JP6251541B2 - Subbase construction method - Google Patents

Description

  The present invention relates to a method for constructing a roadbed of a ballast track.

The ballast track is composed of a ballast roadbed provided on a roadbed made of soil, asphalt, concrete or the like, and a rail laid on the ballast track. When rain falls on the ballast track, rainwater passes through the ballast roadbed and reaches the roadbed. is there. When the roadbed becomes weak, the amount of ballast settlement when the vehicle passes increases, making it easier for the rail to be distorted, and the effect of the track maintenance work becomes difficult to sustain, requiring frequent track maintenance work. .
Therefore, a technique for extending the maintenance cycle of the track by improving the toughness of the roadbed has been studied. Conventionally, as one of the improvement methods of the roadbed, there is a method of constructing a new improved roadbed using the ballast of the ballast roadbed as an aggregate by pouring a liquid filler into the ballast and hardening it, and filling the ballast gap. It has been proposed (see Non-Patent Document 1). This construction method can save time and effort for removing the existing ballast, so that the construction period can be shortened and the environmental load can be reduced.

Railway Technical Research Institute “Facility Research News” No. 274, p3,4

By the way, the stagnant water on the road bed is not limited to the earth road bed but may also affect the improved road bed. Therefore, when providing an improved roadbed, it is required to incline the upper surface of the improved roadbed in a direction perpendicular to the track laying direction so that rainwater or the like flows laterally. This inclination is set to have a gradient of about 3%.
However, the conventional method of filling a ballast with a filler and making it an improved roadbed is intended to partially improve the weakened range of about 5 to 10 m. It has not been turned on or devised.
That is, the conventional roadbed construction method in which the filler is poured into the existing roadbed cannot form a drainage gradient, and thus cannot be adopted for construction of an improved roadbed over a wide range.

  The present invention has been made in view of the above problems, and in a method for constructing a new roadbed by pouring a filler into an existing ballast roadbed, it is possible to easily add a drainage gradient to the upper surface of the roadbed. Objective.

In order to solve the above problems, the present invention provides a roadbed construction method for building a roadbed using ballast as an aggregate by filling at least a part of an existing ballast roadbed with a filler and curing the filled filler. A pair of earth retaining walls are newly provided on both sides of the rail laid on the ballast roadbed so as to extend along the rail laying direction and at least from the upper surface of the existing roadbed. The ballast roadbed is installed so as to have a height exceeding the upper surface height of the roadbed to be installed, and is sandwiched between the pair of retaining walls from the vicinity of one of the pair of retaining walls. In addition, it has a hardening characteristic that loses fluidity after a predetermined time has elapsed from the start of filling, and after a predetermined time has elapsed from the start of filling, reaches the predetermined height of the other retaining wall of the pair of retaining walls, one It poured from the earth retaining wall filler having a condition to become such flowability with gradient as going down at a predetermined rate toward to the other of the earth retaining wall, by curing the filler, A roadbed having a ballast track above is constructed .

According to the present invention, “at least a part of the existing ballast roadbed is filled with a filler”. Therefore, when the upper part of the existing ballast roadbed is continuously used as the ballast roadbed, or the existing ballast roadbed is the bone of the new roadbed. The case of using for a material is included.
In addition, in “Installing earth retaining walls on both sides in the width direction of the rail”, there are cases where all existing ballasts are sandwiched on the side of the existing ballast roadbed, and where the existing ballast roadbed is in the middle The case where it is provided so as to be divided is included.

  In this way, just by pouring the filler into the existing ballast roadbed, the filler is further filled and leveled on the cured filler, or the upper surface of the cured filler is scraped diagonally, etc. Since a predetermined gradient can be given to the upper surface of the roadbed without going through the process, a roadbed that extends long over a wide area and has a predetermined drainage gradient on the upper surface can be easily installed.

In the above invention, for example, as the filler, a powder material containing an ultra-fast hard material, water, and a water reducing agent, the ratio of the weight of water to the total weight of the powder material is 50% or more and 55% or less. It is advisable to use such a mixture.
In this way, even when a roadbed having a width of about 2 to 5 m required as a roadbed for a single track is constructed, the fluidity that the filler can reach from one earth retaining wall to the other earth retaining wall. Therefore, a roadbed having a gradient on the upper surface can be easily installed.

Preferably, in the above invention, the weather conditions at a construction site are measured before filling with the filler, and based on the measured weather conditions, a setting retarder is added to the filler, and the filler starts filling. It is good to measure and add the quantity which loses fluidity | liquidity after the time of 20 minutes or more and 40 minutes or less, and is filled with the said filler after that.
In this way, it is possible to prevent the filler from hardening before the filler reaches the other earth retaining wall or before the gradient of the upper surface of the filler falls within a predetermined range.

  According to the present invention, in a method for constructing a new roadbed by pouring a filler into an existing ballast roadbed, a drainage gradient can be easily provided on the upper surface of the roadbed.

It is the figure which showed the outline | summary of the experiment conducted in order to determine the component of the filler of embodiment. It is the table | surface which showed the various conditions of the experiment conducted using the instrument of FIG. It is the graph which showed the experimental result at the time of using the filler of samples 1 and 2. FIG. It is the graph which showed the experimental result at the time of using the filler of samples 3 and 4. FIG. It is the graph which showed the experimental result at the time of using the filler of the sample 5. FIG. It is the graph which showed the experimental result at the time of using the filler of the sample 6. FIG. It is the figure which showed the outline | summary of the experiment conducted in order to determine the component of the filler of embodiment. It is the graph which showed the detail of the experimental result at the time of using the filler of samples 5 and 6. FIG. It is the figure which showed the flow of the roadbed construction method of 1st Embodiment. It is the figure which showed the flow of the roadbed construction method of 2nd Embodiment. It is the figure which showed the flow of the roadbed construction method of 3rd Embodiment.

<First Embodiment>
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Filler)
First, the filler used in the roadbed construction method of this embodiment will be described.
In the present embodiment, as the filler, a mixture of a super fast hard material, a filler, water, a water reducing agent, and a setting retarder is used.

The super fast hard material is, for example, a powder material such as a jet cement clinker.
The filler is a powder material added to prevent breathing.
The water reducing agent is a liquid material that is added to disperse the super fast hard material to increase the fluidity of the filler and to increase the strength of the filler after curing.
Note that the degree of fluidity of the filler can be adjusted by adjusting the ratio of the weight of water to the total weight of the powder material (super-hard material and filler) (hereinafter referred to as W / material value) and the amount of water reducing agent added. Is possible. In the present embodiment, the W / material value is in the range of 50 to 55%. By setting it as such a mixing ratio, the filler of this embodiment has fluidity | liquidity whose JA funnel flow-down time is about 12.9 to 14.5 seconds.

The setting retarder is added to delay the time until the filler is cured. By increasing the addition amount of the setting retarder, the time until the fluidity is lost after the filler is kneaded (hereinafter referred to as pot life) becomes longer than when the additive is not added.
Even if the same amount of setting retarder is mixed, the pot life varies depending on the weather conditions (temperature, etc.) at the time of construction, so add an appropriate amount according to the weather conditions immediately before using the filler. To. In the present embodiment, an amount such that the pot life is in the range of 20 to 40 minutes is added.

(Concrete example)
Here, the content of the experiment conducted in order to narrow down the W / material value and pot life of the filler of this embodiment to the said range is demonstrated. FIG. 1 is a diagram showing the experimental method, FIG. 2 is a table summarizing the experimental conditions, and FIGS. 3 to 6 are the distance from the pouring position and the ballast top surface of the solidified surface for the roadbed sample formed using each filler. It is the graph which showed the relationship with the distance from.

  First, five types of filler samples 1 to 5 having different fluidity and pot life, and a small formwork having a width (D) of 0.3 m, a height (H) of 0.4 m, and a length (W) of 2.4 m. M1 and a large mold M2 having a width (D) of 0.3 m, a height (H) of 0.4 m, and a length (W) of 4.8 m were prepared. Sample 1 has a W / material value of 60% and a pot life of 20 minutes. Sample 2 has a W / material value of 70% and a pot life of 20 minutes. Sample 3 has a W / material value of 60% and a pot life. The sample 4 has a W / material value of 55% and a pot life of 40 minutes, and the sample 5 has a W / material value of 50% and a pot life of 40 minutes.

Next, the specific gravity of each filler sample 1 to 5 was measured. As a result, sample 1 is 1.67 kg / m ³ , sample 2 is 1.63 kg / m ³ , sample 3 is 1.67 kg / m ³ , sample 4 is 1.72 kg / m ³ , and sample 5 is 1.76 kg / m ² . It was m ^3.
Moreover, each filler sample 1-5 was measured by predetermined amount (1000 cc), and each JA funnel flow time was investigated. As a result, Sample 1 was 12.6 seconds, Sample 2 was 11.6 seconds, Sample 3 was 12.3 seconds, Sample 4 was 12.9 seconds, and Sample 5 was 14.5 seconds.
Next, the ballast B is packed in the small formwork M1 or the large formwork M2 so that the upper surface is horizontal and the height (h) from the bottom surface to the upper surface of the formwork M1, M2 is 0.3 m, One of the five kinds of filler samples 1 to 5 is continuously poured from one end of the molds M1 and M2 into a plurality of times from one end of the molds M1 and M2 as shown in FIG. The grade of the gradient of the upper surface of the roadbed sample (cases 1 to 6) formed by curing samples 1 to 5 was examined.

In case 1, first, the filler sample 1 was poured into a small mold M1 filled with ballast B and cured. As shown in FIG. 3, the upper surface of the roadbed sample thus obtained had a steep gradient from a distance of 1500 mm from one end of the mold, and the average gradient greatly exceeded 3%.
In case 2, sand was spread on the bottom surface of the small formwork M1, and ballast was filled from above, and the filler sample 1 was poured and cured. The average slope of the upper surface of the obtained roadbed sample was steeper than in Case 1 in which the sand was not sprinkled. This is probably because the pot life of the filler sample 1 is too short or the fluidity is too low, so that the upper surface of the filler sample 1 has begun to harden before being leveled. In the following cases 3 to 6, the experiment was performed by sanding the bottom surfaces of the molds M1 and M2 and then filling the ballast.

In case 3, the filler sample 2 was poured into the small mold M1 and cured. As shown in FIG. 4, the upper surface of the obtained roadbed sample had a gentle gradient as a whole, and the average gradient did not reach 3%. This is probably because the upper surface of the filler material sample 2 was leveled more than necessary after filling because the pot life was longer than the fluidity of the filler material sample 2.
In case 4, the filler sample 3 was poured into the small mold M1 and cured. The upper surface of the obtained roadbed sample formed a gradient almost the same as Case 3, and the average gradient did not reach 3%. This is thought to be because the filler material 3 was leveled after filling because the fluidity of the filler sample 3 was too high. In addition, the filler sample 3 was separated due to the excessive amount of water.

In case 5, filler sample 4 was poured into large mold M2 and cured. As shown in FIG. 5, the upper surface of the obtained roadbed sample did not reach a slight average gradient of 3%, but was able to have a gradient in a generally targeted range.
In case 6, the filler sample 5 was poured into the large mold M2 and cured. As shown in FIG. 6, the average slope of the upper surface of the obtained roadbed sample was approximately 3%.
Based on the above experimental results, it is considered that the mixing ratio of sample 4 or sample 5 used in cases 5 and 6 is appropriate, and in this embodiment, the W / material value of the filler is 50 to 55%, the pot life Was set to 20 to 40 minutes.

For the cases 5 and 6, as shown in FIG. 7, a plurality of detector tubes d for detecting how much concrete is filled in the large formwork M2 at predetermined (1000 mm) intervals are installed and filled. Each time the material G was poured once, the depth of the concrete at the location where each detector tube was installed was examined. FIG. 8A is a graph summarizing the results for sample 4, and FIG. 8B is a graph summarizing the results for sample 5. FIG.
As a result, the upper surface of the filler G rises stepwise, and a gradient of about 3% is formed on the upper surface of the filler G poured last (sample 4 is the 10th time and sample 5 is the 13th time). Was confirmed.

[Roadbed construction method]
Next, an example of a roadbed construction method using the filler will be described. FIG. 9 shows the construction flow.

  The construction site before construction is as shown in FIG. That is, a track 2 including a ballast roadbed (hereinafter, existing roadbed 21) and a rail 22 is provided on an existing earth roadbed (hereinafter, existing roadbed 1).

First, as shown in FIG. 9B, the retaining walls 11 and 12 are provided on both sides of the existing roadbed 21 so as to follow the laying direction of the track 2. In this embodiment, a steel plate or the like is provided by driving into the existing roadbed 1. The heights of the earth retaining walls 11 and 12 are set such that their upper ends are higher than the upper surface of the new roadbed to be provided. And between one earth retaining wall 11 (first earth retaining wall) and the rail 22 and between the other earth retaining wall 12 (second earth retaining wall) and the rail 22, a new aggregate is used. The ballast B1 is introduced within a range that does not interfere with the construction limit of the vehicle passing over the rail 22.
Next, the rail 22 is removed, and, as shown in FIG. 9C, a new aggregate ballast B2 is also put on the trace of the existing roadbed 21 from which the rail 22 has been removed. Then, the ballast B1 and B2 are shaped while being compacted to a predetermined density, whereby a ballast roadbed 21A is newly provided, and a rail 22A is newly laid thereon. After laying the rail 22A, the train can pass even before the roadbed is newly constructed.

  Next, the temperature or the like is measured, and an optimal amount of a setting retarder is mixed into the filler G so that the pot life of the filler G becomes a desired time (for example, 40 minutes). After the adjustment of the filler G, as shown in FIG. 9 (d), the filler G is poured into the aggregate ballast B1 from the vicinity of one retaining wall 11. In this embodiment, in order to prevent the filling material from being leveled by the vibration of the passing train, after the train has passed, it will be poured in anticipation that there will be a vacant time or longer before the next train comes . When pouring the filler G, the whole amount may be poured at once, or a small amount may be poured in multiple times. In addition, when dividing into multiple times, after pouring once, the next filling material may be poured without inserting a gap, or after pouring once, after a certain amount of time, the next filling is performed. The material G may be poured.

  The filler G has an appropriate fluidity, and after being poured into the aggregate ballast B1, it passes through the existing roadbed 21 and the newly formed voids of the aggregate ballasts B1 and B2 by its own weight. When seen from above, it spreads in a semicircular shape centering on the spout of the filler G. Since the filler G also has an appropriate viscosity, when the space between the ballast of the existing roadbed 21 and the newly built aggregate ballasts B1 and B2 is completely filled, one end side is formed on the upper surface of the filler G. A gradient of about 3% can be made from the bottom to the other end. The usable time of the filler G is approximately at this timing, and the filler G starts to lose its fluidity with a predetermined gradient on the upper surface.

  When the filler G is cured, the means for pouring the filler G is moved a predetermined distance along the laying direction of the track 2, and the filler G is poured and cured from the place in the same manner as described above. . By repeating this pouring operation of the filler G, the new roadbed 1A is constructed on the existing roadbed 1 so as to extend in the track attaching direction, as shown in FIG.

Second Embodiment
Next, a second embodiment of the present invention will be described. Here, only differences from the first embodiment will be described.

  In the first embodiment, a new roadbed is constructed in a place where there is no structure around it, and a new track is laid thereon (the track is raised above), but in this embodiment, the improvement construction site of the station ( A new roadbed is built near the platform) to move the track up and move horizontally. FIG. 10 shows the flow of construction.

  The construction site before construction is as shown in FIG. That is, a track 2 including a ballast roadbed (hereinafter, existing roadbed 21) and a rail 22 is provided on an existing earth roadbed (hereinafter, existing roadbed 1). The side surface of the existing roadbed 1 is earthed by a earth retaining wall 12 (second earth retaining wall). In addition, a platform (hereinafter referred to as an existing platform 3) is provided above the rail 22 and on one side of the rail 22 (left side in FIG. 10A) along the laying direction of the track 2.

  First, as shown in FIG. 10 (b), the earth retaining wall is further added to the upper end of the earth retaining wall 12 to make it higher, and the earth retaining wall 21 between the rail 22 and the existing home 3 on the existing road floor 21. 11 (first earth retaining wall) is driven so as to penetrate the existing roadbed 21 and to be fitted into the existing roadbed 1. Hereinafter, the other retaining wall which has been added and extended in height is referred to as retaining wall 12A. And, in the space sandwiched between one earth retaining wall 11 and the other earth retaining wall 12A, a new aggregate ballast B1 is placed on the other earth retaining wall 12A side of the existing road floor 21, The vehicle is introduced within a range that does not interfere with the construction limit of the vehicle passing through the rail 22. Next, the rail 22 is removed, and as shown in FIG. 10C, a new aggregate ballast B2 is also put on the trace of the rail 22 of the existing roadbed 21 removed. Then, the upper surfaces of the aggregate ballasts B1 and B2 are leveled while being inclined to the same extent as the inclination of the upper surface of the new roadbed to be constructed.

  Next, as shown in FIG. 10D, the existing home 3 is removed. And the filler G similar to 1st Embodiment was prepared, and the filler G was piled up between the one retaining wall 11 and the other retaining wall 12A from the vicinity of one retaining wall 11. Pour into aggregate ballast B2 and cure. And the new roadbed 1A is constructed | assembled by repeating the pouring operation | work of this filler G similarly to 1st Embodiment. When the new roadbed 1A is completed, a ballast roadbed 21A is newly provided on the new roadbed 1A as shown in FIG. In addition, since the upper surface of the new roadbed 1A is given a gradient, the upper surface of the ballast roadbed 21A is made horizontal by increasing the amount of ballast on the retaining wall 11 side. Then, a rail 22A is newly laid on the newly established ballast roadbed 21A. In addition, since the position of the rail 22A has been changed, a platform 3A is newly provided in accordance therewith. In this way, the improvement work of the roadbed of the station is completed.

  In addition, in this embodiment, the case where a roadbed is newly installed in the station premises has been described, but even in a place where there is no structure around as in the first embodiment, if the removal / installation process of the platform is omitted, A new roadbed 1A can be constructed in the same manner.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. Here, only differences from the first embodiment will be described.

  In the first embodiment, a new roadbed is constructed, and a track is newly laid on the track (the track is raised above), but in this embodiment, the new roadbed is constructed without changing the position of the rail. I am doing so. FIG. 11 shows the flow of construction.

  The construction site before construction is as shown in FIG. That is, a track 2 including a ballast roadbed (hereinafter, existing roadbed 21) and a rail 22 is provided on an existing earth roadbed (hereinafter, existing roadbed 1). In addition, the existing roadbed 21 made into construction object by this embodiment is higher than the 1st, 2nd embodiment. That is, the distance between the existing roadbed 1 and the rail 22 is greater than that in the first embodiment.

First, as shown in FIG. 11 (b), the retaining walls 11 and 12 are passed through both sides of the existing road bed 21 so as to extend along the laying direction of the track 2 on both sides of the existing road bed 21, and The upper end is provided so as to be exposed from the side surface. And the filler G similar to 1st Embodiment is prepared, and as shown in FIG.11 (c), from the vicinity of one earth retaining wall 11, the filler G is made into one earth retaining wall 11 and the other earth retaining wall 11. Pour into the ballast of the existing roadbed 21 built between the retaining walls 12 and harden. And the new roadbed 1A is constructed in the lower part of the existing roadbed 21 by repeating this pouring operation of the filler G in the same manner as in the first embodiment.
If the installation positions of the retaining walls 11 and 12 are adjusted so that the upper end of the new roadbed 1A is partially exposed from both surfaces of the existing roadbed 21, the side surface of the existing roadbed 21 and the other retaining wall 12 Depending on whether or not the filler G oozes out in between, the filling state of the filler G can be confirmed.

  Thus, in the said embodiment, the roadbed construction which builds the new roadbed 1A which makes a ballast an aggregate by filling at least one part of the existing roadbed 21 with the filler G, and hardening the filled filler G. In the method, a pair of retaining walls 11, 12, 12 </ b> A are provided along the laying direction of the rail 22 on both sides in the width direction of the rail 22 laid on the existing roadbed 21, and at least the existing roadbed It installs so that it may become the height which exceeds the height of the upper surface of the new roadbed 1A to be newly provided from the upper surface of 1, and a pair of earth retaining from the vicinity of one earth retaining wall 11 of the pair of earth retaining walls The existing roadbed 21 and / or aggregate ballasts B1 and B2 sandwiched between the walls 11, 12, and 12A have a hardening characteristic that loses fluidity after a predetermined time has elapsed from the start of filling, and a predetermined time has elapsed since the start of filling. The ratio of about 3% of the pair of earth retaining walls reaches the predetermined height of the other earth retaining wall 12, 12A and goes from the one earth retaining wall 11 to the other earth retaining wall 12, 12A on the upper surface. Then, the filler G having fluidity so as to be in a state of having a gradient such that the filler G is lowered is poured to cure the filler G.

  In this way, just by pouring the filler G, the filler G is further filled with the filler and smoothed, or the upper surface of the cured filler G is cut diagonally. Therefore, it is possible to provide a slope of about 3% on the upper surface of the newly installed roadbed 1A. Therefore, a new roadbed 1A that extends long over a wide area and has a drainage gradient of, for example, about 3% is easily installed. be able to.

Moreover, in the said embodiment, the ratio of the weight of the water with respect to the total weight of a powder material is set to 50% or more and 55% or less of the powder material containing a super-fast-hardening material, water, and a water reducing agent as the filler G. What was mixed in was used.
In this way, even when a roadbed having a width of about 2 to 5 m necessary as a roadbed for a single track is constructed, the filler can reach from one earth retaining wall 11 to the other earth retaining wall 12, 12A. Since it has the fluidity that can be achieved, a new roadbed 1A having a gradient of 3% on the upper surface can be easily installed.

Moreover, in the said embodiment, the temperature of a construction site is measured before filling with the filler G, Based on the measured temperature, a setting retarder is used for the filler G, and the filler G is 20 minutes or more from the start of filling. It is good to measure and add the quantity which loses fluidity | liquidity after progress for 40 minutes or less, and to make it fill with the filler G after that.
This prevents the filler G from hardening before the filler G reaches the other earth retaining wall 12, 12A or before the gradient of the upper surface of the filler G reaches about 3%. I can do it.

As mentioned above, although this invention was concretely demonstrated based on embodiment, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary.
For example, in the first embodiment, a new track is provided before the construction of the new roadbed, and the train is allowed to pass before the construction of the new roadbed. However, a new track is created after the construction of the roadbed as in the second embodiment. A track may be provided. Conversely, in the second embodiment, a new track may be provided before the construction of the new roadbed.
Moreover, in the said embodiment, although the ballast B1 for aggregates was thrown into one side of space first and the ballast B2 for aggregates was thrown in after removing the rail 22, the rail 22 was removed first and bone The material ballast may be charged once.

In the above embodiment, the filler G is poured from the vicinity of one of the retaining walls 11, but the filler G is poured from an intermediate point between the one retaining wall 11 and the other retaining walls 12, 12A, and both sides from the center. You may make it possible to make a mountain-shaped slope that goes down as you go.
Further, in the second embodiment, the existing home is removed and the filler G is filled from the existing home, but it may be poured from the opposite side of the existing home 3. If it does so, it will also become possible to perform the filling operation | work of the filler G and the removal operation | work of the existing home 3 in parallel.
Moreover, in the said embodiment, after filling with the filler G in a certain location, the place was moved and it was filled again with the filler G. However, the filling means of the filler G is moved along the laying direction of the track. However, it may be filled by pouring continuously, or a plurality of filling means may be arranged at predetermined intervals and filled by pouring simultaneously.
In the second embodiment, the earth retaining wall is added to the upper end of the existing earth retaining wall 12 to form a new earth retaining wall 12A. However, an earth retaining wall different from the existing earth retaining wall 12 is used as the existing road base 1. You may be allowed to type in.

21 Existing roadbed (existing ballast roadbed)
22 Existing gauge 11 Earth retaining wall (One earth retaining wall)
12,12A earth retaining wall (the other earth retaining wall)
G Filler

Claims (4)

In a roadbed construction method for building a roadbed using ballast as an aggregate by filling at least a part of an existing ballast roadbed with a filler and curing the filled filler,
On both sides in the width direction of the rail laid on the ballast roadbed, a pair of retaining walls are newly provided along the rail laying direction and at least from the upper surface of the existing roadbed Installed so that the height exceeds the top surface height of the roadbed,
The ballast roadbed sandwiched between the pair of retaining walls from the vicinity of one of the pair of retaining walls has a hardening characteristic that loses fluidity after a predetermined time has elapsed from the start of filling, and filling After the elapse of a predetermined time from the start, it reaches the predetermined height of the other retaining wall of the pair of retaining walls, and descends at a predetermined rate toward the upper surface from the one retaining wall toward the other retaining wall. A roadbed construction method characterized by constructing a roadbed having a ballast track on the upper side by pouring a filler having fluidity so as to be in a state of having a gradient, and curing the filler.   The filler is characterized by using a powder super-hard material, water, and a water reducing agent mixed so that the ratio of water to the total weight of the powder material is 50% or more and 55% or less. The roadbed construction method according to claim 1. Before filling the filler, measure the temperature at the construction site,
Based on the measured temperature, a setting retarder is added to the filler so that the filler loses fluidity after a lapse of 20 minutes to 40 minutes from the start of filling,
3. The roadbed construction method according to claim 2, wherein the filling material is poured thereafter.   In a roadbed construction method for building a roadbed using ballast as an aggregate by filling at least a part of an existing ballast roadbed with a filler and curing the filled filler,
  On both sides in the width direction of the rail laid on the ballast roadbed, a pair of retaining walls are newly provided along the rail laying direction and at least from the upper surface of the existing roadbed Installed so that the height exceeds the top surface height of the roadbed,
  Between the pair of earth retaining walls, the ballast roadbed sandwiched between the pair of earth retaining walls has a curing characteristic that loses fluidity after a predetermined time has elapsed from the start of filling, and after the elapse of a predetermined time from the beginning of filling, It reaches a predetermined height of the pair of retaining walls, and the upper surface is in a state of being inclined so as to descend at a predetermined rate from the space between the pair of retaining walls toward the pair of retaining walls. A roadbed construction method characterized in that a roadbed having a ballast track upward is constructed by pouring a filler having a proper fluidity and curing the filler.

Images