Corrugated steel round pipe ventilation roadbed structure

Abstract

The utility model discloses a corrugated steel pipe ventilation roadbed structure, including the inside of roadbed is buried with a plurality of section corrugated steel pipe, and is laid with medium coarse sand cushion layer in the top and bottom of corrugated steel pipe, wherein: the end of corrugated steel pipe is equipped with the connecting assembly, and the connecting assembly is connected between a plurality of section corrugated steel pipes, the connecting assembly includes fixed seat and protection shell, one end of protection shell is connected with the end of corrugated steel pipe, and the other end is connected with fixed seat, the outer edge of fixed seat is equipped with two connecting pieces symmetrically, the outer surface of protection shell is equipped with locating block respectively on both sides, locating block is equipped with threaded hole, and is connected with a long screw rod I, and the outer surface of protection shell is equipped with support assembly respectively on both sides. The utility model discloses a corrugated steel pipe through connecting assembly and is connected with each other, and adopts support assembly and supports the corrugated steel pipe connecting part, and reduces the influence of foundation settlement to the corrugated steel pipe connecting part.

Description

Technical Field

[0001] This utility model belongs to the technical field of roadbed structure in permafrost areas, specifically relating to a corrugated steel round pipe ventilation roadbed structure. Background Technology

[0002] Ventilation pipe subgrade is a special subgrade structure that actively protects permafrost. It forms a ventilation pipe by embedding transversely running reinforced concrete pipes in the cross-section of the subgrade. By utilizing the flow of cold air from the outside, the heat of the subgrade soil is carried away, thereby reducing the subgrade temperature, preventing the permafrost from melting, and maintaining the stability and strength of the subgrade. It has been widely used in the permafrost region of the Qinghai-Tibet Plateau.

[0003] However, traditional ventilation ductwork has the following drawbacks: (1) Due to the special geographical features of the Qinghai-Tibet Plateau permafrost region, there are environmental challenges such as strong freeze-thaw cycles and lack of oxygen. Traditional reinforced concrete ventilation pipes are prefabricated in factories and assembled on site. Because reinforced concrete itself has low tensile strength, the length of each pipe section is generally less than 3m, while the roadbed width is generally more than 15m. Therefore, multiple assembly is required, the process is complicated, and it is difficult to ensure smoothness during the assembly process. (2) Due to the low tensile strength of concrete, the roadbed in permafrost areas is prone to large deformation, which can cause pipe section cracking and pipe section breakage, making subsequent maintenance extremely difficult. (3) The inner wall of traditional reinforced concrete pipes is smooth, and turbulence cannot be achieved when the wind speed is low, resulting in limited heat exchange efficiency and insufficient heat removal.

[0004] Corrugated steel pipes are commonly used for culverts with larger diameters. The corrugated structure gives the pipe body axial compressibility and radial deformation capacity, which can absorb displacements such as foundation settlement and frost heave. In frozen soil areas, it can withstand frost heave displacements of ±30cm. In mountainous landslide areas, it can avoid shear damage to the pipe. The weight of a single pipe section is only 1 / 10 of that of a concrete pipe. Bolted splicing eliminates the need for large machinery, increasing construction efficiency by more than 50%. Civil engineering and installation can be carried out separately. Some corrugated steel pipes are protected by multiple layers of galvanization, thickened aluminum-zinc coating, or epoxy resin coating. Laboratory tests show that their service life can reach more than 50 years. They are suitable for corrosive environments such as saline-alkali land and acidic soil.

[0005] To address this, a solution has been proposed to apply corrugated steel pipes to ventilation duct subgrades. For example, Chinese patent application number 201911075741.5 describes a ventilation duct subgrade structure for low embankments in permafrost regions of high-altitude areas. This subgrade structure includes a subgrade pit backfill section below ground level and a subgrade embankment backfill section above ground level. Stone retaining walls are installed on both sides of the subgrade embankment backfill section. Transverse ventilation pipes are installed above the natural upper limit of the permafrost in the subgrade pit backfill section, arranged longitudinally at intervals. Both ends of the ventilation pipes extend upwards along the subgrade slope into the stone retaining walls and lead to the outside. The ventilation pipes are assembled corrugated pipes, with pipe sections connected by sleeves or flanges. For example, Chinese patent application number 201621462776.6 discloses a composite roadbed structure of corrugated steel pipe and crushed stone, which includes a roadbed and a pavement structure from bottom to top; the roadbed is a crushed stone layer, and transverse corrugated ventilation pipes are set in the crushed stone layer along the direction of the line, with the ends of the corrugated ventilation pipes extending out of the crushed stone layer from both sides; the corrugated ventilation pipes are composed of multiple pipe sections, which are spliced ​​and fixed by flanges and bolts.

[0006] The above solutions have solved the technical problems of permafrost thawing and ground settlement in the permafrost region of the plateau to a certain extent. However, the above multi-section corrugated pipes are all directly spliced ​​and fixed by flanges and bolts. The connection part cannot be fixed well, which makes it susceptible to the impact of ground settlement. The connecting bolts are under great stress and are easily damaged. Utility Model Content

[0007] The purpose of this utility model is to provide a corrugated steel round pipe ventilation roadbed structure to solve the shortcomings of the existing technology.

[0008] The present invention adopts the following technical solution: A corrugated steel pipe ventilation roadbed structure includes several sections of corrugated steel pipes buried inside the roadbed, with medium-coarse sand cushion layers laid on the top and bottom of the corrugated steel pipes; wherein: the ends of the corrugated steel pipes are provided with connecting components, and the several sections of corrugated steel pipes are connected to each other through the connecting components; the connecting components include a fixing base and a protective shell; one end of the protective shell is connected to the end of the corrugated steel pipe, and the other end is connected to the fixing base; two connecting pieces are symmetrically provided on the outer edge of the fixing base; positioning blocks are respectively provided on the upper and lower sides of the outer surface of the protective shell; the positioning blocks are provided with threaded through holes and threadedly connected to a long screw I; support components are respectively provided on the front and rear sides of the outer surface of the protective shell.

[0009] In this invention, adjacent corrugated steel pipe sections are connected to each other via a connecting assembly. A support assembly is provided on the outer surface of the connecting assembly to support the connecting portion of the corrugated steel pipes, reducing the impact of foundation settlement on the connecting portion. The protective outer shell of the connecting assembly fits over the end of the corrugated steel pipe, providing protection. The outer edge of the fixing seat of the connecting assembly is stepped, with its lower inner side embedded within the protective outer shell, and can connect to the end of the corrugated steel pipe inside the protective shell. After the end of the long screw I is screwed into the positioning block, it abuts against the protruding edge of the fixing seat, allowing for minor adjustments to the position of the fixing seat while the protective outer shell is fixed.

[0010] As a further preferred embodiment of this utility model, the support assembly includes a support platform and two long screws II; one side of the support platform is fixedly connected to the outer surface of the protective shell, and the other side is slidably connected to two displacement blocks; the top end of the long screws II is connected to the displacement blocks, the bottom end is provided with a first ground stake, and the middle part is threadedly connected to a movable block; the movable block is provided with an angle seat; the angle seat is hinged to an angle block; the bottom end of the angle block is provided with a second ground stake.

[0011] In this invention, the support platform can be a rectangular block with a groove or insertion hole. The displacement block slides in the groove or is inserted into different insertion holes to adjust the position of the long screw II. The movable block can move up and down on the long screw II. The angle seat is fixedly installed on the side of the movable block, and the angle seat is provided with a hinge shaft. The top of the angle block is hinged to the hinge shaft and rotates within a certain angle range along the hinge shaft, thereby changing and adjusting the position of the second ground stake.

[0012] During construction, the user adjusts the position of the first ground pile by sliding the displacement block along the support platform, and the first ground pile is inserted into the place of use. Then, the user rotates the movable block relative to the long screw II, and the movable block rotates and rises and falls relative to the long screw II to adjust the height of the second ground pile. The user rotates the angle block relative to the angle seat so that there is a certain angle between the second ground pile and the first ground pile, so that the corrugated steel round pipe is stably supported in a triangular shape at the place of use.

[0013] As a further preferred embodiment of this invention, a fixing nut is provided on the long screw I. The fixing nut limits the long screw I, allowing it to more firmly abut against the fixing seat. That is, when the user rotates the long screw I, the threads on the surface of the long screw I match the threads on the inner wall of the positioning block. The long screw I is limited by the fixing seat, so the positioning block slides relative to the long screw I, adjusting the distance between the protective shell and the fixing seat, and adjusting the protective area of ​​the protective shell. The user then tightens the fixing nut to fix the long screw I onto the positioning block.

[0014] As a further preferred embodiment of this utility model, the connecting piece is provided with a threaded hole, and the corresponding connecting pieces between the two corrugated steel pipe sections are fixedly connected by a locking nut and a locking screw. The user rotates the locking screw through the corresponding threaded hole to assemble the two corresponding connecting pieces together, and then the user rotates the locking nut to fix the locking screw on the two connecting pieces.

[0015] When the roadbed structure of this utility model is applied during construction, the layering of the corrugated steel round pipe ventilated roadbed should be determined comprehensively based on the roadbed height, local prevailing wind direction and speed, surface runoff, wind and sand, and snow accumulation.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The corrugated steel pipes of this utility model are connected by a connecting component. The protective shell of the connecting component can protect the ends of the corrugated steel pipes. A support component is set on the protective shell. By adjusting the position of the first and second ground piles of the support component, the corrugated steel pipes can be stably supported in a triangular structure, which effectively reduces the impact of foundation settlement on the connection part of the corrugated steel pipes.

[0017] 2. This utility model, by incorporating corrugated steel pipes, possesses a unique corrugated structure that makes its compressive strength more than 15 times higher than that of cement pipes of the same diameter. It can effectively distribute the load to the surrounding soil. The flexible structure of the corrugated steel pipe can better adapt to uneven settlement of the foundation, deforming in tandem with the surrounding soil. This effectively spreads the upper load to a wider area of ​​the foundation, reducing stress concentration and thus improving the overall bearing capacity. The excellent shear and deformation resistance of the corrugated steel pipe structure effectively absorbs and adapts to this settlement, avoiding brittle fracture like that of rigid concrete structures. Moreover, it can achieve high turbulence strength even at low wind speeds, greatly increasing heat exchange efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the connection structure of the corrugated steel pipe in one embodiment of the present invention.

[0019] Figure 2 This is a perspective view of the connecting component in one embodiment of the present invention.

[0020] Figure 3 This is a side view of the connecting component in one embodiment of the present invention.

[0021] Figure 4 This is a side view of the support component in one embodiment of the present invention.

[0022] Figure 5 This is a diagram showing the corrugation parameters of an embodiment of the present invention.

[0023] In the diagram: 1-Corrugated steel pipe; 2-Connecting assembly; 21-Fixing seat; 22-Protective shell; 23-Positioning block; 24-Long screw I; 25-Fixing nut; 26-Connecting piece; 27-Threaded hole; 3-Locking nut; 4-Locking screw; 6-Support assembly; 61-Support platform; 62-Displacement block; 63-Long screw II; 64-First ground pile; 65-Modible block; 66-Angle seat; 67-Angle block; 68-Second ground pile. Detailed Implementation

[0024] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying structural drawings.

[0025] Example: A corrugated steel pipe ventilation roadbed structure includes several sections of corrugated steel pipe 1 buried inside the roadbed, and a medium-coarse sand cushion layer is laid on both the top and bottom of the corrugated steel pipe 1; wherein: as Figure 1 As shown, the ends of the corrugated steel pipe 1 are provided with connecting components 2, and the several sections of corrugated steel pipe 1 are connected to each other through the connecting components 2; as Figure 2-3 As shown, the connecting assembly 2 includes a fixing base 21 and a protective shell 22; one end of the protective shell 22 is connected to the end of the corrugated steel pipe 1, and the other end is connected to the fixing base 21; two connecting pieces 26 are symmetrically arranged on the outer edge of the fixing base 21; positioning blocks 23 are respectively provided on the upper and lower sides of the outer surface of the protective shell 22; the positioning block 23 is provided with a threaded through hole and a long screw I 24 is threadedly connected to it; support assemblies 6 are respectively provided on the front and rear sides of the outer surface of the protective shell 22.

[0026] The long screw I 24 is provided with a fixing nut 25; that is, when the user rotates the long screw I 24, the thread on the surface of the long screw I 24 matches the thread on the inner wall of the positioning block 23. The long screw I 24 is limited by the fixing seat 21, so the positioning block 23 slides relative to the long screw I 24, adjusting the distance between the protective shell 22 and the fixing seat 21, and adjusting the protective area of ​​the protective shell 22. The user then tightens the fixing nut 25 to fix the long screw I 24 on the positioning block 23.

[0027] The connecting piece 26 is provided with a threaded hole 27, and the corresponding connecting pieces 26 between the two corrugated steel pipes 1 are fixedly connected by a locking nut 3 and a locking screw 4; that is, the user rotates the locking screw 4 through the threaded hole 27 to assemble the two opposite connecting pieces 26 together, and then the user rotates the locking nut 3 to fix the locking screw 4 on the two connecting pieces 26.

[0028] This embodiment further illustrates, as follows: Figure 4As shown, the support assembly 6 includes a support platform 61 and two long screw rods II 63; one side of the support platform 61 is fixedly connected to the outer surface of the protective shell 22, and the other side is slidably connected to two displacement blocks 62; the top end of the long screw rods II 63 is connected to the displacement blocks 62, the bottom end is provided with a first ground stake 64, and the middle is threadedly connected to a movable block 65; the movable block 65 is provided with an angle seat 66; the angle seat 66 is hinged to an angle block 67; the bottom end of the angle block 67 is provided with a second ground stake 68.

[0029] During construction, the user slides the displacement block 62 along the support platform 61 to adjust the position of the first ground pile 64, and the first ground pile 64 is inserted into the place of use; then the user rotates the movable block 65 relative to the long screw II 63, and the movable block 65 rotates and rises and falls relative to the long screw II 63 to adjust the height of the second ground pile 68. The user rotates the angle block 67 relative to the angle seat 66 so that there is a certain angle between the second ground pile 68 and the first ground pile 64, so that the corrugated steel round pipe is stably supported in a triangular shape at the place of use.

[0030] In this embodiment, the corrugated steel pipe 1 is a spiral corrugated steel round pipe or an annular corrugated steel round pipe. When the roadbed width is less than 15m, a single integral corrugated steel round pipe should be used. When the width is greater than 15m, multiple corrugated steel round pipes can be spliced ​​together.

[0031] Application of the corrugated steel round pipe ventilation roadbed structure in this embodiment: The placement of corrugated steel round pipe ventilation subgrade layers should be determined comprehensively based on the subgrade height, local prevailing wind direction and speed, surface runoff, wind erosion, and snow accumulation. In this embodiment, the top of the ventilation pipe should be no less than 0.5m from the top surface of the subgrade; the distance between the ventilation pipe and the ground surface should not be less than 0.5m; a medium-coarse sand cushion layer of no less than 0.3m should be placed at the bottom, and a medium-coarse sand cushion layer of 0.1-0.2m should be laid at the top; the length of the ventilation pipe extending beyond the subgrade slope at both ends should be greater than 0.2-0.4m; the spacing of the ventilation pipes along the driving direction should be determined based on the effective cooling radius determined by on-site engineering tests, and should be less than twice the outer diameter of the ventilation pipe; the inner diameter of the ventilation pipe should not be less than 1 / 8 of the subgrade height; for separated subgrades of expressways and Class I highways, and subgrades of Class II and lower highways, it should not be less than 0.4m; for integral subgrades of expressways and Class I highways, it should not be less than 0.6m; the pipe wall thickness should be determined based on mechanical calculations, and generally should not be less than 2mm, referring to the appendix of the instruction manual. Figure 5 , wave height Wavelength , peak and trough radius The corrugated parameters are determined based on mechanical and thermal calculations. Corrugation height is the most significant factor affecting structural stiffness and heat transfer intensity; therefore, a larger corrugation height should be prioritized. A corrugation height of 55mm or 68mm is recommended. / wavelength The ratio should ideally be greater than 4. Recommended sizes are 68×13mm or 55×12.7mm, offering excellent ring stiffness and anti-turbulence effects. In practical engineering, wave height... Wavelength Wall thickness These three parameters must be considered together: Step 1: Investigate the foundation and determine the foundation modulus (Es): Low Es soft soil: The core design principle is "strong structure," and priority should be given to selecting soils with high wave height (Es). To achieve extremely high ring stiffness, the corrugated specifications of the pipe should be used, and the pipe diameter should not be too large. Simultaneously, foundation treatment (refilling with gravel, etc.) is necessary to improve the equivalent Es. For high Es hard foundations, the core design principle is "wide diffusion," and larger pipe diameters can be prioritized. To expand the load distribution range, the requirement for corrugated stiffness can be appropriately reduced; the second step is to initially select the pipe diameter based on thermal and fluid requirements. The minimum required pipe diameter is determined based on the ventilation volume calculation. Step 3: Determine the corrugation parameters based on stress diffusion and load-bearing capacity requirements, using the formula: ,

[0032] Estimation is required; low Es soft foundation: requires very high Value, selection Specifications ≥68mm (e.g., 150×50, 125×25, 100×33, 68×13); High Es hard base Lower requirements, can be selected Specifications of 55mm or 38mm, such as 55×12.7, 38×6.5, can be adjusted by changing the plate thickness. Make minor adjustments to meet the strength safety factor; Step 4: Numerical simulation verification: For important projects, finite element analysis must be performed to establish a detailed model including the foundation, pipelines, and backfill. Stress cloud diagrams and deformation diagrams can be directly visualized under different load conditions to quantitatively verify whether the stress diffusion effect meets the requirements. The steel performance requirements for corrugated steel pipe 1 are as follows: mechanical properties: yield strength ≥355MPa, yield strength ratio ≤0.80, elongation after fracture ≥22%, and total elongation at maximum force ≥12%; achieving high strength, low yield strength ratio, and high ductility; low temperature performance: Charpy V-notch impact energy ≥47J at -60℃, ductile-brittle transition temperature ≤-50℃; corrosion resistance: compared with Q235, the relative corrosion rate is less than 70%, and the annual average corrosion rate is ≤0.03mm / a, ensuring that the corrugated steel pipe meets the comprehensive requirements of load-bearing capacity, deformation adaptability, and long-term durability under the complex and harsh working conditions of frozen soil areas, which is the fundamental material guarantee for achieving a 100-year lifespan of the entire engineering structure.

[0033] Obviously, the above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description; it is neither necessary nor possible to exhaustively list all possible implementations; however, obvious variations or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A corrugated steel pipe ventilation roadbed structure, comprising several sections of corrugated steel pipe (1) embedded inside the roadbed, wherein a medium-coarse sand cushion layer is laid on both the top and bottom of the corrugated steel pipe (1); characterized in that: The corrugated steel pipe (1) is provided with a connecting component (2) at its end, and the corrugated steel pipe (1) sections are connected to each other through the connecting component (2); the connecting component (2) includes a fixing seat (21) and a protective shell (22); one end of the protective shell (22) is connected to the end of the corrugated steel pipe (1), and the other end is connected to the fixing seat (21); two connecting pieces (26) are symmetrically provided on the outer edge of the fixing seat (21); positioning blocks (23) are provided on the upper and lower sides of the outer surface of the protective shell (22); the positioning block (23) is provided with a threaded through hole and a long screw I (24) is threadedly connected to it; support components (6) are provided on the front and rear sides of the outer surface of the protective shell (22).

2. The corrugated steel circular pipe ventilation roadbed structure according to claim 1, characterized in that: The support assembly (6) includes a support platform (61) and two long screws II (63); one side of the support platform (61) is fixedly connected to the outer surface of the protective shell (22), and the other side is slidably connected to two displacement blocks (62); the top of the long screw II (63) is connected to the displacement block (62), the bottom end is provided with a first ground stake (64), and the middle is threadedly connected to a movable block (65); the movable block (65) is provided with an angle seat (66); the angle seat (66) is hinged to an angle block (67); the bottom end of the angle block (67) is provided with a second ground stake (68).

3. The corrugated steel circular pipe ventilation roadbed structure according to claim 1, characterized in that: The long screw I (24) is provided with a fixing nut (25).

4. The corrugated steel circular pipe ventilation roadbed structure according to claim 1, characterized in that: The connecting piece (26) is provided with a threaded hole (27), and the corresponding connecting pieces (26) between the two corrugated steel pipes (1) are fixedly connected by a locking nut (3) and a locking screw (4).

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