JP2544891B2 - Ballast fixing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing ballast, such as ballast ballast on railroad tracks.

[0002]

2. Description of the Related Art Conventionally, a railroad track has a structure in which a roadbed made of ballast such as crushed stone or gravel is placed on the roadbed, and sleepers are further placed on it to fasten rails, that is, a so-called roadbed track. Occupy most. The ballast made of the ballast has a role of dispersing the train load transmitted from the sleepers and transmitting it to the lower roadbed and absorbing vibrations when the train passes.

However, the ballast using a ballast has the following problems, for example. Ballast collapses ... The roadbed is several tens of hours due to passing trains.
Repeated vibration of z or more. Due to this vibration,
It is necessary to perform repair work because the compacted state of the ballast loosens and collapses. In particular, in the curved part of the track, in order to maintain the running safety of the train, the outer rail is attached with a "cant" that is higher than the inner rail, so crushed stones etc. that have been subjected to the above-mentioned vibration The ballast collapses over time, moving from the high part outside the track to the low part inside the track. As a result, the resistance of the sleepers to the rolling stock lateral pressure is reduced, resulting in a dangerous condition. For this reason, the flat part usually does not need to be repaired for one year or more, whereas the curved part needs to be repaired in a short period of time. Also,
Ballast tracks have a roundabout shape as the train passes, so repair work is required in a shorter period than concrete slab tracks such as slab tracks.

Ballast scattering due to snow damage ... In cold regions where there is snow in winter, snow blocks (ice blocks) often adhere to trains. The snow mass (ice mass) attached to the train melts and falls as the train moves to a warm area, and collides with the ballast. In particular, when the train is running, the impact is temporary but extremely large, and the ballast scatters, damaging surrounding private houses and parked cars.

Ballast scattering due to wind pressure: When a train passes over the roadbed at a high speed (for example, 200 km / h or more), the surface layer of the roadbed floats up due to the wind pressure of the train and collides with a train passing directly above. , Crushed stones are scattered.
Since the scattered crushed stones have the same speed as a passing train, they may damage the private houses along the line or parked cars, and inspect passengers and tracks waiting for the train on the platform. There is a risk of harming track maintenance workers.

Conventionally, as a method for solving the problem of such a roadbed, there have been, for example, the following methods (1) to (3). (1) A method of preventing ballast scattering or strengthening a ballast ballast by spraying a chemical solution in which rubber latex, synthetic resin, and cement are mixed to consolidate the ballast (JP-A-49-32306). Japanese Patent Laid-Open Publication No. 52-16810, etc.).

(2) A method of setting a net for preventing ballast scattering. (3) A method of forming a ballast using concrete or asphalt without using ballast. However, the method (1) is currently mostly used for reasons such as difficulty in controlling the rate of hardening of cement, high cost, and difficulty in keeping track of ballast due to hardness of cement after spraying a chemical solution. Absent.

Further, the method (2) is partly due to the reasons such as difficulty in attaching and removing the net, high cost, and risk of accident due to train being caught in the net. Only done. Furthermore, the method (3) is very expensive, and thus only partially performed.

As a method for solving these problems, a method has been developed in which a ballast-fixing chemical liquid composed of an aqueous resin (hereinafter, simply referred to as "aqueous resin") is sprayed. That is, it is a method of fixing the ballasts by spraying the aqueous resin on the ballast, allowing the aqueous resin to permeate between the ballasts, and then naturally drying to form a film.

According to this method, it is possible to prevent ballast collapse, snow damage, ballast scattering due to wind pressure, etc., without impairing the train load dispersion, vibration absorption, porosity, drainage, etc. of the roadbed using ballast. In addition, the spraying work is easy and inexpensive, and a film having a fixing force that does not hinder track maintenance work such as ballast compaction, scraping, and leveling can be formed.

[0011]

However, the medium of the aqueous resin needs to have water as a main component in view of environmental pollution. Therefore, if there is rainfall etc. before drying,
Since the resin flows out, the work is very sensitive to the weather and it is difficult to adjust the work schedule. Further, the ballast fixing strength does not appear until the resin is dried to form a film, but immediately after the work is completed, the fixing strength sufficient to prevent ballast scattering due to the wind pressure of the train does not appear.

In view of such circumstances, the present invention provides a ballast fixing method capable of preventing the outflow due to rainfall or the like immediately after spraying the water-based resin and providing the ballast fixing strength sufficient to prevent the ballast scattering due to wind pressure. provide.

[0013]

In order to solve the above-mentioned problems, the ballast fixing method according to the present invention is characterized in that an aqueous resin is sprayed on the ballast and then an aqueous flocculant solution is sprayed. Examples of the water-based resin used in the present invention include resin emulsions and water-soluble resins, but the dispersion medium or solvent must be water as a main component from the viewpoint of environmental pollution.

The ionicity of the aqueous resin is not particularly limited, but it is preferably anionic in order to enhance the cohesiveness of the coagulant. Nonionic nature makes it difficult to aggregate,
If it is cationic, there is fear of toxicity. The method of using the water-based resin is not particularly limited, but usually, a method of spraying the water-based resin on the ballast using a rain dew or a spraying machine and allowing the water-based resin to permeate between the ballasts is adopted. In order to prevent the ballast from scattering due to wind pressure, the water-based resin does not have to penetrate the entire track. This is because even if the water-based resin is infiltrated only in the ballast of the surface layer of the roadbed to fix the ballast, the effect of preventing the ballast from scattering due to the wind pressure can be sufficiently obtained and the cost can be reduced.

Although the viscosity of the aqueous resin is not particularly limited,
It is preferably not too low for fixing only the surface layer portion of the ballast. The aqueous resin used in the present invention is not particularly limited, and examples thereof include acrylics, styrene-acrylics, vinyl acetate-acrylics, styrene-butadienes, vinyl acetates, ethylene-vinyl acetates, and vinylidene chloride. Aqueous resins can be used.

The method for obtaining this aqueous resin is not particularly limited, and the same method as that for obtaining a conventional resin emulsion or water-soluble resin can be used. For example, as a method for obtaining an emulsion, a polymerizable monomer may be emulsion polymerized in water, or,
After polymerizing the polymerizable monomer by a polymerization method other than emulsion polymerization to obtain a polymer, the polymer may be emulsified in water. Further, as a method of obtaining a water-soluble resin, by polymerizing a polymerizable monomer in a solvent that can be dissolved in water,
If necessary, it may be dissolved in water after neutralization, or after the polymerizable monomer is polymerized in a solvent insoluble in water, the solvent is removed and the polymer may be dissolved in water. The temperature and the like for polymerizing the polymerizable monomer are not particularly limited. If necessary, an emulsifier, a polymerization initiator or the like may be appropriately used.

The polymerizable monomer used is not particularly limited, but the aggregating efficiency varies depending on the type of aggregating agent.
For example, in the case of an aggregating agent containing aluminum, it is preferable to use a carboxyl group-containing monomer in an amount of 0.1% by weight or more, and more preferably 1% by weight or more, based on the entire polymerizable monomer component. preferable. The carboxyl group-containing polymerizable monomer, acrylic acid, methacrylic acid,
Examples thereof include crotonic acid, itaconic acid, fumaric acid, maleic acid, vinylbenzoic acid, cinnamic acid and the like. In the case of a flocculant containing calcium, the proportion of the carboxyl group-containing monomer used with respect to the entire polymerizable monomer component is preferably 8% by weight or less, more preferably 4% by weight or less.

The emulsifier used to obtain the resin emulsion is not particularly limited. An anionic emulsifier is preferably used for efficiently aggregating with the aggregating agent, but a nonionic emulsifier may be used in combination. Examples of the anionic emulsifier include sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium dialkyl sulfosuccinate, polyoxyethylene alkyl ether sulfate ammonium salt, alkyl ether phosphate and the like. Examples of the nonionic emulsifier include polyoxyethylene nonyl phenyl ether, polyethylene glycol monostearate, sorbitan monostearate and the like.

The polymerization initiator is not particularly limited, but persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, cumene hydroperoxide,
Organic peroxides such as diisopropylbenzene hydroperoxide and benzoyl peroxide, azo compounds such as azobisisobutyronitrile, hydrogen peroxide and the like can be used.

As the solvent soluble in water, alcohols such as ethanol, isopropyl alcohol and butyl cellosolve, ketones and the like can be used. Further, in order to promote emulsion polymerization, a reducing agent such as sodium pyrobisulfite, sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, glucose, formaldehyde, sodium sulfoxylate, and L-ascorbic acid may be used in combination. .

The water-based resin used in the present invention is not particularly limited in its physical properties, but in order to improve the dispersibility of the water-based resin, the permeability between ballasts, and the drying property, it must have the following physical properties. Is preferred. The viscosity of the aqueous resin is
It is preferably 10 to 10,000 cps. If the viscosity exceeds 10,000 cps, it may be difficult to uniformly disperse the resin emulsion on the ballast, and if it is less than 10 cps, the yield near the surface layer may deteriorate.

The nonvolatile content of the aqueous resin is preferably 5% by weight or more with respect to the entire aqueous resin. This is because if the nonvolatile content concentration is less than 5% by weight, the amount of resin adhered to the ballast will be too small after drying, and the desired prevention effect will not be obtained. The average particle size of the resin emulsion is
Affects the dryness and viscosity of the resin emulsion. In general, the smaller the average particle diameter, the better the drying property, but the higher the viscosity, and the poorer the sprayability and the penetrability of the resin emulsion. Therefore, the average particle size of the resin emulsion is preferably about 10 nm to 10 μm.

The viscosity of the aqueous flocculant solution used in the present invention is not particularly limited, but is preferably 10,000 cps or less. The coagulant aqueous solution is usually sprayed on the ballast using a raindrop or a spraying machine. Therefore, the viscosity is 10,000
This is because if it exceeds cps, it will be difficult to evenly spread it on the ballast. The aggregating agent is not particularly limited, but a water-soluble one is preferable. In particular, polyvalent metal salts such as aluminum sulfate, aluminum chloride, polyaluminum chloride, calcium chloride, calcium hypophosphite, calcium acetate, calcium propionate, magnesium chloride and magnesium acetate are preferable. This is because when these polyvalent metal salts are used, an aqueous solution having a high concentration and a low viscosity can be easily obtained. On the other hand, a polyacrylamide-based, polymethacrylic acid-based, or polyamine-based polymer flocculant can also be used, but in that case, since it is difficult to obtain a high-concentration, low-viscosity aqueous solution, a polyvalent metal salt is also used. Is preferred.

[0024]

When the aqueous resin is sprayed on the ballast and then the aqueous flocculant solution is sprayed, a film is instantaneously formed on the surface of the aqueous resin. This is because the aqueous resin is electrically neutralized by the aggregating agent to cause an aggregating reaction. The agglomerated film formed at this time does not elute due to rainfall, etc.,
Even if there is rainfall or the like immediately after the resin is sprayed, the resin can be prevented from flowing out, and the ballast fixing strength can be provided to the extent that the ballast scattering due to the wind pressure of the train can be prevented.

[0025]

EXAMPLES Examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples. In addition,
In each example, "part" and "%" are based on weight. -Reference Example 1 (Production Method of Resin Emulsion)-400 parts of deionized water was placed in a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel.
1 part of "HITENOL N-08" (polyoxyethylene nonylphenyl ammonium sulfate; manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and 0.5 part of ammonium persulfate were charged, and the internal temperature was adjusted to 80.
It was set to ° C. In this, 160 parts of methyl methacrylate,
230 parts of butyl acrylate, 10 parts of acrylic acid, 9 parts of “HITENOL N-08” and 185 parts of deionized water, 3 parts of 10% ammonium persulfate aqueous solution, and 5 parts of sodium bisulfite. % Aqueous solution and 3 parts simultaneously were allowed to flow in simultaneously for 3 hours. 8 more after the inflow
The mixture was stirred at 0 ° C for 2 hours. Then, after cooling, the produced content was taken out through an 80-mesh filter. Thus, the nonvolatile content is 40% and the viscosity is 20.
A resin emulsion of 0 cps was obtained.

-Reference Example 2 (Manufacturing Method of Water-Soluble Resin)-400 parts of isopropyl alcohol was charged into a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen introducing tube and a dropping funnel, and the internal temperature was 80 ° C. I chose In this
A mixed solution of 90 parts of styrene, 50 parts of methyl methacrylate, 180 parts of 2-ethylhexyl acrylate, 80 parts of acrylic acid, and 12 parts of azobisisobutyronitrile was added dropwise over 3 hours. After the dropping was completed, the mixture was further stirred at 80 ° C. for 2 hours.
Then, after cooling, it was neutralized with 28% ammonia water in an equivalent amount, and water was added. Thus, a water-soluble resin having a nonvolatile content of 25% and a viscosity of 100 cps was obtained.

The nonvolatile content and the viscosity value of the aqueous resin obtained in the above Reference Example are measured by the following methods. Measurement of non-volatile content : About 1 g of the aqueous resin was weighed in an aluminum dish of known weight, dried in a hot air dryer at 105 ° C for 2 hours, cooled, and then weighed. The nonvolatile content concentration was calculated from the following formula.

Nonvolatile content concentration (%) = {(weight after drying-weight of aluminum dish) / (aqueous resin)} × 100 Measurement of viscosity : A container containing the aqueous resin is kept in a constant temperature bath at 25 ° C. for 2 hours or more. After standing, it was measured using a Brookfield type rotational viscometer (manufactured by Tokyo Keiki Co., Ltd .; BM type, rotation speed 30 rotations).

Further, the following spraying test was carried out on the aqueous resin obtained in the above reference example, and the results are shown in Table 1. Dispersion test of aqueous resin: 500 g of the aqueous resin was put into a rain dew and sprayed on gravel (spraying area 1 m ² ), and the easiness of spraying and the wettability of the gravel surface were evaluated according to the following.
However, the gravel used was crushed stone having a weight of 30 to 80 g / piece.

◯: Easy to spread, and the gravel surface was uniformly wet. Δ: It is easy to spray, but there is unevenness in how the gravel surface gets wet. X: Difficult to spray, and unevenness was observed in the way the gravel surface was wet. -Reference Example 3 (Production Method of Aqueous Flocculant Solution) -Aluminum Sulfate (Hayashi Pure Chemical Industries, Ltd., Pure Reagent Grade 1) 10
Part was dissolved in 90 parts of ion-exchanged water to obtain a coagulant aqueous solution.

Reference Example 4 (Preparation of Aqueous Flocculant Solution) -Calcium propionate (Hayashi Junyaku Kogyo KK, first grade reagent)
10 parts was dissolved in 90 parts ion-exchanged water to obtain an aqueous flocculant solution. The following experiment was conducted using the above-mentioned aqueous resin and aqueous flocculant solution. -Example 1-The resin emulsion obtained in Reference Example 1 was exposed to 500 g of rain and dew.
g, spray on gravel (scattering area 1 m ² ), and after 1 minute, 100 g of the flocculant aqueous solution obtained in Reference Example 3 was sprayed on the resin emulsion spraying spot by rain and dew (scattering area 1 m 2
² ) I did.

-Example 2-The resin emulsion obtained in Reference Example 1 was exposed to 500 g of rain and dew.
g, spray on gravel (scattering area 1 m ² ), and after 1 minute, 100 g of the flocculant aqueous solution obtained in Reference Example 4 was sprayed on the resin emulsion spraying spot by rain and dew (scattering area 1 m 2
² ) I did. -Comparative Example 1-A procedure was performed in the same manner as in Example 1 except that the aqueous flocculant solution was not sprayed.

Example 3-500 g of the water-soluble resin obtained in Reference Example 2 was placed in rain dew and sprayed on gravel (spraying area 1 m ² ), and after 1 minute, the agglomeration obtained in Reference Example 3 Spray 100 g of the aqueous solution of the agent with rain and dew on the resin emulsion spraying area (spraying area 1 m ² ).
did. -Comparative Example 2-A procedure similar to that of Example 3 was performed except that the aqueous flocculant solution was not sprayed.

The test points of the above-mentioned Examples and Comparative Examples were evaluated for runoff prevention by rain and scattering prevention by wind pressure immediately after spraying, and the results shown in Table 1 were obtained. The evaluation test method at this time is as follows. Preventing runoff due to rainfall : 1 minute after spraying the coagulant aqueous solution, 500 g of ion-exchanged water
Was sprayed on the test point in the rain dew was observed the condition of the effluent.

O: The effluent was transparent. × ... The effluent was cloudy. Immediately after spraying, scattering prevention by wind pressure : Coagulant solution spray 1
After a minute, a wind speed of 50 m / s was applied and the movement of the gravel was observed. The results were evaluated according to the following.

O: It did not move at all. X: Scattered.

[0037]

[Table 1]

[0038]

EFFECTS OF THE INVENTION According to the ballast fixing method according to the present invention, a film is instantaneously formed after the aqueous resin is sprayed and then the aqueous flocculant solution is sprayed. Therefore, even if there is rainfall or the like before drying, the resin does not flow out, so the work is not affected by the weather. In addition, immediately after spraying, it is possible to obtain the ballast fixing strength to the extent that ballast scattering due to the wind pressure of the train can be prevented.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Koshino 2-4-24 Shibata, Kita-ku, Osaka West Japan Railway Company (72) Inventor Koichi Tate 2-4-24 Shibata, Kita-ku, Osaka West Japan Passenger Railway Co., Ltd. (72) Inventor Teruo Kikuta 5-8 Nishimitabicho, Suita City, Osaka Prefecture Nippon Shokubai Co., Ltd. in Suita Works (72) Inventor Kazuhiko Nakamura 5-8 Nishimitabicho, Suita City, Osaka Stocks Incorporated Nippon Catalyst Co., Ltd. in Suita Plant (72) Inventor Kenji Miyata 5-8 Nishimitabicho, Suita City, Osaka Stock Company In Japan Catalyst, Suita Plant (56) References Japanese Patent Publication No. 52-4802 (JP, B2)

Claims (2)

(57) [Claims] 1. A method for fixing ballast, which comprises spraying an aqueous resin on the ballast and then spraying an aqueous flocculant solution. 2. The ballast fixing method according to claim 1, wherein a polyvalent metal salt is used as the aggregating agent.