Composite roadbed structure

Abstract

The invention discloses a composite roadbed structure, and relates to the field of roadbed engineering. Gravel piles penetrate through a frozen soil foundation and an unfrozen soil foundation; the heat exchange pipe sets and the gravel piles are the same in number and are in one-to-one correspondence, the vertical heat exchange pipes and the transverse heat exchange pipes are arranged on the outer sides of the corresponding gravel piles, and the vertical heat exchange pipes communicate with the corresponding transverse heat exchange pipes. The water absorption piece is laid above the gravel pile; and a part of the water absorption part extends into the water pumping pipeline. Therefore, the heat exchange pipe sets and the gravel piles are correspondingly arranged, the temperature of the gravel piles can be actively adjusted through the heat exchange pipe sets, the freezing and thawing cycle phenomenon is reduced, and the risks of cracking and differential settlement of the composite roadbed structure are reduced; the drainage performance of the composite roadbed structure can be remarkably improved, the water accumulation phenomenon of the composite roadbed structure can be reduced, the frost heaving and cracking risks of the composite roadbed structure in a cold region are reduced, and the bearing capacity and stability of the composite roadbed structure can be improved.

Description

Technical Field

[0001] The present invention relates to the field of roadbed engineering, in particular to a composite roadbed structure. Background Art

[0002] In related technologies, in seasonally frozen soil areas, gravel pile composite roadbeds will experience freeze-thaw cycles. The freeze-thaw cycles will cause repeated phase changes in the soil pore water of the roadbed structure, triggering frost heave and thaw settlement, which in turn will lead to cracking and uneven settlement of the road surface. In addition, the drainage capacity of existing roadbed structures is limited, and condensation water from evaporation of water vapor is prone to accumulation, thereby increasing the risk of frost heave and cracking of the roadbed structure and affecting the bearing capacity and stability of the roadbed structure. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a composite roadbed structure that can actively regulate temperature and has strong drainage capacity, effectively reducing the risk of frost heave and cracking of the roadbed structure, and has excellent bearing capacity and stability.

[0004] According to the present invention, the composite roadbed structure includes: a foundation, which includes: an unfrozen soil foundation and a frozen soil foundation, and along the height direction of the composite roadbed structure, the unfrozen soil foundation is located below the frozen soil foundation; a plurality of gravel piles, and the gravel piles are passed through the frozen soil foundation and the unfrozen soil foundation; a plurality of heat exchange tube groups, and the number of the heat exchange tube groups is the same as that of the gravel piles and they correspond one to one, and the heat exchange tube groups include: vertical heat exchange tubes and horizontal heat exchange tubes, and the vertical heat exchange tubes and the horizontal heat exchange tubes are both arranged on the outside of the corresponding gravel piles and the vertical heat exchange tubes are connected to the corresponding horizontal heat exchange tubes, and the adjacent heat exchange tube groups are connected; a water absorption part, and along the height direction of the composite roadbed structure, the water absorption part is laid above the gravel piles; a water pumping pipe, and part of the structure of the water absorption part extends into the water pumping pipe.

[0005] According to the composite roadbed structure of the present invention, by arranging the heat exchange tube group and the gravel piles in correspondence, the temperature of the gravel piles can be actively adjusted by the heat exchange tube group, thereby reducing the freeze-thaw cycle phenomenon and reducing the risk of cracking and uneven settlement of the composite roadbed structure. In addition, by laying the water-absorbing parts above the gravel piles along the height direction of the composite roadbed structure, the drainage performance of the composite roadbed structure can be significantly improved, the water accumulation phenomenon of the composite roadbed structure can be reduced, and the risk of frost heave and cracking of the composite roadbed structure in cold areas can be reduced, which is conducive to improving the bearing capacity and stability of the composite roadbed structure.

[0006] In some examples of the present invention, each group of the heat exchange tube groups has two vertical heat exchange tubes, and the two vertical heat exchange tubes are distributed on both sides of the corresponding gravel pile along the radial direction of the gravel pile. The transverse heat exchange tube is constructed as an arc tube and is wound around the outside of the gravel pile. The transverse heat exchange tube is connected between the corresponding two vertical heat exchange tubes.

[0007] In some examples of the present invention, the composite roadbed structure further includes: a plurality of connecting pipes, wherein in adjacent heat exchange tube groups, the vertical heat exchange tube relatively close to the other heat exchange tube group in one heat exchange tube group is connected to the vertical heat exchange tube relatively close to the other heat exchange tube group in the other heat exchange tube group through the connecting pipes;

[0008] The horizontal heat exchange tube is connected between the bottoms of the corresponding two vertical heat exchange tubes, and the connecting tube is connected between the tops of the corresponding two vertical heat exchange tubes.

[0009] In some examples of the present invention, the composite roadbed structure further includes: a connecting piece, and the vertical heat exchange tubes and the horizontal heat exchange tubes are fixed to the corresponding gravel piles through the connecting piece.

[0010] In some examples of the present invention, the gravel pile includes: a geogrid and gravel, the geogrid is arranged around to form a hollow columnar structure, and the gravel is filled in the geogrid arranged around.

[0011] In some examples of the present invention, the water pumping pipe has an opening, and the water absorbing member is arranged through the opening, so that a part of the structure of the water absorbing member extends into the water pumping pipe.

[0012] In some examples of the present invention, the length of the water absorbing member extending into the water pumping pipe is A, which satisfies the relationship: 12 cm ≤ A ≤ 18 cm.

[0013] In some examples of the present invention, the composite roadbed structure further includes: a thermal insulation component and a waterproof component. Along the height direction of the composite roadbed structure, the thermal insulation component is laid above the water absorbing component, and the waterproof component is laid above the thermal insulation component.

[0014] In some examples of the present invention, the composite roadbed structure further includes: a sand cushion layer, which is laid along the height direction of the composite roadbed structure below the water absorbing component, between the thermal insulation component and the water absorbing component, between the thermal insulation component and the waterproof component, and above the waterproof component.

[0015] In some examples of the present invention, the composite roadbed structure further includes: a fine sand protective layer, and the fine sand protective layer is arranged outside the gravel pile.

[0016] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0018] Figure 1 is a structural schematic diagram of a composite roadbed structure according to an embodiment of the present invention;

[0019] Figure 2 is a partial structural schematic diagram of a composite roadbed structure according to an embodiment of the present invention;

[0020] Figure 3 It is a structural schematic diagram of the water absorbing member and the water pumping pipe according to an embodiment of the present invention.

[0021] Reference numerals:

[0022] Composite roadbed structure 100;

[0023] Foundation 10; unfrozen soil foundation 11; frozen soil foundation 12; gravel piles 13; heat exchange tube group 14; vertical heat exchange tube 141; horizontal heat exchange tube 142; connecting pipe 143; water absorbing part 15; thermal insulation part 16; waterproof part 17; pumping pipe 18; opening 19; connecting part 20; geogrid 21; gravel 22; sand cushion layer 23; fine sand protective layer 24; gravel embankment layer 25; pavement structure layer 26; drainage ditch 27; collecting pipe 28; through shallow trough 29. DETAILED DESCRIPTION

[0024] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0025] Reference below Figure 1-Figure 3 A composite roadbed structure 100 according to an embodiment of the present invention is described.

[0026] like Figure 1-Figure 3 As shown, the composite roadbed structure 100 according to an embodiment of the present invention includes: a foundation 10 , a plurality of gravel piles 13 , a plurality of heat exchange tube groups 14 , a water absorbing member 15 and a water pumping pipe 18 .

[0027] The foundation 10 includes: an unfrozen soil foundation 11 and a frozen soil foundation 12. Along the height direction of the composite roadbed structure 100, the unfrozen soil foundation 11 is located below the frozen soil foundation 12; gravel piles 13 are arranged through the frozen soil foundation 12 and the unfrozen soil foundation 11; the heat exchange pipe group 14 is the same in number as the gravel piles 13 and corresponds one to one, and the heat exchange pipe group 14 includes: a vertical heat exchange pipe 141 and a horizontal heat exchange pipe 142. The vertical heat exchange pipe 141 and the horizontal heat exchange pipe 142 are both arranged outside the corresponding gravel pile 13 and the vertical heat exchange pipe 141 is connected to the corresponding horizontal heat exchange pipe 142, and the adjacent heat exchange pipe groups 14 are connected; along the height direction of the composite roadbed structure 100 (i.e. Figure 1 The water absorbing member 15 is laid above the gravel pile 13 ; a portion of the structure of the water absorbing member 15 extends into the water pumping pipe 18 .

[0028] The foundation 10 includes an unfrozen soil foundation 11 and a frozen soil foundation 12. Figure 1 The unfrozen soil foundation 11 is located below the frozen soil foundation 12. The frozen soil foundation 12 is affected by the low temperature, and the moisture in the soil will freeze into ice, while the unfrozen soil foundation 11 will not freeze all the year round.

[0029] The number of the gravel piles 13 is multiple, and the number of the gravel piles 13 can be but is not limited to six, seven, etc. As some embodiments of the present application, the number of the gravel piles 13 is seven, and the seven gravel piles 13 are arranged along the first direction (i.e. Figure 1 The gravel piles are arranged in an interval manner along the second direction (ie Figure 2 The gravel piles 13 are arranged in the Y direction of the composite roadbed structure 100. Figure 1 Furthermore, the gravel piles 13 can be inserted into the frozen soil foundation 12 and the unfrozen soil foundation 11.

[0030] The number of heat exchange tube groups 14 and gravel piles 13 is the same and they correspond one to one, that is, one heat exchange tube group 14 corresponds to one gravel pile 13. In some embodiments of the present application, the number of gravel piles 13 is seven, and the number of heat exchange tube groups 14 and gravel piles 13 are the same and they correspond one to one.

[0031] The heat exchange tube group 14 includes a vertical heat exchange tube 141 and a horizontal heat exchange tube 142. The vertical heat exchange tube 141 is connected to the horizontal heat exchange tube 142. The vertical heat exchange tube 141 is connected to the horizontal heat exchange tube 142 along the first direction (ie Figure 1 The X direction shown in FIG. 1 is provided on the outside of the corresponding gravel pile 13, and the transverse heat exchange tube 142 is provided along the first direction (ie Figure 1The heat exchange tube groups 14 are arranged outside the corresponding gravel piles 13 in the X direction shown in the figure, and the adjacent heat exchange tube groups 14 are connected. In some embodiments of the present application, the adjacent heat exchange tube groups 14 are connected through connecting pipes 143.

[0032] The heat exchange medium in the vertical heat exchange tube 141 and the horizontal heat exchange tube 142 can be but is not limited to water, ethylene glycol aqueous solution, etc. As some embodiments of the present application, the heat exchange medium in the vertical heat exchange tube 141 and the horizontal heat exchange tube 142 is ethylene glycol aqueous solution.

[0033] Along the height direction of the composite roadbed structure 100 (ie Figure 1 The water-absorbing member 15 is laid above the gravel pile 13. The water-absorbing member 15 can be, but is not limited to, a water-absorbing geotextile, a composite drainage net, etc. As some embodiments of the present application, the water-absorbing member 15 is constructed as a water-absorbing geotextile. The water-absorbing geotextile has good tensile strength (tensile strength ≥ 1500 kN / m) and elongation (elongation ≤ 5%). The water-absorbing member 15 is arranged in this way to withstand the stress transmitted by the gravel pile 13. Moreover, by arranging the water-absorbing member 15, the water in the composite roadbed structure 100 can be absorbed to reduce the water content of the composite roadbed structure 100, thereby reducing the phenomenon of freeze-thaw cycles.

[0034] The number of the water pumping pipes 18 can be, but is not limited to, one, two, three, etc. In some embodiments of the present application, the number of the water pumping pipes 18 is two, and the two water pumping pipes 18 are arranged along the first direction (i.e. Figure 1 The X direction shown in the figure) is distributed on both sides of the water absorbing member 15, and the first direction (i.e. Figure 1 The X direction shown in FIG) and the height direction of the composite roadbed structure 100 (ie Figure 1 Part of the structure of the water absorbing member 15 can be extended into the water pumping pipe 18, so that the water absorbed by the water absorbing member 15 can be pumped out through the water pumping pipe 18 to discharge the water in the water absorbing member 15.

[0035] It should be noted that in seasonally frozen areas, the composite roadbed structure 100 can continuously exchange heat with the gravel piles 13 through the heat exchange pipe group 14 to achieve temperature control, so as to increase the temperature of the gravel piles 13 in the unfrozen foundation 11 and the frozen foundation 12, form a stable temperature field, reduce the repeated phase change of the pore water in the composite roadbed structure 100, reduce the risk of freeze-thaw cycles in the composite roadbed structure 100, and reduce the risk of cracking and uneven settlement of the composite roadbed structure 100. In addition, the water content of the composite roadbed structure 100 can be reasonably controlled through the pumping pipe 18 and the water absorbing member 15, and the excess water in the composite roadbed structure 100 can be continuously discharged, which can reduce the water accumulation phenomenon in the composite roadbed structure 100 and reduce the risk of slurry, mud and erosion in the composite roadbed structure 100, which is beneficial to improving the bearing capacity and stability of the composite roadbed structure 100.

[0036] Therefore, by arranging the heat exchange tube group 14 corresponding to the gravel piles 13, the temperature of the composite roadbed structure 100 can be actively adjusted by the heat exchange tube group 14, the freeze-thaw cycle phenomenon can be reduced, and the risk of cracking and uneven settlement of the composite roadbed structure 100 can be reduced. In addition, by laying the water absorbent member 15 above the gravel piles 13 along the height direction of the composite roadbed structure 100, the drainage performance of the composite roadbed structure 100 can be significantly improved, the water accumulation phenomenon of the composite roadbed structure 100 can be reduced, and the risk of frost heave and cracking of the composite roadbed structure 100 in cold areas can be reduced, which is conducive to improving the bearing capacity and stability of the composite roadbed structure 100.

[0037] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, each heat exchange tube group 14 has two vertical heat exchange tubes 141, which are distributed on both sides of the corresponding gravel pile 13 along the radial direction of the gravel pile 13. The transverse heat exchange tube 142 is constructed as an arc tube and is wound around the outside of the gravel pile 13. The transverse heat exchange tube 142 is connected between the corresponding two vertical heat exchange tubes 141.

[0038] The number of vertical heat exchange tubes 141 in each heat exchange tube group 14 is two, and the two vertical heat exchange tubes 141 are distributed on both sides of the corresponding gravel pile 13 along the radial direction of the gravel pile 13. For example, the two vertical heat exchange tubes 141 are arranged along the first direction (i.e. Figure 1 The X direction shown in the figure is distributed on both sides of the radial direction of the corresponding gravel pile 13.

[0039] The transverse heat exchange pipe 142 is constructed as an arc-shaped pipe, and the transverse heat exchange pipe 142 is wound around the outside of the gravel pile 13. As some embodiments of the present application, along the height direction of the composite roadbed structure 100 (i.e. Figure 1 The horizontal heat exchange pipe 142 is connected between the bottoms of the corresponding two vertical heat exchange pipes 141, and the horizontal heat exchange pipe 142 is wound around the outside of the gravel pile 13.

[0040] As some embodiments of the present application, the horizontal heat exchange tube 142 and the vertical heat exchange tube 141 are connected by hot melting, and the hot melting temperature needs to be ensured to be above 200° C. to ensure the sealing of the pipeline.

[0041] Such an arrangement enables the vertical heat exchange tubes 141 to be arranged symmetrically on both sides of the gravel pile 13, and enables the arc-shaped transverse heat exchange tubes 142 to match the outer contour of the gravel pile 13, thereby increasing the contact area between the heat exchange tube group 14 and the gravel pile 13, which is beneficial to improving the heat exchange efficiency of the heat exchange tube group 14, effectively reducing the disturbance of the freeze-thaw cycle, and reducing the risk of cracking and uneven settlement of the composite roadbed structure 100.

[0042] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the composite roadbed structure 100 further includes: a plurality of connecting pipes 143, wherein in adjacent heat exchange tube groups 14, a vertical heat exchange tube 141 in one heat exchange tube group 14 that is relatively close to another heat exchange tube group 14 is connected with a vertical heat exchange tube 141 in another heat exchange tube group 14 that is relatively close to one of the heat exchange tube groups 14 via the connecting pipes 143; the horizontal heat exchange tube 142 is connected between the bottoms of the corresponding two vertical heat exchange tubes 141, and the connecting pipe 143 is connected between the tops of the corresponding two vertical heat exchange tubes 141.

[0043] There are multiple connecting pipes 143, which can be, but are not limited to, two, three, or four. In some embodiments of the present application, there are six connecting pipes 143. The connecting pipes 143 can connect adjacent heat exchange tube groups 14. Specifically, the composite roadbed structure 100 has multiple heat exchange tube groups 14, wherein a vertical heat exchange tube 141 in one heat exchange tube group 14 that is relatively close to another heat exchange tube group 14 is connected to a vertical heat exchange tube 141 in another heat exchange tube group 14 that is relatively close to one of the heat exchange tube groups 14 via the connecting pipe 143. In other words, the connecting pipe 143 connects between the vertical heat exchange tubes 141 in two adjacent heat exchange tube groups 14 that are close to each other.

[0044] As some embodiments of the present application, along the height direction of the composite roadbed structure 100 (ie Figure 1 In the Z direction shown in FIG. 1 , the horizontal heat exchange tubes 142 of the heat exchange tube group 14 are connected between the bottoms of two corresponding vertical heat exchange tubes 141 of the same heat exchange tube group 14. In some embodiments of the present application, the connecting tube 143 is connected between the tops of the vertical heat exchange tubes 141 of two adjacent heat exchange tube groups 14 that are close to each other.

[0045] As some embodiments of the present application, the connecting pipe 143 and the vertical heat exchange pipe 141 are connected by hot melting, and the hot melting temperature needs to be ensured to be above 200° C. to ensure the sealing of the pipeline.

[0046] Such a configuration enables the heat exchange tube groups 14 to be connected through the connecting pipe 143 , balances the temperature between adjacent heat exchange tube groups 14 , reduces the risk of local temperature deviation in the composite roadbed structure 100 , and is beneficial to improving the uniformity of heat exchange.

[0047] In some embodiments of the present invention, Figure 2 As shown, the composite roadbed structure 100 further includes a connector 20 , through which the vertical heat exchange pipes 141 and the horizontal heat exchange pipes 142 are fixed to the corresponding gravel piles 13 .

[0048] Among them, the connecting member 20 can be constructed as but not limited to high-strength nylon cable ties, U-shaped nails, etc. As some embodiments of the present application, the connecting member 20 is constructed as a U-shaped nail, and the vertical heat exchange tube 141 and the horizontal heat exchange tube 142 are fixed to the corresponding gravel piles 13 by U-shaped nails. The size of the bent part of the U-shaped nail can be adapted to the size of the vertical heat exchange tube 141 and the horizontal heat exchange tube 142, so that the vertical heat exchange tube 141 and the horizontal heat exchange tube 142 can be stably matched with the U-shaped nail.

[0049] Such an arrangement can stably fix the vertical heat exchange tubes 141 and the horizontal heat exchange tubes 142 to the corresponding gravel piles 13 , thereby improving the stability of the connection between the vertical heat exchange tubes 141 and the horizontal heat exchange tubes 142 and the corresponding gravel piles 13 .

[0050] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the gravel pile 13 includes a geogrid 21 and gravels 22 . The geogrid 21 is arranged around to form a hollow columnar structure, and the gravels 22 are filled in the geogrid 21 arranged around.

[0051] Among them, the geogrid 21 can be constructed as but not limited to a bidirectional geogrid, etc. As some embodiments of the present application, the geogrid 21 is constructed as a bidirectional geogrid. The bidirectional geogrid can improve the vertical bearing capacity of the composite roadbed structure 100. The bidirectional geogrid has high tensile strength (tensile strength ≥ 50kN / m) and low elongation (elongation ≤ 10%). In addition, the bidirectional geogrid is arranged in the height direction of the composite roadbed structure 100 (i.e., Figure 1 The Z direction shown) and the first direction (ie Figure 1 The X direction shown) has high strength.

[0052] The geogrid 21 is disposed around to form a hollow columnar structure, and the crushed stones 22 are filled in the hollow columnar structure formed by the geogrid 21 disposed around to form a crushed stone pile 13 .

[0053] As some embodiments of the present application, the diameter of the combination of the gravel pile 13 and the corresponding heat exchange tube group 14 can be but is not limited to 0.8m, 1.2m, 1.5m, etc. For example, the diameter of the combination of the gravel pile 13 and the corresponding heat exchange tube group 14 can be 1.2m, and the spacing between adjacent gravel piles 13 can be but is not limited to 2m, 3.5m, 5m, etc. For example, the spacing between adjacent gravel piles 13 can be 3.5m.

[0054] In some embodiments of the present application, the mud content of the gravel 22 in the gravel pile 13 is ≤3%. This configuration can improve the permeability and strength of the gravel pile 13 , which is beneficial to improving the structural strength of the composite roadbed structure 100 .

[0055] As some embodiments of the present application, the geogrid 21 and the gravel 22 can form drainage channels, which can effectively reduce the sudden increase in pore water pressure of the composite roadbed structure 100 during an earthquake, enhance the liquefaction resistance of the composite roadbed structure 100, and reduce the risk of uneven earthquake subsidence of the composite roadbed structure 100.

[0056] Such an arrangement can limit the lateral displacement of the gravel 22 , which is beneficial to improving the structural strength of the gravel pile 13 .

[0057] In some embodiments of the present invention, Figure 3 As shown, the water suction pipe 18 has an opening 19 , and the water absorbing member 15 is disposed through the opening 19 so that a portion of the structure of the water absorbing member 15 extends into the water suction pipe 18 .

[0058] The opening 19 can be configured as, but not limited to, a card slot, etc. As some embodiments of the present application, the card slot is arranged along the second direction (ie Figure 2 The water absorbing member 15 is provided to extend in the Y direction (as shown), and the water absorbing member 15 is provided in a retaining groove, which can retain the water absorbing member 15 to reduce the risk of the water absorbing member 15 falling out of the water pumping pipe 18. In some embodiments of the present application, the portion of the water absorbing member 15 extending into the water pumping pipe 18 is curved and arranged close to the inner wall of the water pumping pipe 18. This arrangement allows more of the water absorbing member 15 structure to extend into the water pumping pipe 18, thereby improving the water pumping efficiency of the water pumping pipe 18. In some embodiments of the present application, the water pumping pipe 18 is connected to a vacuum pump, which can generate negative pressure in the water pumping pipe 18 to extract water from the water absorbing member 15.

[0059] In some embodiments of the present application, the opening 19 has an extension portion, which can reduce the risk of the water absorbent member 15 jumping out.

[0060] Such an arrangement enables the reasonable arrangement of the water pumping pipe 18 and the water absorbing member 15, and can remove the moisture in the composite roadbed structure 100 through the natural penetration of the water absorbing member 15, and further extract the moisture from the water absorbing member 15 through the water pumping pipe 18, which is beneficial to controlling the water content of the composite roadbed structure 100. By providing the water pumping pipe 18 with the opening 19, the water absorbing member 15 can be firmly fixed to the water pumping pipe 18, which is beneficial to improving the stability of the composite roadbed structure 100.

[0061] In some embodiments of the present invention, Figure 3 As shown, the length of the water absorbing member 15 extending into the water pumping pipe 18 is A, which satisfies the relationship: 12 cm ≤ A ≤ 18 cm.

[0062] Among them, the length A of the water-absorbing component 15 extending into the water-pumping pipe 18 satisfies the relationship: 12cm≤A≤18cm, that is, the length A of the water-absorbing component 15 extending into the water-pumping pipe 18 can be any value between 12cm and 18cm. For example, the length A of the water-absorbing component 15 extending into the water-pumping pipe 18 can be but is not limited to 12cm, 14cm, 18cm, etc. As some embodiments of the present application, the length A of the water-absorbing component 15 extending into the water-pumping pipe 18 can be 14cm.

[0063] By allowing the length A of the water absorbing member 15 extending into the water pumping pipe 18 to be any value between 12 cm and 18 cm, more water absorbing members 15 can be extended into the water pumping pipe 18, which is beneficial to improving the water pumping rate of the water pumping pipe 18. In addition, such an arrangement can ensure a stable connection between the water absorbing member 15 and the water pumping pipe 18, which is beneficial to improving the stability of the fixation of the water absorbing member 15.

[0064] In some embodiments of the present invention, Figure 1 As shown, the composite roadbed structure 100 further includes: a thermal insulation component 16 and a waterproof component 17 . Along the height direction of the composite roadbed structure 100 , the thermal insulation component 16 is laid above the water absorbing component 15 , and the waterproof component 17 is laid above the thermal insulation component 16 .

[0065] Among them, along the height direction of the composite roadbed structure 100 (i.e. Figure 1 The heat-insulating member 16 is laid on the water-absorbing member 15, and the waterproof member 17 is laid on the heat-insulating member 16. That is, along the height direction of the composite roadbed structure 100 (ie Figure 1 The water absorbing member 15, the heat-insulating member 16 and the waterproof member 17 are sequentially arranged from bottom to top.

[0066] The material of the thermal insulation member 16 can be, but is not limited to, polyurethane foam, extruded polystyrene board, etc. In some embodiments of the present application, the material of the thermal insulation member 16 is polyurethane foam. In some embodiments of the present application, the thermal conductivity K of the material of the thermal insulation member 16 satisfies the relationship: K ≤ 0.05 W / m·K.

[0067] The material of the waterproof member 17 can be constructed as, but not limited to, highly elastic modified asphalt, PVC (Polyvinylchloride), etc. In some embodiments of the present application, the material of the waterproof member 17 is highly elastic modified asphalt.

[0068] By providing the thermal insulation component 16, temperature transfer can be isolated, heat transfer from below can be blocked from transferring upward, and seasonal temperature fluctuations of the composite roadbed structure 100 can be reduced. By providing the waterproof component 17, the risk of precipitation infiltrating the composite roadbed structure 100 into the thermal insulation component 16 can be reduced, and the risk of moisture rising through capillary action can be reduced, which is beneficial to improving the temperature and moisture content control of the composite roadbed structure 100.

[0069] In some embodiments of the present invention, Figure 1 As shown, the composite roadbed structure 100 further includes: a sand cushion layer 23, along the height direction of the composite roadbed structure 100 (ie Figure 1 A sand cushion layer 23 is laid below the water absorbing member 15, between the heat-insulating member 16 and the water absorbing member 15, between the heat-insulating member 16 and the waterproof member 17, and above the waterproof member 17.

[0070] Among them, along the height direction of the composite roadbed structure 100 (i.e. Figure 1 In the Z direction shown in FIG, a sand cushion layer 23 is laid below the water absorbing member 15, between the heat-insulating member 16 and the water absorbing member 15, between the heat-insulating member 16 and the waterproof member 17, and above the waterproof member 17. That is, along the height direction of the composite roadbed structure 100 (i.e. Figure 1 The water absorbing member 15, the heat-insulating member 16 and the waterproof member 17 are all laid on the sand cushion layer 23. Sand cushion layers 23 are laid below the water absorbing member 15, between the heat-insulating member 16 and the water absorbing member 15, between the heat-insulating member 16 and the waterproof member 17, and above the waterproof member 17.

[0071] As some embodiments of the present application, the thickness of the sand cushion layer 23 laid below the water absorbing member 15, between the heat-insulating member 16 and the water absorbing member 15, between the heat-insulating member 16 and the waterproof member 17, and above the waterproof member 17 is at least 3 cm.

[0072] It should be noted that the sand cushion layer 23 is a flexible transition layer. By laying the sand cushion layer 23 below the water-absorbing part 15, between the thermal insulation part 16 and the water-absorbing part 15, between the thermal insulation part 16 and the waterproof part 17, and above the waterproof part 17, the interlayer force stability can be improved, and the load and frost heave stress between the thermal insulation part 16 and the water-absorbing part 15, between the thermal insulation part 16 and the waterproof part 17, and above the waterproof part 17 can be effectively dispersed, thereby reducing the risk of local pressure rupture of the thermal insulation part 16, the waterproof part 17, and the water-absorbing part 15. In addition, such a setting can utilize the high permeability of the sand cushion layer 23 to assist drainage, accelerate the discharge of infiltrated water, and reduce the risk of the thermal insulation part 16 failing due to moisture.

[0073] In some embodiments of the present invention, Figure 1 As shown, the composite roadbed structure 100 further includes a fine sand protective layer 24 , which is arranged outside the gravel pile 13 .

[0074] Among them, the fine sand protective layer 24 is arranged outside the gravel pile 13. As some embodiments of the present application, the foundation 10 is formed with a pile hole, the gravel pile 13 is accommodated in the pile hole, and the fine sand protective layer 24 is arranged between the gravel pile 13 and the inner wall of the pile hole.

[0075] As some embodiments of the present application, the fine sand protective layer 24 is filled in layers, and the filling thickness of each layer of the fine sand protective layer 24 is less than or equal to 30 cm, and is compacted with a small rammer. This can increase the filling density of the fine sand protective layer 24, reduce the risk of sand liquefaction during an earthquake, and improve the stability of the composite roadbed structure 100.

[0076] By arranging the fine sand protective layer 24 outside the gravel pile 13 , the gaps around the gravel pile 13 can be filled, and the pressure of pore water during an earthquake can be dissipated, which is beneficial to improving the bearing capacity and stability of the composite roadbed structure 100 .

[0077] As some embodiments of this application, Figure 1 As shown, the composite roadbed structure 100 further includes: a crushed stone embankment layer 25, a pavement structure layer 26, a drainage ditch 27, a flow collecting pipe 28 and a through shallow groove 29. The crushed stone embankment layer 25 is laid on the sand cushion layer 23 above the waterproof member 17, the pavement structure layer 26 is laid on the crushed stone embankment layer 25, the drainage ditch 27 is provided on both sides of the composite roadbed structure 100, and the flow collecting pipe 28 is provided under the water absorbing member 15, along the first direction (i.e. Figure 1 The collecting pipes 28 are provided on both sides of the composite roadbed structure 100 and are connected to the connecting pipe 143 . The through shallow grooves 29 are provided on the gravel piles 13 to accommodate the connecting pipe 143 .

[0078] As some embodiments of this application, Figure 1 As shown, the composite roadbed structure 100 further includes: a heat pump system, a drive pump, a plurality of temperature sensors, and a plurality of moisture content sensors.

[0079] As some embodiments of the present application, the heat pump system is constructed as a ground source heat pump system. This setting can use clean energy to regulate the temperature of the composite roadbed structure 100, making the composite roadbed structure 100 energy-saving and environmentally friendly, and reducing the pressure of carbon emissions on the ecological environment.

[0080] As some embodiments of the present application, when constructing the composite roadbed structure 100, it is first necessary to level the site, make preparatory work before construction, and measure and lay out the lines to mark the pile hole positions of the gravel piles 13 in the composite roadbed structure 100;

[0081] Next, the pile holes are excavated to the designed elevation using the vibro-flotation method, and then a through shallow trench 29 is excavated horizontally from the top of the same row of pile holes;

[0082] Next, the geogrid 21 is rolled into a cylindrical shape and an overlap length is reserved. The overlap length can be, but is not limited to, 20 cm, 25 cm, 30 cm, etc. The overlap is anchored by a connector 20;

[0083] Next, the heat exchange tube group 14 is installed on the outer edge of the geogrid 21, and the vertical heat exchange tubes 141 are installed on both sides of the geogrid 21. The vertical heat exchange tubes 141 are anchored to the outer edge of the geogrid 21 through the connecting parts 20. The top of the vertical heat exchange tube 141 is flush with the top surface of the cylinder curled into the geogrid 21, and the bottom end of the vertical heat exchange tube 141 is hot-melt-jointed through the horizontal heat exchange tube 142 to connect the two vertical heat exchange tubes 141.

[0084] Next, place the geogrid 21 and the heat exchange tube group into the excavated pile hole and fix them with pre-buried brackets;

[0085] Then, along the first direction (ie Figure 1 The two adjacent vertical heat exchange tubes 141 of the two adjacent heat exchange tube groups 14 in the same horizontal row are connected through a connecting pipe 143, and the connecting pipe 143 is buried in the through shallow groove 29 to connect the heat exchange tube groups 14 of the same horizontal row of gravel piles 13. Figure 1 The connecting pipes 143 on both sides are connected to the pre-buried header pipe 28. In some embodiments of the present application, the connecting pipes 143 and the header pipe 28 are connected via a diverter valve. The material of the header pipe 28 can be, but is not limited to, high-density polyethylene, cross-linked polyethylene, etc. In some embodiments of the present application, the material of the header pipe 28 is high-density polyethylene. In some embodiments of the present application, the diameter of the header pipe 28 can be any value between 20 cm and 25 cm, for example, the diameter of the header pipe 28 is 22 cm.

[0086] Next, the geogrid 21 is filled with gravel 22, and the geogrid 21 is circumferentially tensioned every time the gravel pile 13 is filled with 0.5m of gravel 22, which can improve the structural strength and support force of the gravel pile 13.

[0087] Next, a fine sand protective layer 24 is built between the outside of the gravel pile 13 and the pile hole, and compacted around the heat exchange tube group 14 using a small rammer to reduce mechanical damage to the pipes.

[0088] Next, a sand cushion layer 23 is laid on top of the gravel pile 13, and the water absorbent member 15 and the pumping pipe 18 are assembled. The water absorbent member 15, the heat-insulating member 16, and the waterproof member 17 are laid in the sand cushion layer 23 from bottom to top. The sand cushion layer 23 is laid between the water absorbent member 15 and the heat-insulating member 16, and the sand cushion layer 23 is laid between the heat-insulating member 16 and the waterproof member 17.

[0089] Next, the slope is cut on the sand cushion layer 23, and the gravel embankment layer 25 is laid in layers. The slope surface on both sides of the gravel embankment layer 25 is poured with anti-frost heave waterproof concrete surface layer;

[0090] Next, a pavement structure layer 26 is laid on the gravel embankment layer 25, and drainage ditches 27 are excavated and arranged on both sides of the gravel embankment layer 25 close to the slope surface;

[0091] Next, multiple temperature sensors are deployed on the heat-insulating element 16, the unfrozen ground 11, and the frozen ground 12 to form a temperature sensor network, through which temperature changes of the composite roadbed structure 100 can be monitored. Multiple moisture content sensors are deployed on the water-absorbing element 15, the unfrozen ground 11, and the frozen ground 12 to form a moisture content sensor network, through which moisture content changes of the composite roadbed structure 100 can be monitored.

[0092] Next, the water pumping pipe 18 is connected to the vacuum pump system to form a negative pressure in the water pumping pipe 18 through the vacuum pump system to achieve moisture content control of the composite roadbed structure 100;

[0093] Finally, the heat exchange tube group 14 is integrated with the heat pump system and the drive pump to achieve temperature control of the composite roadbed structure by the heat exchange tube group 14 .

[0094] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0095] In the description of the present invention, "first feature" or "second feature" may include one or more of the features.

[0096] In the description of the present invention, "plurality" means two or more.

[0097] In the description of the present invention, a first feature being “on” or “under” a second feature may include the first and second features being in direct contact with each other, or the first and second features not being in direct contact with each other but being in contact with each other via another feature therebetween.

[0098] In the description of the present invention, “on”, “above” and “above” a first feature of a second feature include the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0099] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0100] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A composite roadbed structure, characterized in that: include: A foundation, the foundation comprising: an unfrozen soil foundation and a frozen soil foundation, wherein along the height direction of the composite roadbed structure, the unfrozen soil foundation is located below the frozen soil foundation; a plurality of gravel piles, wherein the gravel piles are penetrated through the frozen soil foundation and the unfrozen soil foundation; Multiple groups of heat exchange tubes, the number of the heat exchange tubes is the same as that of the gravel piles and they correspond one to one, the heat exchange tube groups comprising: vertical heat exchange tubes and horizontal heat exchange tubes, the vertical heat exchange tubes and the horizontal heat exchange tubes are both arranged outside the corresponding gravel piles and the vertical heat exchange tubes are connected to the corresponding horizontal heat exchange tubes, and adjacent heat exchange tube groups are connected; a water absorbing member, which is laid above the gravel pile along the height direction of the composite roadbed structure; A water pumping pipe, wherein a part of the structure of the water absorbing member extends into the water pumping pipe.

2. The composite roadbed structure according to claim 1, characterized in that: Each group of the heat exchange tube groups has two vertical heat exchange tubes, which are distributed on both sides of the corresponding gravel pile along the radial direction of the gravel pile. The transverse heat exchange tube is constructed as an arc tube and is wound around the outside of the gravel pile. The transverse heat exchange tube is connected between the corresponding two vertical heat exchange tubes.

3. The composite roadbed structure according to claim 2, characterized in that: Also includes: a plurality of connecting pipes, wherein in adjacent heat exchange tube groups, the vertical heat exchange tube in one heat exchange tube group that is relatively close to the other heat exchange tube group is connected with the vertical heat exchange tube in the other heat exchange tube group that is relatively close to the one heat exchange tube group through the connecting pipes; The horizontal heat exchange tube is connected between the bottoms of the corresponding two vertical heat exchange tubes, and the connecting tube is connected between the tops of the corresponding two vertical heat exchange tubes.

4. The composite roadbed structure according to claim 1, characterized in that: Also includes: Connecting pieces, the vertical heat exchange tubes and the horizontal heat exchange tubes are fixed to the corresponding gravel piles through the connecting pieces.

5. The composite roadbed structure according to claim 1, characterized in that: The gravel pile comprises a geogrid and gravel, wherein the geogrid is arranged around to form a hollow columnar structure, and the gravel is filled in the geogrid arranged around.

6. The composite roadbed structure according to claim 1, characterized in that: The water pumping pipe has an opening, and the water absorbing member is passed through the opening so that a part of the structure of the water absorbing member extends into the water pumping pipe.

7. The composite roadbed structure according to claim 1, characterized in that: The length of the water absorbing member extending into the water pumping pipe is A, which satisfies the relationship: 12cm≤A≤18cm.

8. The composite roadbed structure according to claim 1, characterized in that: Also includes: The heat-insulating component and the waterproof component are laid on the water-absorbing component along the height direction of the composite roadbed structure, and the waterproof component is laid on the heat-insulating component.

9. The composite roadbed structure according to claim 8, characterized in that: Also includes: A sand cushion layer is laid along the height direction of the composite roadbed structure, below the water absorbing component, between the heat-insulating component and the water-absorbing component, between the heat-insulating component and the waterproof component, and above the waterproof component.

10. The composite roadbed structure according to any one of claims 1 to 9, characterized in that: Also includes: A fine sand protective layer is arranged outside the gravel pile.

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