Subgrade frozen soil protection structure

Abstract

The utility model relates to the technical field of frozen soil protection discloses sub -frozen soil protection structure of roadbed, the lower part of foundation has frozen soil layer, the both sides of roadbed have side slope respectively, the side slope is covered with the breathable refrigeration layer, the breathable refrigeration layer is covered with sunshade, is equipped with the air hole in the sunshade, the air hole inside and outside penetrates the sunshade. Covering the breathable refrigeration layer on the side slope, the breathable refrigeration layer is favorable to the heat dissipation of roadbed in cold season, the air hole in the sunshade can avoid its influence to the refrigeration effect of breathable refrigeration layer, the sunshade can block the sunlight and reduce the solar radiation heat into roadbed and foundation, the sunshade can also block and prevent rainwater, wind sand from passing through, avoid the frozen soil layer degradation due to rainwater carrying heat and infiltrating roadbed and foundation, avoid the weathering of breathable refrigeration layer, the sand dust blockage and affect its durability and refrigeration effect. Therefore, can realize the better protection to frozen soil layer, and the protection effect is better.

Description

Technical Field

[0001] This utility model patent relates to the technical field of permafrost protection, specifically to permafrost protection structures under roadbeds. Background Technology

[0002] China's permafrost is mainly distributed on the Qinghai-Tibet Plateau, covering an area of ​​approximately 1.15 × 10⁶ km². On the Qinghai-Tibet Plateau, the Qinghai-Tibet Engineering Corridor contains major projects such as railways, highways, oil pipelines, communication optical cables, and power grids, traversing approximately 700 km of permafrost area.

[0003] Currently, climate warming is causing permafrost temperatures to rise, and coupled with the impact of engineering activities, some permafrost is in a state of degradation. Permafrost degradation has a particularly significant impact on railway and highway subgrades, and permafrost degradation and the resulting thaw settlement are the main problems in subgrade engineering in permafrost regions.

[0004] Surveys show that the main subsidence-related diseases on the Qinghai-Tibet Highway are uneven settlement, cracking, and frost heave, accounting for over 75% of the total disease rate. Protecting permafrost is crucial to the success of both new roadbed construction and the maintenance of existing roadbeds; therefore, researching permafrost protection measures is of great significance.

[0005] In existing technologies, there are many measures to protect the frozen soil under the roadbed, which can be summarized into two main categories: The first category is to prevent heat from entering the roadbed and foundation, mainly through shading, heat insulation, and reflection; the second category is to promote "cold in and heat out", which promotes the entry of cold into the foundation and the discharge of heat from the foundation through natural air convection or artificial means, so as to increase the cold storage capacity of the foundation. Specific engineering measures include: dry-laid rubble (crushed stone) slope protection, block stone base roadbed, dry-laid rubble (crushed stone) slope protection + block stone base roadbed, sunshade slope, etc.

[0006] Sunshade panels belong to the first category of engineering measures. They are placed on the side slopes, with a 30-50 cm gap typically left at the bottom as an airflow channel. Sunshade panels can be made of metal sheets or photovoltaic modules, etc. According to test and monitoring results, sunshade panels have a significant protective effect on permafrost.

[0007] The riprap subgrade belongs to the second category of engineering measures. It involves first filling the foundation with a layer of riprap, then filling with subgrade soil. The riprap layer contains numerous interconnected pores, creating an air-cooled structure. During the warm season, hot air rises and stagnates, forming an insulating layer; during the cold season, cold air infiltrates, and the internal air is in a state of thermal convection. This utilizes the density difference between hot and cold air to trigger heat shielding and cold exchange.

[0008] The laying width of dry-laid rubble (crushed stone) slope protection on the sunny side is generally about 1.6m. Dry-laid rubble (crushed stone) slope protection can block the solar radiation heat from entering the roadbed and can also dissipate heat from the roadbed in the cold season. It has the functions of both Class I and Class II engineering measures and has a good protective effect on frozen soil.

[0009] Engineering measures such as riprap subgrade, dry-laid rubble (crushed stone) slope protection, and dry-laid rubble (crushed stone) slope protection + riprap subgrade have been widely used in railway and highway subgrade engineering in the Qinghai-Tibet Plateau region. Engineering practice shows that these measures have good protective effects on permafrost. However, some problems have also been exposed in engineering practice, as follows: 1) Durability issues: For dry-laid rubble (crushed stone) slope protection and block stone base roadbed, the exposed stones are easily weathered due to the harsh environment of the plateau. Affected by wind and sand, the gaps between the stones are easily blocked by sand and dust. The filling of gaps caused by wind and sand and stone weathering will affect air convection, weaken the cooling capacity of the block stone (crushed stone) structure, and even cause it to fail. 2) Water and heat erosion problem; Under the warm and humid climate conditions of the Qinghai-Tibet Plateau, the increase in rainfall has a significant impact on the water and heat changes of permafrost. For engineering measures such as dry-laid rubble (crushed stone) slope protection, block stone base roadbed, and sunshade, rainwater seepage into the side slope and foundation has not been prevented. Rainwater carrying heat seeps in, which may lead to the degradation of permafrost. 3) Dry-laid rubble (crushed stone) slope protection and block stone base roadbed require a large amount of stone, and the mining and transportation of stone may have a significant impact on the environment. 4) Regarding the sunshade measures, the main considerations were sunshade, heat insulation, and reflection, but the heat dissipation and cooling of the roadbed during the cold season were not taken into account. Utility Model Content

[0010] The purpose of this invention is to provide a structure for protecting frozen soil under roadbeds, aiming to solve the problem of poor protection effect of frozen soil under roadbeds in the existing technology.

[0011] This utility model is implemented as follows: a roadbed-frozen soil protection structure includes a roadbed arranged on a foundation, with a frozen soil layer below the foundation, and inclined side slopes on both sides of the roadbed. A breathable cooling layer is covered on the side slopes, and a sunshade is covered on the breathable cooling layer to restrict the passage of rainwater and windblown sand. The sunshade has ventilation holes that penetrate through the sunshade.

[0012] Furthermore, the breathable cooling layer is permeated with breathable gaps, which penetrate the breathable cooling layer.

[0013] Furthermore, the breathable cooling layer is formed by the accumulation of slabs or gravel, and the breathable gaps are formed between adjacent slabs or gravel.

[0014] Furthermore, the breathable cooling layer is laid along the inclined direction of the side slope.

[0015] Furthermore, the sunshade is laid along the inclined direction of the side slope.

[0016] Furthermore, the sunshade is provided with a plurality of ventilation holes, which are arranged along the inclined direction of the side slope.

[0017] Furthermore, the sunshade includes a middle portion, in which the ventilation holes are formed, and a support structure is provided on the outer periphery of the middle portion. The support structure abuts against the breathable cooling layer, and there is a breathable gap between the middle portion and the breathable cooling layer.

[0018] Furthermore, a plurality of sunshades are laid on the breathable cooling layer, and the outer periphery of the sunshades has an outer peripheral sidewall, with the outer peripheral sidewalls of adjacent sunshades abutting each other.

[0019] Furthermore, the front of the sunshade is provided with a nano-reflective heat-insulating coating.

[0020] Compared with existing technologies, the permafrost protection structure provided by this utility model covers the side slope with a breathable cooling layer. The breathable cooling layer helps the roadbed dissipate heat during the cold season. The sunshade has ventilation holes, which can prevent it from affecting the cooling effect of the breathable cooling layer. The sunshade can block direct sunlight, thereby reducing the transfer of solar radiation heat to the roadbed and foundation. The sunshade can also prevent rainwater and windblown sand from passing through, avoiding the degradation of permafrost caused by rainwater carrying heat seeping into the roadbed. It also prevents the breathable cooling layer from being weathered or blocked by sand and dust, thus affecting its durability and cooling effect. Therefore, it can achieve better protection of the permafrost layer and has a better protection effect. Attached Figure Description

[0021] Figure 1 This is a cross-sectional schematic diagram of the roadbed frost protection structure provided by this utility model; Figure 2 This is a front view of the sunshade provided by this utility model; Figure 3 This is a side view of the sunshade provided by this utility model; Figure 4 This is a top view of the sunshade provided by this utility model; Figure 5 This is a cross-sectional view of the sunshade provided by this utility model along the AA direction; Figure 6 This is a schematic diagram showing the tilt angle design of the ventilation holes of the sunshade provided by this utility model. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model 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 merely illustrative of the present utility model and are not intended to limit the present utility model.

[0023] The implementation of this utility model will be described in detail below with reference to specific embodiments.

[0024] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] Reference Figure 1-6 The image shown is a preferred embodiment of the present invention.

[0026] The roadbed frost protection structure includes a roadbed 100 arranged on a foundation 200, a frost layer 300 below the foundation 200, and sloping side slopes 101 on both sides of the roadbed 100. A breathable cooling layer 400 is covered on the sloping side slopes 101, and a sunshade 500 is covered on the breathable cooling layer 400 to restrict the passage of rainwater and wind and sand. The sunshade 500 has ventilation holes 502, which penetrate the sunshade 500 inside and out. In this way, the air inside the breathable cooling layer 400 can communicate with the outside through the ventilation holes 502.

[0027] The aforementioned permafrost protection structure for the roadbed includes a breathable cooling layer 400 covering the side slope 101. This layer 400 facilitates heat dissipation from the roadbed 100 during the cold season. The sunshade 500 has ventilation holes to prevent it from affecting the cooling effect of the breathable cooling layer 400. The sunshade 500 blocks direct sunlight, reducing the transfer of solar radiation heat to the roadbed 100 and foundation 200. It also prevents rainwater and windblown sand from penetrating the roadbed 100 and foundation 200, thus preventing the permafrost layer 300 from degrading due to heat-carrying rainwater seeping into them. Furthermore, it prevents the breathable cooling layer 400 from weathering or becoming clogged by sand and dust, thus maintaining its durability and cooling effect. Therefore, it provides better protection for the permafrost layer 300 with superior protection.

[0028] The subgrade frost protection structure of this embodiment has a wide range of applications, and is widely applicable to new and existing subgrades of railways and highways. It is easy to construct and has low engineering costs throughout its entire life cycle.

[0029] In this embodiment, the breathable cooling layer 400 is permeated with breathable gaps that penetrate the entire layer, forming an air-cooled structure. During the warm season, hot air rises and stagnates, forming an insulation layer. During the cold season, cold air infiltrates, and the internal air is in a state of thermal convection. This utilizes the density difference effect of hot and cold air to trigger heat shielding and cold exchange, promoting the entry of cold energy into the roadbed 100 and foundation 200 while simultaneously expelling heat from the roadbed 100 and foundation 200, thereby increasing the cold storage capacity of the foundation 200 and thus protecting the permafrost layer 300.

[0030] In this embodiment, the breathable cooling layer 400 is formed by the accumulation of slabs or gravel, and the breathable gaps are formed between adjacent slabs or gravel. Alternatively, the breathable cooling layer 400 may also be composed of other materials.

[0031] In this embodiment, the breathable cooling layer 400 is laid along the inclined direction of the side slope 101, thus ensuring that the entire side slope 101 is completely covered by the breathable cooling layer 400, so as to achieve overall protection of the side of the roadbed 100.

[0032] In this embodiment, the sunshade 500 is laid along the inclined direction of the side slope 101, so as to ensure that the sunshade 500 can completely cover the breathable cooling layer 400, and the sunshade 500 provides full coverage protection for the breathable cooling layer 400.

[0033] In this embodiment, the vents 502 are arranged at an upward angle along the direction from the outside to the inside of the sunshade 500. This prevents sunlight from passing through the vents 502 and directly hitting the breathable cooling layer 400. Since the vents 502 are arranged at an upward angle, their angle design must be sufficient to limit horizontally incident sunlight from passing through the vents 502. As the sun rises higher, the angle of sunlight increases, making it even more difficult for it to pass through the vents 502. Furthermore, the vents 502 can maintain their ventilation function and do not affect the heat dissipation of the breathable cooling layer 400 to the roadbed 100.

[0034] Of course, the tilt angle of the vent 502 can be determined according to the actual situation and adjusted accordingly based on the tilt angle of the side slope 101.

[0035] As attached Figure 6 As shown, to limit horizontally incident sunlight from passing through the vent 502, the tilt angle of the vent 502 must satisfy the following formula:

[0036] in, This indicates the tilt angle of the vent 502. This indicates the thickness of the middle portion 504 of the sun visor 500. This indicates the angle between the slope surface of the roadbed and the ground. This indicates the width of the vent 502.

[0037] In this embodiment, the sunshade 500 is formed by concrete pouring, and the concrete surface is coated with anti-corrosion coating, which can resist the erosion of harsh environment and improve the durability of the sunshade 500.

[0038] In this embodiment, the sunshade 500 is provided with a plurality of ventilation holes 502, which are arranged along the inclined direction of the side slope 101, thus forming a louvered arrangement in the sunshade 500. In this embodiment, the sunshade 500 includes a middle portion 504, in which the ventilation holes 502 are formed. A support structure 503 is provided on the outer periphery of the middle portion 504, which abuts against the breathable cooling layer 400. A breathable gap 501 is provided between the middle portion 504 and the breathable cooling layer 400.

[0039] By forming the support structure 503, the sunshade 500 can be supported and fixed on the breathable cooling layer 400. When the sunshade 500 is supported on the breathable cooling layer 400, there is a breathable gap 501 between the middle part 504 and the breathable cooling layer 400, so as to prevent the breathable cooling layer 400 from being densely covered.

[0040] The sunshade 500 is cuboid in shape. The support structure 503 can be two support strips arranged on the left and right sides of the sunshade 500, or two support strips arranged on the top and bottom of the sunshade 500, or the support structure 503 can be four corner supports.

[0041] In this embodiment, a plurality of sunshades 500 are laid on the breathable cooling layer 400. Each sunshade 500 has an outer peripheral sidewall, and the outer peripheral sidewalls of adjacent sunshades 500 abut against each other. Thus, the plurality of sunshades 500 are arranged in an array on the breathable cooling layer 400, with their outer peripheral sidewalls directly abutting against each other. The support portion 503 abuts against and supports the breathable cooling layer 400, which can maintain the tight fit of the plurality of sunshades 500.

[0042] In this embodiment, the front surface of the sunshade 500 is provided with a nano-reflective heat-insulating coating. By applying the nano-reflective heat-insulating coating, the amount of heat absorbed by the sunshade 500 from solar radiation can be reduced. The nano-reflective heat-insulating coating can be a three-in-one nano-reflective heat-insulating coating that combines reflective, radiative, and heat-insulating properties.

[0043] The nano-reflective heat insulation coating has three main functions: 1) Reflecting solar radiation, which can significantly reduce the amount of solar radiation heat entering the sunshade 500; 2) Emitting the heat on the surface of the sunshade 500 outward in the form of infrared long-wave radiation, further achieving cooling; 3) Blocking the heat on the surface of the sunshade 500 from being conducted into the interior of the sunshade 500.

[0044] By applying a nano-reflective heat-insulating coating, although most of the solar radiation is reflected by the coating, a small amount is still absorbed. Since the sunshade 500 is supported only by the support structure 503 on the breathable cooling layer 400, and there is a breathable gap 501 between the middle part 504 and the breathable cooling layer 400, it is in an elevated state with a small contact area, which can further reduce the heat absorbed by the sunshade 500 from being conducted into the breathable cooling layer 400.

[0045] In addition, rainwater falling on the sunshade 500 can be guided by the sunshade 500 to be discharged into the side ditch at the foot of the slope, preventing rainwater carrying heat from seeping into the roadbed 100 and foundation 200 and aggravating permafrost degradation.

[0046] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A frozen soil protection structure under a roadbed, characterized in that, It includes a roadbed laid on a foundation, the foundation having a frozen soil layer below it, and the roadbed having inclined side slopes on both sides. The side slopes are covered with a breathable cooling layer, and the breathable cooling layer is covered with a sunshade to restrict the passage of rainwater and windblown sand. The sunshade has ventilation holes that penetrate through the sunshade.

2. The roadbed frost protection structure as described in claim 1, characterized in that, The breathable cooling layer is permeated with breathable gaps, which penetrate the breathable cooling layer.

3. The roadbed frost protection structure as described in claim 2, characterized in that, The breathable cooling layer is formed by the accumulation of slabs or gravel, and the breathable gaps are formed between adjacent slabs or gravel.

4. The roadbed frost protection structure as described in claim 1, characterized in that, The breathable cooling layer is laid along the sloping direction of the side slope.

5. The roadbed frost protection structure as described in any one of claims 1 to 4, characterized in that, The sunshade panels are laid along the sloping direction of the side slope.

6. The roadbed frost protection structure as described in any one of claims 1 to 4, characterized in that, The sunshade has multiple ventilation holes, which are arranged along the slope direction of the side slope.

7. The roadbed frost protection structure as described in any one of claims 1 to 4, characterized in that, The sunshade includes a middle section, in which the ventilation holes are formed. A support structure is provided on the outer periphery of the middle section, and the support structure abuts against the breathable cooling layer. There is a breathable gap between the middle section and the breathable cooling layer.

8. The roadbed frost protection structure as described in any one of claims 1 to 4, characterized in that, Multiple sunshades are laid on the breathable cooling layer. Each sunshade has an outer peripheral sidewall, and the outer peripheral sidewalls of adjacent sunshades abut against each other.

9. The roadbed frost protection structure as described in any one of claims 1 to 4, characterized in that, The front of the sunshade is provided with a nano-reflective heat-insulating coating.

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