Bionic drainage I-shaped beam structure

Abstract

The bionic drainage I-shaped beam structure comprises an I-shaped beam body, drainage faces used for draining water flow are arranged on the top faces of lower flanges on the two symmetrical sides of the I-shaped beam body, and slotting drainage structures are arranged on the drainage faces and used for guiding the water flow to be drained outwards; the grooving drainage structure is arranged to be a plurality of sets of drainage grooves perpendicular to the beam shaft, the drainage grooves are arranged to be in a semi-frustum shape or a semi-cone shape, and the width and the depth of the drainage grooves are gradually increased in the outward direction. According to the invention, the drainage channel is designed into the semi-circular truncated cone shape or the semi-circular cone shape capable of generating Laplace pressure difference, and the cone shape and the circular truncated cone shape which are subjected to axial section cutting are ingeniously integrated into the design of the drainage channel of the lower flange of the I-shaped beam, so that the channel body has a self-driven directional water delivery function, and the water flow moving effect of the drainage channel is improved.

Description

Technical Field

[0001] The invention relates to the technical field of drainage structures, and in particular to a bionic drainage I-beam structure. Background Art

[0002] Corrosion is the core factor affecting the durability of steel bridges, and weathering steel is favored for its excellent corrosion resistance. Weathering steel, with its unique naked use method, forms a dense and stable rust layer, effectively isolates the contact between the corrosive medium and the steel matrix, achieves long-term anti-corrosion goals, and significantly reduces maintenance costs. However, its effectiveness is restricted by environmental factors, especially in poor drainage environments, where it is difficult to achieve the expected effect.

[0003] In-depth investigations into corrosion problems on a large number of weathering steel bridges revealed that the corrosion problem of the lower flange plate of the I-beam is particularly prominent. This is because water from the bridge deck or upper flange easily splashes onto the lower flange during its downward flow, causing the lower flange to be in a wet state for a long time, making it difficult to form a stable rust layer, which in turn causes continuous corrosion, posing a serious threat to the structural function and safety of the bridge.

[0004] Therefore, most existing technologies solve this problem by optimizing structural details and drainage systems, especially at the lower flange of the I-beam, to promote the formation of a stable rust layer and address the application limitations in different climates and bridge scales.

[0005] However, various solutions have certain advantages and disadvantages in practical applications and need to be selected and optimized according to specific engineering conditions and requirements, such as:

[0006] (1) The inclined drainage solution of the lower flange plate proposed in the Japanese technical standard has advantages in short-distance drainage, but it is difficult to process;

[0007] (2) The longitudinal slope drainage scheme proposed in the US NCHRP314 report may be effective when the bridge length is short, but for bridges with large spans and bridge lengths, the longitudinal water flow may cause serious erosion of the surface rust layer, especially at the ends of the bridge, where the erosion phenomenon is particularly prominent;

[0008] (3) The drainage effect of the conventional solution of removing part of the stiffening ribs is greatly affected by natural wind and has uncertainty;

[0009] (4) The conventional solution of sealing corners with welded inclined plates can improve the problem of water accumulation, but the newly formed corner structure may become a new water accumulation point.

[0010] To this end, the present application proposes a bionic drainage I-beam structure to solve the above technical problems. Summary of the invention

[0011] The main purpose of the present invention is to provide a bionic drainage I-beam structure, which is based on the bionic water collection structure, considers the driving effect of Laplace pressure difference and surface energy gradient driving the directional transport of droplets, and improves the traditional I-beam structure to solve the above technical problems.

[0012] The present invention adopts the following technical solutions to solve the above technical problems:

[0013] A bionic drainage I-beam structure comprises an I-beam main body, wherein the top surfaces of lower flanges on two symmetrical sides of the I-beam main body are provided with drainage surfaces for discharging water.

[0014] Preferably, a grooved drainage structure is provided on the drainage surface to guide water to be discharged outwards.

[0015] Preferably, the grooved drainage structure is configured as a plurality of drainage grooves perpendicular to the beam axis.

[0016] Preferably, the drainage groove is arranged in a semi-conical shape, and the width and depth of the drainage groove gradually increase in the outward direction. The dimensional parameters of the drainage groove include groove depth, top width and bottom width, inclination slope of the groove bottom surface and the spacing between grooves, and all are numerically simulated by finite element to meet the generated Laplace pressure difference and surface energy gradient to achieve the optimal moisture migration effect.

[0017] Preferably, the drainage groove is arranged in a semi-conical shape, and the width and depth of the drainage groove gradually increase in the outward direction. The dimensional parameters of the drainage groove include groove depth, top width and bottom width, inclination slope of the groove bottom surface and spacing between grooves, and all are numerically simulated by finite element to meet the generated Laplace pressure difference and surface energy gradient to achieve the optimal moisture migration effect.

[0018] Preferably, the specific parameter selection includes:

[0019] (1) For the groove depth h c , there is a thickness t2 of the lower flange of the I-beam, so:

[0020]

[0021] (2) For the top width B1 and bottom width B2 of the drainage trough, we have:

[0022]

[0023] (3) For the groove bottom slope i B , exists: i B ∈[2%, 7%];

[0024] (4) For the spacing l between adjacent grooves, there exists: l∈[10cm, 15cm].

[0025] Preferably, the drainage surface is configured as a homogeneous inclined surface for cooperating with the drainage groove to guide water to be discharged outwards.

[0026] Preferably, the drainage surface has an inclination gradient p∈[1%, 2%].

[0027] The present invention provides a bionic drainage I-beam structure. Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention designs the drainage trough to be a semi-conical or semi-conical shape that can generate a Laplace pressure difference, and cleverly integrates the cone and truncated cone shapes cut through the axial section into the drainage trough design of the lower flange of the I-beam, so that the trough body can have a self-driven directional water delivery function, thereby improving the water flow movement effect of the drainage trough.

[0029] 2. The present invention sets the drainage surface as a homogeneous inclined surface and utilizes the drainage grooves that can generate Laplace pressure difference arranged on the homogeneous inclined surface, which can cooperate with the homogeneous inclined surface to further significantly enhance the drainage effect of the top surface of the lower flange. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 It is an overall three-dimensional schematic diagram of the I-beam structure of the present invention;

[0032] Figure 2 It is a three-dimensional schematic diagram of a homogeneous inclined surface of an I-beam structure of the present invention;

[0033] Figure 3 The overall three-dimensional schematic diagram of the drainage groove structure arranged on the I-beam structure of the present invention Figure 1 ;

[0034] Figure 4 The overall three-dimensional schematic diagram of the drainage groove structure arranged on the I-beam structure of the present invention Figure 2 ;

[0035] Figure 5 It is a plan view of the semi-conical drainage trough structure of the present invention;

[0036] Figure 6 It is a plan view of a semi-conical drainage trough structure of the present invention;

[0037] Figure 7 The overall three-dimensional schematic diagram of the drainage groove structure provided on the homogeneous inclined surface of the present invention Figure 1 ;

[0038] Figure 8The overall three-dimensional schematic diagram of the drainage groove structure provided on the homogeneous inclined surface of the present invention Figure 2 ;

[0039] Fig. 9 It is a schematic diagram of the principle of directional movement of water droplets in a semi-conical drainage groove of the present invention;

[0040] Fig.10 It is a schematic diagram of the principle of directional movement of water droplets in a semi-conical drainage groove of the present invention;

[0041] Fig.11 This is an example diagram comparing the effects of the drainage ditch foundation on different drainage surfaces of the present invention.

[0042] In the figure:

[0043] 1. I-beam body; 2. Drainage surface; 3. Drainage trough. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0045] In the embodiment, see Figures 1 to 11 .

[0046] The current I-beam structural design and drainage measures of weathering steel bridges have failed to effectively promote the formation of a stable rust layer on the surface of weathering steel. Among the corrosion problems of a large number of weathering steel bridges, the corrosion problem of the lower flange plate of the I-beam is particularly prominent. This is because the water flow on the bridge deck or upper flange easily splashes to the lower flange during the downward flow, causing the lower flange to be in a wet state for a long time, making it difficult to form a stable rust layer, and then causing continuous corrosion, which poses a serious threat to the structural function and safety of the bridge.

[0047] Therefore, in the prior art, Japan has put forward specific suggestions for the structural design of I-beams in the "Design and Construction Guidelines for Uncoated Weather-Resistant Bridges", that is, when welding the web and the lower flange, appropriate anti-deformation treatment should be carried out first to prevent water accumulation.

[0048] Meanwhile, the US NCHRP314 report puts forward a different viewpoint, arguing that rolling the inclined lower flange is difficult, and similar drainage effects can be achieved by setting a longitudinal slope in the longitudinal direction of the beam, that is, a certain angle of inclination from the mid-span to the end of the beam. In addition, the report also discusses the design of vertical stiffening ribs, and proposes a solution of removing some stiffening ribs or opening openings to promote ventilation and drainage.

[0049] In summary, the existing technical requirements and design recommendations for the I-beam structure of weathering steel bridges mainly revolve around the core issue of drainage.

[0050] However, the inclined drainage scheme of the lower flange plate proposed by the current Japanese technical standards has advantages in short-distance drainage, but it is difficult to process. The longitudinal slope drainage scheme in the US report may be effective when the bridge length is short, but for bridges with large spans and bridge lengths, the longitudinal water flow may cause serious surface rust scouring, especially at both ends of the bridge. As for the scheme of cutting off part of the stiffening ribs, its drainage effect is greatly affected by natural wind and is uncertain. The scheme of using welded inclined plates to close corners can improve the problem of water accumulation, but the newly formed corner structure may become a new water accumulation point.

[0051] Therefore, Fig. 9 and Fig.10 As shown, the present invention combines a bionic water collection mechanism (for example, water collection by cactus and spider silk, through the conical structure with its own curvature gradient, so that the local radii at the two ends of the droplet are different, thereby generating a Laplace pressure difference, thereby realizing directional transport of the droplet), considers the movement behavior of water droplets on the conical fiber, and the driving force for the directional transport of the droplets mainly comes from the Laplace pressure difference and the surface energy gradient, among which the Laplace pressure difference is affected by the curvature gradient and capillary effect, etc., provides a bionic drainage I-beam structure, and proposes a structural design that applies the water collection mechanism of a bionic structure to the lower flange of the I-beam of a weathering steel bridge.

[0052] The bionic drainage I-beam structure comprises an I-beam body 1, and the top surfaces of the lower flanges on both sides of the I-beam body 1 are symmetrically provided with drainage surfaces 2 (such as Figure 1 As shown in FIG. 1 , a grooved drainage structure is provided on the drainage surface 2. The grooved drainage structure is configured as a plurality of drainage grooves 3 perpendicular to the beam axis, which are used to guide the water flow to be discharged outward. At this time, the drainage grooves 3 have two specific structures that meet the Laplace pressure difference and the surface energy gradient:

[0053] (1) Figure 4 and Figure 6 As shown, the drainage groove 3 of the simulated spider silk water collection structure is set to a semi-conical shape, and the width and depth of the drainage groove 3 gradually increase in the outward direction. The size parameters of the drainage groove 3 include the groove depth, the top width and the bottom width, the inclination slope of the groove bottom surface and the spacing between the grooves, and all are numerically simulated by finite element to meet the generated Laplace pressure difference and surface energy gradient to achieve the optimal water migration effect;

[0054] (2) Figure 3 and Figure 5As shown, simulating a cactus water collection structure, the drainage groove 3 is set to a semi-conical shape, and the width and depth of the drainage groove 3 gradually increase in the outward direction. The dimensional parameters of the drainage groove 3 include the groove depth, top width and bottom width, the inclination slope of the groove bottom surface and the spacing between the grooves, and all are numerically simulated by finite element to meet the generated Laplace pressure difference and surface energy gradient to achieve the optimal water migration effect.

[0055] In summary, the drainage groove 3 at this time is endowed with the Laplace pressure gradient of the lower flange bionic drainage groove 3 through shape design, and the Laplace pressure gradient is quantified.

[0056] In a specific embodiment, the size parameter selection of the drainage groove 3 can be specifically quantified as follows:

[0057] a1. For groove depth h c , there is a thickness t2 of the lower flange of the I-beam, so:

[0058]

[0059] a2. In order to satisfy the Laplace pressure difference and surface energy gradient, for the top width B1 and bottom width B2 of the drainage groove, we have:

[0060]

[0061] a3. For the groove bottom slope i B , exists: i B ∈[2%, 7%];

[0062] a4. For the spacing l between adjacent slots, there exists: l∈[10cm, 15cm].

[0063] Therefore, the drainage trough 3 simulates the cone structure and truncated cone structure of cactus and spider silk. By designing the drainage trough 3 to be a semi-truncated cone or semi-conical shape that can generate a Laplace pressure difference, the cone and truncated cone shapes cut through the axial section are cleverly integrated into the design of the drainage trough 3 at the lower flange of the I-beam, which can enable the trough body to have a self-driven directional water supply function, thereby improving the water flow movement effect of the drainage trough 3.

[0064] In general, the drainage slope cannot be lower than 0.3% and not greater than 7%. Therefore, from the perspective of economy and stress safety, the groove depth cannot be too large, otherwise the interface will be excessively weakened. Therefore, the design of the depth of the bionic drainage groove is mainly to limit the maximum depth of the drainage groove to no more than 4mm; because when the depth is 4mm, the most unfavorable situation corresponds to a relatively small plate thickness, reaching ≤16mm. At this time, the groove depth accounts for 1 / 4 of the plate thickness, and the net thickness of the plate is 3 / 4, accounting for 75%, which can ensure the section strength.

[0065] In addition, the surface energy gradient provides a way to drive the movement of droplets other than gravity. Through clever surface design, precise control of droplet morphology and dynamic behavior can be achieved.

[0066] Therefore, by using multiple parameter control variables, multiple parameters and value ranges of the drainage trough can be provided, and the practical feasibility of the parameters and value ranges can be demonstrated based on actual experiments.

[0067] Further, such as Figure 2 As shown, the drainage surface 2 is configured as a homogeneous inclined surface for guiding water to be discharged outwardly, and combined with the above-mentioned drainage groove, the inclination parameters of the homogeneous inclined surface can be further limited: the inclination slope of the drainage surface p∈[1%, 2%].

[0068] At this time, when designing the lower flange plate, a gradient surface element is innovatively introduced. The reverse bending deformation scheme recommended in the Japanese standard is referred to and improved. The bottom surface of the lower flange is kept horizontal, and an inclined slope is set on the top surface, that is, an inclined uniform surface. The inclined slope refers to the drainage slope value commonly used in highway bridge decks. It can be further combined with the shape of the bionic drainage groove 3 (such as Figure 7 and Figure 8 As shown in the figure, two types of gradient surfaces, including horizontal gradient surface and inclined gradient surface, are set to significantly enhance the drainage effect of the top surface of the lower flange.

[0069] Therefore, by arranging the drainage groove 3 capable of generating the Laplace pressure difference on the homogeneous inclined surface, the drainage effect of the top surface of the lower flange can be further significantly enhanced in coordination with the homogeneous inclined surface.

[0070] In a specific embodiment, the following experiment (hereinafter referred to as part of the experimental data) was performed to determine some parameters of the drainage trough of the present application:

[0071] (1) For the truncated cone-shaped drainage trough, the top width B1 below the horizontal drainage surface is:

[0072]

[0073]

[0074] (2) For conical drainage grooves and truncated cone drainage grooves, the bottom surface slope i B , taking the truncated cone-shaped drainage trough as an example:

[0075]

[0076] (3) For the spacing l between adjacent grooves of conical drainage grooves and truncated cone drainage grooves, take the truncated cone drainage groove as an example:

[0077]

[0078] In a specific embodiment, the following experiments were performed to demonstrate the effectiveness of the present application in practical applications:

[0079] The thickness of the lower flange of the I-beam is 30mm. After the corresponding drainage groove is precisely chiseled, the following is found:

[0080] (1) After 30 minutes in a humid environment, the moisture content on the top surface of the lower flange is tested:

[0081]

[0082] (2) After testing the moisture content on the top surface of the lower flange in a humid environment for 1 hour, the following are obtained:

[0083]

[0084]

[0085] (3) After testing the moisture content on the top surface of the lower flange in a humid environment for 2 hours, the following are obtained:

[0086]

[0087] In summary, if Fig.11 As shown, it can be clearly seen that during the use of I-beams with different drainage surfaces and drainage grooves, there is an obvious drainage difference in the moisture content on the top surface of the lower flange. Therefore, the application of the present invention on actual bridge foundations should also have a good corrosion resistance effect.

[0088] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0089] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, in the embodiments of the present invention, "multiple" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A bionic drainage I-beam structure, comprising an I-beam body (1), characterized in that: The top surfaces of the lower flanges on both sides of the I-beam body (1) are symmetrically provided with drainage surfaces (2) for draining water, and the drainage surfaces (2) are provided with a grooved drainage structure for guiding the water to be discharged outwards; The grooved drainage structure is configured as a plurality of drainage grooves (3) perpendicular to the beam axis; the drainage grooves (3) are configured in a semi-conical shape or a semi-conical shape, and the width and depth of the drainage grooves (3) gradually increase in an outward direction.

2. The bionic drainage I-beam structure according to claim 1, characterized in that: The dimensional parameters of the drainage groove (3) include groove depth, top width and bottom width, the inclination slope of the groove bottom surface and the spacing between grooves, and all are simulated by finite element numerical simulation to meet the generated Laplace pressure difference and surface energy gradient to achieve the optimal water migration effect.

3. The bionic drainage I-beam structure according to claim 2, characterized in that: The specific parameter selection includes: (1) For the groove depth h c , there is a thickness t2 of the lower flange of the I-beam, so: (2) For the top width B1 and bottom width B2 of the drainage trough, we have: (3) For the groove bottom slope i B , exists: i B ∈[2%, 7%]; (4) For the spacing l between adjacent grooves, there exists: l∈[10cm, 15cm].

4. The bionic drainage I-beam structure according to any one of claims 1 to 3, characterized in that: The drainage surface (2) is configured as a homogeneous inclined surface, and is used to guide water to be discharged outwards.

5. The bionic drainage I-beam structure according to claim 4, characterized in that: The drainage surface (2) has an inclination gradient p∈[1%, 2%].

6. A drainage method for an I-beam structure, characterized in that: The bionic drainage I-beam structure according to any one of claims 1 to 5 is implemented, including the following process: S1. When liquid contacts the top surface of the lower flanges on both sides of the symmetrical I-beam, the droplets gather on the weathering steel bridge I-beam and enter into a plurality of densely parallel drainage grooves (3); S2. The drainage groove (3) is configured to be semi-conical or semi-conical, and the width and depth of the drainage groove (3) gradually increase in the outward direction to form a Laplace pressure difference and a surface energy gradient; S2. Based on the Laplace pressure difference and surface energy gradient, the drainage groove (3) self-drives the droplets to move toward the outer edge of the I-beam in the drainage groove (3) until the I-beam separates and discharges the droplets.

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