Pile-arch mutual supporting type partial load heat-resistant roadbed structure and construction method

Abstract

The invention relates to the field of roadbed engineering, in particular to a pile-arch mutual-supporting type load-sharing heat-resistant roadbed structure and a construction method thereof.The pile-arch mutual-supporting type load-sharing heat-resistant roadbed structure comprises piles driven into a frozen earth stratum; the counter-force pile cap is connected to the pile top and exposed out of the ground; the force holding arch pieces are arranged in an array in the line direction, arch feet of the force holding arch pieces are connected to the counter-force pile caps, an empty space is formed between the force holding arch pieces and the surface of the frozen earth stratum, an empty space channel is transversely arranged relative to the line direction, and the upper filling soil is arranged on the force holding arch piece array. The arch mechanical advantage and an air convection heat regulation and control mechanism are spatially integrated, pavement dynamic loads are converted into axial pressure and uniformly dispersed to piles, an efficient two-way air convection channel is constructed through a continuous empty space, accumulation of frozen soil cold reserves is accelerated in winter, and a dynamic heat insulation barrier is formed in summer; the method has the advantages of high stability, low cost, strong heat dissipation and easy construction, reduces the influence of the roadbed in the permafrost region on the heat collection and support of the underlying frozen soil, and increases the service life and structural rigidity of the roadbed.

Description

Technical Field

[0001] The present invention relates to the field of subgrade engineering, in particular to a pile-arch mutual bearing and load-sharing heat-insulating subgrade structure and a construction method thereof. Background Technique

[0002] Frozen soil refers to various rocks and soils with ice content at temperatures below zero degrees Celsius. Frozen soil has rheological properties and is extremely sensitive to temperature, with its long-term strength being much lower than its instantaneous strength characteristics. In the cold season, frozen soil freezes like ice and expands in volume as the temperature drops, causing the engineering structures built in the frozen soil area to be lifted and squeezed by the "swollen" frozen soil; in summer, the volume of the melted frozen soil shrinks, and the engineering structures will become loose and tilted. The core challenge of subgrade engineering in frozen soil areas lies in how to maintain the thermal stability of the frozen soil layer and ensure the long-term reliability of the structural mechanical properties. Although various technical paths have been formed in the traditional design of frozen soil subgrades, their limitations have become increasingly prominent under the background of climate change and the upgrading of engineering requirements.

[0003] Currently, the existing frozen soil subgrade technologies generally have the design defect of thermal-mechanical decoupling, resulting in the difficulty for the structural system to achieve long-term stability. Taking the block stone ventilation subgrade as an example, although the natural convection formed by the voids in the crushed stones can achieve seasonal cold storage, the modulus difference between the block stone layer and the upper fill soil is prone to cause interfacial shear slip under the action of freeze-thaw cycles, resulting in the degradation of the structural integrity. When the thickness of the block stone layer is less than 1.2 m, there is a non-linear attenuation relationship between the ventilation volume and the accumulated temperature in the cold season of the frozen soil (attenuation index α = 0.83 - 1.06), resulting in the effective cooling depth being less than 65% of the design value. The thermosyphon technology actively conducts the heat of the foundation through the passive heat pipe effect, but its vertically inserted layout will change the continuity of the temperature field inside the frozen soil, inducing uneven thermal stress concentration. The on-site monitoring data shows that the fluctuation range of the frozen soil upper limit within 3 m around the thermosyphon can reach 2.5 times that of the traditional area, and the operation efficiency of the thermosyphon system strongly depends on the geothermal gradient of the frozen soil. When the temperature at the bottom of the active layer is higher than -3°C, the heat dissipation per unit length decays to less than 25% of the theoretical value. Although the ventilation pipe subgrade constructs an air circulation channel through prefabricated pipes, the closed cross-section characteristics of the tubular structure result in strong selectivity for the air flow direction, and the measured ventilation efficiency in the multi-wind direction environment of the Qinghai-Tibet Plateau is only 40% - 60% of the design value. The insulation layer subgrade relies on the low thermal conductivity characteristics of organic materials such as XPS to block the downward transfer of heat, but the performance degradation caused by material aging shortens its service life by more than 50% in the scenario of an annual average temperature increase of 1°C. At the mechanical level, its mechanical creep characteristics result in a long-term compressive deformation reaching 15% of the initial thickness, causing a step-by-step degradation of the overall stiffness of the subgrade.

[0004] The prior art generally has the defect of functional decoupling, that is, the thermal protection system and the mechanical bearing structure are designed separately. This "physical collage" mode not only increases the structural complexity, but also exacerbates the thermal-mechanical mismatch effect at the material interface, accelerates the evolution of structural damage, and more frequently causes secondary diseases due to the mismatch of the thermal expansion coefficients at the material interface. Numerical simulation studies show that after 10 years of operation of traditional composite subgrades, the attenuation rate of their thermal resistance effect can reach 35%, and the bearing capacity loss caused by interface peeling exceeds 20%. Summary of the Invention

[0005] The purpose of the present invention is to provide a pile-arch mutual bearing and load-sharing heat insulation subgrade structure and construction method in view of the problems existing in the prior art that the existing frozen soil subgrade technology generally has the defect of functional decoupling, which accelerates the evolution of structural damage, reduces the overall structural rigidity, and shortens the service life of the frozen soil subgrade.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows: In the first aspect, the present invention provides a pile-arch mutual bearing and load-sharing heat insulation subgrade structure, including upper fill, and further including: Several piles driven into the frozen soil layer; Several reaction pile caps connected to the tops of the piles and exposed on the ground; Several load-bearing arch slices arranged in an array along the line direction. The arch feet of the load-bearing arch slices are connected to the reaction pile caps. An air space is formed between the load-bearing arch slices and the surface of the frozen soil layer. The air space channel is arranged transversely with respect to the line direction, and the upper fill is arranged on the load-bearing arch slice array.

[0007] Adopting the pile-arch mutual bearing and load-sharing heat insulation subgrade structure of the present invention, the mechanical advantages of the arch and the air convection heat regulation mechanism are spatially integrated. A stable spatial framework is formed by the piles, the reaction pile caps and the load-bearing arch slices. Through the design of the rise-span ratio, the load-bearing arch slices have excellent load transfer efficiency, and the dynamic load on the road surface can be converted into axial pressure and evenly distributed to the piles, significantly reducing the risk of uneven settlement; an efficient two-way air convection channel is constructed through the continuous air space. In winter, cold air penetrates through the air space to the lower part of the subgrade under the drive of the negative temperature gradient, accelerating the accumulation of cold storage in the frozen soil. In summer, the chimney effect promotes the hot air to rise and be discharged, forming a dynamic heat insulation barrier; from the perspective of thermal-mechanical collaborative design, this structure solves the problem of interface weakening caused by the separation of the thermal protection system and the bearing structure in the traditional technology; this structure has the advantages of high stability, low cost, strong heat dissipation and easy construction, reduces the influence of the subgrade in the permafrost area on the heat budget of the underlying frozen soil, and increases the service life of the subgrade and the overall structural rigidity.

[0008] As a preferred technical solution of the present invention, the piles adopt prestressed piles.

[0009] As a further preferred technical solution of the present invention, the pile adopts a prestressed pipe pile.

[0010] As a preferred technical solution of the present invention, the cross-section of the reaction pile cap is trapezoidal, and the two sides of the trapezoid correspond to the reaction surfaces, and the reaction surfaces support the arch feet of the bearing arch sheet.

[0011] As a further preferred technical solution of the present invention, a buried seat plate is provided at each of the four corners of the bearing arch sheet, and the buried seat plate is fitted to the reaction surface.

[0012] As a further preferred technical solution of the present invention, a number of embedded bolts are provided on the reaction surface, and a number of through holes are provided on the buried seat plate, and the through holes are arranged corresponding to the embedded bolts.

[0013] As a preferred technical solution of the present invention, the bearing arch sheet is split-type and includes two half-widths; The two half-widths are butted at the arch crown, a tenon head is provided on the butting surface of one half-width, and a mortise groove is provided on the butting surface of the other half-width, and the tenon head is adapted to the mortise groove for concave-convex limit.

[0014] As a further preferred technical solution of the present invention, both the tenon head and the mortise groove are provided along the entire length of the bearing arch sheet in the length direction.

[0015] As a further preferred technical solution of the present invention, at least one group of hand holes are correspondingly provided at the tops of the two half-widths, and each group of hand holes are communicated through an arc-shaped hole, and an arc-shaped bolt is provided in the arc-shaped hole to connect the two half-widths.

[0016] As a preferred technical solution of the present invention, the width of the upper fill soil is less than or equal to the width of the bearing arch sheet array.

[0017] In a second aspect, the present invention also provides a construction method for the pile-arch mutual bearing and load-sharing heat-insulating subgrade structure as described in any one of the above, including the following steps: S1. Drive the pile into the frozen soil layer, and connect the reaction pile cap to the top of the pile; S2. Set the bearing arch sheet on the reaction pile cap to form the bearing arch sheet array, and an air layer is formed between the bearing arch sheet and the surface of the frozen soil layer; S3. Set the upper fill soil on the bearing arch sheet array according to the designed height and compact it.

[0018] The construction method of a pile-arch mutual bearing and load-sharing heat-insulating subgrade structure according to the present invention spatially integrates the mechanical advantages of the arch and the air convection heat regulation mechanism. A stable spatial framework is formed by the pile, the reaction pile cap, and the load-bearing arch sheet. Through the design of the rise-span ratio, the load-bearing arch sheet has excellent load transfer efficiency, can convert the dynamic load of the road surface into axial pressure and evenly disperse it to the pile, significantly reducing the risk of uneven settlement. An efficient two-way air convection channel is constructed through the continuous overhead layer. In winter, cold air penetrates through the overhead layer to the lower part of the subgrade under the drive of the negative temperature gradient, accelerating the accumulation of cold storage in the frozen soil. In summer, the chimney effect promotes the rise and discharge of hot air, forming a dynamic heat insulation barrier. From the perspective of thermo-mechanical collaborative design, this structure solves the problem of interface weakening caused by the separation of the thermal protection system and the load-bearing structure in traditional technologies. This structure has the advantages of high stability, low cost, strong heat dissipation, and easy construction, reduces the impact of the subgrade in permafrost regions on the heat budget of the underlying frozen soil, and increases the service life of the subgrade and the rigidity of the overall structure.

[0019] In a third aspect, the present invention also provides an application of the pile-arch mutual bearing and load-sharing heat-insulating subgrade structure as described in any one of the above or the construction method of the pile-arch mutual bearing and load-sharing heat-insulating subgrade structure as described above in the fields of highways, railways, airports, cables, wires, or oil and gas pipelines in frozen soil areas.

[0020] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are: A pile-arch mutual bearing and load-sharing heat-insulating subgrade structure and construction method according to the present invention spatially integrate the mechanical advantages of the arch and the air convection heat regulation mechanism. A stable spatial framework is formed by the pile, the reaction pile cap, and the load-bearing arch sheet. Through the design of the rise-span ratio, the load-bearing arch sheet has excellent load transfer efficiency, can convert the dynamic load of the road surface into axial pressure and evenly disperse it to the pile, significantly reducing the risk of uneven settlement. An efficient two-way air convection channel is constructed through the continuous overhead layer. In winter, cold air penetrates through the overhead layer to the lower part of the subgrade under the drive of the negative temperature gradient, accelerating the accumulation of cold storage in the frozen soil. In summer, the chimney effect promotes the rise and discharge of hot air, forming a dynamic heat insulation barrier. From the perspective of thermo-mechanical collaborative design, this structure solves the problem of interface weakening caused by the separation of the thermal protection system and the load-bearing structure in traditional technologies. This structure has the advantages of high stability, low cost, strong heat dissipation, and easy construction, reduces the impact of the subgrade in permafrost regions on the heat budget of the underlying frozen soil, and increases the service life of the subgrade and the rigidity of the overall structure. Description of the Drawings

[0021] Figure 1 It is a three-dimensional structure schematic diagram of the pile-arch mutual bearing and load-sharing heat-insulating subgrade structure; Figure 2 It is a three-dimensional structure schematic diagram of the pile; Figure 3 Schematic three-dimensional structure diagram of the reaction force pile cap; Figure 4 Schematic three-dimensional structure diagram of the bearing arch slice; Figure 5 Schematic plan structure diagram of the bearing arch slice; Figure 6 Schematic connection diagram of the bearing arch slice.

[0022] Markings in the figure: 01 - Frozen soil layer; 1 - Pile; 2 - Reaction force pile cap, 21 - Reaction surface, 22 - Embedded bolt; 3 - Bearing arch slice, 31 - Embedded seat plate, 32 - Tenon head, 33 - Mortise groove, 34 - Manhole; 4 - Arc bolt, 41 - Gasket, 42 - First nut; 5 - Upper fill; 6 - Aerial layer. Specific implementation manners

[0023] The present invention will be further described in detail below in combination with test examples and specific implementation manners. However, this should not be understood as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. All technologies implemented based on the content of the present invention belong to the scope of the present invention.

[0024] In the description of the specific embodiments of the present invention, without special explanation, the expression terms of orientation or positional relationship such as "upper", "lower", "left", "right", "center", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the invention product / device / device is commonly used. These terms of orientation or positional relationship are only for the convenience of describing the solution of the present invention or simplifying the description in the specific embodiments, so as to facilitate technicians to quickly understand the solution, rather than indicating or implying that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, it should not be understood as a limitation to the present invention.

[0025] In addition, when terms such as "horizontal", "vertical", "hanging", "parallel" appear, it does not mean that the corresponding device / component / element is required to be absolutely horizontal or vertical or hanging or parallel, but it can be slightly inclined or deviated. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and it does not mean that the structure must be completely horizontal, but it can be slightly inclined. Or, it can be simply understood that the corresponding device / component / element is arranged in directions such as "horizontal", "vertical", "hanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0026] In addition, when expressions such as "first", "second", "third", etc. appear in the terms, they are only used to distinguish the descriptions of the same or similar components, and should not be understood as emphasizing or implying the relative importance of specific components.

[0027] In addition, in the description of the embodiments of the present invention, "several", "multiple", "a number of" represent at least 2. It can be any situation such as 2, 3, 4, 5, 6, 7, 8, 9, etc., and even can be a situation exceeding 9.

[0028] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, when terms such as "set", "installed", "connected", "connected", "provided with", "laid", "arranged" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be connection means commonly used in the art such as welding, riveting, bolting, threaded connection, etc. Such a connection can be a mechanical connection, an electrical connection or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components.

[0029] In the related art, the existing frozen soil subgrade technology generally has the defect of functional decoupling, that is, the thermal protection system and the mechanical bearing structure are designed separately. This "physical collage" mode not only increases the structural complexity, but also exacerbates the thermal-mechanical mismatch effect at the material interface, accelerates the structural damage evolution, and more frequently causes secondary diseases due to the mismatch of the thermal expansion coefficients at the material interface. Numerical simulation studies show that after 10 years of operation of the traditional composite subgrade, the attenuation rate of its thermal resistance effect can reach 35%, and the bearing capacity loss caused by interface peeling exceeds 20%, and the overall structural rigidity decreases, resulting in a shortened service life of the frozen soil subgrade. Therefore, the technical solution of this application is generated. The following is described in combination with Figures 1 to 6 is elaborated.

[0030] Example 1 As Figures 1 to 6 shown, a pile-arch mutual bearing and load-sharing heat-insulating subgrade structure according to the present invention includes upper fill soil 5, and further includes a plurality of piles 1, a plurality of reaction pile caps 2 and a plurality of load-bearing arch sheets 3.

[0031] As Figure 1 and Figure 2 shown, the pile 1 adopts a prestressed pipe pile. The pile length and pile layout mode of the pile 1 are determined according to the geological conditions, and then the pile 1 is driven into the frozen soil layer 01.

[0032] As Figure 1 and Figure 3 shown, the reaction pile cap 2 is connected to the top of the pile 1 and exposed on the ground. The reaction pile cap 2 is a stepped body, and the cross-section along its width direction is generally trapezoidal. The two sides of the trapezoid correspond to reaction surfaces 21, and the reaction surfaces 21 support the arch feet of the load-bearing arch sheet 3.

[0033] As Figure 1 shown, the load-bearing arch sheets 3 are arranged in an array along the line direction. The arch feet of the load-bearing arch sheets 3 are connected to the reaction pile caps 2. An overhead layer 6 is formed between the load-bearing arch sheets 3 and the surface of the frozen soil layer 01. The passage of the overhead layer 6 is arranged transversely with respect to the line direction, and the upper fill soil 5 is arranged on the array of the load-bearing arch sheets 3.

[0034] In some alternative embodiments, as Figure 4 and Figure 5 shown, the load-bearing arch sheet 3 is split-type and includes two half-widths; the two half-widths are butted at the arch top. A tenon 32 is provided on the butting surface of one half-width, and a mortise 33 is provided on the butting surface of the other half-width. The tenon 32 is adapted to the mortise 33 for concave-convex limit. The tenon 32 and the mortise 33 are both arranged longitudinally along the length direction of the load-bearing arch sheet 3; through the cooperation of the tenon 32 and the mortise 33, on the one hand, positioning is carried out when the two half-widths are installed, and on the other hand, vertical shear limit can be carried out.

[0035] In some alternative embodiments, as Figure 4 and Figure 6 shown, at least one group of manholes 34 are correspondingly provided at the tops of the two half-widths. Each group of manholes 34 are communicated through an arc-shaped hole. An arc-shaped bolt 4 is arranged in the arc-shaped hole. Gaskets 41 and first nuts 42 are respectively arranged at both ends of the arc-shaped bolt 4 to tightly connect the two half-widths.

[0036] In some alternative embodiments, as Figure 3As shown, in order to adapt to the connection between the reaction force pile cap 2 and the bearing arch sheet 3, a number of embedded bolts 22 are provided on the reaction force surface 21, and the axial direction of the embedded bolts 22 is perpendicular to the reaction force surface 21; specifically, two rows of 12 embedded bolts 22 can be evenly arranged on each reaction force surface 21. The reaction force pile cap 2 is a concrete structure, and the embedded bolts 22 are cast integrally with it when the reaction force pile cap 2 is precast. In this embodiment, the embedded bolts 22 are of M16 type.

[0037] In some alternative embodiments, such as Figure 4 As shown, a pre-embedded seat plate 31 is provided at each of the four corners of the bearing arch sheet 3. The bearing arch sheet 3 is a concrete structure, and the pre-embedded seat plate 31 is cast integrally with it when the bearing arch sheet 3 is precast. The pre-embedded seat plate 31 is matched with the reaction force surface 21, that is, the inclination rate of the pre-embedded seat plate 31 is the same as that of the reaction force surface 21, so that the pre-embedded seat plate 31 and the reaction force surface 21 can be closely attached, and the force of the bearing arch sheet 3 can be transmitted to the reaction force pile cap 2; a number of through holes are provided on the pre-embedded seat plate 31, and the through holes are arranged corresponding to the embedded bolts 22. The embedded bolts 22 are threadedly connected through second nuts to connect the reaction force surface 21 and the pre-embedded seat plate 31, thereby connecting the arch foot of the bearing arch sheet 3 and the reaction force pile cap 2.

[0038] In some alternative embodiments, the bearing arch sheet 3 adopts an arch structure with a catenary as the reasonable arch axis, which can convert the dynamic load on the road surface into axial pressure and evenly disperse it to the reaction force pile cap 2, and finally transmit it to the pile 1.

[0039] In some alternative embodiments, such as Figure 1 As shown, two adjacent reaction force pile caps 2 in the transverse direction of the line can be connected into one body, that is, a reaction force pile cap 2 with a length twice that of the reaction force pile cap 2 in Figure 3 is formed. In this way, two rows of 24 embedded bolts 22 are evenly arranged on a single reaction force surface 21. Then, such a longer reaction force pile cap 2 can connect four adjacent bearing arch sheets 3 at the same time to enhance the stability of the overall structure.

[0040] In some alternative embodiments, such as Figure 1 As shown, the width of the upper fill 5 is less than or equal to the width of the array of bearing arch sheets 3.

[0041] A pile-arch mutually supporting and load-sharing heat-insulating subgrade structure described in this embodiment integrates the mechanical advantages of an arch and the air convection heat regulation mechanism in space. A stable space frame is formed by the pile 1, the reaction pile cap 2, and the load-bearing arch slice 3. Through the design of the rise-span ratio, the load-bearing arch slice 3 has excellent load transfer efficiency, can convert the dynamic load of the road surface into axial pressure and evenly disperse it to the pile 1, significantly reducing the risk of uneven settlement; an efficient two-way air convection channel is constructed through the continuous air layer 6. In winter, cold air penetrates through the air layer 6 to the lower part of the subgrade under the drive of the negative temperature gradient, accelerating the accumulation of cold storage in frozen soil. In summer, the chimney effect promotes the rise and discharge of hot air, forming a dynamic heat insulation barrier; from the perspective of thermal-mechanical collaborative design, this structure solves the problem of interface weakening caused by the separation of the thermal protection system and the load-bearing structure in traditional technologies; this structure has the advantages of high stability, low cost, strong heat dissipation, and easy construction, reducing the impact of the subgrade in permafrost regions on the heat budget of the underlying frozen soil, increasing the service life of the subgrade and the rigidity of the overall structure; in extremely cold regions, the air layer 6 can be used to actively introduce cold air in winter to establish an artificial frozen soil core; through structural innovation, double breakthroughs in heat regulation and mechanical load-bearing are achieved, providing a more adaptable solution for the construction of transportation infrastructure in frozen soil areas.

[0042] Embodiment 2 As Figure 1 Figure 6 shown, a construction method of a pile-arch mutually supporting and load-sharing heat-insulating subgrade structure as described in Embodiment 1 of the present invention includes the following steps: Step 1: Determine the geological conditions and the span size, mainly including: determining the results of stratum exploration, the type of frozen soil, the surface undulation, surface water, etc. Under the condition of complex frozen soil types, for unfavorable positions such as large surface undulations, insufficient foundation bearing capacity, or developed surface water, this structural form can be adopted.

[0043] Step 2: Determine the pile length and pile layout method of the pile 1 according to the geological conditions, drive the pile 1 into the frozen soil layer 01, and then connect the reaction pile cap 2 to the top of the pile 1. The length direction of the reaction pile cap 2 is arranged along the transverse direction of the line.

[0044] Step 3: Place the split load-bearing arch slice 3 on the reaction pile cap 2, achieve the alignment and butting of the two half-widths through the tenon 32 and the mortise 33, then pass the arc-shaped bolt 4 through the hand hole 34 and the arc-shaped hole, connect the crown of the load-bearing arch slice 3 through the first nut 42, and then connect the reaction pile cap 2 and the load-bearing arch slice 3 through the second nut; finally, form an array of the load-bearing arch slices 3, and an air layer 6 is formed between the load-bearing arch slice 3 and the surface of the frozen soil layer 01.

[0045] Step 4: Set the upper fill soil 5 and the pavement structure layer on the load-bearing arch slab 3 array according to the designed height and compact them.

[0046] In the construction method of a pile-arch mutual bearing and load-sharing heat-insulating subgrade structure described in this embodiment, the mechanical advantages of the arch and the air convection heat regulation mechanism are spatially integrated. A stable spatial framework is formed by the pile 1, the reaction pile cap 2, and the load-bearing arch slab 3. Through the design of the rise-span ratio, the load-bearing arch slab 3 has excellent load transfer efficiency, can convert the pavement dynamic load into axial pressure and evenly disperse it to the pile 1, significantly reducing the risk of uneven settlement; an efficient two-way air convection channel is constructed through the continuous air layer 6. In winter, cold air penetrates through the air layer 6 to the lower part of the subgrade under the drive of the negative temperature gradient, accelerating the accumulation of cold storage in the frozen soil. In summer, the chimney effect promotes the rise and discharge of hot air, forming a dynamic heat insulation barrier; from the perspective of thermal-mechanical collaborative design, this structure solves the problem of interface weakening caused by the separation of the thermal protection system and the load-bearing structure in traditional technologies; this structure has the advantages of high stability, low cost, strong heat dissipation, and easy construction, reducing the impact of the subgrade in permafrost regions on the heat budget of the underlying frozen soil, increasing the service life of the subgrade and the rigidity of the overall structure; in extremely cold regions, the artificial frozen soil core can be established by actively introducing cold air through the air layer 6 in winter; through structural innovation, a double breakthrough in heat regulation and mechanical load-bearing is achieved, providing a more adaptable solution for the construction of transportation infrastructure in frozen soil areas.

[0047] Example 3 The application of the construction method of a pile-arch mutual bearing and load-sharing heat-insulating subgrade structure as described in Example 1 or a pile-arch mutual bearing and load-sharing heat-insulating subgrade structure as described in Example 2 of the present invention in the fields of highways, railways, airports, cables, wires, or oil and gas pipelines in frozen soil areas.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pile-arch mutually supporting and load-sharing heat-insulating subgrade structure, comprising upper fill soil (5), characterized in that, It further includes: A number of piles (1) driven into the frozen soil layer (01); A number of reaction pile caps (2) connected to the tops of the piles (1) and exposed above the ground; A number of load-bearing arch sheets (3) arranged in an array along the line direction. The arch feet of the load-bearing arch sheets (3) are connected to the reaction pile caps (2). An overhead layer (6) is formed between the load-bearing arch sheets (3) and the surface of the frozen soil layer (01). The passage of the overhead layer (6) is arranged transversely with respect to the line direction. The upper fill soil (5) is arranged on the array of the load-bearing arch sheets (3).

2. The pile-arch mutual bearing and load-sharing heat insulation subgrade structure according to claim 1, wherein The pile (1) is a prestressed pile.

3. The pile-arch mutual bearing and load-sharing heat-insulating subgrade structure according to claim 1, wherein The cross-section of the reaction pile cap (2) is trapezoidal, and the two sides of the trapezoid correspond to reaction surfaces (21). The reaction surfaces (21) support the arch feet of the load-bearing arch sheets (3).

4. The pile-arch mutual bearing and load-sharing heat-insulating subgrade structure according to claim 3, characterized in that One embedded seat plate (31) is provided at each of the four corners of the load-bearing arch sheet (3). The embedded seat plate (31) is fitted to the reaction surface (21).

5. The pile-arch mutual bearing and load-sharing heat insulation subgrade structure according to claim 4, wherein, A number of embedded bolts (22) are provided on the reaction surface (21). A number of through holes are provided on the embedded seat plate (31). The through holes are arranged corresponding to the embedded bolts (22).

6. The pile-arch mutual bearing and load-sharing heat insulation subgrade structure according to claim 1, characterized in that, The load-bearing arch sheet (3) is split-type and includes two half-widths; The two half-widths are butted at the arch top. A tenon head (32) is provided on the butting surface of one half-width, and a mortise groove (33) is provided on the butting surface of the other half-width.

7. The pile-arch mutual bearing and load-sharing heat insulation subgrade structure according to claim 6, characterized in that At least one set of manholes (34) are provided corresponding to the tops of the two half-widths. Each set of manholes (34) are connected through an arc-shaped hole. An arc-shaped bolt (4) is provided in the arc-shaped hole. The arc-shaped bolt (4) connects the two half-widths.

8. The pile-arch mutual bearing and load-sharing heat-insulating subgrade structure according to any one of claims 1-7, characterized in that, The width of the upper fill soil (5) is less than or equal to the width of the array of the load-bearing arch sheets (3).

9. A construction method of the pile-arch mutual bearing and load-sharing heat-insulating subgrade structure according to any one of claims 1-8, characterized in that, It includes the following steps: S1. Drive the pile (1) into the frozen soil layer (01), and connect the reaction pile cap (2) to the top of the pile (1); S2. Set the load-bearing arch sheet (3) on the reaction pile cap (2) to form the array of the load-bearing arch sheets (3), and form the overhead layer (6) between the load-bearing arch sheet (3) and the surface of the frozen soil layer (01); S3. Set the upper fill soil (5) on the array of the load-bearing arch sheets (3) according to the designed height and compact it.

10. Application of the pile-arch mutual bearing and load-sharing heat insulation subgrade structure according to any one of claims 1-8 or the construction method of the pile-arch mutual bearing and load-sharing heat insulation subgrade structure according to claim 9 in the fields of highways, railways, airports, cables, wires or oil and gas pipelines in frozen soil areas.

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