JPS6117974B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving a track bed that prevents mud from forming on the surface of a track bed on which rails are laid.

In this invention, mud blowing refers to a phenomenon in which fine powder in the roadbed and soil particles constituting the roadbed rise in the gap between the roadbeds due to the weight of the vehicle and are ejected onto the roadbed surface, or are ejected in this way. It is said that the movement of pore water contained in the road bed and roadbed is what mediates the rise or eruption of substances. From the mechanism of generation, there are two types of mud foam: roadbed mud and roadbed mud.
It is divided into two parts.

Roadbed mud blowing is when the gaps in the roadbed ballast are filled with mud, creating an impermeable layer, and as a result, surface water accumulates in the roadbed, especially near the bottom of the sleepers, and mud is ejected. This is a case where the soil of the roadbed, softened by surface water or groundwater, passes through gaps in the roadbed and rises directly to the surface of the roadbed.

Mud eruptions often occur at or near rail joints, and in roadbed mud eruptions, it almost always occurs at the joints, but in roadbed mud eruptions, it can also be seen in other areas. .

In addition, the water content of the roadbed soil in the cut portion of the ground is high, and when this contains a large amount of clay, its shear strength decreases, and as shown in FIG. It sinks into the soil of roadbed 5. This condition is called a water pocket 6 and causes mud plumes.
That is, the repeated loads of the train cause the pumping action of pressurization and depressurization, causing the roadbed surface to knead, rise through gaps in the trackbed, and eject onto the trackbed surface. This water pocket often contains a large amount of surface water, and has an extremely unstable structure consisting of sunken roadbed ballast 4a and mud sludge 7. Further, the depth of the water pocket 6 is slightly deeper just below the rail, and intersects with the construction base near the bottom end of the trackbed cross section. Also, in the longitudinal section, it is slightly deeper just below sleeper 8.
It is especially deep near the seam. However, in general, the depth rarely exceeds 1 m.

As is clear from the above, the main causes of mud spouting are thought to be the presence of water, the nature of the soil that makes it easy to spew mud, and the train load. Mud blowing was prevented and reduced by eliminating, reducing, and improving. However, in reality, various factors are intricately intertwined, and the expected effects have not been achieved.

This invention targets all of the above-mentioned factors and aims to further ensure their preventive effects.
In other words, (1) the majority of the train load is carried by the piles, reducing the train load on the roadbed between the piles, and (2) the roadbed soil is sandwiched with cement paste in the form of a sandwich to immediately stop water and mud from flowing in and out. (3) The piles are used as a type of soil cement pile to improve soil quality.

Depends on things etc.

In this invention, the load sharing ratio of the train is determined by the above (1) elastic modulus of the piles, elastic modulus of the roadbed between the piles, horizontal cross-sectional area of the piles, and horizontal cross-sectional area of the roadbed between the piles. , the pile strength and the pile cross-sectional area should be determined so that the stress due to the load acting on each of them is within the respective allowable stress. Regarding (2) above,
It is only necessary to securely connect the fins extending from adjacent pile bodies, block the subgrade soil, and block the subgrade soil. This purpose can be achieved by thoroughly stirring the soil and roadbed soil to create a uniform pile body.

This invention will be explained in detail below using examples shown in FIG. 2 and below.

The construction example shown in FIG. 2 is a case where a pile having the structure shown in FIG. 3 is constructed.

First, the boring rod 11 is set correctly at the pouring position. This boring rod 11 has a cement paste injection port 12 and an air injection port 13 at its tip.
and a pair of stirring blades 14, 14 (see Fig. 6).

Next, without rotating the boring rod 11,
The ballasts 15a, 15a... are punched out from above 5, and the tips are driven into the base of the roadbed 16. When the drilling into the base of the roadbed is completed, the boring rod 11 is rotated to blow out air while penetrating into the roadbed (see Fig. 2a). When the tip of the rod reaches a predetermined depth, cement paste is injected for a certain period of time to form the lowest fin 17a extending horizontally around the bottom of the pile (see FIG. 2b).

When the fin 17a is formed, the boring rod 11 is slowly pulled up to the next predetermined stop position while rotating and injecting cement paste, and the diameter of the pile body 18 is determined according to the pulling speed. (see Figure 2c).

When the next position is reached, the bowling rod 11
Stop only pulling up the fin 17, and hold the fin 17 at that position.
The cement paste is again injected until a fin 17b similar to that in a is formed (see FIG. 2d).

Thereafter, the lifting and stopping of the boring rod 11 is repeated in the same manner as shown in FIG.
A stake 19 having the structure shown in FIG. 3 with protruding portions a, 17b...17n is constructed.

The construction example shown in FIG. 4 is a case where a pile (see FIG. 5) having a wall between each fin is constructed.

In the construction example described above, the penetration of the boring rod 11 was carried out while rotating, but in this second construction example, the boring rod 11 was moved to the position shown in FIG. 4a while jetting cement paste and air. It penetrates without rotation to a predetermined depth as shown in FIG.

When the tip of the boring rod 11 reaches a predetermined depth, the tip of the rod is stopped at that position, and cement paste is sprayed for a certain period of time, causing the lowest fin 17 to protrude horizontally around the bottom of the pile.
a (see Figure 4b).

Once the fins 17a are formed, FIG.
As shown in e, the boring rod 11 is repeatedly pulled up and stopped in the same manner as in the construction example described above.
A plurality of fins 17a, 17b, 17n, which protrude at required intervals around the final body 18.
and a wall 20 that partitions each fin.
1 (see Figure 4 f). In each construction example, air is ejected from the stirring blade 1, which also serves as a digging blade.
This is done in order to effectively stir the roadbed soil and cement paste according to steps 4 and 14.

Therefore, the said pile 19 or 21 into the roadbed
Construction is carried out by simultaneously operating a pair of boring rods suspended from a turret at a certain distance.

7 and 8 schematically show the pile driving device, in which 22 is a pile driving platform movably mounted on the rear part of the truck 23, and 24 is a pile driving platform fixed to the rear end of the pile driving platform. It is a turret. The boring rod 11 has a motor 25, a speed reducer 26, a cement paste inlet, etc. at the top of the hollow rod on the rear side of the pile driving tower, and a vibrator 27 on the fastening slide device. A pair is suspended parallel to the railroad ties 28.

Further, on the front half of the truck 23, various devices necessary for pile driving such as a water tank 29, a grout pump 30, a mixer 31, a motor 32, and materials 33 such as cement are mounted. locomotive 3
4 allows for movement.

The piles are driven into the road bed between each sleeper 28, and the pair of boring rods 11 are alternately driven in the width direction along the sleepers 28 so that the fins cover the entire width of the trackbed 15. Drive and create multiple stakes with adjacent fins connected.

FIG. 9 shows an example in which the piles 21, in which the pile body 18, fins 17, and wall bodies 20 are integrally formed, are driven and arranged in a square shape. The wall body 20 is connected not only to the same position but also to the pile fins and wall bodies located in the front and back to form a square block of roadbed soil.

This blocking of the roadbed soil extends to the entire roadbed below the roadbed 15, as schematically shown in FIG.
7n will bear most of the train loads P ₁ and P ₂ , and the roadbed soil will be blocked and cut off by the reliable mutual connection of the fins.

Therefore, the method for improving the track base according to the present invention reduces the train load on the base between the gaps and prevents water, mud, etc. from entering and exiting.
Even if the pressurization and depressurization effects caused by the repeated loads of the train occur, it is extremely difficult for mud to form.

[Brief explanation of the drawing]

The drawings illustrate the method for improving the track base according to the present invention, and FIG. 1 is a sectional view of the track base where water pockets have occurred, FIG. 2 is a schematic sectional view showing the construction of piles in order, and FIG. The figure is a sectional view of the pile, Figure 4 is a schematic cross-sectional view showing the construction of the pile with a wall body, Figure 5 is a perspective view of the pile with a wall body, and Figure 6 is a front view of the tip of the boring rod. 7 is a schematic plan view of the pile driving device, FIG. 8 is a side view thereof, FIG. 9 is a cross-sectional plan view showing an example of the arrangement of piles with walls, and FIG. 10 is a schematic plan view of the pile driving device. FIG. 11... Boring rod, 12... Cement paste injection port, 13... Air injection port, 14
... Stirring blade, 15 ... Roadbed, 16 ... Roadbed, 1
7, 17a, 17b, 17n...fin, 18...
Pile body, 19, 21...Piece, 20...Wall body.

Claims (1)

[Claims] 1. A method of improving the roadbed of a track to prevent mud from spewing, in which a hollow rod with stirring blades is inserted into the roadbed from above the roadbed, the rod is rotated, and mud is fed from the hollow part. Cement paste is injected from the tip of the rod to form a horizontal plate-shaped fin, then the rod is pulled up and rotated, and cement paste is injected from near the stirring blade to form a soil cement pile. By stopping pulling up the rod and forming the next stage of fins in the same way and forming the pile body on the upper surface of the roadbed, piles having fins in multiple stages at predetermined intervals around the pile body are created. Furthermore, a track characterized in that a large number of piles of the same structure are constructed in succession adjacent to these piles so that the adjacent fins connect with each other to partition the inside of the roadbed and prevent the movement of mud. How to improve the roadbed.