CN110644297A - A kind of anti-bulge support structure and construction method of ballastless track high-speed railway - Google Patents

Abstract

The invention discloses an anti-bulge support structure and a construction method for a ballastless track high-speed railway. The anti-bulge support structure includes a bottom arch arranged on the base surface of a road cutting excavation. The bottom arch is a plate structure and is bent downward. A plurality of prestressed anchor cables are arranged in rows and intervals in the expansive soil foundation under the bottom arch, and frame-type retaining walls are respectively provided on both sides of the bottom arch, and the frame-type retaining walls are in contact with the cutting slope. , and form a rigid connection with the side of the bottom arch. The invention restrains the expansion and deformation of the base by setting the bottom arch and the prestressed anchor cable, bears the expansion force of the base, and finally converts the expansion force into the thrust in the tangential direction at both ends of the bottom arch, and transmits it to the frame type retaining walls on both sides. The structure not only prevents the upper arch deformation of the expansive soil base, but also is beneficial to the stability of the expansive soil slope, and reduces the excavation of the slopes on both sides. The structure is novel, the construction is simple, and it has broad application prospects.

Description

A kind of anti-bulge support structure and construction method of ballastless track high-speed railway

technical field

The invention relates to the field of roadbed engineering, in particular to an anti-bulge support structure and a construction method suitable for a ballastless track high-speed railway.

Background technique

High-speed railways, especially ballastless track railways, have strict control over the deformation of subgrade arches and the stability of slopes. However, with the rapid development of high-speed railways, it is inevitable to encounter deep excavation of cuttings in expansive soil areas during the construction process. Under the condition of infiltration, the humidified soil weight increases, the shear strength decreases, and the expansion effect occurs, which causes the instability of the slope and the uplift of the base, which seriously affects the operation safety of the train.

At present, flexible measures such as anchor cables and pile-sheet structure reinforcement measures are often used to resist base uplift. Practice has proved that the anchor cables and other flexible measures are not effective in resisting the uplift, while the simple pile-sheet structure reinforcement measures have shortcomings such as excessively large pile section size; Slope reinforcement often adopts the support structure of gravity retaining wall, but due to the expansion of the slope soil and the action of earth pressure, the section size of the gravity retaining wall is large, and the number of masonry is large, which is uneconomical. Therefore, for the ballastless track high-speed railway project in the expansive land area, an anti-bulge support structure is urgently needed to solve the existing problems, and it should have the characteristics of convenient construction, economical rationality, safety and environmental protection.

SUMMARY OF THE INVENTION

The purpose of the invention is to provide a ballastless track high-speed railway anti-bulge support structure and construction method in order to solve the problems of ballastless track subgrade base deformation and slope stability in deep cutting and expansive soil sections, which can effectively prevent and control The arch deformation of the expansive soil subgrade base ensures the stability of the expansive soil slope and meets the requirements of high-speed railways for line smoothness and slope stability.

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

An anti-bulge support structure for a ballastless track high-speed railway, comprising a bottom arch arranged on the base surface of a cutting excavation, the bottom arch is a plate structure and is bent downward, and is arranged in rows in the expansive soil foundation under the bottom arch A plurality of prestressed anchor cables are arranged at intervals, and frame-type retaining walls are respectively provided on both sides of the bottom arch. The frame-type retaining walls are in contact with the cutting side slope and form a rigid connection with the side surface of the bottom arch.

The invention constrains the expansion and deformation of the base by arranging the bottom arch and the prestressed anchor cable on the base, bears the expansion force of the base, and finally converts the expansion force into the thrust in the tangential direction at both ends of the bottom arch, and transmits it to the frame type on both sides. The retaining wall balances a part of the thrust of the side slopes on both sides; the frame retaining walls on the left and right sides of the cutting are connected by the bottom arch to form a combined structure, which can make full use of the thrust on both sides of the cutting to balance the thrust on the opposite side and reduce the size of the structure , the overall soil wall composed of frame retaining wall and frame inner soil jointly bear the pressure generated by the soil behind the wall, so as to realize the support of the slope soil; prestressed anchor cables, frame retaining wall and frame inner soil The integral earth wall is composed of balancing the expansion force borne by the bottom arch, effectively controlling the upper arch deformation of the ballastless track high-speed railway; this structure not only prevents the upper arch deformation of the expansive soil base, but also facilitates the stability of the expansive soil slope, reducing the The excavation of the side slopes on both sides has novel structure and simple construction, and has broad application prospects.

As a preferred solution of the present invention, the framed retaining wall includes a foundation, a wall panel, a transverse rib and a longitudinal partition, wherein the transverse rib and the longitudinal partition form a lattice frame, and the wall panel is located on the transverse rib. The end is connected to the side of the bottom arch, and the foundation is located in the soil below the wall panel. The frame-type retaining wall and the soil inside the frame are subjected to the frictional resistance of the side walls of the longitudinal diaphragm and transverse rib, and move together with the frame to form an integral earth wall. The rupture surface is located in the soil behind the end of the rib, and the frame-type retaining wall The integral earth wall composed of the soil in the frame jointly bears the pressure generated by the soil behind the wall, and realizes the support of the slope soil.

As a preferred solution of the present invention, a plurality of capillary drainage pipes are arranged in the transverse direction in the grid frame, and a plurality of drainage holes are arranged on the wall panel. By setting the capillary drainage pipe deep into the slope soil, it is beneficial to divert the water of the slope and the soil in the frame to the scupper holes of the wall panel, so as to avoid the swelling effect caused by the accumulation of water in the slope soil.

As a preferred solution of the present invention, a water-proof and anti-seepage layer is laid on the top surface of the bottom dome. The waterproof and seepage barrier layer has good sealing performance, which blocks the surface seepage water on the top surface of the bottom vault, and facilitates the discharge of the surface seepage water.

As a preferred solution of the present invention, a drainage dead pipe is arranged above the water-proof and anti-seepage layer, and the drainage dead pipe is longitudinally arranged at the lowest part of the mid-span of the top surface of the bottom vault. The drain blind pipe is beneficial to discharge the ground seepage water blocked on the top surface of the bottom vault.

As a preferred solution of the present invention, a reverse filter layer is provided on the side of the wall panel in contact with the soil and outside the drainage blind pipe. By arranging a filter layer on the side of the wall panel in contact with the soil and outside the drainage blind pipe, the loss of fine-grained soil at the bottom of the subgrade and the clogging of the drainage blind pipe can be prevented.

As a preferred solution of the present invention, the bottom arch, the wall panels on both sides, and the lattice frame are an integral structure of reinforced concrete.

As a preferred solution of the present invention, the waterproof and anti-seepage layer is a composite waterproof and drainage board.

As a preferred solution of the present invention, the filter layer is geotextile and sand and gravel.

A construction method for an anti-bulge support structure of a ballastless track high-speed railway, comprising the following steps:

Step 1. Excavate expansive soil cutting slopes in stages and protect them, and do temporary drainage until the design elevation of the top surface of the frame retaining wall is reached;

Step 2: Excavate transverse rib grooves and longitudinal partition grooves in the slope soil body, and clean the slag body in the grooves;

Step 3: Bind steel bars in the transverse rib grooves and the longitudinal partition grooves and reserve connecting steel bars for connecting the wall panels, pre-embed capillary drainage pipes, and then pour concrete to form a lattice frame with exposed connecting steel bars;

Step 4: Excavate the wall panel foundation groove and the bottom arch groove, clean the slag in the groove, construct prestressed anchor cables on the expansive soil foundation, and press grouting to form a prestressed anchor cable reinforcement structure;

Step 5, erect the construction formwork, place the bottom arch reinforcement cage, reserve the connecting steel bars for connecting the wall panels, build the foundation and pour the bottom arch concrete;

Step 6: Bind the reinforcement cage of the wall panel on the foundation, and connect the connecting steel bar to the reinforcement bar of the wall panel, then set up the panel formwork, and pre-embed the drain pipe, and then pour concrete in the panel formwork;

Step 7: Lay a water-proof and anti-seepage layer on the top surface of the bottom arch, lay an anti-filter layer on the soil-facing part of the wall panel, and then backfill the soil between the anti-filter layer of the wall panel and the side slope and compact it until the top of the wall;

Step 8. Set up a drainage dead pipe along the longitudinal direction of the bottom arch at the lowest part of the bottom arch, and set a reverse filter layer outside the drainage dead pipe;

Step 9: Fill the bottom layer of the foundation bed and the surface layer of the foundation bed in layers.

In the present invention, through steps 1 to 9, the bottom arch of the reinforced concrete integral structure and the frame type retaining wall are arranged on the base, and a plurality of prestressed anchor cables are arranged under the bottom arch, which can effectively prevent the upper arch deformation of the expansive soil base. It is also conducive to the stability of expansive soil slopes, meeting the requirements of high-speed railways for line smoothness and slope stability, and has the characteristics of convenient construction, economical rationality, safety and environmental protection.

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

1. The present invention constrains the expansion and deformation of the base by setting the bottom arch and prestressed anchor cables on the base, bears the expansion force of the base, and finally converts the expansion force into the thrust in the tangential direction at both ends of the base arch, and transmits it to the two sides of the base. The frame-type retaining wall balances a part of the thrust of the side slopes on both sides; the frame-type retaining walls on the left and right sides of the cutting are connected by the bottom arch to form a combined structure, which can make full use of the thrust on both sides of the cutting to balance the thrust on the opposite side and reduce the Structural size, the integral earth wall composed of frame retaining wall and frame inner soil jointly bear the pressure generated by the soil behind the wall, so as to realize the support of the slope soil; prestressed anchor cable, frame retaining wall and frame The integral earth wall composed of inner soil balances the expansion force borne by the bottom arch and effectively controls the upper arch deformation of the ballastless high-speed railway; this structure not only prevents the upper arch deformation of the expansive soil base, but also facilitates the stability of the expansive soil slope. The excavation of the side slopes on both sides is reduced, the structure is novel, the construction is simple, and has broad application prospects;

2. The frame-type retaining wall and the soil in the frame are subjected to the frictional resistance of the longitudinal diaphragm and the lateral rib, and move together with the frame to form an integral soil wall. The rupture surface is located in the soil behind the end of the rib, and the frame-type retaining The overall soil wall composed of the soil wall and the soil in the frame jointly bears the pressure generated by the soil behind the wall, and realizes the support of the slope soil;

3. By setting the capillary drainage pipe deep into the slope soil, it is beneficial to divert the water of the slope and the soil in the frame to the drain hole of the wall panel, so as to avoid the swelling effect caused by the accumulation of water in the slope soil;

4. By laying a waterproof and seepage-proof layer on the top surface of the bottom arch, the waterproof and seepage-proof layer has good sealing performance, and the surface seepage water is blocked on the top surface of the bottom arch, which is convenient for the discharge of surface seepage water;

5. Drainage blind pipes are arranged above the water-proof and anti-seepage layer, and the drainage blind pipes are arranged longitudinally along the line at the lowest part of the mid-span of the top surface of the bottom arch, which is beneficial to discharge the surface seepage water blocked on the top surface of the bottom arch;

6. By setting a filter layer on the side of the wall panel in contact with the soil and outside the drainage blind pipe, it can prevent the loss of fine-grained soil at the bottom of the subgrade and block the drainage blind pipe.

Description of drawings

FIG. 1 is a schematic cross-sectional view of the anti-uplift support structure of the ballastless track high-speed railway in the present invention.

FIG. 2 is a schematic plan view of the anti-uplift support structure of the ballastless track high-speed railway in the present invention.

Marked in the figure: bottom arch 1, prestressed anchor cable 2, frame retaining wall 3, foundation 4, wall panel 5, transverse rib 6, longitudinal partition 7, drainage blind pipe 8, waterproof and anti-seepage layer 9, reverse The filter layer 10 , the drain hole 11 , and the capillary drain pipe 12 .

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 1

This embodiment provides an anti-bulge support structure for a ballastless track high-speed railway;

As shown in Figures 1 and 2, the anti-bulge support structure of the ballastless track high-speed railway in this embodiment includes a bottom arch 1 arranged on the base surface of the cutting excavation. The bottom arch 1 is a plate structure and faces downwards. Bending, a plurality of prestressed anchor cables 2 are arranged in rows and intervals in the expansive soil foundation below the bottom arch 1, and frame-type retaining walls 3 are respectively provided on both sides of the bottom arch 1. The frame-type retaining wall 3. It is in contact with the cutting slope and forms a rigid connection with the side of the bottom arch 1.

The invention constrains the expansion and deformation of the base by arranging the bottom arch and the prestressed anchor cable on the base, bears the expansion force of the base, and finally converts the expansion force into the thrust in the tangential direction at both ends of the bottom arch, and transmits it to the frame type on both sides. The retaining wall balances a part of the thrust of the side slopes on both sides; the frame retaining walls on the left and right sides of the cutting are connected by the bottom arch to form a combined structure, which can make full use of the thrust on both sides of the cutting to balance the thrust on the opposite side and reduce the size of the structure , the overall soil wall composed of frame retaining wall and frame inner soil jointly bear the pressure generated by the soil behind the wall, so as to realize the support of the slope soil; prestressed anchor cables, frame retaining wall and frame inner soil The integral earth wall is composed of balancing the expansion force borne by the bottom arch and effectively controlling the upper arch deformation of the ballastless track high-speed railway. The excavation of the side slopes on both sides has novel structure and simple construction, and has broad application prospects.

In this embodiment, the frame-type retaining wall 3 includes a foundation 4, a wall panel 5, a transverse rib 6 and a longitudinal partition 7, wherein the transverse rib 6 and the longitudinal partition 7 form a lattice frame, and the wall The panel 5 is located at the end of the transverse rib 6 and connected to the side of the bottom arch 1 , and the foundation 4 is made of concrete and is located in the soil below the wall panel 5 . The frame-type retaining wall and the soil inside the frame are subjected to the frictional resistance of the side walls of the longitudinal diaphragm and transverse rib, and move together with the frame to form an integral earth wall. The rupture surface is located in the soil behind the end of the rib, and the frame-type retaining wall The integral earth wall composed of the soil in the frame jointly bears the pressure generated by the soil behind the wall, and realizes the support of the slope soil.

In this embodiment, a plurality of capillary drainage pipes 12 are arranged in the transverse direction in the grid frame, and the capillary drainage pipes 12 are arranged in parallel between each transverse rib 6 , and a plurality of drainage holes are arranged on the wall panel 5 11. By setting the capillary drainage pipe deep into the slope soil, it is beneficial to divert the water of the slope and the soil in the frame to the scupper holes of the wall panel, so as to avoid the swelling effect caused by the accumulation of water in the slope soil. In order to improve the drainage effect, all capillary drainage pipes are arranged in a plum blossom shape in the grid frame, and the inclination angle is 5°. The soil in the grid frame is drilled and the capillary drainage pipes are passed through.

In this embodiment, the top surface of the bottom arch 1 is covered with a water-proof and anti-seepage layer 9 . The waterproof and seepage barrier layer has good sealing performance, which blocks the surface seepage water on the top surface of the bottom vault, and facilitates the discharge of the surface seepage water.

In this embodiment, a drainage blind pipe 8 is arranged above the water-proof and anti-seepage layer 9 . Multiple water seepage holes block the surface seepage water on the top surface of the bottom arch and enter the drainage blind pipe through the seepage holes for drainage.

In this embodiment, a reverse filter layer 10 is provided on the side of the wall panel 5 that is in contact with the soil and outside the drainage blind pipe 8 . The capillary drainage pipe diverts the seepage water from the slope soil to the side where the wall panel is in contact with the soil, and then drains away through the drain holes on the wall panel. By arranging a filter layer on the side of the wall panel in contact with the soil and outside the drainage blind pipe, the loss of fine-grained soil at the bottom of the subgrade and the clogging of the drainage blind pipe can be prevented.

In this embodiment, the bottom arch 1, the wall panels 5 on both sides, and the lattice frame are an integral structure of reinforced concrete.

In this embodiment, the waterproof and anti-seepage layer 9 is a composite waterproof and drainage board. The composite waterproof and drainage board is a composite structure with drainage and isolation functions composed of a three-dimensional geonet core and acupuncture perforated geotextiles adhered on both sides.

In this embodiment, the filter layer 10 is geotextile and sand and gravel. Geotextile, also known as geotextile, is a permeable geosynthetic material made of synthetic fibers by needle punching or weaving. After the surface seepage water passes through the anti-filtration layer formed by geotextile and sand and gravel, it enters the drainage blind pipe through the seepage hole.

Example 2

The present embodiment provides a construction method of the anti-bulge support structure of the ballastless track high-speed railway in Embodiment 1, comprising the following steps:

Step 1. Excavate expansive soil cutting slopes in stages and protect them, and do temporary drainage until the design elevation of the top surface of the frame retaining wall 3 is reached;

Step 2, excavate 6 grooves of transverse ribs and 7 grooves of longitudinal partitions in the slope soil body, and clean the slag body in the grooves;

Step 3: Bind steel bars in the 6 grooves of the transverse rib and the 7 grooves of the longitudinal partition, and reserve the connecting steel bars for connecting the wall panels 5 at the ends of the steel bars of the transverse rib 6. After drilling the soil between each transverse rib 6 Pre-embedded capillary drainage pipes 12, and then poured concrete to form a lattice frame with exposed connecting steel bars;

Step 4: Excavate the wall panel 5 foundation groove and the bottom arch 1 groove, clean the slag body in the groove, use concrete to construct the foundation 4, construct the prestressed anchor cable 2 on the expansive soil foundation, and form the prestressed anchor by high-pressure grouting cable reinforcement structure;

Step 5, erect the construction template, place the bottom arch 1 steel cage, and reserve the connecting steel bars for connecting the wall panel 5, build the foundation and pour the bottom arch concrete;

Step 6. Bind the reinforcement cage of the wall panel 5 on the foundation 4, and connect all the connecting steel bars with the reinforcement bars of the wall panel 5, then set up the wall panel formwork, and pre-embed the drain hole 11 pipe, and then pour concrete in the wall panel formwork , after the concrete is solidified, remove the wall panel formwork to form the wall panel 5;

Step 7. Lay a layer of composite waterproof and drainage board on the top surface of the bottom arch 1 as the water-proof and anti-seepage layer 9, lay geotextiles and sand gravel on the soil surface of the wall panel 5 as the reverse filter layer 10, and then reverse filter on the wall panel. Backfill the soil between the layer and the slope and compact it until the top of the wall;

Step 8: A drain blind pipe 8 is arranged longitudinally along the line at the lowest part of the bottom arch 1, and a geotextile and sand gravel are arranged outside the drain blind pipe 8 as a filter layer 10;

Step 9: Fill the bottom layer of the foundation bed and the surface layer of the foundation bed in layers.

In the present invention, through steps 1 to 9, the bottom arch of the reinforced concrete integral structure and the frame type retaining wall are arranged on the base, and a plurality of prestressed anchor cables are arranged under the bottom arch, which can effectively prevent the upper arch deformation of the expansive soil base. It is also conducive to the stability of expansive soil slopes, meeting the requirements of high-speed railways for line smoothness and slope stability, and has the characteristics of convenient construction, economical rationality, safety and environmental protection.

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 principles of the present invention shall be included in the protection scope of the present invention. Inside.

Claims (10)

1. A ballastless track high-speed railway anti-hump supporting structure is characterized by comprising a bottom arch arranged on a cutting excavation basement surface, wherein the bottom arch is of a plate type structure and is bent downwards, a plurality of prestressed anchor cables are arranged in rows at intervals in an expansive soil foundation below the bottom arch, frame type retaining walls are arranged on two sides of the bottom arch respectively and are in contact with cutting slopes and are in rigid connection with the side surfaces of the bottom arch.

2. The anti-hump supporting structure of a ballastless track high-speed railway according to claim 1, wherein the frame-type retaining wall comprises a foundation, a wall panel, a transverse rib plate and a longitudinal partition plate, wherein the transverse rib plate and the longitudinal partition plate form a square frame, the wall panel is positioned at the end of the transverse rib plate and connected with the side face of the bottom arch, and the foundation is positioned in the soil body below the wall panel.

3. The anti-bulging supporting structure of the ballastless track high-speed railway of claim 2, wherein a plurality of capillary drainage pipes are transversely arranged in the square frame, and a plurality of drainage holes are arranged on the wall panel.

4. The anti-hump supporting structure of the ballastless track high-speed railway of claim 3, wherein a water-resisting and impervious layer is paved on the top surface of the bottom arch.

5. The anti-hump supporting structure of the ballastless track high-speed railway according to claim 4, wherein a drainage blind pipe is arranged above the water-resisting and seepage-proofing layer, and the drainage blind pipe is longitudinally arranged at the lowest position in the top span of the bottom arch along a line.

6. The anti-hump supporting structure of the ballastless track high-speed railway of claim 5, wherein a side of the wall panel contacting with the soil body and the outside of the drainage blind pipe are provided with an inverted filter layer.

7. The anti-hump supporting structure of the ballastless track high-speed railway of claim 6, wherein the bottom arch, the wall panels at two sides and the square frame are of reinforced concrete integral structure.

8. The anti-hump supporting structure of the ballastless track high-speed railway of claim 4, wherein the water-resisting and impervious layer is a composite waterproof and drainage plate.

9. The anti-hump supporting structure of the ballastless track high-speed railway of claim 6, wherein the inverted filter is geotextile and sand gravel.

10. The construction method of the anti-ridge supporting structure of the ballastless track high-speed railway of claim 7, characterized by comprising the following steps:

step one, excavating expansive soil cutting slopes in a grading manner, protecting, and performing temporary drainage until the top surface design elevation of the frame type retaining wall is reached;

step two, digging transverse rib plate grooves and longitudinal partition plate grooves in a side slope soil body, and cleaning slag bodies in the grooves;

binding reinforcing steel bars in the transverse rib plate grooves and the longitudinal partition plate grooves, reserving connecting reinforcing steel bars for connecting wall panels, pre-burying capillary drainage pipes, and then pouring concrete to form a square frame with the exposed connecting reinforcing steel bars;

fourthly, excavating a wall panel foundation trench and a bottom arch trench, cleaning slag in the trench, constructing a prestressed anchor cable on the expansive soil foundation, and performing pressure grouting to form a prestressed anchor cable reinforcing structure;

erecting a construction template, placing a bottom arch reinforcement cage, reserving connecting reinforcements for connecting wall panels, building a foundation and pouring bottom arch concrete;

step six, binding a wall panel reinforcement cage on the foundation, connecting the connecting reinforcement with the wall panel reinforcement, then erecting a wall panel template, pre-embedding a drainage hole pipe, and then pouring concrete in the wall panel template;

step seven, paving a waterproof impermeable layer on the top surface of the bottom arch, paving a reverse filter layer on the soil facing surface of the wall panel, and then backfilling soil between the reverse filter layer of the wall panel and the side slope and tamping until the wall top is reached;

step eight, arranging drainage blind pipes at the lowest positions of the bottom arches along the line longitudinally, and arranging an inverted filter layer outside the drainage blind pipes;

and step nine, filling the bottom layer and the surface layer of the foundation bed layer by layers.

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