.

[0023]

[Function] Since the above water-stopping filler has a high curing speed and excellent water resistance, it has excellent resistance to waves and the like, and can withstand construction in seawater at a depth of several tens of meters. Have. Further, since it is also excellent in flexibility, even if the joint portion is deformed by external stress, it can be in close contact with it and deform. For this reason, the water-blocking effect is stably exhibited even after curing, and the damaging of the deadline composition is prevented by absorbing the impact of waves and construction. In addition, the impact on the environment is minimal.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings. [Composition of Water-Filling Filler] A liquid consisting of water, magnesium chloride and an organic amine, and B liquid consisting of a prepolymer which is a reaction product of a polyol and tolylene diisocyanate, and a diluent, in a mixing ratio shown in Table 1. Compositions 1-3 were prepared according to. The results of measuring the physical properties of each liquid according to the usual methods are as follows. Liquid A viscosity: 12 cps / 25 ° C Same specific gravity: 1.32 Liquid B viscosity: 800 cps / 25 ° C Same specific gravity: 1.09

[0025]

[Table 1]

[Characteristics of Cured Product] Curing speed (gel time) when the filler having the composition 1 in Table 1 is cured, tensile strength, elasticity (elongation at break), hardness and compression of the resulting cured product. The results of measuring the stress and the density are shown in Table 2. The properties of the cured product were measured by the following methods. Gel time: The time when the container was tilted to stop flowing was measured. Tensile strength: Measured with a tensile tester using JIS No. 1 dumbbell. Elongation at break: Measured by JIS No. 1 dumbbell by a tensile tester. Hardness: Measured with an Asker F hardness meter. Stress during compression: 1m 5cm cube with compression speed 5m
Measured in m / min.

[0027]

[Table 2]

When the same tests were conducted on the compositions 2 and 3, the gel time was slightly increased in the composition 2, but the other properties were not significantly changed. On the other hand, composition 3
Then, although the gel time was slightly decreased, the specific gravity was smaller than that of water as a result of foaming about twice.

[Construction] As shown in FIG. 1, a joint 3 having a slit formed by cutting out a part of the diameter in the length direction and another joint 3 having the same shape are fitted in a hook shape. Steel pipe sheet piles 1 were connected and driven to form caisson joints with a depth of about 15 m and an area of about 900 m ² .

As shown in FIG. 5, the grout jackets 16 (made of polyester-nylon, W840B series of fiber engineering works Co., Ltd.) are respectively immersed in the joint spaces (9 in FIG. 3 and 15 in FIG. 5) immersed below the sea level L. Inserted all the way to the bottom of the joint space. The jacket has a pipe (20) having a mixing unit (17) as shown in FIG.
A) and (20B) were inserted near the bottom. The other end of the pipe (20A) is connected to the liquid A tank by the pipe (20B)
Was connected to the liquid B tank, and a water-stopping filler having the composition 1 (liquid A: liquid B = 1: 1) shown in Table 1 was injected using an air-driven press-fitting pump. During the injection, the pipe was pulled up in accordance with the filling speed so that the discharge end of the pipe was always moved above the filled filler (18).

The injected filler filled the jacket from the bottom according to the specific gravity and solidified successively in water for several minutes. Similarly, each joint space was filled with a filling material to construct a closed structure, and after drawing water, a caisson was installed. The caisson interface constructed in this way is then
During the day, the water was kept in the sea with an average head difference of 11 m, but during that time, no water leaked from the joint.

[0032]

According to the water blocking method of the present invention, the water blocking operation is accomplished in a short time because the water blocking filler used is rapidly cured. Moreover, since the generated urethane resin is heavier than water, the joint space is automatically filled by gravity without using any special equipment, and reliable water stop is realized. Further, since the urethane resin used in the present invention is rich in elasticity, water stopping is stable, and further, the durability of the shutoff structure is increased by absorbing external stress such as impact applied to the joint. Therefore, it can be particularly usefully used in a steel pipe sheet pile construction method in a shallow sea of about several tens of meters exposed to repeated impacts by waves.

[Brief description of drawings]

FIG. 1 is a sectional view and a side view showing the outline of a steel pipe sheet pile.

FIG. 2 is a cross-sectional view showing a structural example of a joint portion.

FIG. 3 is a cross-sectional view showing another structural example of the joint portion.

FIG. 4 is a cross-sectional view showing another structural example of the joint portion.

FIG. 5 is an explanatory diagram of an embodiment of the present invention.

[Explanation of symbols]

 1 Steel Pipe Sheet Pile (Main Body) 2 Joint 3 Slit 4 Slit 5 Joint 6 Joint Space 7 Slit 8 Joint 9 Joint Space 10 Slit 11 Joint 12 Joint Space 15 Joint Space 16 Grout Jacket 17 Mixing Unit 20A Pipe 20B Pipe

Front page continuation (72) Inventor Kiyoji Iijima 1 Tomiie-cho, Kanagawa-ku, Yokohama, Kanagawa 1 Kumagai Gumi Co., Ltd. Yokohama Branch (72) Inventor Jun Higuchi 1-Fujiya-cho, Kanagawa-ku, Yokohama, Kanagawa Kumagai Gumi Yokohama Branch (72) Inventor Kazunari Mitsuishi 1 Tomiie-cho, Kanagawa-ku, Yokohama, Kanagawa 1 Kumagai Gumi Yokohama Branch

Claims (4)

[Claims] 1. A stop for a joint portion in a steel pipe sheet pile construction method for connecting a joint of steel pipe sheet piles to construct a closed structure and injecting a filler into a joint space formed by the joints to prevent water leakage. In the water method, the ratio of the specific gravity of the cured polymer produced by the reaction of both liquid A containing a metal salt and water and liquid B containing a urethane prepolymer as the filler to be equal to or higher than the specific gravity of environmental water. A water stopping method characterized by being used in. 2. The water stopping method according to claim 1, wherein a flexible bag is inserted into the joint space up to the bottom thereof, and the filler is injected into the bag through a pipe. 3. The urethane prepolymer in the liquid B is a diisocyanate represented by the following formula: OCN-Ar-NCO (wherein Ar represents an optionally substituted benzene nucleus) and a bifunctional polyisocyanate. The water stopping method according to claim 1, which is a urethane prepolymer obtained by reacting with oxyalkylene glycol. 4. The water stopping method according to claim 3, wherein the bifunctional polyoxyalkylene glycol comprises an addition compound of ethylene oxide and propylene oxide.