CN111235967A - High-speed railway water-soaking embankment structure in seasonal frozen soil area and construction method - Google Patents

Abstract

The invention discloses a submerged embankment structure of a high-speed railway in a seasonally frozen soil area, comprising an upper embankment, a lower embankment, a bored pile, an elastic support layer, and a bearing device. At the upper end, the elastic support layer is located on the top of the upper embankment, the bearing device is located on the top of the elastic support layer, the number of bored piles is at least two, and the at least two bored piles are arranged in the foundation in a row along the longitudinal interval of the line. At least two rows of bored cast-in-place piles are arranged in the transverse direction of the road, and the tops of the bored cast-in-situ piles protrude from the foundation and are fixedly connected with the bearing device. The bored pile supports the bearing device. When the lower embankment is deformed due to frost heave, the elastic support layer shrinks and deforms to reduce the influence of the frost heave force on the bearing device, and the elastic support layer shrinks and deforms to restore the bearing device when it is not frost heave. Provide surface supporting force to save the engineering investment of the bearing device, so that the structure has a good ability to resist the upper arch deformation.

Description

Structure and construction method of flooded embankment for high-speed railway in seasonally frozen soil area

technical field

The invention relates to railway engineering, in particular to a high-speed railway flooded embankment structure and a construction method in seasonal frozen soil area.

Background technique

Seasonal frozen soil accounts for more than half of my country's territory. It is very difficult to build high-speed railway subgrade projects in seasonally frozen soil areas, and it is necessary to solve the problem of subgrade arch deformation due to frost heave. At present, the problems encountered in the construction of high-speed railway subgrade projects in seasonally frozen soil areas do not involve the impact of water level. Even if there is groundwater impact, they can be solved by setting up drainage ditches to lower the groundwater level. At present, the focus of solving problems is concentrated on the subgrade. There are two aspects of filler selection and waterproof and drainage measures. At present, there is no case of building flooded embankments for high-speed railways in seasonally frozen soil areas. When the construction of high-speed railways without ballast tracks in seasonally frozen soil areas encounters flooded embankments, the existing problem of arch deformation on the subgrade will be more complicated and more significant, and it will be solved. The problem of this kind of upper arch deformation is very difficult.

SUMMARY OF THE INVENTION

The purpose of the present invention is to: solve the problem that the upper arch deformation is very difficult when building a ballastless track high-speed railway in the seasonally frozen soil area, and provide a kind of high-speed railway flooded embankment structure and construction method in the seasonally frozen soil area .

In order to achieve the above object, the technical scheme adopted in the present invention is:

A submerged embankment structure of a high-speed railway in a seasonally frozen soil area, comprising an upper embankment, a lower embankment, a bored cast-in-place pile, an elastic support layer, and a bearing device;

The lower embankment is filled at the upper end of the foundation, and the upper embankment is located at the upper end of the lower embankment;

The elastic support layer is located on the top of the upper embankment, and the bearing device is located on the top of the elastic support layer;

The number of bored cast-in-place piles is at least two, at least two bored cast-in-place piles are arranged in the foundation at intervals along the longitudinal direction of the line, at least two rows of bored cast-in-situ piles are arranged laterally along the line, and the tops of the bored cast-in-place piles protrude from the foundation and fixedly connected to the carrying device.

Through the above structure, the bored pile supports the bearing device, and when the lower embankment is deformed due to frost heave, the elastic support layer at the bottom of the bearing device shrinks and deforms, so that the influence of the frost heave force on the bearing device can be greatly reduced. When the elastic support layer shrinks and deforms during expansion, it can provide surface support for the bearing device, thus saving the engineering investment of the bearing device, and making the constructed submerged embankment structure have a good ability to resist the deformation of the upper arch.

As a preferred solution of the present invention, the embankment structure further includes a geogrid, the geogrid is laid on the foundation and is fixedly connected with the bored piles, and the lower embankment is filled on the top of the geogrid. Through the above structure, the geogrid is used for foundation reinforcement, and is fixedly connected with the bored piles to form a stable plane. The bored cast-in-place pile exerts a large downward pulling force, which can effectively balance the upper arch friction force transmitted to the bored cast-in-place pile when the lower embankment is frost heaving, thereby avoiding the upper arch deformation of the top bearing device caused by the bored cast-in-place pile.

As a preferred solution of the present invention, the embankment structure further includes a partition layer, the partition layer is located between the upper embankment and the lower embankment, the lower embankment is filled with water seepage soil, and the upper embankment is used as qualified filler. Through the above structure, the seepage soil filler has good water permeability, which can increase the drainage of the foundation and reduce the settlement of the foundation. The isolation layer can effectively prevent the upward migration of water in the lower embankment and avoid the unfavorable frost heave deformation of the upper embankment.

As a preferred solution of the present invention, the embankment structure further includes a track structure, and the track structure is fixedly arranged on the top of the carrying device. Through the above structure, the track structure is prevented from being affected by the arch and settlement deformation of the railway.

As a preferred solution of the present invention, the outside of the pile body of the bored cast-in-place pile extending out of the foundation is provided with a coating of lubricating material. Through the above structure, the lubricating material on the outside of the pile body can weaken the transmission of frost heave force, so that the constructed embankment structure has a good ability to resist the upper arch deformation.

As a preferred solution of the present invention, the elastic support layer is composed of a bottom plate, a spring structure, a top plate and a flexible side wall, the bottom plate, the top plate and the flexible side wall form a closed structure, the spring structure is located in the closed structure, and the two ends of the spring structure are respectively connected to the bottom plate connected to the top plate. Through the above structure, the spring structure can absorb and store the force that causes the embankment to deform upward and downward, so that the embankment has good deformation resistance. The flexible side wall in the present invention refers to the side wall with a certain amount of deformation, so that the When the spring structure is deformed, the bottom plate and the top plate are allowed to approach or move away from each other with the deformation of the spring structure.

A method for constructing a flooded embankment of a high-speed railway in a seasonally frozen soil area, which is used to construct the above-mentioned embankment structure, comprising the following steps:

S1: Arrange bored piles in the foundation in a row along the longitudinal direction of the line, and extend the top of the bored piles out of the foundation;

S2: Fill the lower embankment on the foundation;

S3: Fill the upper embankment at the upper end of the lower embankment;

S4: Excavate the elastic support layer on top of the upper embankment;

S5: The bearing device is installed on the top of the elastic support layer, and is fixedly connected with the top of the pile body of the bored cast-in-place pile protruding from the foundation.

The above-mentioned construction method ensures the effective realization of the above-mentioned embankment structure functions, the construction is simple, the quality is controllable, the economical efficiency is good, the environmental protection is favorable, and the promotion is favorable.

As a preferred solution of the present invention, after the step S1 is completed, lubricating material is applied to the outside of the pile body of the bored cast-in-place pile extending out of the foundation.

As a preferred solution of the present invention, the road embankment structure includes a blocking layer, and the blocking layer is located between the upper road embankment and the lower road embankment. In step S3, the upper road embankment is filled on top of the blocking layer.

As a preferred solution of the present invention, the embankment structure further includes a track structure. After the step S5 is completed, the track structure is fixedly installed on the top of the carrying device.

To sum up, due to the adoption of the above-mentioned technical solutions, the beneficial effects of the present invention are:

The bored pile supports the bearing device. When the lower embankment is deformed due to frost heave, the elastic support layer at the bottom of the bearing device shrinks and deforms, which can greatly reduce the influence of the frost heave force on the bearing device, and elastically support the bearing device during non-frost heave. The recovery of layer shrinkage deformation can provide surface support force for the bearing device, thus saving the engineering investment of the bearing device, so that the constructed submerged embankment structure has a good ability to resist the upper arch deformation.

The construction method ensures the effective realization of the above-mentioned embankment structure functions, the construction is simple, the quality is controllable, the economy is good, the environment is environmentally friendly and it is beneficial to popularization.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a flooded embankment structure of a high-speed railway in a seasonally frozen soil area according to the present invention.

FIG. 2 is a schematic structural diagram of the elastic support layer described in the present invention.

Icon: 1- bored cast-in-place pile; 2- geogrid; 3- lower embankment; 4- partition layer; 5- upper embankment; 6- elastic support layer; 61- bottom plate; 62- top plate; 63- spring structure; 64 -Flexible side walls; 7-carrying device; 8-track structure; A-foundation; B-highest water line.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings.

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Example

As shown in Figures 1-2, this embodiment provides a submerged embankment structure for a high-speed railway in a seasonally frozen soil area, including an upper embankment 5, a lower embankment 3, a geogrid 2, a partition layer 4, a bored pile 1, Elastic support layer 6 , carrying device 7 and track structure 8 .

There are two bored cast-in-place piles 1. The bored cast-in-place piles 1 are arranged in the foundation A in a row along the longitudinal direction of the line, and at least two rows of bored cast-in-place piles 1 are arranged laterally along the line. Out of the foundation A and fixedly connected with the bottom of the bearing device 7, the outside of the pile body of the bored pile 1 extending out of the foundation A is coated with lubricating material.

The geogrid 2 is laid on the foundation A and is fixedly connected to the bored pile 1 . Specifically, the geogrid 2 and the bored pile 1 are tightened and fixedly connected.

The lower embankment 3 is filled on the top of the geogrid 2 with water-permeable soil filler.

The blocking layer 4 is arranged on the top of the lower embankment 3 . Specifically, the blocking layer 4 is composed of medium and coarse sand sandwiched with two layers of composite geomembrane, and the setting position is higher than the highest water level line B.

The upper embankment 5 is filled on the top of the isolation layer 4, and the upper embankment 5 is filled with qualified high-speed railway fillers.

The elastic support layer 6 is arranged on the top of the upper embankment 5. The elastic support layer 6 is composed of a bottom plate 61, a spring structure 63, a top plate 62 and a flexible side wall 64. The bottom plate 61, the top plate 62 and the flexible side wall 64 form a closed structure. The spring structure 63 is located in the closed structure, and two ends of the spring structure 63 are respectively connected with the bottom plate 61 and the top plate 62 .

The bearing device 7 is arranged on the top of the elastic support layer 6, and the bottom of the bearing device 7 is fixedly connected with the top of the pile body of the bored pile 1 extending out of the foundation A. Specifically, the bearing device 7 is a bearing plate.

The number of the track structures 8 is two, and they are fixedly arranged on the top of the carrying device 7 .

The present embodiment also provides a method for constructing a flooded embankment of a high-speed railway in a seasonally frozen soil area, which is used to construct the above-mentioned embankment structure, including the following steps:

S1: Arrange the bored piles 1 in the foundation A in rows longitudinally along the line, and extend the top of the bored piles 1 out of the foundation A;

Specifically, connecting steel bars are inserted around the pile body at the intersection of the bored pile 1 and the ground, the length of the top steel bar of the bored pile 1 protruding from the top of the pile is not less than 0.3m, and the length of the top steel bar of the bored pile 1 protruding from the foundation is not less than 0.3m. The exterior of the pile body above A is lubricated with asphalt smear;

S2: Fill the lower embankment 3 on the foundation A;

Specifically, a geogrid 2 is laid on the foundation A, and it is cut off when it intersects with the bored pile 1, and the cut-off tie is tightly connected with the connecting steel bar of the bored pile 1, and the geogrid 2 is tightened and fixed on the On the foundation A, the lower embankment 3 is filled in layers on the upper end of the geogrid 2;

S3: Fill the upper embankment 5 at the upper end of the lower embankment 3;

Specifically, the partition layer 4 is installed on the top of the lower embankment 3, and the upper embankment 5 is constructed on the top of the partition layer 4;

S4: excavate and construct the elastic support layer 6 on the top of the upper embankment 5;

S5: The bearing device 7 is installed on the top of the elastic support layer 6, and is fixedly connected with the top of the pile body of the bored pile 1 extending out of the foundation A;

Specifically, the reinforced concrete of the bearing plate is poured in the vertical form, and is fixedly connected with the protruding steel bars on the top of the bored pile 1, and the connecting steel bars are embedded in the top of the bearing plate;

After step S5 is completed, the track structure 8 is constructed and fixedly connected with the pre-embedded connecting steel bars on the top of the bearing plate.

The beneficial effects of the submerged embankment structure and construction method of a high-speed railway in a seasonally frozen soil area provided by the present embodiment are:

There are two bored cast-in-place piles 1. The bored cast-in-place piles 1 are arranged in the foundation A in a row along the longitudinal direction of the line, and at least two rows of bored cast-in-place piles 1 are arranged laterally along the line. Out of the foundation A and fixedly connected to the bottom of the bearing device 7, the bearing device 7 is arranged on the top of the elastic support layer 6, the lower embankment 3 is filled with water-seepage soil filler on the top of the geogrid 2, and the lower embankment 3 is deformed due to frost heave When the elastic support layer 6 at the bottom of the bearing device 7 shrinks and deforms, the influence of the frost heave force on the bearing device 7 can be greatly reduced, and the elastic support layer 6 recovers from shrinkage and deformation during non-frost heave, which can provide a surface for the bearing device 7 The supporting force can save the engineering investment of the bearing device 7, so that the constructed submerged embankment structure has a good ability to resist the upper arch deformation;

The outside of the pile body of the bored pile 1 extending out of the foundation A is coated with lubricating material, which can reduce the transmission of frost heave force and make the constructed embankment structure have a good ability to resist upper arch deformation;

The geogrid 2 is laid on the foundation A and is fixedly connected with the bored pile 1. The geogrid 2 is used for the reinforcement of the foundation A, and is fixedly connected with the bored pile 1 to form a stable plane. The lower embankment 3 and the partition layer 4 , The upper embankment 5 and the elastic support layer 6 subsidence the foundation A under the action of gravity, so that the geogrid 2 exerts a large downward pulling force on the bored pile 1, which can effectively balance the frost heave of the lower embankment 3 and transmit it to the driller. The upper arch friction force of the bored cast-in-place pile 1, thereby avoiding the upper arch deformation of the top bearing device 7 caused by the bored cast-in-place pile 1;

The lower embankment 3 adopts water-permeable soil filler, the upper embankment 5 adopts qualified filler, and the blocking layer 4 is located between the upper embankment 5 and the lower embankment 3 . The seepage soil filler has good water permeability, which can increase the drainage of the foundation A and reduce the settlement of the foundation A. The isolation layer 4 can effectively prevent the upward migration of moisture in the lower embankment 3 and avoid the unfavorable frost heave deformation of the upper embankment 5;

The above-mentioned construction method ensures the effective realization of the above-mentioned embankment structure functions, the construction is simple, the quality is controllable, the economical efficiency is good, the environmental protection is favorable, and the promotion is favorable.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. A high-speed railway immersion embankment structure in a seasonal frozen soil area is characterized by comprising an upper embankment (5), a lower embankment (3), bored cast-in-place piles (1), an elastic supporting layer (6) and a bearing device (7);

the lower embankment (3) is filled at the upper end of a foundation (A), and the upper embankment (5) is positioned at the upper end of the lower embankment (3);

the elastic supporting layer (6) is positioned on the top of the upper embankment (5), and the bearing device (7) is positioned on the top of the elastic supporting layer (6);

the quantity of bored concrete pile (1) is at least two, at least two bored concrete pile (1) is in line longitudinal interval row setting along the route in ground (A), transversely is equipped with at least two rows along the route bored concrete pile (1), bored concrete pile (1) top stretches out ground (A) and with bear device (7) fixed the linking to each other.

2. The embankment structure for high-speed railway flooding in seasonal frozen soil area according to claim 1, characterized by further comprising a geogrid (2), wherein the geogrid (2) is laid on the foundation (A) and is fixedly connected with the cast-in-situ bored pile (1), and the lower embankment (3) is filled on top of the geogrid (2).

3. The immersed embankment structure for high-speed railways in the seasonal frozen soil area according to claim 1, further comprising a partition layer (4), wherein the partition layer (4) is located between the upper embankment (5) and the lower embankment (3), the lower embankment (3) is filled with permeable soil, and the upper embankment (5) is filled with qualified materials.

4. The embankment structure for flooding high-speed railways in seasonal frozen soil areas according to claim 1, characterized by further comprising a track structure (8), wherein the track structure (8) is fixedly arranged on top of the carrying device (7).

5. The embankment structure for flooding high-speed railways in seasonal frozen soil areas according to claim 1, characterized in that the bored pile (1) is provided with a coating of lubricating material extending outside the pile body of the foundation (a).

6. The embankment structure for high-speed railway flooding in seasonal frozen soil area according to claim 1, characterized in that the supporting resilient layer (6) is composed of a bottom plate (61), a spring structure (63), a top plate (62) and flexible side walls (64), the bottom plate (61), the top plate (62) and the flexible side walls (64) form a closed structure, the spring structure (63) is located in the closed structure, and both ends of the spring structure (63) are respectively connected with the bottom plate (61) and the top plate (62).

7. A method for constructing a submerged embankment for a high-speed railway in a seasonally frozen soil area, which is used for constructing the embankment structure according to any one of claims 1 to 6, comprising the steps of:

s1: arranging the cast-in-situ bored piles (1) in the foundation (A) at intervals in rows along the longitudinal direction of the line, and extending the top of the cast-in-situ bored piles (1) out of the foundation (A);

s2: -filling said lower embankment (3) on said foundation (a);

s3: filling the upper embankment (5) at the upper end of the lower embankment (3);

s4: excavating and constructing the elastic support layer (6) on the top of the upper embankment (5);

s5: and (3) installing the bearing device (7) on the top of the elastic supporting layer (6) and fixedly connecting the bearing device with the top of the pile body of the cast-in-situ bored pile (1) extending out of the foundation (A).

8. The method for constructing a submerged embankment for a high-speed railway in a seasonal frozen soil area according to claim 7, wherein after the step of S1 is completed, a lubricating material is applied to the outside of the pile body of the cast-in-situ bored pile (1) extending out of the foundation (A).

9. The method for constructing a flooded embankment for a high-speed railway in a seasonally frozen soil area according to claim 7, wherein the embankment structure comprises a partition layer (4), the partition layer (4) is located between the upper embankment (5) and the lower embankment (3), and the upper embankment (5) is filled on top of the partition layer (4) in the step S3.

10. The method for constructing a submerged embankment for a high-speed railway in a seasonal frozen soil area according to claim 7, wherein the embankment structure further comprises a track structure (8), and after the step of S5 is completed, the track structure (8) is fixedly installed on the top of the bearing device (7).

Images