Roadbed anti-freezing and anti-thawing device

Abstract

The utility model relates to the technical field of road construction, in particular to an anti-freezing and anti-thawing device for a roadbed. Comprising a road surface layer, a base layer arranged below the road surface layer and drainage ditches arranged on the two sides of the road surface layer, a salt-containing layer is arranged between the base layer and the road surface layer, a semi-permeable membrane layer is arranged between the salt-containing layer and the road surface layer, a waterproof layer is arranged between the salt-containing layer and the base layer, and a liquid storage tank is arranged on the side face of the salt-containing layer. And the liquid storage tank is connected with the drainage ditch through a channel with a valve. The salt-containing layer in the anti-freezing and anti-thawing device can absorb residual moisture in the roadbed, the moisture content of the roadbed is reduced, the anti-freezing and anti-thawing effect is improved, and meanwhile the high anti-freezing and anti-thawing effect can be kept by adding a salt solution; the salt-containing layer is in a closed state, so that the salt cannot diffuse to the outside, and the environment-friendly effect is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of road construction more particularly, relate to a kind of roadbed freeze-thaw device. BACKGROUND

[0002] Seasonal frozen soil area, simply season frozen area, with the change of season, the temperature of season frozen area fluctuates around freezing point, the surface layer of soil will produce periodic freezing in winter, thawing in summer freeze-thaw phenomenon in seasonal change. Because water will expand after freezing, and the roadbed of road is directly paved on soil layer, soil layer contains a large amount of water, therefore, the road of season frozen area often produces damage in periodic freeze-thaw, and service life decreases sharply. Usually, the main disaster effect and phenomenon produced by freeze-thaw of soil layer are: 1) frost heaving and thaw settlement: soil layer freezing produces volume expansion, thawing makes soil layer soft and produces subsidence, even soil and stone slurry, thereby forming frost heaving and thaw settlement effect. It is the most important disaster effect in seasonal frozen soil area. It often causes road foundation damage deformation, ground subsidence, threatens driving safety, and affects traffic transportation etc. 2) freeze-thaw slide, collapse and freeze-thaw mud flow: freeze-thaw changes the balance state of soil body. When this effect occurs in slope area, slide, collapse can be produced; and when soil layer melts into liquid, mud flow is formed. Freeze-thaw slide, collapse and freeze-thaw mud flow are more common in high altitude area, cause great harm to engineering construction, and even cause personal injury and death. 3) freeze-thaw subsidence: strong freeze-thaw of soil layer makes ground subsidence, thereby causing subsidence. This effect is also common in vast seasonal frozen soil area, and causes a large number of roadbed damage, engineering building damage and other vicious events. Improving the drainage efficiency of road, reducing the downward penetration of water on road surface, and reducing the water content of roadbed can effectively reduce the freeze-thaw damage of roadbed. The common method is to build drainage ditch on both sides of road to drain the rainfall on road surface to drainage ditch in time. But because road surface and roadbed have certain water permeability, after a long time of rainfall penetration, a large amount of water will still penetrate into roadbed soil layer, and cause damage to roadbed under the action of freeze-thaw. Chinese patent 2018116467943 discloses "stable roadbed structure and construction process for preventing freeze-thaw in season frozen area", and the authorization announcement number is CN109680584B. The roadbed structure reduces the melting point of water in salt-doped roadbed layer by setting salt-doped roadbed layer containing inorganic salt admixture, avoids the expansion of ice in roadbed, and further avoids the deformation and damage of road surface. But with the extension of time, the salt-doped roadbed layer of this roadbed structure will absorb water in surrounding soil layer, so that the salt content gradually decreases, and the freeze-thaw prevention effect of roadbed gradually decreases. In addition, with the extension of time, the salt in the salt-doped roadbed layer will diffuse upwards, downwards and to both sides, increase the salt content of soil layer, be not friendly to environment, cause salinization of roadbed slope, and the green plants and turf on slope cannot grow. SUMMARY

[0003] The utility model discloses a kind of environmental friendly, freeze-thawing effect good time long roadbed freeze-thawing prevention devices.

[0004] The utility model discloses a technical scheme for solving technical problems is:

[0005] The utility model discloses a kind of roadbed freeze-thawing prevention devices, including pavement layer, the foundation layer being set in the lower pavement layer, drainage ditch being set in the both sides of pavement layer, the salt-containing layer is arranged between the foundation layer and pavement layer, the semi-permeable membrane layer is arranged between the salt-containing layer and pavement layer, the waterproof layer is arranged between salt-containing layer and foundation layer, the side of salt-containing layer is provided with liquid storage tank, the liquid storage tank is connected between drainage ditch by passage with valve.

[0006] By the scheme, the salt-containing layer in the freeze-thawing prevention device can absorb residual moisture in the roadbed, reduce the moisture content of the roadbed, improve the freeze-thawing prevention effect, and also maintain a high freeze-thawing prevention effect by adding salt solution. The salt-containing layer is in a closed state, and the salt does not diffuse to the outside, which is environmentally friendly.

[0007] Preferably, the salt-containing layer includes fine gravel layer, coarse gravel layer and lower gravel layer arranged in sequence from top to bottom.

[0008] By the scheme, the salt-containing layer with the composite layered structure is stable in structure, conducive to the penetration and flow of water, and can prevent the gravel from piercing the semi-permeable membrane layer and the waterproof layer.

[0009] Preferably, a side slope is arranged between the pavement layer and the drainage ditch, the liquid storage tank is embedded in the side slope, the side wall of the liquid storage tank towards the salt-containing layer is provided with filter holes, and the top end of the liquid storage tank is provided with an openable inspection hole.

[0010] By the scheme, the side slope can improve the drainage efficiency of the pavement layer, the liquid storage tank is blocked on the side of the salt-containing layer to prevent the salt solution from diffusing to the surroundings, and the inspection hole can be used to check the concentration of the salt solution in the liquid storage tank and add salt in time.

[0011] Preferably, the side of the salt-containing layer extends to the side wall of the liquid storage tank, the side of the semi-permeable membrane layer is butt-jointed with the upper end of the liquid storage tank, and the side of the waterproof layer is butt-jointed with the lower end of the liquid storage tank.

[0012] By the scheme, the salt-containing layer has good sealing effect and can minimize the impact on the environment.

[0013] Preferably, the liquid storage tank contains salt solution.

[0014] By the scheme, the concentration of the salt solution can be adjusted in time to change the freeze-thawing prevention effect according to the change of environmental temperature.

[0015] Due to the above structure, the salt-containing layer in the anti-freezing and thawing device can absorb the residual moisture in the roadbed, reduce the water content of the roadbed, improve the anti-freezing and thawing effect, and also improve the anti-freezing and thawing effect by adding salt solution, and reduce the effect; the salt-containing layer is in a closed state, and the salt will not diffuse to the outside, which is environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0017] Figure 1 is a half-section structure schematic diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0018] The following description of at least one exemplary embodiment is, therefore, not to be taken in a limiting sense as the sole exemplary embodiment is merely representative of the general application.

[0019] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, where appropriate, such techniques, methods, and devices can be considered part of the present application.

[0020] In all the examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0021] It should be borne in mind, that, as the use of night letters and designations are optional, the same part can be designated by a different letter or alphabetical designation, and, currently, no special significance should be attached to any designations or drawings.

[0022] As Figure 1 shown, the anti-freezing and thawing device for roadbeds includes a road surface layer 1, a foundation layer 2 arranged below the road surface layer 1, and a drainage ditch 30 arranged on both sides of the road surface layer 1. In addition, a side slope 8 can be arranged between the road surface layer 1 and the drainage ditch 30, so that the position of the drainage ditch 30 is lower than that of the road surface layer 1, and the water of the road surface layer 1 flows quickly to the drainage ditch 30 along the side slope 8 when it rains, reducing the time of rainwater infiltration, improving the drainage efficiency of the road surface layer 1, and reducing the amount of rainwater infiltration.

[0023] A salt-containing layer 3 is provided between the base layer 2 and the road surface layer 1. This salt-containing layer 3 is formed by mixing gravel and inorganic salt admixtures and then laying it. A semi-permeable membrane layer 4 is provided between the salt-containing layer 3 and the road surface layer 1, and a waterproof layer 5 is provided between the salt-containing layer 3 and the base layer 2. In this way, the salt-containing layer 3 is blocked by the semi-permeable membrane layer 4 above and the waterproof layer 5 below, preventing salt from diffusing to the upper and lower sides. A semi-permeable membrane is a thin film that only allows certain smaller molecules and ions to diffuse in and out. Generally, semi-permeable membranes only allow ions and small molecules to pass through, while biological macromolecules cannot freely pass through semi-permeable membranes. This embodiment uses a semi-permeable membrane that allows water molecules to pass through. When it rains, a small amount of rainwater permeates through the road surface layer 1 to the area above the semi-permeable membrane layer 4, forming a freshwater layer above the semi-permeable membrane layer 4. Since the salt content of the salt-containing layer 3 below the semi-permeable membrane layer 4 is greater than that of the freshwater layer, under the action of osmotic pressure, the freshwater passes through the semi-permeable membrane layer 4 into the salt-containing layer 3, increasing the water content of the salt-containing layer 3. The salt-bearing layer 3 can be a single layer or can be, for example, a single layer. Figure 1 The three-layer structure shown in this embodiment includes a salt-containing layer 3 consisting of a fine gravel layer 31, a coarse gravel layer 32, and a lower gravel layer 33 arranged from top to bottom. All three gravel layers contain inorganic salt admixtures. The only difference is that the gravel particles in the middle layer are larger, while the gravel particles in the upper and lower layers are smaller. The coarse gravel layer 32 has larger particles and larger gaps between the particles, which is conducive to the flow of the brine solution. The fine gravel layer 31 and the lower gravel layer 33 have relatively smaller particles, which can provide a smoother bonding surface for the semi-permeable membrane layer 4 and the waterproof layer 5, preventing large gravel particles from piercing the semi-permeable membrane layer 4 or the waterproof layer 5.

[0024] In addition, a storage tank 6 is provided on the side of the salt-bearing layer 3. The storage tank 6 is arranged parallel to the drainage ditch 30, and its inner wall is treated with waterproofing and corrosion resistance. The storage tank 6 and the drainage ditch 30 are connected by a channel with a valve 7. When the valve 7 is closed, the storage tank 6 and the drainage ditch 30 are isolated from each other. When the valve 7 is opened, the storage tank 6 and the drainage ditch 30 are connected. The storage tank 6 contains a salt solution, which can be an aqueous solution of sodium chloride or other inorganic salt solutions. In winter, when the valve 7 is closed, the salt solution in the storage tank 6 permeates into the entire salt-bearing layer 3 under capillary action, increasing the osmotic pressure of the salt-bearing layer 3, absorbing the moisture above the semi-permeable membrane layer 4, reducing the moisture content of the pavement layer 1, and improving the freeze-thaw resistance. On the other hand, the brine in the salt-bearing layer 3 has a lower freezing point and naturally has freeze-thaw resistance. The freezing point of the brine depends on its concentration, and the concentration of the salt solution in the salt-bearing layer 3 and the storage tank 6 can be adjusted according to the local temperature.

[0025] As further improvement of the utility model, the liquid storage tank 6 is embedded in the slope 8, the side wall of the liquid storage tank 6 towards the salt-containing layer 3 is provided with filter holes 61, and the top end of the liquid storage tank 6 is provided with an openable inspection hole 62. The side of the salt-containing layer 3 extends to the side wall of the liquid storage tank 6, the side of the semi-permeable membrane layer 4 is butted with the upper end of the liquid storage tank 6, and the side of the waterproof layer 5 is butted with the lower end of the liquid storage tank 6. When the salt solution in the salt-containing layer 3 flows to the side, it can only pass through the filter holes 61 to enter the liquid storage tank 6, and is blocked upwards by the semi-permeable membrane layer 4 and downwards by the waterproof layer 5, so the salt solution cannot diffuse upwards or downwards.

[0026] The filter holes 61 can block the gravel in the salt-containing layer 3 but allow the salt solution to pass through, so that the water level of the salt solution in the salt-containing layer 3 and the liquid storage tank 6 is basically consistent, and the concentration of the salt solution is also basically consistent. The inspection hole 62 is closed to prevent surface water flowing on the slope 8 from flowing into the liquid storage tank 6, and the water level and concentration of the salt solution in the liquid storage tank 6 can be checked at any time through the inspection hole 62.

[0027] In use, when winter comes, the inspection hole 62 on the liquid storage tank 6 is opened. The water level height and salt content concentration of the salt solution are checked. If the water level is too high, the valve 7 can be opened to discharge part of the salt solution to ensure that the liquid storage tank 6 has sufficient free capacity to accommodate the increased moisture during the whole winter. If it is found that the concentration of the salt solution is low, inorganic salt can be put into the liquid storage tank 6 through the inspection hole 62 to increase the concentration of the salt solution. During winter, the rain and snow moisture on the road surface layer 1 will mostly flow along the slope 8 into the drainage ditch 30, and a small amount of water that penetrates through the road surface layer 1 will combine with the salt solution in the salt-containing layer 3 after meeting the semi-permeable membrane layer 4 under the action of the high osmotic pressure of the salt solution in the salt-containing layer 3, and become part of the salt solution. The excess salt solution will flow along the salt-containing layer 3 to both sides and eventually enter the liquid storage tank 6 for temporary storage. Road maintenance personnel regularly patrol and adjust the water level height and salt content concentration of the salt solution in the liquid storage tank 6.

[0028] Although some specific embodiments of the utility model have been described in detail above through specific embodiments, those skilled in the art should understand that the above examples are only for illustration, and are not intended to limit the protection scope of the utility model. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the utility model. The protection scope of the utility model is defined by the appended claims.

Claims

1. A freezing and thawing resistant device for subgrade, comprising a pavement layer (1), a foundation layer (2) arranged below the pavement layer (1), and a drainage ditch (30) arranged on both sides of the pavement layer (1), characterized in that The base layer (2) is provided with a salt-containing layer (3) between the base layer (2) and the road surface layer (1), the salt-containing layer (3) is provided with a semi-permeable membrane layer (4) between the salt-containing layer (3) and the road surface layer (1), the salt-containing layer (3) is provided with a waterproof layer (5) between the salt-containing layer (3) and the base layer (2), the side of the salt-containing layer (3) is provided with a liquid storage tank (6), and the liquid storage tank (6) is connected with the drainage ditch (30) through a channel with a valve (7).

2. The device for preventing freezing and thawing of roadbed according to claim 1, wherein The salt-containing layer (3) comprises, from top to bottom, a fine gravel layer (31), a coarse gravel layer (32) and a lower gravel layer (33).

3. The device for preventing freeze-thaw of roadbed according to claim 1, wherein The road surface layer (1) is provided with a side slope (8) between the road surface layer (1) and the drainage ditch (30), the liquid storage tank (6) is embedded in the side slope (8), the side wall of the liquid storage tank (6) towards the salt-containing layer (3) is provided with a filter hole (61), and the top end of the liquid storage tank (6) is provided with an openable inspection hole (62).

4. The device for preventing freeze-thaw of roadbed according to claim 3, wherein The side of the salt-containing layer (3) extends to the side wall of the liquid storage tank (6), the side of the semi-permeable membrane layer (4) is connected with the upper end of the liquid storage tank (6), and the side of the waterproof layer (5) is connected with the lower end of the liquid storage tank (6).

5. The device for preventing freeze-thaw of roadbed according to claim 1 or 2, characterized in that, The liquid storage tank (6) contains a salt solution.

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