JPH029123B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a water-stop wall. The purpose is to propose a water stop wall that is simple and easy to construct and can be easily removed when no longer needed.

When excavating the ground to a depth below the groundwater level to form slopes or construct underground structures, it is necessary to prevent leakage of groundwater, and many methods include installing waterstop walls. Ta. Traditional water-stop walls are formed by excavating the ground and pouring concrete,
Since sheet piles and the like are built in, construction is time-consuming, and when they are no longer needed, it takes a great deal of time and effort to remove them. In addition, in ground with high permeability (for example, permeability coefficient kw > 10 cm/sec),
When there is a large supply of groundwater, it is necessary to also inject a chemical solution, which becomes more labor-intensive and increases costs. Moreover, if you try to construct a water-stop wall by excavating the ground or driving sheet piles, the vibrations may cause the excavation slope to collapse, making it impossible to use a water-stop wall. For example, it may be necessary to change the water at a well point, etc.
In some cases, operation and management became complicated.

This invention was made in view of the above-mentioned circumstances, and its characteristic feature is that resin powder (hereinafter simply referred to as resin powder) that has the property of swelling and gelling by absorbing water is mixed in. A method for constructing a water-stop wall in which a wall-like ground zone containing resin powder is formed, and the resin powder absorbs moisture in the ground and swells to form a gel, forming a wall shape and making the ground impervious to water. It is.

The resin used in this invention that swells and gels when it absorbs water is one that does not dissolve in water but absorbs water and swells from several times to nearly 1,000 times its volume. Examples include starch-acrylotrile or starch-methacrylate graft copolymers, partial hydrolysates of polyacrylonitrile and vinyl ester-ethylenically unsaturated carboxylic acid copolymers, polymers with hydrophilic groups such as sulfonated styrene, and polyethylene oxide. , polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, polyacrylamide, carboxymethyl cellulose, sodium polyacrylate polyacrylamide copolymer, irradiated products of water-soluble polymer compounds such as bullulan, methylene bisacrylamide,
Examples include crosslinked products using crosslinking agents such as dichloroacetic acid, epichlorohydrin, and aldehydes, those in which part of the hydrophilic groups are replaced with lipophilic groups, and copolymers of isobutylene and maleic anhydride.

These resin powder particles absorb underground water in the mixed ground, swell and gel, fill the soil voids in the ground, and become water-stopping ground. Therefore, if this resin powder is distributed and mixed into the ground in the form of a wall, a water-stopping wall can be formed.

Furthermore, these resins generally lose their ability to swell and gel when they come into contact with an aqueous electrolyte solution such as calcium chloride. Therefore, after functioning as a water-stopping wall for a required period of time, when it is no longer needed, the swollen gelled resin powder is returned to its original powder form by injecting these electrolyte aqueous solutions to restore water permeability. can do.

Resin powder particles having a particle size of about 0.05 mm to 1.0 mm are usually used. If the slurry is too large, it will be difficult to uniformly fill narrow voids in the ground, and if mixed with a non-aqueous liquid, the slurry will become unstable and swelling and gelation will be delayed, which is undesirable.

Immediately after, the resin powder can be mixed into the ground by stirring the ground with an auger, or mixed with a non-aqueous liquid to form a slurry, which can be press-fitted into the ground.

The non-aqueous liquid can be selected from oils (fatty glycerides, petroleum-based high-boiling substances, etc.), alcohols, ethylene glycol, glycerin, etc., and can be used alone or as a mixture. When water-soluble or hydrophilic liquids such as alcohols, ethylene glycol, and glycerin are used, when they are injected into the ground, they are quickly replaced with groundwater and are effective in hastening the swelling and gelation of the resin powder. The composition of the non-aqueous liquid is determined by considering these conditions, the target, the ground, the water stop level, working conditions, etc.

Examples will be described below.

Example 1 Water cut-off wall for the purpose of slope protection When excavating the ground 2 with a high groundwater level 1 and high water permeability as shown in Fig. 1 to form a slope 3, To prevent collapse and water leakage,
A water stop wall 4 was constructed.

Construction conditions Resin powder (acrylic acid polymer, product name Sumikagel, average particle size 0.2 mm) 1 part by weight Non-aqueous liquid (turbine oil) 1.75 parts by weight was stirred into a slurry form, and the injection pipe 5 was inserted into the ground. Then, it was pressed into the ground.

Although not shown, as a result of injecting the resin powder slurry multiple times parallel to the slope at predetermined intervals, the resin powder mixed into the ground forms a continuous wall-like ground zone, and at the same time, the resin powder slurry is mixed into the ground. The resin powder 6 absorbs moisture and becomes a gelatinized resin powder, which completely fills the water-permeable soil voids, forms a wall, and makes the ground impermeable, making it possible to construct a water-stopping wall 4.

As a result, it was possible to stop the groundwater without causing any damage to the excavated slope 3, thereby protecting the slope and preventing water leakage.

Example 2 Simple water cutoff wall As shown in Figure 2, on the ground 7 where the water cutoff wall is to be constructed,
An auger 8 was inserted to stir the ground, and at the same time, resin powder that absorbed water and swelled into a gel was directly mixed in. This was repeated at predetermined intervals to form a wall-like ground zone in which the resin powder was mixed. The resin powder in the ground absorbs moisture in the ground and becomes a swollen gelled resin powder 6, completely filling the water-permeable soil voids and forming a wall-like structure, making the ground impermeable. Simple water stop wall 9 was completed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a water-stopping wall for protecting a slope according to a first embodiment, and FIG. 2 is a plan view of a simple water-stopping wall according to a second embodiment. 1... Groundwater level, 2... Ground, 3... Slope, 4
... Water stop wall, 5 ... Injection pipe, 6 ... Swelling gelled resin powder, 7 ... Ground, 8 ... Auger, 9 ... Simple water stop wall.

Claims (1)

[Claims] 1. A resin powder having the property of absorbing water and swelling and gelling is mixed into the ground to form a wall-like ground zone containing the resin powder, and the resin powder absorbs water in the ground. A water-stop wall construction method characterized by swelling gelatinization to form a wall-like structure and making the ground impervious to water.