A corrugated outer profile embankment box culvert

Abstract

The utility model provides a kind of corrugated outer contour embankment box culvert, by the geometric optimization of traditional hidden embankment box culvert outer contour, by being respectively provided with continuous, equidistant, same direction's concave-convex corrugation on box culvert pipe body top plate outer surface and bottom plate outer surface, increase the resistance between box culvert and soil, so that the resistance to slide changes from simple friction to the combination of friction and soil shear resistance, significantly improve the interface shear strength, at the same time, the outer contour of concave-convex corrugation forces seepage must go along the tortuous corrugated surface, its path is much longer than straight line path, the extension of seepage diameter will directly lead to seepage hydraulic gradient significantly reduce, when hydraulic gradient is lower than the critical slope of soil, seepage cannot carry away soil particle, thereby fundamentally inhibits the occurrence of contact scour and piping, guarantees that seepage is stable under the condition that seepage gradient is certain, can effectively prevent the generation of joint part leakage.

Description

Technical Field

[0001] This utility model relates to the field of water conservancy engineering technology, and in particular to a corrugated outer contour box culvert. Background Technology

[0002] Culverts are common intersecting structures in infrastructure projects such as water conservancy and transportation, used to transport water or allow roads to pass through dams. Traditional culverts have smooth outer walls. These structures rely on the interfacial friction between the backfill soil and the concrete surface, as well as passive earth pressure, to resist potential slippage along the axis. However, during long-term operation, due to factors such as frequent water level fluctuations, soil consolidation, and uneven settlement, shear displacement deformation easily occurs at the interface between the soil and the concrete structure. This relative displacement will destroy the compactness of the joint, leading to contact scouring and forming potential seepage channels, which seriously threatens the overall safety and stability of the dam.

[0003] To address the aforementioned slippage and leakage issues, existing technologies typically employ additional water-stopping measures such as adding water-stopping rings and high-pressure grouting curtains. While water-stopping rings can increase the seepage path, their construction disrupts the continuity of backfilling operations, and their surrounding area is difficult to compact, easily creating weak points. Grouting curtains, on the other hand, are concealed works, making construction quality difficult to control, costly, and almost impossible to inspect and maintain once they fail. Therefore, a culvert structure that can simultaneously improve anti-slip resistance and seepage path length using only its own geometry, without the need for additional water-stopping materials, is proposed to solve the problem of easy slippage and leakage in concealed box culverts that penetrate dikes.

[0004] In view of this, the inventor specifically designed a corrugated outer contour box culvert, which led to this invention. Utility Model Content

[0005] To solve the above problems, the technical solution of this utility model is as follows: A corrugated outer contour box culvert includes several box culvert pipe sections, which are arranged along the length direction. The sections of the box culvert pipe sections are connected by tongue and groove joints and waterstops. Several concave and convex corrugations are continuously provided along the length direction on the outer surface of the top plate and the outer surface of the bottom plate of the box culvert pipe sections. The length direction of the concave and convex corrugations is consistent with the width direction of the box culvert pipe sections.

[0006] Preferably, the cross-sectional shape of the corrugated pattern is sinusoidal, and the angle between the tangent of the arc in the cross-section and the horizontal plane is 15° to 20°.

[0007] Preferably, the wave height of the undulating ripples is 5cm to 10cm.

[0008] Preferably, the cross-sectional shape of the corrugated pattern is a trapezoid with two hypotenuses of equal length, and the angle between the hypotenuses and the horizontal plane is 15° to 20°. Preferably, the height of the cross-section of the corrugated pattern is 5cm to 10cm. Preferably, the wavelength of the undulating ripples is 30cm to 50cm.

[0009] Preferably, the corrugated pattern covers the entire section of the box culvert body buried in the dam soil.

[0010] Preferably, the culvert body and the corrugated surface are precast integrally from concrete.

[0011] The technical solution provided by this utility model has the following beneficial effects: This invention geometrically optimizes the outer contour of traditional concealed box culverts through dikes. By setting continuous, equidistant, and unidirectional concave-convex corrugations on the outer surfaces of the top and bottom plates of the culvert body, the anti-sliding force between the culvert and the soil is increased. This transforms the anti-sliding resistance from simple friction to a combination of friction and soil shear resistance, significantly improving the shear strength of the interface. At the same time, the concave-convex corrugated outer contour forces the seepage to meander along the corrugated surface, with a path much longer than a straight path. The extension of the seepage path directly leads to a significant reduction in the hydraulic gradient of the seepage. When the hydraulic gradient is lower than the critical gradient of the soil, the seepage cannot carry away soil particles, thus fundamentally inhibiting contact scouring and piping, ensuring stable seepage. Under a certain seepage gradient, it can effectively prevent leakage at the joint. Attached Figure Description

[0012] The accompanying drawings, which are provided to further illustrate the present invention and constitute a part of the present invention, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention.

[0013] in: Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present utility model; Figure 2 This is the maximum principal stress cloud diagram of the entire longitudinal section when this utility model is implemented; Figure 3 This is a cloud diagram of the maximum principal stress of the soil in the longitudinal section during the implementation of this utility model; Figure 4 This is a longitudinal shear stress cloud diagram of the soil in the longitudinal section during the implementation of this utility model; Figure 5 This is a cloud diagram of the axial displacement of the soil in the longitudinal section during the implementation of this utility model; Figure 6 This is a longitudinal displacement cloud diagram of the soil in the longitudinal section during the implementation of this utility model; Figure 7 This is a schematic diagram of the overall structure of a specific embodiment two of this utility model.

[0014] Label Explanation: 1. Box culvert body; 2. Corrugated surface. Detailed Implementation

[0015] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model. Specific Implementation Example 1 Please see Figures 1-6 This is a corrugated outer contour box culvert, the preferred embodiment of the present invention, comprising several box culvert pipe sections 1, arranged along their own length. The sections of the box culvert pipe sections 1 are connected by tongue and groove joints and waterstops. Several convex and concave corrugations 2 are continuously provided along the length direction on the outer surface of the top and bottom plates of the box culvert pipe sections 1. The length direction of the convex and concave corrugations 2 is consistent with the width direction of the box culvert pipe sections 1. The continuous corrugations form a strong mechanical interlock with the surrounding soil, significantly improving the box culvert's ability to resist slippage along the axial direction and effectively preventing slippage due to water level fluctuations or settlement. The shear displacement caused by the corrugated structure significantly enhances the anti-sliding stability. The corrugated geometry forces the seepage path to be extremely tortuous, effectively increasing the seepage diameter and reducing the hydraulic gradient. This prevents the seepage from carrying away soil particles, thus achieving permanent and reliable seepage stability without any additional materials. It significantly reduces the seepage gradient, fundamentally inhibiting contact scouring and the formation of concentrated seepage channels, ensuring dam safety. Furthermore, continuous, equidistant, and unidirectional corrugated patterns 2 are installed on the outer surfaces of the top and bottom plates of the culvert body 1, achieving full coverage and all-around reinforcement in contact with the soil. Whether it's top earth pressure, bottom reaction force, or lateral earth pressure, all can be effectively improved through the corrugated interface. The continuous, equidistant corrugated patterns 2 ensure the uniformity of anti-sliding resistance and seepage diameter growth, avoiding stress concentration or seepage short-circuiting.

[0017] Please see Figure 1The cross-sectional shape of the corrugated 2 is sinusoidal, with the angle between the tangent of the arc in the cross-section and the horizontal plane being 15° to 20°. The sinusoidal curve has a smooth transition without any sharp corners, which eliminates stress concentration at the crests and troughs, greatly reducing the risk of concrete cracking at sharp corners during demolding, load-bearing, or temperature changes, thus improving the durability of the structure. At the same time, the smooth and continuous curve shape better simulates the deformation characteristics of natural soil, making the contact stress distribution between the soil and the structure more uniform, reducing the possibility of local compression failure, promoting the co-deformation of the soil and the structure, and making the mechanical interlocking action more gentle and effective. Furthermore, the streamlined shape of the sinusoidal waveform offers less resistance to seepage water (compared to a trapezoid with a sudden change in direction), allowing for smoother guidance of water flow along a tortuous path. Under the same diameter increase effect, its hydrodynamic characteristics are superior, making it less prone to eddy currents and further reducing the potential risk of contact scouring. A tangent angle of 15° to 20° means that the ripples have sufficient steepness. This angle range ensures that sufficient "lifting" resistance must be overcome when the soil slides, thus providing a significant anti-sliding effect. If the angle is too small (too gentle), the interlocking effect weakens; if the angle is too large (too steep), although it is beneficial for anti-sliding, it is not conducive to demolding and the stress will increase.

[0018] Please see Figure 1 The wave height of the corrugated 2 is 5cm to 10cm, the width of a single section of the box culvert 1 is 1m to 1.5m, and the wavelength of the corrugated 2 is 30cm to 50cm. In this embodiment, the wave height is 8cm and the wavelength of the corrugated 2 is 40cm. When the wave height is 5cm to 10cm, when the soil slides relative to the box culvert, the soil must be forcibly lifted to a sufficiently significant height to cross the wave crest. This requires overcoming the soil's own gravity and shear force, thus consuming a huge amount of energy, which manifests as a significant increase in anti-sliding resistance. At the same time, seepage must bypass the wave crests and troughs. A wave height of 5cm to 10cm results in a tortuous seepage path, which significantly increases the mechanical interlocking force and the seepage path length, providing a significant and reliable improvement in anti-sliding and seepage prevention performance. Furthermore, limiting the wave height to within 10cm ensures that the effective thickness of the box culvert wall is not excessively weakened, and the bending moment and shear force at the root of the corrugation are controlled within the range that the concrete can withstand, avoiding cracking caused by stress concentration. This is a safe range determined through structural mechanics calculations and finite element analysis. Moreover, the trench depth of 5cm to 10cm ensures that conventional vibrating equipment on the market can work effectively. Its vibration radius is sufficient to affect the concrete at the deepest part of the trough, thereby ensuring its density. In actual engineering, this wave height range, combined with the optimal concave and convex angles, together form an ideal demolding slope, allowing the formwork to be smoothly separated from the concrete surface during removal.

[0019] Please see Figure 1The corrugated steel 2 covers the entire section of the box culvert body 1 buried in the dam soil. By ensuring seamless coverage of all contact areas between the box culvert and the dam soil, it achieves comprehensive and seamless protection against sliding and seepage. Its beneficial effect is the complete elimination of weak points caused by traditional smooth box culverts or interruptions due to local reinforcement measures. This allows the soil and structure to work synergistically at any contact point through mechanical interlocking and increased seepage path, thus ensuring the long-term stability and safety of the dam as a whole. This effect is achieved through a simple and reliable process: during the prefabrication or cast-in-place construction of the box culvert, the corrugated steel mold is formed and installed on the outer surface of the entire buried section in one step, achieving a significant performance improvement without additional steps.

[0020] Please see Figure 1 The box culvert body 1 and the corrugated sections 2 are precast from a single piece of concrete. By casting the box culvert body 1 and the corrugated sections 2 in a single process at the factory or on-site, a high degree of unity between structural integrity and functionality is achieved. Its core benefit is the complete elimination of weak areas at the interface that may result from phased construction, ensuring a seamless, high-strength connection between the corrugations and the main structure, thus allowing its anti-slip and seepage-proof properties to be fully realized and durable. This effect is achieved by using a specially designed detachable corrugated steel mold as the overall outer mold, completing the casting and vibration in one step during conventional precast or cast-in-place concrete processes. This not only does not increase construction complexity but also ensures uniform and reliable quality by simplifying the process, and eliminates the cost and time required for subsequent additional measures.

[0021] Please see Figure 1 In this embodiment, the cross-sectional shape of the convex-concave corrugation 2 is sinusoidal, the angle between the tangent of the arc in the cross-section and the horizontal plane is 15° to 20°, the wave height h = 5cm to 10cm, and the wavelength λ = 30cm to 50cm. Numerical simulation experiments were conducted, and the results based on the deterministic analysis model show that: Please refer to Figures 1-6 As can be seen from the maximum principal stress cloud diagram, significant stress concentration occurs at the junction of the culvert structure and the soil embankment. Tensile stress is observed at the top of the embankment, while significant shear stress is observed at the contact point between the riverbed and the upper side of the culvert. This is clearly due to the increased resistance to sliding between the culvert's uneven surface and the soil. Please refer to [reference needed]. Figures 2 to 6 In the cloud diagram, U1 represents the displacement in the x-direction, U2 represents the displacement in the y-direction, and U3 represents the displacement in the z-direction. The largest number in the cloud diagram scale represents its maximum settlement displacement. The simulation results in the figure show that the optimization of the culvert structure can reduce the settlement displacement of the dike by about 1.4 mm (under normal water level conditions), reduce the horizontal slippage at the junction of the soil and concrete structure by 1.0 mm (under normal water level conditions), and reduce the shear stress between the inclined culvert pad beam and the soil by 0.2 kPa.

[0022] Mechanical analysis of the optimized culvert reveals that the uneven surface increases the interfacial friction coefficient by 20%–30%, increases passive earth pressure, and significantly reduces relative displacement. In terms of seepage control, the seepage path length increases by approximately 1.4 times, effectively reducing the seepage gradient. Furthermore, compared to traditional precast concrete culvert construction, the new culvert uses detachable corrugated steel formwork, eliminating the need for additional construction steps and resulting in approximately 15% cost savings compared to adding a water-cutting ring. Specific Implementation Example 2 Please see Figure 7 The difference between this embodiment and Embodiment 1 is that the cross-sectional shape of the corrugated 2 is a trapezoid with two inclined sides of equal length, the angle between the inclined side and the horizontal plane is 15° to 20°, and the height of the cross-section of the corrugated 2 is 5cm to 10cm. By precisely controlling the angle between the inclined side and the horizontal plane to 15° to 20° and limiting the wave height to 5cm to 10cm, the anti-slip performance, structural efficiency and construction convenience are optimized. This angle range can most effectively convert soil shear force into soil lifting effect, thereby stimulating the maximum mechanical interlocking force and passive earth pressure, significantly enhancing anti-sliding stability; at the same time, this parameter ensures that the formwork is easy to manufacture and demold, and the concrete pouring density is high. Combined with a wave height of 5cm to 10cm, it provides a significant tooth depth to increase the seepage path and improve the anti-sliding force, while avoiding structural weakening and construction difficulties. It achieves the most reliable technical and economic benefits with the least engineering cost. When the cross-sectional shape of the concave-convex corrugation 2 is an isosceles trapezoid, the trapezoidal cross-section (especially the isosceles trapezoid) has a higher moment of inertia than the arc cross-section. This means that, with the same amount of concrete, trapezoidal corrugations have greater stiffness and strength, less deformation when subjected to external earth pressure, and can more reliably transfer loads to the surrounding soil, resulting in higher structural efficiency. Straight trapezoidal formwork is easier to manufacture, more precise, and cheaper than complex curved surface (such as sine) formwork. Trapezoidal shapes can also achieve the purpose of extending the seepage path. Although the transition of trapezoidal shapes is not as uniform as that of sine waves, trapezoidal sheet metal construction is more convenient and has lower construction costs.

[0024] In summary, this utility model optimizes the outer contour of a traditional concealed culvert by geometrically modifying it. Continuous, equidistant, and unidirectional corrugated patterns 2 are provided on the outer surfaces of the top and bottom plates of the culvert body 1. This increases the anti-sliding force between the culvert and the soil, transforming the sliding resistance from simple friction to a combination of friction and soil shear resistance. This significantly improves the shear strength of the interface. Simultaneously, the corrugated pattern 2 forces seepage to circumvent the tortuous surface, resulting in a much longer path than a straight path. This extended seepage path directly reduces the hydraulic gradient. When the hydraulic gradient is lower than the critical gradient of the soil, the seepage cannot carry away soil particles, thus fundamentally inhibiting contact scouring and piping. This ensures stable seepage under a given seepage gradient and effectively prevents leakage at the joint.

[0025] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A corrugated outer contour box culvert, comprising several box culvert pipe sections (1), the several box culvert pipe sections (1) being arranged along the length direction, and the sections of the several box culvert pipe sections (1) being connected by tongue and groove joints and waterstops, characterized in that, The outer surface of the top plate and the outer surface of the bottom plate of the box culvert (1) are continuously provided with a number of concave and convex corrugations (2) along the length direction. The length direction of the concave and convex corrugations (2) is consistent with the width direction of the box culvert (1).

2. A corrugated outer contour box culvert according to claim 1, characterized in that, The cross-sectional shape of the undulating ripples (2) is sinusoidal, and the angle between the tangent of the arc in the cross-section and the horizontal plane is 15° to 20°.

3. A corrugated outer contour box culvert for embankment penetration according to claim 2, characterized in that, The wave height of the undulating ripples (2) is 5cm to 10cm.

4. A corrugated outer contour box culvert according to claim 1, characterized in that, The wavelength of the undulating ripples (2) is 30cm to 50cm.

5. A corrugated outer contour box culvert according to claim 1, characterized in that, The cross-sectional shape of the undulating ripples (2) is a trapezoid with two hypotenuses of equal length, and the angle between the hypotenuses and the horizontal plane is 15° to 20°.

6. A corrugated outer contour box culvert for embankment penetration according to claim 5, characterized in that, The height of the cross section of the undulating ripples (2) is 5cm to 10cm.

7. A corrugated outer contour box culvert according to claim 1, characterized in that, The corrugated pattern (2) covers the entire section of the box culvert (1) buried in the soil of the dam.

8. A corrugated outer contour box culvert according to claim 1, characterized in that, The box culvert body (1) and the corrugated (2) are precast from concrete.

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