CN112012051B

CN112012051B - Treatment method for deformation of ballastless track

Info

Publication number: CN112012051B
Application number: CN201910463876.2A
Authority: CN
Inventors: 王鹏程; 张千里; 陈锋; 李中国; 闫鑫; 张新冈; 尧俊凯; 刘景宇; 刘振宇; 陈志旺
Original assignee: China Academy of Railway Sciences Corp Ltd CARS; Railway Engineering Research Institute of CARS
Current assignee: China Academy of Railway Sciences Corp Ltd CARS; Railway Engineering Research Institute of CARS
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2021-12-31
Anticipated expiration: 2039-05-30
Also published as: CN112012051A

Abstract

The invention provides a method for treating deformation of a ballastless track, which comprises the following steps: step A, monitoring the elevation of a track, and determining the section of the track to be adjusted and the track falling amount or the lifting amount; step B, determining a replacement depth h 1; c, breaking and supporting the supporting layer, and excavating a roadbed with the height h2 and a foundation with the height h3 below the supporting layer by layer from top to bottom to form a replacement region, wherein h2+ h3> h 1; step D, placing a replacement material into the partial replacement area, wherein the compressive strength and the deformation modulus of the replacement material are not less than those of the roadbed; step E, lowering or lifting the supporting layer by the track dropping amount or the lifting amount and synchronously monitoring the track elevation; step F, continuously filling the replacement material until the replacement material is filled; and G, repairing the lines and/or the road shoulders. The method realizes the thorough treatment of the deformation of the track structure with high efficiency and low cost.

Description

Treatment method for deformation of ballastless track

Technical Field

The invention relates to a method for adjusting the elevation of a track, in particular to a method for adjusting the elevation of a ballastless track.

Background

At present, high-speed railways in China develop rapidly, but are affected by factors such as roadbed filling, expansion or contraction of deep foundations and the like, some high-speed railway lines adopting ballastless track lines have diseases such as arching or sinking and the like in succession, in order to ensure the operation safety, speed-limiting measures have to be taken, and the normal operation of the high-speed railway lines in China is seriously affected.

In view of the above problems, those skilled in the art generally adopt methods such as digging out part of roadbed drop roads, grouting lifting, mechanical jacking and the like to adjust the elevation of the track, but the expansion or contraction of the roadbed or the foundation is continuously performed, and after a period of time, the adjusted track section still may be arched or sunk again, and this method cannot fundamentally control the arching or sinking of the track.

Disclosure of Invention

In order to overcome the defects, the invention provides a method for adjusting the height of a ballastless track. The method thoroughly controls the upwarp or settlement of the track by replacing the roadbed and the deep foundation with replacement materials with lower expansibility and compressibility.

The invention provides a method for treating deformation of a ballastless track, wherein the ballastless track comprises a foundation, a roadbed and a supporting layer from bottom to top, and the method comprises the following steps: step A, monitoring the elevation of a track, and determining the section of the track to be adjusted and the track falling amount or the lifting amount; step B, determining a replacement depth h 1; c, breaking lines and/or shoulders on two sides of the supporting layer in the track section to be adjusted, supporting the supporting layer, and excavating a roadbed with the height h2 and a foundation with the height h3 below the supporting layer by layer from top to bottom to form a replacement region, wherein h2+ h3> h 1; step D, placing a replacement material into the replacement area, and reserving a gap between the replacement material and the supporting layer, wherein the gap is designed to be not less than the falling amount or the lifting amount, and the compressive strength and the deformation modulus of the replacement material are not less than those of the roadbed; step E, lowering or lifting the supporting layer by the track dropping amount or the lifting amount and synchronously monitoring the track elevation; step F, continuing to fill the replacement material between the inserted replacement material and the supporting layer until the replacement material is filled; and G, repairing the lines and/or the road shoulders. Through the method, the deformation of the track structure is thoroughly treated.

Preferably, in step C, the displacement region is excavated from the toe of the rail section to be adjusted, perpendicularly to the direction of extension of the rail, into the underside of the carrier layer.

Preferably, the displacement areas are dug at intervals along the track extension direction.

Preferably, before performing said step E, adjustable support means are arranged between said replacement material and said supporting layer.

Preferably, the remaining areas between adjacent displacement areas are excavated layer by layer from top to bottom for at least 0.5 m.

Preferably, before step F, formworks are erected at the bottom of the supporting layer and a carrier plate is cast, the thickness of the carrier plate being smaller than the height of the supporting means.

Preferably, in step F, a filler is interposed between the carrier plate and the displacement material, the compressive strength and the deformation modulus of the filler being not less than the compressive strength and the deformation modulus of the displacement material.

Preferably, in the step C, after the roadbed is excavated, the section of the formed replacement area corresponding to the roadbed is subjected to side wall support, then the roadbed is excavated continuously, and after the roadbed is excavated, the section of the formed replacement area corresponding to the roadbed is subjected to side wall support.

Preferably, in step D, a polyethylene film is laid on the bottom surface of the replacement region before the replacement material is filled into the replacement region.

Preferably, the replacement material is C30 early strength concrete with embedded steel bars.

Drawings

Fig. 1 is a schematic structural diagram of a ballastless track;

FIG. 2 is a schematic diagram of a replacement area.

List of reference numerals

1. A support layer;

2. a roadbed;

3. a foundation;

4. a replacement region;

5. a residual region;

6. displacing the material;

7. a support device;

8. a carrier plate.

Detailed Description

As shown in fig. 1, the ballastless track structure roughly includes, from bottom to top, a foundation 3, a roadbed 2 laid with crushed stones or the like, a support layer 1 generally cast with concrete, a track generally cast with reinforced concrete, a sleeper fixed in the track slab, and a rail coupled to the sleeper. The method for adjusting the height of the ballastless track mainly comprises the steps of determining a track section to be adjusted, determining a replacement depth h1, supporting a supporting layer 1 and digging a replacement area 4, filling the replacement area 4 with replacement material 6, adjusting the height of the track, filling the replacement material 6 again, repairing the track and the like.

The foregoing method will be described in detail below with reference to the drawings, which although provided to illustrate certain embodiments of the invention, are not necessarily drawn to scale of particular embodiments and certain features may be exaggerated, removed, or sectioned to better illustrate and explain the present disclosure. The position of some components in the drawings can be adjusted according to actual requirements on the premise of not influencing the technical effect. The appearances of the phrase "in the drawings" or similar language in the specification are not necessarily referring to all drawings or examples.

Certain directional terms used hereinafter to describe the accompanying drawings, such as "upper" and "lower", will be understood to have their normal meaning and refer to those directions as normally referred to in the drawings. Unless otherwise indicated, the directional terms described herein are generally in accordance with conventional directions as understood by those skilled in the art. In particular, the longitudinal direction of the track structure refers to the direction in which the length of the track extends, and the transverse direction of the track structure refers to the direction perpendicular to the direction in which the length of the track structure extends.

According to the first embodiment of the present invention, in the first step, preparation work before replacement should be performed. Specifically, the height of the ballastless track is monitored, and a track section to be adjusted and the track dropping amount or the lifting amount are determined. In this step, the excavated spoil transport route should be planned in advance to determine the position of the buried cable. And then determining the replacement depth h1 of the soil body according to the variation of the track elevation and the parameters of the foundation, the subgrade soil quality and the like.

Next, the rail structure is preferably reinforced before the replacement. Possible measures include: firstly, arranging a longitudinal continuous variable beam between a road shoulder and a line; secondly, the track plate and the supporting layer 1 are connected in an anchoring mode through steel bar planting; thirdly, spacing mechanisms are arranged on two transverse sides of the track section to be adjusted at intervals.

Next, the replacement region 4 is dug out. The lines and shoulders on both sides of the carrier layer 1 in the rail section to be adjusted are first broken. And excavating the roadbed 2 with the height h2 and the foundation 3 with the height h3 layer by layer from the bottom of the supporting layer 1 to form a replacement region 4, wherein in order to ensure that all deformed soil is excavated, the actually excavated soil depth is larger than the theoretically calculated replacement depth h1, namely h2+ h3> h 1. It should be noted that, in the case where the foundation 3 is not deformed or the amount of deformation is small, it may not be excavated, and h3 may be 0.

In this step, the excavating machine for performing the excavation preferably penetrates from the toe of the rail section to be adjusted perpendicularly to the rail direction of extension into the underside of the carrier layer 1 in order to excavate the replacement region 4. The digging from the slope toe can be carried out by adopting a large-sized digging machine, the digging efficiency is high, and the working space is large.

In addition, in this step, it is preferable to perform the side wall support in time during the excavation of the replacement area 4 according to the soil properties. Specifically, the roadbed 2 is excavated, the section of the formed replacement area 4 corresponding to the roadbed 2 is subjected to side wall support after the roadbed 2 is excavated, the foundation 3 is then excavated, and the section of the formed replacement area 4 corresponding to the foundation 3 is subjected to side wall support after the roadbed 2 is excavated. Excavation of the next layer should be performed after the previous layer is firmly supported, thereby preventing the soil bodies on both sides from falling. In addition, the support can be reinforced appropriately according to the excavation condition.

Next, the displacement material 6 is filled into the displacement region 4. Wherein the compressive strength and the deformation modulus of the replacement material 6 are not less than the compressive strength and the deformation modulus of the roadbed 2. Preferably, the replacement material 6 is cast in place. For example, reinforcing bars are tied longitudinally and transversely in the displacement zone 4, and early strength, sulfate attack resistant concrete (preferably C30 early strength concrete) is poured therein.

It is also preferable to lay one or more impermeable films on the bottom surface of the replacement area 4 before filling the replacement material 6 into the replacement area 4 to prevent the replacement material 6 from affecting the underlying roadbed 2 or foundation 3. The barrier film may be, for example, a high density polyethylene film.

In order to ensure the accuracy of the rail height adjustment, the displacement material 6 which is introduced into the displacement region 4 for the first time cannot completely fill the space between the displacement region 4 and the carrier layer 1. A gap should be left between the first filling of replacement material 6 and the support layer 1, which gap should not be less than the drop or lift.

Next, the track structure position is adjusted. Namely, the position of the supporting layer 1 is lowered or lifted according to the previously measured lane falling amount or lifting amount, and meanwhile, the track deformation is synchronously and strictly monitored by adopting devices such as a level gauge, a total station, a track detection trolley and the like in the process until the supporting layer 1 and other track structures above the supporting layer are adjusted to proper positions.

After the above steps have been carried out, there is still a remaining space between the support layer 1 and the replacement material 6 which was first introduced, and this space is filled again with the replacement material 6 until the space is filled. Thereby completing the deep replacement of the roadbed 2 and the foundation 3 and the track adjustment.

Finally, the shoulders and/or lines are repaired. Meanwhile, related equipment such as cables and the like are recovered according to design requirements.

The present invention also provides a second embodiment which is substantially the same as the steps of the first embodiment, one difference being that in this embodiment the replacement regions 4 are dug out at intervals in the track extension direction, thereby reducing the workload of deep replacement while minimally affecting the normal operation of high-speed rails and the like. Another difference is that instead of refilling the replacement material 6 between the first inserted replacement material 6 and the carrier layer, adjustable support means 7, such as screws, jacks or the like, are arranged between the first inserted replacement material 6 and the carrier layer. The arrangement mode facilitates accurate adjustment of the elevation of the track, and meanwhile, under the condition that the track is found to be deformed in the future, a large amount of excavation operation is not required, and only one channel leading to the supporting device 7 needs to be excavated.

In particular, as shown in fig. 2, the displacement zones 4 are cut at intervals along the extension of the rail, and adjustable support means 7 are arranged between the inserted displacement material 6 and the carrier layer 1. In order to prevent further deformation of the soil in the unearthed remaining areas 5 between adjacent displacement areas 4 from affecting the track, the soil in the remaining areas 5 should be at least partially excavated. Preferably at least 0.5m of earth is excavated layer by layer from top to bottom.

In this case the track structure will only be supported by the spacing. In order to support the track structure more stably. At the bottom of the supporting layer 1, steel reinforcement is tied, formworks are erected and a carrier plate 8, for example 0.5m thick, is poured, the thickness of which carrier plate 8 can be smaller than the height of the supporting means 7. It is also preferred to fill the space between the carrier plate 8 and the inserted displacement material 6 with a filler whose compressive strength and deformation modulus are not less than those of the displacement material 6, for example, fine-grained concrete. In the case of the formation of the carrier plate 8, the cut-out in the remaining region 5 need not be filled again.

The invention adopts a deep replacement method to treat the deformation of the ballastless track structure, thereby fundamentally solving the influence of the deformation of the roadbed and the foundation on the smoothness of the track structure. Meanwhile, the device can be operated in a skylight time, and has the advantages of high efficiency, economy and the like.

Claims

1. A treatment method for deformation of a ballastless track, which comprises a foundation, a roadbed and a supporting layer from bottom to top, is characterized by comprising the following steps:

step A, monitoring the elevation of a track, and determining the section of the track to be adjusted and the track falling amount or the lifting amount;

step B, determining a replacement depth h 1;

c, breaking lines and/or shoulders on two sides of the supporting layer in the track section to be adjusted, supporting the supporting layer, and excavating a roadbed with the height h2 and a foundation with the height h3 below the supporting layer by layer from top to bottom to form a replacement region, wherein h2+ h3> h 1;

step D, placing a replacement material into the replacement area, and reserving a gap between the replacement material and the supporting layer, wherein the gap is designed to be not less than the falling amount or the lifting amount, and the compressive strength and the deformation modulus of the replacement material are not less than those of the roadbed;

step E, lowering or lifting the supporting layer by the track dropping amount or the lifting amount and synchronously monitoring the track elevation;

step F, continuing to fill the replacement material between the inserted replacement material and the supporting layer until the replacement material is filled;

and G, repairing the lines and/or the road shoulders.

2. A method according to claim 1, characterized in that in step C the displacement zone is excavated from the toe of the rail section to be adjusted perpendicularly to the direction of rail extension into the underside of the bearing layer.

3. The method of claim 2, wherein the displacement zones are dug at intervals along the direction of extension of the track.

4. A method according to claim 3, wherein step H is performed before step E, with adjustable support means being arranged between said displacement material and said support layer.

5. The method of claim 4, wherein after step H is performed and before step E is performed, the remaining regions between adjacent ones of said displaced regions are excavated layer-by-layer from top to bottom for at least 0.5 meters.

6. Method according to claim 5, characterised in that before step F, formworks are erected at the bottom of the supporting layer and a carrier plate is cast, the thickness of which is smaller than the height of the supporting means.

7. The method as claimed in claim 6, wherein in step F, a filler is interposed between the carrier plate and the displacement material, the filler having a compressive strength and a deformation modulus that are not less than the compressive strength and the deformation modulus of the displacement material.

8. The method as claimed in any one of claims 1 to 7, wherein in step C, the section of the formed replacement area corresponding to the subgrade is subjected to side wall bracing after the subgrade is excavated, the excavation of the subgrade is continued, and the section of the formed replacement area corresponding to the subgrade is subjected to side wall bracing after the subgrade is excavated.

9. The method as claimed in claim 1, wherein in step D, a polyethylene film is applied to the bottom surface of the displacement region before the displacement material is filled into the displacement region.

10. The method of claim 1, wherein the replacement material is C30 early strength concrete with embedded steel reinforcement.