Construction method of anti-seismic assembly type railway foundation bed surface layer structure and surface layer structure

Abstract

The invention discloses an anti-seismic assembly type railway foundation bed surface layer structure and a construction method thereof, and aims to greatly improve the site construction efficiency of a newly-built railway and improve the rapid reconnection capability of a railway foundation in extreme disaster and special geological climate environments. Comprising the steps that an assembly type railroad bed is laid above a foundation, and a waterproof layer is arranged above the assembly type railroad bed; the waterproof layer is a novel asphalt graded broken stone full-section closed layer, the subgrade bed surface layer structure is formed by combining a main body base block, a left side slope protection triangular base block and a right side slope protection triangular base block, a base block structure form main body is of a cube structure, and the two sides of a slope are of a triangular structure; each base block is prepared from a foam light material consisting of Portland cement, fly ash, a foaming agent, tap water and hollow glass beads; the surface layer of the anti-seismic assembly type railway foundation bed adopts a single-point mortise and tenon connection mode, that is, adjacent foundation blocks are embedded into a whole in a concave-convex mode. The method is suitable for railroad bed engineering in a high-intensity earthquake area; the method can be used for rapid repair of railroad beds in extreme disasters and special geological climate environments.

Description

Technical Field

[0001] The invention belongs to the technical field of railway roadbed structures, and in particular relates to a construction method for an earthquake-resistant assembled railway bed surface structure and a surface structure thereof. Background Art

[0002] The structural vibration caused by high-speed rail vehicles spreads outward through the roadbed to the surrounding strata, which not only endangers the safety performance of the wheel-rail system itself, but also has an adverse effect on the durability of the high-speed rail roadbed structure. There are many types of vibration reduction measures for high-speed railway roadbeds, and the vibration reduction effects vary. Generally speaking, there are disadvantages of high cost and insufficient effect.

[0004] A large number of studies on roadbed fillings have shown that the deformation of the surface and bottom layers of the subgrade can account for more than 50% of the total deformation of the entire roadbed. With the rapid development of high-speed railways, the study of the strength and deformation characteristics of high-speed railway subgrade fillings has become a hot topic. The use of seismic reduction and isolation materials can effectively reduce the deformation behavior of high-speed railway subgrades under dynamic loads. If a new type of assembled railway subgrade surface structure can be designed and a lightweight seismic filler can be developed, and it can be widely used in the roadbed materials of high-speed railways and industrialized and promoted, it will solve the current problem to a great extent. At present, assembled structures and construction technology have become one of the important trends in the development of railway engineering construction.

[0005] Existing technical solutions

[0006] (1) A fast-construction lightweight earthquake-resistant roadbed structure and its construction method (CN109440561A)

[0007] Disclosed is a fast-constructed lightweight earthquake-resistant roadbed structure and a construction method thereof, comprising a reinforced concrete base, reinforced concrete rib columns and reinforced concrete prefabricated panels, wherein the reinforced concrete base is arranged at intervals along the longitudinal direction of the roadbed in a foundation pit of a mountain outside the roadbed, the lower end of the reinforced concrete rib column is consolidated with the reinforced concrete base, and a steel plate limit pier connected to the reinforced concrete rib column is fixedly arranged on each reinforced concrete base. A fixed-bar concrete prefabricated panel is installed between two adjacent steel reinforced concrete rib columns, a shock-absorbing buffer filter layer is arranged on the back of the steel concrete prefabricated panel, and foam lightweight soil is poured on the back of the shock-absorbing buffer filter layer on the mountain slope to form a roadbed.

[0008] The main disadvantage of this structure is that when the structure is damaged, it needs to be dismantled and replaced as a whole, which does not achieve a good balance between economy and practicality. The structural filler uses a common type of foam lightweight soil filler. When used in the transition section, when there is a difference in stiffness or uneven deformation in its lower structure, especially on a foundation with weak bearing capacity, it is easy to cause instability in the overall structure. This instability first forms cracks in the lower part of the structure, and then the cracks extend to the top, which may lead to the destruction of the overall structure. Since the elastic modulus of lightweight fillers is lower than that of traditional concrete, this difference exacerbates the risk of uneven settlement.

[0009] (2) A fast-assembly block-type railway roadbed structure and its construction method (CN118166583A)

[0010] A fast-assembly block-type railway roadbed structure is disclosed, including an assembled block-type railway roadbed laid on top of a foundation, a waterproof layer is arranged on top of the assembled block-type railway roadbed; the waterproof layer is cast by asphalt concrete, the assembled block-type railway roadbed is composed of blocks, the block structures are rectangular or cube-shaped, and the blocks are prefabricated from foam lightweight soil materials; the assembled block-type railway roadbed adopts a single-point mortise and tenon connection method, that is, the blocks are connected to adjacent blocks in a concave-convex manner as a whole. The present invention can effectively improve on-site construction efficiency; effectively solve the problem that conventional roadbeds occupy a large amount of land due to slope reduction requirements; effectively control roadbed settlement when replacing soft soil foundations and widening the roadbed of new lines connected to existing high-speed railway stations, thereby improving the stability, smoothness and reliability of the track structure, and ensuring the smoothness and comfort of train operation.

[0011] The main disadvantage of this structure is that the outer side of the prefabricated roadbed adopts a vertical slope, which will cause rainwater to accumulate when it rains, and enter the roadbed and foundation through the tiny cracks at the connection of the blocks, further causing roadbed diseases such as mud bubbling. In addition, the asphalt concrete waterproof layer laid on the prefabricated roadbed of this structure may cause cracks on the surface of the waterproof layer in areas with frequent earthquakes and extreme climates, and cannot effectively protect the prefabricated roadbed blocks, resulting in the prefabricated roadbed blocks being exposed, causing cracks, settlement or other roadbed diseases, and thus destroying the overall stability of the railway roadbed structure.

[0012] (3) Foamed concrete for bridge arch filling (CN107265953B)

[0013] The invention relates to a lightweight filler for filling on a bridge arch. The lightweight filler is composed of the following parts by mass: 500-600 parts of PⅡ52.5 or 42.5 cement, 60-240 parts of lithium slag, 2-3 parts of foaming agent, 3-4 parts of water reducer, 10-30 parts of alkali-resistant glass fiber, 2-5 parts of emulsion waterproofing agent, 12-100 parts of styrene-acrylic latex powder, 1-3 parts of thickener, and 250-300 parts of water. After the lightweight filler is poured for 28 days, a silane hybrid organic silicon waterproof coating is impregnated on the surface of the lightweight filler concrete. This method uses cement, lithium slag, water, water reducing agent, styrene acrylic latex powder, alkali-resistant glass fiber, fluorosilicone acrylate emulsion waterproofing agent, etc. to prepare lightweight filler, and impregnates the surface of the lightweight filler with silane hybrid silicone waterproof coating. Compared with ordinary lightweight fillers, the lightweight filler has higher strength, greatly reduced water absorption and sedimentation rate, and significantly enhanced durability. It can be used as filler on bridge arches to solve the problems of high water absorption, severe sedimentation and poor durability of ordinary lightweight fillers.

[0014] The main disadvantage of this structure is that the lightweight fill roadbed used in this structure may be affected in harsh climate conditions, especially in rainy and snowy weather, extreme low temperatures and repeated freeze-thaw cycles. Under these conditions, the integrity of the roadbed structure and function may be destroyed, resulting in cracks, settlement or other roadbed diseases. Especially in winter, freeze-thaw cycles may cause microscopic damage to the lightweight fill structure, which in turn affects its macroscopic performance. Summary of the invention

[0015] The purpose of the present invention is to propose an earthquake-resistant assembled railway subgrade surface structure to meet the basic functional requirements of the existing assembled railway subgrade, such as the complex structure, cumbersome connection forms, and weak ability of the subgrade to quickly open under extreme disasters, so as to improve the on-site construction efficiency, the toughness of the railway subgrade engineering, the overall stability and durability of the subgrade structure, and reduce the occurrence of railway subgrade diseases. The hollow glass microsphere material is added to the conventional foam lightweight soil because the hollow glass microsphere material is evenly distributed in the lightweight filler, which can effectively absorb and disperse these vibration waves, thereby reducing the impact on the railway subgrade, extending the service life of the subgrade, and providing a smoother riding experience for train passengers. In addition, the waterproof layer is changed from the traditional asphalt concrete layer to a new asphalt graded gravel sealing layer. This structural layer can not only serve as a waterproof layer for the earthquake-resistant assembled subgrade, but also as a reinforcement layer, which serves the purpose of water isolation, improving the stress of the subgrade, and reducing shock and noise.

[0016] The present invention discloses a construction method of an assembled railway bed surface structure, which is characterized by comprising the following steps:

[0017] Step 1: Level the foundation, lay the roadbed below the base bed on top of the foundation, and lay the base bed bottom layer on top of the roadbed below the base bed;

[0018] Step 2: prefabricate the main foundation block of the base bed surface layer, the left slope protection triangular foundation block, and the right slope protection triangular foundation block in the factory; the main foundation block of the base bed surface layer, the left slope protection triangular foundation block, and the right slope protection triangular foundation block are all foam lightweight materials, and the foam lightweight materials are composed of silicate cement, fly ash, foaming agent, tap water, and hollow glass microsphere materials;

[0019] Step 3: First lay the main foundation blocks of the base surface layer on the base bottom layer, and after the laying is completed, start to assemble the left slope protection triangular foundation blocks and the right slope protection triangular foundation blocks;

[0020] Step 4: Lay a certain thickness of asphalt-graded gravel above the main foundation block of the base surface and between the left and right slope protection triangular foundation blocks as a waterproof layer and reinforcement layer for the seismic-resistant prefabricated roadbed base.

[0021] The present invention also discloses an earthquake-resistant assembled railway bed surface structure, which is applied to the above-mentioned construction method and is characterized in that it includes a foundation, a roadbed structure below the bed, a bottom layer structure of the bed, a left slope protection triangular base block, a right slope protection triangular base block, a main base block of the bed surface, and a waterproof layer; the roadbed structure below the bed is laid above the foundation, the bottom layer structure of the bed is laid above the roadbed structure below the bed, the main base block of the assembled railway bed surface is assembled above the bottom layer structure of the bed, the left slope protection triangular base block and the right slope protection triangular base block are assembled on the left and right sides of the main base block of the assembled railway bed surface, and the main base block and the slope protection base block have a height difference; a waterproof layer is provided above the earthquake-resistant assembled railway bed.

[0022] The present invention also discloses a railway roadbed, including a railway subgrade surface structure, which is characterized in that the structure adopts the above-mentioned earthquake-resistant assembled railway subgrade surface structure.

[0023] The invention also discloses a railway roadbed, including a railway subgrade surface structure, which is characterized in that the structure is designed by adopting the construction method of the above-mentioned assembled railway subgrade surface structure.

[0024] Beneficial Effects

[0025] 1. Improve construction efficiency

[0026] The cube main base block of the surface layer of the assembled railway subgrade and the triangular base blocks on the left and right sides of the slope protection are connected as a whole by simple mortise and tenon connections and direct prefabrication and assembly, avoiding the drawbacks of complicated connection methods such as on-site cast-in-place reinforced concrete connections and the presence of various limiting structures in concave and convex grooves in traditional assembled structures, thereby quickly improving on-site construction efficiency.

[0027] 2. Strong engineering resilience

[0028] The surface structure of the prefabricated railway subgrade is simple in form and easy to connect. It has a high level of assembly technology, can resist earthquakes and quickly clear damaged roadbeds after earthquakes, and is also suitable for construction in a variety of extreme areas.

[0029] 3. Improve stability

[0030] The main blocks of the surface of the assembled railway subgrade contain hollow glass beads, which is conducive to increasing the stability of the blocks after being assembled as a whole. This stability is crucial for high-speed railway subgrades, especially when subjected to long-term vibration and impact from high-speed trains, to ensure the stability, smoothness and reliability of the track structure and the smooth operation of the train.

[0031] 4. Enhanced durability

[0032] The main base blocks of the surface layer of the prefabricated railway subgrade contain hollow glass microspheres, which have the characteristics of chemical corrosion resistance and wear resistance, making the lightweight filler mixed with this material have better long-term durability, which is beneficial to extend the service life of the railway subgrade.

[0033] 5. Reduce the occurrence of diseases

[0034] The surface of the prefabricated railway subgrade is provided with an asphalt graded crushed stone layer as a waterproof layer and a strengthening layer, which plays a role in water isolation, improving the stress of the subgrade, and reducing vibration and noise. At the same time, it can also reduce the traditional waterproof sealing layer (full-section asphalt concrete sealing layer) which is prone to cracking and water seepage, causing frost heave, slurry and other diseases, and reduce operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a flow chart of the construction method of the assembled railway bed surface structure. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. The examples given are only for illustrating the present invention, not for limiting the scope of the present invention. The structural blocks can be customized and combined according to different railway subgrade requirements. According to the characteristics of lightweight soil materials, the following specific implementation cases are only described based on general railway subgrade construction requirements.

[0037] Example 1

[0038] The present invention discloses an earthquake-resistant assembled railway bed surface structure, comprising a foundation, a roadbed structure below the bed, a bed bottom structure, a left slope protection triangular base block, a right slope protection triangular base block, a bed surface main body base block, and a waterproof layer, and is characterized by:

[0039] The subgrade structure below the subgrade is laid on the foundation, the subgrade bottom structure is laid on the subgrade structure below the subgrade, the main foundation block of the surface layer of the assembled railway subgrade is assembled above the subgrade bottom structure, the left slope protection triangular foundation block and the right slope protection triangular foundation block are assembled on the left and right of the main foundation block of the surface layer of the assembled railway subgrade, and the height difference between the main foundation block and the slope protection foundation block is 6 cm. A waterproof layer is provided above the seismic-resistant assembled railway subgrade to prevent the surface layer foundation block of the assembled subgrade from being eroded by rainwater;

[0040] The waterproof layer is a new type of asphalt graded crushed stone sealing layer, which can be used as a reinforcement layer of the surface of the assembled railway subgrade, and has the functions of waterproofing and isolation. The main foundation block of the surface of the assembled railway subgrade, the left slope protection triangular foundation block and the right slope protection triangular foundation block are respectively composed of a combination of a cube configuration foundation block and a triangular structure foundation block. The main foundation block and the slope protection foundation block of the seismic assembled subgrade surface are relatively simple in structure, and can also be all paved with trapezoidal structure foundation blocks as the surface structure of the assembled railway subgrade;

[0041] The earthquake-resistant main foundation block and the slope protection foundation block are prefabricated with lightweight soil materials with light weight, high strength, green environmental protection, good stability and durability, so as to ensure that the surface layer of the subgrade produces a small post-construction settlement after the railway subgrade construction is completed and the overall stability of the subgrade structure;

[0042] The main surface base blocks and slope protection of the earthquake-resistant assembled railway subgrade are directly assembled as a whole by single-point mortise and tenon connection, avoiding the drawbacks of the complicated connection methods of traditional assembled structures, quickly improving on-site construction efficiency, and also facilitating the rapid repair of railway subgrades in extreme disasters and special geological and climatic environments.

[0043] Example 2

[0044] The present invention provides a construction method for an assembled railway bed surface structure, comprising the following steps:

[0045] Step 1: Level the foundation in advance, lay the roadbed below the base bed on top of the foundation, and lay the base bed bottom layer on top of the roadbed below the base bed;

[0046] Step 2: prefabricate the main foundation block of the subgrade surface layer, the left slope protection triangular foundation block, and the right slope protection triangular foundation block in advance in the factory. The main foundation block of the subgrade surface layer, the left slope protection triangular foundation block, and the right slope protection triangular foundation block are all foam lightweight materials, and the foam lightweight materials are composed of silicate cement, fly ash, foaming agent, tap water, and hollow glass microsphere materials;

[0047] (1) The design method of foam lightweight materials is as follows:

[0048] 1) Raw materials and ratio design

[0049] Raw materials include silicate cement, fly ash, foaming agent, tap water, hollow glass microspheres

[0050] The proportion of foam lightweight materials meets the following formula:

[0051]

[0052] m c +m f +m w +m p +m z =ρ (2)

[0053] m c —Amount of cement used per cubic meter of foam lightweight soil, in kg; ρ c - cement density;

[0054] m f —Amount of fly ash used per cubic meter of foamed lightweight soil, in kg; ρ f —Fly ash density;

[0055] m w —Water consumption per cubic meter of foamed lightweight soil (excluding 400 kg of water used to prepare the foam), in kg; ρ w — water density;

[0056] m p —Amount of foam (prepared by foaming agent and water) per cubic meter of foam lightweight soil, in kg; ρ p - density of foam (made from a blowing agent and water);

[0057] m z —Amount of hollow glass microspheres per cubic meter of foam lightweight soil, in kg; ρ z —Density of hollow glass beads;

[0058] ρ—Design wet density of foam lightweight material.

[0059] 2) Wet density design

[0060] The foam lightweight material is designed with a wet density of 700kg / m 3 In the composition of the foam lightweight material, the amounts of silicate cement, fly ash and tap water are fixed at 305kg, 55kg and 600kg respectively, and only the amounts of foam (made of foaming agent and tap water) and hollow glass microspheres are changed. The density and amount of each material are shown in Table 1.

[0061] Table 1 Density and dosage of each material

[0062]

[0063] The unconfined compressive strength of the foamed lightweight materials prepared with dosage 1, dosage 2, and dosage 3 was tested for 1 day, 3 days, 7 days, 14 days, and 28 days, respectively, and the results are shown in Table 2. It can be seen from Table 2 that changing the dosage of foam and hollow glass microspheres has a more obvious effect on the foamed lightweight materials. In general, when the dosage of foam is 22kg and the dosage of hollow glass microspheres is 120kg, the foamed lightweight material has the best compression effect. Therefore, 305kg of silicate cement, 55kg of fly ash, 600kg of tap water, 22kg of foam (prepared by a mass ratio of 1:40 for foaming agent and water), and 120kg of hollow glass microspheres were finally selected to prepare the foamed lightweight material.

[0064] Table 2 Comparison of unconfined compressive strength of foam lightweight materials under different dosage groups

[0065]

[0066] (2) The preparation process of the main base block of the base surface layer, the left slope protection triangular base block, and the right slope protection triangular base block is as follows (taking the dosage 2 in Table 1 as an example):

[0067] The foaming agent and water are mixed in a mass ratio of 1:40 (10 kg foaming agent, 400 kg tap water) and then loaded into a liquid storage tank for dilution. The air compressor is used to pressurize the mixture to 0.5 MPa until the density reaches 50 kg / m 3 of bubbles;

[0068] 305kg of cement, 55kg of fly ash and 200kg of tap water are placed in a stirring pot and stirred for 2 minutes to fully stir into a uniform slurry; 22kg of foam made of a foaming agent and water is added to the uniform slurry of cement, fly ash and tap water, and stirred in a stirring pot for 3-5 minutes, and finally 120kg of hollow glass microspheres of 15-85μm are added and stirred evenly for 5 minutes; the wet density of the foamed lightweight soil slurry after stirring is measured, and the stirring can be stopped when the measured value reaches the designed wet density error range (±5%);

[0069] Pour the foamed lightweight soil slurry into the mold for making the base block and vibrate it slightly. Cover the surface of the cast base block with plastic wrap and seal it. Transfer it to the curing room and control the temperature at 20℃±2℃. Demould after 48 hours and finally cure it naturally in the curing room.

[0070] Step 3: First lay the main foundation blocks of the base surface layer on the base bottom layer, and after the laying is completed, start to assemble the left slope protection triangular foundation blocks and the right slope protection triangular foundation blocks;

[0071] Step 4: Lay 6 cm thick asphalt graded gravel on the vacant parts of the main foundation block on the surface of the base bed and the left and right slope protection triangular foundation blocks as a waterproof layer and reinforcement layer for the seismic prefabricated roadbed base bed, which serves the purpose of water isolation, improving the stress of the base bed, and reducing shock and noise.

[0072] Example 3

[0073] The comparison of the advantages and applicable scenarios of conventional high-speed railway subgrades and lightweight seismic-resistant prefabricated railway subgrade structures is shown in Table 3. It can be seen intuitively from Table 3 that due to its symmetrical geometric shape, the cube base block can provide uniform contact surface and force conditions in all directions. When encountering uneven loads, such as near-fault earthquakes, it can more effectively disperse and alleviate the concentration of force, thereby reducing deformation and damage to the foundation. In addition, the overall stiffness of the foundation of the cube base block is relatively large, providing more solid support for projects that require high stability, such as high-speed railways. Therefore, the cube base block subgrade can maximize the stability, economy and construction efficiency of the project according to the specific needs and environmental conditions of the project.

[0074] Table 3 Advantages of base block structure and applicable scenarios

[0075]

[0076] Example 4

[0077] The mechanical properties of conventional high-speed railway subgrade and lightweight seismic resistant prefabricated railway subgrade under gravity and equivalent uniformly distributed load are shown in Table 4. It can be seen that the change of the subgrade structure has a great influence on the maximum vertical stress and maximum vertical displacement. The cube foundation block is 68.6% smaller than the conventional subgrade. This is because the prefabricated subgrade is composed of integrally cast and high-strength foundation blocks, and the overall structural performance is better. Compared with the conventional subgrade compacted by graded fillers, it has stronger deformation resistance.

[0078] Table 24 Comparison of maximum vertical stress and displacement

[0079]

[0080] The purpose of the present invention is to propose an earthquake-resistant assembled railway subgrade surface structure to meet the basic functional requirements of the existing assembled railway subgrade, such as the complex structure, cumbersome connection forms, and weak ability of the subgrade to quickly open under extreme disasters, so as to improve the on-site construction efficiency, the toughness of the railway subgrade engineering, the overall stability and durability of the subgrade structure, and reduce the occurrence of railway subgrade diseases. The hollow glass microsphere material is added to the conventional foam lightweight soil because the hollow glass microsphere material is evenly distributed in the lightweight filler, which can effectively absorb and disperse these vibration waves, thereby reducing the impact on the railway subgrade, extending the service life of the subgrade, and providing a smoother riding experience for train passengers. In addition, the waterproof layer is changed from the traditional asphalt concrete layer to a new asphalt graded gravel sealing layer. This structural layer can not only serve as a waterproof layer for the earthquake-resistant assembled subgrade, but also as a reinforcement layer, which serves the purpose of water isolation, improving the stress of the subgrade, and reducing shock and noise.

[0081] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A construction method for an assembled railway bed surface structure, characterized in that: The steps include: Step 1: Level the foundation, lay the roadbed below the base bed on top of the foundation, and lay the base bed bottom layer on top of the roadbed below the base bed; Step 2: prefabricate the main foundation block of the base bed surface layer, the left slope protection triangular foundation block, and the right slope protection triangular foundation block in the factory; the main foundation block of the base bed surface layer, the left slope protection triangular foundation block, and the right slope protection triangular foundation block are all foam lightweight materials, and the foam lightweight materials are composed of silicate cement, fly ash, foaming agent, tap water, and hollow glass microsphere materials; Step 3: First lay the main foundation blocks of the base surface layer on the base bottom layer, and after the laying is completed, start to assemble the left slope protection triangular foundation blocks and the right slope protection triangular foundation blocks; Step 4: Lay a certain thickness of asphalt-graded gravel above the main foundation block of the base surface and between the left and right slope protection triangular foundation blocks as a waterproof layer and reinforcement layer for the seismic-resistant prefabricated roadbed base.

2. The construction method of a prefabricated railway bed surface structure according to claim 1 is characterized by: The proportion of foam lightweight materials meets the following formula: m c +m f +m w +m p +m z =ρ (2) m c —Amount of cement used per cubic meter of foamed lightweight soil, in kg; ρ c - cement density; m f —Amount of fly ash used per cubic meter of foamed lightweight soil, in kg; ρ f —Fly ash density; m w —The amount of water used per cubic meter of foamed lightweight soil, excluding the amount of water used to prepare the foam, in kg; ρ w — water density; m p —The amount of foam per cubic meter of foamed lightweight soil, prepared by foaming agent and water, in kg; ρ p —Foam density, prepared by foaming agent and water, 50kg / m 3 ; m z —Amount of hollow glass microspheres per cubic meter of foam lightweight soil, in kg; ρ z —Density of hollow glass beads; ρ—Design wet density of foam lightweight material.

3. The construction method of a prefabricated railway bed surface structure according to claim 2 is characterized by: The designed wet density of the main foundation block of the base surface layer, the left slope protection triangular foundation block, and the right slope protection triangular foundation block is 700kg / m 3 The amount of silicate cement used is 305kg, and its density is 3050kg / m 3 The fly ash dosage is 55kg, and its density is 2750kg / m 3 , foaming agent 10kg, its density is 950kg / m 3 The total amount of tap water is 600kg, and its density is 1000kg / m 3 The amount of hollow glass microspheres with a diameter of 15 to 85 μm is 120 kg, and its density is 500 kg / m 3 .

4. The construction method of the assembled railway bed surface structure according to claim 1 is characterized by: The preparation process of the base bed surface main base block, the left slope protection triangular base block, and the right slope protection triangular base block is as follows: The foaming agent and water are mixed in a mass ratio of 1:40, loaded into a liquid storage tank for dilution, and pressurized by an air compressor until the generated density reaches 50kg / m 3 of bubbles; Put a certain amount of cement, fly ash and tap water into a mixing pot and stir them thoroughly to form a uniform slurry; then add foam made of foaming agent and water to the uniform slurry formed by mixing cement, fly ash and tap water, stir in a mixing pot, and finally add hollow glass micro beads and stir evenly; measure the wet density of the foamed lightweight soil slurry after mixing evenly, and stop stirring when the measured value reaches the designed wet density error range of ±5%; Pour the foamed lightweight soil slurry into the mold for making the base block and vibrate it slightly. Cover the surface of the cast base block with plastic wrap and seal it. Transfer it to the curing room and control the temperature at 20℃±2℃. Demould after 48 hours and finally cure it naturally in the curing room.

5. The construction method of the assembled railway bed surface structure according to claim 4 is characterized by: Mix 10kg of foaming agent and 400kg of tap water and put them into the liquid storage tank for dilution. Pressurize to 0.5Mpa by air compressor until the density reaches 50kg / m 3 of bubbles; Put 305kg of cement, 55kg of fly ash and 200kg of tap water into a mixing pot and stir for 2 minutes to fully stir into a uniform slurry; then add 22kg of foam made of foaming agent and water into the uniform slurry made of cement, fly ash and tap water, stir in a mixing pot for 3-5 minutes, and finally add 120kg of 15-85μm hollow glass microspheres and stir evenly for 5 minutes.

6. An earthquake-resistant assembled railway bed surface structure, which is applied to the construction method of claim 1, and is characterized by: It includes a foundation, a roadbed structure below the base bed, a base bed bottom structure, a left slope protection triangular foundation block, a right slope protection triangular foundation block, a base bed surface main foundation block, and a waterproof layer; the roadbed structure below the base bed is laid above the foundation, the base bed bottom structure is laid above the roadbed structure below the base bed, the prefabricated railway base bed surface main foundation block is assembled above the base bed bottom structure, the left slope protection triangular foundation block and the right slope protection triangular foundation block are assembled on the left and right sides of the prefabricated railway base bed surface main foundation block, and there is a height difference between the main foundation block and the slope protection foundation block; a waterproof layer is provided above the seismic-resistant prefabricated railway roadbed.

7. The seismic-resistant assembled railway bed surface structure according to claim 6 is characterized by: The waterproof layer is a full-section sealing layer of asphalt-graded crushed stone, which is composed of asphalt, aggregate, limestone powder, and aggregate interface enhancer for asphalt concrete. It serves as a reinforcement layer for the surface of the prefabricated base bed and has both waterproof and isolation functions. The main base block of the base bed surface, the left slope protection triangular base block, and the right slope protection triangular base block are respectively composed of a combination of a cube configuration base block and a triangular structure base block. The main base block of the base bed surface and the slope protection are directly assembled as a whole by single-point mortise and tenon connection.

8. The seismic-resistant assembled railway bed surface structure according to claim 7 is characterized by: The asphalt accounts for 5.2% of the total mass of the waterproof layer, the aggregate accounts for 86.5% of the total mass of the waterproof layer, the limestone powder accounts for 7.5% of the total mass of the waterproof layer, and the aggregate interface enhancer for asphalt concrete accounts for 0.8% of the total mass of the waterproof layer.

9. A railway roadbed, comprising a railway bed surface structure, characterized by: The structure adopts the earthquake-resistant assembled railway bed surface structure described in any one of claims 6-8.

10. A railway roadbed, comprising a railway subgrade surface structure, characterized by: The structure is designed using the construction method of the assembled railway bed surface structure described in any one of claims 1-5.

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