JP5418456B2 - Roadbed improvement method - Google Patents

Description

  The present invention relates to a roadbed improvement method, and more particularly to a method for reinforcing and improving a roadbed that has been deformed and muddy due to rainwater or the like entering a roadbed under a ballast track of a railway.

  The railroad track is a so-called ballast track that cuts the surface (the roadbed) or piles up soil to form a roadbed, lays crushed stones and gravel (ballast) as a roadbed, and lays sleepers and rails on it. It is common.

  In such a ballast track, the surface of the roadbed becomes soft and mud due to long-term vibration of the train, rise of groundwater, rainwater and long-term inundation, etc., and when pressure such as train load is applied in this state, There is a case where so-called roadbed mud is generated from which mud is ejected from the roadbed. Also on the ballast roadbed, loading and unloading of the train load on the sleepers occur alternately, mud water is sucked at the time of unloading, mud rises through the gap of the ballast at the time of reloading, and mud jets to the roadbed surface So-called roadbed mud may be generated.

  When such mud is generated, the elastic force of the ballast road bed that supports the rails and sleepers is lost, which increases vibration and noise, and increases the risk of track deformation such as depression and overhang. The increase in track subsidence and track misalignment causes problems such as safety concerns and deterioration in ride comfort. For this reason, it is important to hold the roadbed safely and stably, and reduction and simplification of track maintenance work is desired.

Therefore, conventionally, methods such as periodically changing the ballast, thickening the ballast roadbed, coating the roadbed surface with a water shielding sheet or the like, or replacing the roadbed are performed.
The method of periodically replacing ballast and the method of thickening the ballast roadbed cannot reinforce and repair a weakened roadbed.

  In addition, the method of covering the roadbed surface with a water shielding sheet or the like is to remove all ballast from the ballast roadbed, and then lay a laminated sheet material such as a suitable water shielding sheet on the removed roadbed surface, or resin composition After installing the sheet or covering with resin, it is necessary to backfill the ballast and sleepers again, which is extremely burdensome in terms of work and cost.

  In JP-A-2002-363903 (Patent Document 1), after removing the ballast of the ballast roadbed under the railroad track, the two-part urethane coating agent is sprayed on the removed roadbed surface, and then the ballast is backfilled. A mud prevention method is described.

  In Japanese Patent Application Laid-Open No. 2007-112912 (Patent Document 2), a terminal isocyanate group-containing urethane containing an ethylene oxide group and / or a propylene oxide group at a place where the ballast is partially removed after the ballast around the sleeper is partially removed. It comprises a prepolymer (A) and a high-boiling diluent (B), has an isocyanate group content of more than 5% by mass and less than 15% by mass, and a viscosity of more than 10 mPa · s / 23 ° C. and 300 mPa · s / 23. There is described a mud prevention / inhibition construction method in which a one-part moisture-curing type mud consolidation agent, characterized by being less than 0 ° C., is sprayed and then the ballast is backfilled.

However, none of the above methods can repair softened, deformed and muddy roadbeds, and in the current situation, all the rails, sleepers and ballasts are removed and the roadbed itself is replaced. A method of installing a drainage channel is being implemented.
Currently, trains run from early morning to midnight, and the time required for renovation work is required to be very short, and the method of replacing the roadbed requires a large number of work processes and a long work time.
In the drainage installation method, the drainage has to be newly provided, which is costly. Further, the drainage is clogged with soil and sand for many years, and the equipment has a lifetime.

JP 2002-363903 A JP 2007-1112912 A

An object of the present invention is to provide a roadbed improvement method capable of solidifying a soft roadbed under a track that has been deformed and muddy by fluidization with rainwater or the like to form a stable improved soil roadbed.
Another object of the present invention is to provide a roadbed improvement method that can directly modify a muddy roadbed and that is simple and less burdensome.

  According to the present invention, a partially cured body of the hydraulic composition is mixed into a part of the ballast, so that the partially cured body of the hydraulic composition is crushed or worn by a repeated load during train traveling. It was achieved by mixing in the soil and solidifying and improving the soil of the roadbed.

  That is, the roadbed improvement method of the present invention is a hydraulic composition that removes part of the ballast under the railroad track and then backfills the part of the ballast that is backfilled when the ballast is backfilled in the part where the part of the ballast is removed A method for improving a roadbed, comprising substituting a partially cured body of the hydraulic composition obtained by containing less water than the theoretical hydration amount of the hydraulic composition and partially hydrating and hardening the hydraulic composition. .

  Preferably, in the above-described roadbed improving method of the present invention, the partially cured body of the hydraulic composition includes the hydraulic composition and water in a mass ratio of 100: 10 to 100: 15. It is a roadbed improvement method.

  More preferably, in the above-described roadbed improvement method of the present invention, the partially hardened body of the hydraulic composition has a wear loss of 20 to 30% by mass according to JIS A 1121 “Screw test of coarse aggregate using a Los Angeles tester”. There is a method for improving a roadbed.

The roadbed improving method of the present invention replaces a part of the ballast with the partially cured body of the hydraulic composition, so that the partially cured body of the hydraulic composition is crushed and ground by repeated loads during train travel. Then, it falls on the roadbed located below the ballast and mixes with the soil and mud of the roadbed, and the roadbed is solidified by water such as water in the mud and rainwater, especially the softened and deformed roadbed is solidified and stabilized. It is possible to form the improved soil roadbed.
In addition, since the roadbed improving method of the present invention is sufficient to replace a part of the ballast with the partially cured body of the hydraulic composition, work such as removing all sleepers and ballast, or replacing the soil of the roadbed. Is not necessary, the improvement time can be shortened, the workability is good, and the road base improvement method is simple.

  Furthermore, since the roadbed can be reinforced and solidified by a simple method, roadbed mud and roadbed mud can be easily suppressed, and the risk of track deformation such as track depression and overhang can be prevented. Therefore, safety and good riding comfort can be easily maintained.

The present invention will be described by way of the following examples, but is not limited thereto.
The method for improving the roadbed of the present invention, after removing a part of the ballast under the railroad track and then backfilling the ballast in a part where the ballast has been partially removed, A method for improving a roadbed comprising replacing the partially hardened body of the hydraulic composition obtained by containing less water than the amount of hydration and partially hydrating and hardening the hydraulic composition.

In the present invention, when improving the roadbed, it is not necessary to remove rails, sleepers, etc., and a part of the ballast under the railway road is removed, and when the ballast is refilled in the removed part, one of them is used. By replacing the part with the partially cured body of the hydraulic composition and mixing it, the partially cured body of the hydraulic composition is crushed or worn by the repeated load during train traveling, and is positioned below Fall on the roadbed. After that, it is mixed in the soil forming the roadbed, and the remaining hydration activity is expressed and solidified by water such as water in the mud of the roadbed and rainwater, and solidifies to improve the soil of the roadbed.
The roadbed improving method of the present invention is particularly effective in improving a roadbed that has already been muddy and deformed because it is not necessary to remove all sleepers, ballasts, and deformed roadbeds.

Here, the crushed stone and gravel generally used as a ballast have a wear loss of 10 to 20% by mass according to JIS A 1121 “Coarse aggregate grinding test using a Los Angeles testing machine”.
The partially cured body of the hydraulic composition used in the present invention has a large amount of grinding loss according to JIS A 1121 “Coarse aggregate grinding test using Los Angeles testing machine” as compared with the above-mentioned general ballast crushed stone, gravel and the like. Although it does not specifically limit, It is 20-30 mass% suitably.

As a result, the shape can be maintained when granulated, and the partially cured body of the hydraulic composition is crushed or worn earlier than the ballast and pulverized, and the ballast gap falls downward, Improved soil can be formed by mixing with mud and solidifying. Or it can fall on the roadbed, mix with the soil of the roadbed, and solidify with water such as rain water to form improved soil.
Further, the amount of the partially cured body of the hydraulic composition that is replaced with the ballast can be appropriately determined according to the state of the roadbed that has been fluidized and deformed.

  The partially cured body used in the present invention has hydration activity remaining in the partially hydrated cured body, and the partially cured body of the hydraulic composition is crushed or worn by repeated loading during train traveling. By entering and coming into contact with water such as mud in the roadbed, the remaining hydration activity can be used to completely hydrate and solidify the soil of the roadbed for reinforcement improvement.

  The hydraulic composition and water contain water that is less than the theoretical hydration amount to leave an unhydrated portion. Preferably, the hydraulic composition and water have a mass ratio of 100: 10 to 10:10. Mix at a ratio of 100: 15 parts by mass. Usually, the theoretical hydration amount of the hydraulic composition is about 27 to 28 parts by mass of water with respect to 100 parts by mass of the hydraulic composition. In the present invention, water having less than the theoretical hydration amount, ie, hydraulic composition. In order to achieve a water content of 15 parts by mass or less with respect to 100 parts by mass of the product, and to granulate, the hydraulic composition and water should have a mass ratio of 100: 10 or more. It is preferable.

  In addition, the partially cured body of the hydraulic composition of the present invention is granulated by mixing the hydraulic composition and a smaller amount of water than the theoretical amount at which the hydraulic composition exhibits a complete hydration reaction. Manufactured by. Although the particle size is not particularly limited, those having a particle size of 10 to 40 mm (JIS sieve), which is approximately the same size, can be suitably used in view of the relationship with the size of crushed stone and gravel used for ballast.

  Here, the “partially cured body” in the present specification represents an ignition loss value (ignition loss) defined by “cement ignition loss” of JIS R 5202 of less than 15% by mass. For example, when the ignition loss is 15% by mass, the theoretical water amount is usually 28% by mass, so that the remaining 13% by mass is retained and retained in the granulation body while maintaining the hydration activity, and is partially cured. Become a body.

  Here, the theoretical hydration amount of the hydraulic composition is, for example, in the case of ordinary ordinary Portland cement, the theoretical water amount of ordinary Portland cement, that is, the mineral composition of ordinary Portland cement is all hydrated by the hydration reaction. It is the amount of water required to become a product, and is 27 to 28 parts by mass with respect to 100 parts by mass of ordinary Portland cement. Specifically, when 100 g of ordinary Portland cement and 28 g of water are mixed and cured well, hydration proceeds completely over time, and a fully hydrated cured product is obtained. It represents the amount of water to the extent that a hydrated cured product can be obtained.

On the other hand, for example, when kneading a mixture obtained by adding about 10 parts by mass of water to 100 parts by mass of ordinary Portland cement, a mixture lacking water to complete the hydration reaction, That is, a mixture in which only 10 parts by mass of water is required as the theoretical amount of water, but 100 parts by mass of the hydraulic composition is 28 parts by mass, is just a wet powder.
This is granulated by any known granulating apparatus to obtain a partially cured body used in the present invention.

The hydraulic composition used in the partially cured body of the present invention can consist only of hydraulic powder as a powder raw material.
Here, the hydraulic powder means a powder that is hardened by water, preferably ordinary Portland cement, jet cement, alumina cement, super-hard cement, calcium silicate, calcium aluminate, calcium fluoroaluminate, calcium salp. At least one powder selected from the group consisting of foaluminate, calcium aluminoferrite, calcium phosphate, slag, semi-water or anhydrous gypsum and quicklime powder is used.

The particle size and the like of the hydraulic powder is not particularly limited, but in terms of the pot life during granulation and the shape maintaining strength of the resulting granulated body, those having an average particle size of about 10 to 40 μm are preferable. From the viewpoint of securing the shape-maintaining strength of the granulated body, it is preferable that the brain specific surface area is 2500 cm ² / g or more.

Further, the hydraulic composition used in the present invention may contain a non-hydraulic powder in addition to the hydraulic powder.
The non-hydraulic powder means a powder that does not harden when contacted with water alone, but its components are eluted in an alkaline or acidic state, or in a high-pressure steam atmosphere, and other already-eluting components. It also includes powders that react to form products.

The non-hydraulic powder includes at least one powder selected from the group consisting of calcium hydroxide powder, dihydrate gypsum powder, calcium carbonate powder, slag powder, fly ash powder, silica stone powder, clay powder and silica fume powder. The body can be preferably used.
These non-hydraulic powders have a function of increasing strength by a pozzolanic reaction or a microfiller effect.

The average particle diameter of these non-hydraulic powders is preferably one or more orders of magnitude smaller than the average particle diameter of the hydraulic composition powder, more preferably two or more orders of magnitude smaller than that of the hydraulic composition powder. However, the lower limit of the fineness is not particularly limited and is not particularly limited as long as it does not impair the effects of the present invention, but is usually an average particle of a hydraulic powder. It is preferable from the point of granulation property to be about 1/500 of the diameter.
By using the non-hydraulic powder having such a particle size, the shape maintaining property of the granulated body can be further improved.

In order to prepare the partially cured body used in the present invention, first, the hydraulic composition and water are prepared by mixing at the above-mentioned mixing ratio. The mixing method is arbitrary known as long as it can be mixed uniformly. It is possible to mix using methods.
In particular, when using a hydraulic composition containing a hydraulic powder and a non-hydraulic powder, it is preferable to employ a mixing method capable of applying a strong shearing force, such as a proshear type mixer, etc. Knead using By mixing using such a mixer having a high shearing force, the time required for mixing can be shortened.

  In addition, as described above, as a method for adding water, a wet composition is obtained by mixing a hydraulic composition and a smaller amount of water than the theoretical amount at which the hydraulic composition exhibits a complete hydration reaction. While granulating, the hydration reaction of the powder proceeds to partially leave hydration activity. In this case, any method can be used as long as it is a method of adding the hydraulic composition uniformly, whether it is granulated after obtaining the wet powder, or granulated simultaneously with obtaining the wet powder. In order to stably produce a wet powder obtained by adding the above amount of water to the hydraulic composition, it is necessary to pay attention not to cause so-called kneading.

  In order to prevent the formation of kneading balls, it is desirable that the droplet diameter of the added water be equal to or smaller than the particle diameter of the hydraulic composition powder. As a water addition method for this purpose, for example, a dedicated spray nozzle that can be sprayed with a droplet diameter equal to or smaller than that of powder particles, preferably called a commercially available dry fog nozzle, can be used effectively. .

Specifically, a method is preferably used in which powder of the hydraulic composition is put into a mixer, and dry fog is sprayed continuously while the mixer is rotated or mixed.
By carrying out in this way, it is possible to obtain a completely uniform hydraulic composition and water mixture, ie, a wet powder of the hydraulic composition, without any kneading, and by granulating this, A partially cured body used in the present invention can be obtained.

  More preferably, the surface of the obtained partially hydrated cured product can be subjected to an extremely thin coating treatment such as paraffin wax or organic paint. By providing such a coating, it is possible to prevent the remaining hydration activity from being lost by moisture in the air during the storage period of the partially cured body.

  By using such a partially cured body of the hydraulic composition, the roadbed improving method of the present invention does not need to remove all the sleepers and ballasts, but replaces the ballast and mixes it as a part of the ballast, thereby The partially hardened body of the hydraulic composition is crushed or worn by the repeated load and falls to the roadbed. Thereafter, it is mixed in the soil forming the roadbed, and the hydration activity of the unhydrated portion remaining by the water in the mud of the roadbed is developed and solidified, and the soil of the roadbed can be solidified and improved. Therefore, it is not necessary to replace the deformed roadbed, and extremely simple roadbed reinforcement can be applied.

  INDUSTRIAL APPLICABILITY The present invention is effectively used for reinforcing and improving soil of a roadbed that has been deformed or fluidized in a ballast track under a railway track, and can be usefully applied to suppress and prevent mud such as roadbed mud and roadbed mud.

Claims (3)

After removing part of the ballast under the railroad track, when refilling the ballast in the part where the ballast has been partially removed, the part of the ballast to be refilled contains less water than the theoretical hydration amount of the hydraulic composition. A roadbed improvement method comprising replacing the hydraulic composition with a partially cured body of the hydraulic composition obtained by partially hydrating and hardening the hydraulic composition.   In the roadbed improvement method according to claim 1, the partially cured body of the hydraulic composition is characterized in that the hydraulic composition and water are contained in a mass ratio of 100: 10 to 100: 15. Subbase improvement method.   3. The roadbed improvement method according to claim 1, wherein the partially cured body of the hydraulic composition has a wear loss of 20 to 30% by mass according to JIS A 1121 “Screw test of coarse aggregate using a Los Angeles tester”. A roadbed improvement method characterized by