A steel-concrete composite orthotropic bridge deck and a design method thereof

Abstract

The application discloses a steel-concrete composite orthotropic bridge deck and a design method thereof, and relates to the technical field of civil engineering, and solves the technical problem of a heavy self-weight and high steel ratio of a bridge deck in the prior art; the application comprises a concrete layer, a reinforcing mesh and a bottom steel plate are arranged in the concrete layer, the bottom steel plate is arranged at the bottom of the concrete layer, an open-hole steel plate is vertically arranged between the reinforcing mesh and the bottom steel plate, the open-hole steel plates are arranged in an array, the concrete layer between the longitudinally arranged open-hole steel plates is provided with a trapezoidal hollowing-out portion, the reinforcing mesh comprises transverse steel bars and longitudinal steel bars, and when the concrete layer is cast, concrete flows into the round holes of the open-hole steel plates to form concrete dowel shear connectors; and the concrete layer is made of ultra-high performance concrete; the application has a high concrete hollowing-out rate, a small cross-sectional area and a light self-weight, and solves the problem of a heavy self-weight of a steel-concrete composite orthotropic bridge deck.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of civil engineering, in particular to a steel-concrete composite orthotropic bridge deck and a design method thereof. BACKGROUND

[0002] The steel-concrete composite orthotropic deck can obviously improve the stiffness of the steel orthotropic bridge deck and greatly relieve the fatigue problem of the steel orthotropic bridge deck by pouring a layer of ordinary concrete or a layer of ultra-high performance concrete on the steel orthotropic bridge deck. However, the concrete layer of the steel-concrete composite orthotropic deck is usually in the form of a solid plate, which increases the dead load of the structure and the stress of the steel structure under the primary constant load. Meanwhile, due to the high steel ratio and large amount of steel, the economy of the steel-concrete composite orthotropic deck is greatly reduced, and the application range is mainly limited to large-span bridges with strict weight limits on the bridge deck. SUMMARY

[0003] In order to solve the problems in the prior art, the present application provides a steel-concrete composite orthotropic bridge deck and a design method thereof, which solve the technical problems of heavy bridge deck and high steel ratio in the prior art.

[0004] The steel-concrete composite orthotropic bridge deck comprises a concrete layer, a steel mesh and a bottom steel plate. The bottom steel plate is arranged at the bottom of the concrete layer, and the steel mesh is arranged above the bottom steel plate. A perforated steel plate is vertically arranged between the steel mesh and the bottom steel plate. The perforated steel plates are arranged in an array. The concrete layer between the longitudinally arranged perforated steel plates is provided with a trapezoidal hollow. The steel mesh comprises transverse steel bars and longitudinal steel bars. When the concrete layer is poured, the concrete flows into the round holes of the perforated steel plate to form a concrete dowel shear connector. The concrete layer is made of ultra-high performance concrete.

[0005] Specifically, the concrete and the bottom steel plate are longitudinally connected to form a steel-concrete composite plate. The steel mesh is supported on the top of the perforated steel plate. The longitudinal steel bars are arranged in the upper layer, and the transverse steel bars are arranged in the lower layer, thereby forming a reinforced concrete plate reinforced by the transverse steel bars upwardly.

[0006] Further, the thickness of the bottom steel plate is 8-10 mm. The upper base length S3 of the trapezoidal hollow is not greater than 400 mm. The lower base length S4 of the trapezoidal hollow is not greater than 500 mm. The included angle between the inclined edge of the trapezoidal hollow and the horizontal line is not less than 60°. The minimum spacing S2 of the trapezoidal hollow is not less than 100 mm. The diameter of the transverse steel bars of the steel mesh is 8-12 mm. The diameter of the longitudinal steel bars of the steel mesh is 16-22 mm.

[0007] The design method of the steel-concrete composite orthotropic bridge deck comprises the following steps:

[0008] Step 1: determining the spacing S1 of the longitudinally arranged perforated steel plates;

[0009] Step 2: Determine the thickness of the concrete layer h and the effective height h1, which refers to the height from the upper base of the trapezoidal hollow to the top of the concrete layer;

[0010] Step 3: Calculate the shear strength of the bridge deck;

[0011] Step 4: Calculate the bending capacity M of the bridge deck under the action of positive bending moment; max ;

[0012] Step 5: Calculate the bending capacity Mu of the bridge deck under the action of negative bending moment (when the bottom steel plate is in the compression zone).

[0013] Specifically, after the calculation is completed, the relevant construction personnel can verify whether the shear strength, the bending capacity M under the action of positive bending moment max , and the bending capacity Mu under the action of negative bending moment meet the construction requirements.

[0014] Further, the step 1 comprises:

[0015] Step 1.1: Calculate the shear envelope diagram according to the transverse shear influence line, and obtain the maximum shear Q per unit longitudinal length max ;

[0016] Step 1.2: Calculate the number n of concrete dowel shear connectors required for a bridge deck with a width of b2 and a length of a unit length (1 meter)

[0017]

[0018] In the formula: f c is the cube strength of ultra-high performance concrete, f c ≤ 140 MPa, A cj is the area of the concrete dowel;

[0019] Step 1.3: Determine the opening spacing S5 of the perforated steel plate according to the "Design and Construction Specification for Highway Steel-Concrete Composite Bridges";

[0020] Step 1.4: Calculate the spacing S1 of the perforated steel plate

[0021]

[0022] In the formula, n2 is the number of concrete dowel shear connectors per unit length of the bridge deck.

[0023] Further, the step 2 comprises:

[0024] Step 2.1: Calculate the bending moment M borne by the cross section of a single bridge deck unit;

[0025] Step 2.2: Calculate the height of the limit compression zone of the cross section ξ b ;

[0026]

[0027] where β is the conversion coefficient of the height of the cross-section compression zone, f s is the design strength of the bottom steel plate, E s is the elastic modulus of the bottom steel plate, ε cu is the ultimate compressive strain of the concrete, taken as 0.0027;

[0028] Step 2.3: Calculate the theoretical height of the cross-section by the balance of the cross-section bending moment

[0029]

[0030] where A s is the area of the bottom steel plate of a single bridge deck unit, h c is the theoretical height of the cross-section;

[0031] Step 2.4: Calculate the thickness of the concrete layer h

[0032] h = max(h c , (b1+d1+d2+c))

[0033] where b1 is the height of the perforated steel plate, d1 is the diameter of the bottom layer of steel bars, d2 is the diameter of the top layer of steel bars, and c is the thickness of the protective layer;

[0034] Step 2.5: Calculate the effective height of the concrete layer h1

[0035] h1 = ξ b h

[0036] Further, Step 3 includes:

[0037] Step 3.1: Calculate the maximum shear force V borne by a single bridge deck unit by using the method of simulating orthotropic bridge deck u ;

[0038] Step 3.2: Calculate the shear force V borne by the steel fibers in the concrete layer of a single bridge deck unit f ;

[0039]

[0040] where d f is the diameter of the steel fibers, ρ f is the volume content ratio of the steel fibers, l f is the length of the fibers, τ f is the average bond strength, γ is the effective action coefficient of the fibers, λ is the shear span ratio, and S2 is the rib width of a single bridge deck unit, i.e., the minimum distance S2 of the trapezoidal excavation space;

[0041] Step 3.3: Calculate the shear contribution of the concrete in the shear compression zone of the individual deck unit V c

[0042]

[0043] where ρ s is the cross-sectional steel ratio, only the bottom steel plate is counted;

[0044] Step 3.4: Calculate the shear capacity V of the deck, i.e. the shear strength

[0045] V = V c + V f

[0046] Step 3.5: If V ≥ V u , the shear capacity meets the requirements, if V < V u , increase S2, repeat 3.2-3.4 until V ≥ V u .

[0047] Further, the step 5 includes:

[0048] determining whether the neutral axis is in the bottom steel plate and performing corresponding calculations; if formula (8) is met, the neutral axis is in the bottom steel plate, otherwise the neutral axis is in the concrete

[0049]

[0050] where f sb is the design strength of longitudinal reinforcement, A sb is the area of longitudinal reinforcement, is the stress non-uniformity coefficient of the tensile zone ultra-high performance concrete f t is the tensile design strength of ultra-high performance concrete, and Ac is the concrete area;

[0051] Further, if the neutral axis is in the bottom steel plate, the calculation process includes:

[0052] Step 5.11: Calculate the position of the neutral axis

[0053]

[0054] where b is the full width of the deck, x is the height of the compression zone of the bottom steel plate, the position x of the neutral axis is calculated from the formula, and h s is the thickness of the bottom steel plate;

[0055] Step 5.12: Calculate the bending capacity M u

[0056]

[0057] Furthermore, if the central axis is within the concrete, the calculation process includes:

[0058] Step 5.21: Calculate the neutral axis position

[0059] f s bh s +f c bx c =f sb A sb +f t bh1

[0060] Where b is the full width of the bridge deck, x c is the height of the concrete compression zone; the neutral axis position x is calculated from this formula c ;

[0061] Step 5.22: Calculate the bending capacity M u

[0062]

[0063] Substitute x into the above formula and calculate M u .

[0064] The beneficial effects of the present invention include:

[0065] (1) The concrete hollowing rate is high, the cross-sectional area is small, and the deadweight is light, which solves the problem of heavy deadweight of steel-concrete orthotropic bridge deck.

[0066] (2) The steel plate and concrete are far away from the central axis, with high bending efficiency, large cross-sectional inertia moment and high bending stiffness.

[0067] (3) Compared with steel-concrete composite orthotropic bridge decks, the lack of stiffening ribs significantly reduces the amount of steel used and reduces the cost, thus solving the current problem of large steel consumption and high cost of steel-concrete composite orthotropic bridge decks.

[0068] (4) The cross-sectional design method for covering the opening steel plate, concrete layer thickness, concrete effective thickness and bottom steel plate thickness are proposed, which solves the problem of the current steel-concrete orthotropic bridge deck design relying on experience.

[0069] (5) The proposed calculation method does not require finite element modeling and is more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 This is a partial schematic diagram of a steel-concrete composite orthotropic bridge deck.

[0071] Figure 2 Schematic diagram for calculating bending capacity when the neutral axis is inside the steel plate.

[0072] Figure 3 Schematic diagram for calculating the bending resistance of the central axis in the concrete.

[0073] Figure 4 Front view of a steel-concrete composite orthotropic bridge deck.

[0074] Figure 5 Front view of a steel-concrete composite orthotropic bridge deck. Figure 1 .

[0075] Figure 6 Front view of a steel-concrete composite orthotropic bridge deck. Figure 2 .

[0076] Figure 7 Front view of a steel-concrete composite orthotropic bridge deck. Figure 3 .

[0077] Reference signs

[0078] 101 - bottom steel plate, 102 - trapezoidal hollowing, 103 - perforated steel plate, 1031 - round hole, 201 - concrete layer, 202 - steel mesh, 2021 - transverse steel bar, 2022 - longitudinal steel bar. DETAILED DESCRIPTION

[0079] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application and not all the embodiments. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person skilled in the art without creative work fall within the scope of protection of the present application.

[0080] A steel-concrete composite orthotropic bridge deck, as shown in Figures 4-7 , comprises a concrete layer 201, a steel mesh and a bottom steel plate 101 are arranged in the concrete layer 201, the bottom steel plate 101 is arranged at the bottom of the concrete layer 201, the steel mesh is arranged above the bottom steel plate 101, a perforated steel plate 103 is vertically arranged between the steel mesh and the bottom steel plate 101, the perforated steel plates 103 are arranged in an array, the concrete layer 201 between the longitudinally arranged perforated steel plates 103 is provided with a trapezoidal hollowing 102, the steel mesh comprises transverse steel bars 2021 and longitudinal steel bars, and when the concrete layer 201 is poured, the concrete flows into the round holes 1031 of the perforated steel plates 103 to form concrete dowel shear connectors.

[0081] Specifically, the trapezoidal hollow 102 is a longitudinally arranged trapezoidal through hole, and the concrete and the bottom steel plate 101 are longitudinally connected to form a steel-concrete composite plate; the steel bar net is supported on the top of the perforated steel plate 103, the longitudinal steel bars are arranged on the upper layer, and the transverse steel bars 2021 are arranged on the lower layer, thereby forming a reinforced concrete slab reinforced by the transverse steel bars 2021.

[0082] Further, the thickness of the bottom steel plate 101 is 8mm-10mm, the upper base length S3 of the trapezoidal hollow 102 is not greater than 400mm, the lower base length S4 of the trapezoidal hollow 102 is not greater than 500mm, the angle between the inclined side of the trapezoidal hollow 102 and the horizontal line is not less than 60°, and the minimum spacing S2 between the trapezoidal hollows is not less than 100mm; the diameter of the transverse steel bars 2021 of the steel bar net is between 8mm and 12mm, and the diameter of the longitudinal steel bars of the steel bar net is between 16mm and 22mm.

[0083] In another embodiment, a design method of a steel-concrete composite orthotropic bridge deck is disclosed, which is used for designing a steel-concrete composite orthotropic bridge deck, such as Figures 1-3 as shown, comprising the following steps:

[0084] Step 1: determining the spacing S1 between the longitudinally arranged perforated steel plates;

[0085] Step 2: determining the thickness h of the concrete layer and the effective height h1, wherein the effective height h1 refers to the height from the upper base of the trapezoidal hollow to the top of the concrete layer; and the upper base of the trapezoidal hollow refers to the top plane edge of the trapezoidal hollow;

[0086] Step 3: calculating the shear strength of the bridge deck;

[0087] Step 4: calculating the bending capacity M max of the bridge deck under the action of positive bending moment, which is specifically calculated according to the “Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts”;

[0088] Step 5: calculating the bending capacity Mu of the bridge deck under the action of negative bending moment (when the bottom steel plate is located in the compression zone).

[0089] In another embodiment, the step 1 comprises:

[0090] Step 1.1: calculating the shear envelope diagram according to the transverse shear influence line, and obtaining the maximum shear Q max per unit longitudinal length;

[0091] Step 1.2: calculating the number n of concrete dowel shear connectors required for the bridge deck with a width of b2 and a length of unit length (1m);

[0092]

[0093] In the formula, f cFor the ultra-high performance concrete cube strength, f c ≤ 140 MPa, Acj is the concrete dowel area;

[0094] Step 1.3: Determine the hole spacing S5 of the perforated steel plate according to the "Code for Design and Construction of Highway Steel-concrete Composite Bridges";

[0095] Step 1.4: Calculate the spacing S1 of the perforated steel plate:

[0096]

[0097] In the formula, b1 is the full width of the bridge deck, n2 is the number of bridge deck concrete dowel shear connectors per unit length.

[0098] In another embodiment, the step 2 comprises:

[0099] Step 2: Determine the thickness h and effective height h1 of the concrete layer;

[0100] Step 2.1: Calculate the bending moment M borne by a single bridge deck unit;

[0101] Step 2.2: Calculate the cross-section boundary compression zone height ξ of the bridge deck unit b

[0102]

[0103] In the formula: β is the cross-section compression zone height conversion coefficient, f s is the design strength of the bottom steel plate material, E s is the elastic modulus of the bottom steel plate, ε cu is the ultimate compressive strain of concrete, which is taken as 0.0027.

[0104] Step 2.3: Calculate the cross-section theoretical height h

[0105]

[0106] In the formula: A s is the area of the bottom steel plate of a single bridge deck unit, h c is the cross-section theoretical height;

[0107] Step 2.4: Calculate the thickness h of the concrete layer

[0108] h = max(h c , (b1 + d1 + d2 + c))

[0109] In the formula: b1 is the height of the perforated steel plate, d1 is the diameter of the bottom layer of steel bars, d2 is the diameter of the top layer of steel bars, and c is the thickness of the protective layer.

[0110] Step 2.5: Calculate the effective height h1 of the concrete layer

[0111] h1= ξ b h

[0112] In another embodiment, the step 3 comprises:

[0113] Step 3.1: Calculate the maximum shear force V taken by a single bridge deck unit by using the method of analogy orthotropic bridge deck. u ;

[0114] Step 3.2: Calculate the shear force V taken by steel fibers in the concrete layer of a single bridge deck unit. f ;

[0115]

[0116] In the formula, d is the diameter of steel fiber, p is the volume fraction of steel fiber, l is the fiber length, τ is the average bond strength, and γ is the effective action coefficient of fiber, γ = 0.763, λ is the shear span ratio, and S2 is the rib width of a single bridge deck unit, that is, the minimum distance S2 of the trapezoidal excavation space. f ; f ; f ; f ; γ is the effective action coefficient of fiber, γ = 0.763, λ is the shear span ratio, and S2 is the rib width of a single bridge deck unit, that is, the minimum distance S2 of the trapezoidal excavation space.

[0117] Step 3.3: Calculate the shear resistance contribution V of the compression zone concrete of a single bridge deck unit. c

[0118]

[0119] In the formula, p is the cross-sectional steel ratio, which only includes the bottom steel plate. s

[0120] Step 3.4: Calculate the shear capacity V of the bridge deck, that is, the shear strength.

[0121] V = V c + V f

[0122] Step 3.5: If V ≥ V, the shear capacity meets the requirements, if V < V, increase S2, and repeat 3.2-3.4 until V ≥ V. u . u u .

[0123] In another embodiment, the step 5 comprises:

[0124] Determine whether the neutral axis is in the bottom steel plate. If the following formula is met, the neutral axis is in the bottom steel plate, otherwise the neutral axis is in the concrete.

[0125] ​​

[0126] where f sb is the design strength of longitudinal reinforcement, A sb is the area of longitudinal reinforcement, is the stress non-uniformity factor of UHPC in tension zone f t is the design strength of UHPC in tension, A c is the area of UHPC;

[0127] If the neutral axis is in the bottom steel plate, as shown in Fig. 5.1, the calculation procedure includes: Figure 2 Step 5.11: Calculate the position of the neutral axis

[0128]

[0129]

[0130] where b is the full width of the deck, x is the height of the compression zone of the bottom steel plate; the position of the neutral axis x is calculated from this equation, h s is the thickness of the bottom steel plate;

[0131] Step 5.12: Calculate the flexural capacity M u

[0132]

[0133] If the neutral axis is in the concrete, as shown in Fig. 5.2, the calculation procedure includes: Figure 3

[0134] Step 5.21: Calculate the position of the neutral axis

[0135] f s bh s +f c bx c = f sb A sb +f t bh1

[0136] where b is the full width of the deck, x c is the height of the compression zone of the concrete; the position of the neutral axis x c is calculated from this equation.

[0137] Step 5.22: Calculate the flexural capacity M u

[0138]

[0139] Substitute x into the above equation, and the calculation can be obtained M u .

[0140] ​​Specifically, after the above calculation is completed, the relevant construction personnel can verify whether the shear strength, the bending capacity under the action of the positive bending moment M max and the bending capacity under the action of the negative bending moment Mu meet the construction requirements.

[0141] The above-described embodiments only express the specific implementation of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the protection scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the technical concept of the present application, a number of modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. A design method for a steel-concrete composite orthotropic bridge deck, characterized in that: The steel-concrete composite orthotropic bridge deck comprises a concrete layer (201), wherein a steel mesh and a bottom steel plate (101) are provided in the concrete layer (201), wherein the bottom steel plate (101) is provided at the bottom of the concrete layer (201), wherein the steel mesh is provided above the bottom steel plate (101), and wherein a perforated steel plate (103) is vertically provided between the steel mesh and the bottom steel plate (101), wherein the perforated steel plates (103) are arranged in an array, and wherein the concrete layer (201) between the longitudinally arranged perforated steel plates (103) is provided with a trapezoidal hollowing (102), wherein when the concrete layer (201) is poured, the concrete flows into the circular holes (1031) of the perforated steel plates (103) to form a concrete tenon shear connector, and wherein the concrete layer (201) is made of ultra-high performance concrete; The following steps are involved: Step 1: Determine the longitudinal spacing of the perforated steel plates ; Step 2: Determine the thickness of the concrete layer h and effective height h 1. The effective height refers to the height from the upper bottom edge of the trapezoidal hollowing to the top of the concrete layer; Step 3: Calculate the shear strength of the bridge deck; Step 4: Calculate the flexural capacity of the bridge deck under positive bending moment M max ; Step 5: Calculate the flexural capacity of the bridge deck under negative bending moment M u ; The step 2 includes: Step 2.1: Calculate the bending moment borne by a single bridge deck element M The bridge deck unit refers to the bridge deck between the midpoints of two adjacent trapezoidal hollows; Step 2.2: Calculate the height of the compression zone of the cross section of a single bridge deck element ； ； Where: β is the conversion factor of the cross-section compression zone height, f s is the design strength of the bottom steel plate material, E s is the elastic modulus of the bottom steel plate, ε cu is the ultimate compressive strain of concrete; Step 2.3: Calculate the theoretical height of the cross section based on the moment balance of the cross section of a single bridge deck unit; ； Where: A s is the bottom steel plate area of ​​a single calculated bridge deck unit, h c is the theoretical height of the cross section; Step 2.4: Calculate the thickness of the concrete layer h ； Where: b 1 is the height of the perforated steel plate, d 1 is the bottom steel bar diameter, d 2 is the diameter of the top steel bar, c is the thickness of the protective layer; Step 2.5: Calculate the effective height of the concrete layer h 1 。 2. The design method of a steel-concrete composite orthotropic bridge deck according to claim 1 is characterized in that: The thickness of the bottom steel plate (101) is 8 mm to 10 mm, the length S3 of the upper bottom of the trapezoidal hollowing (102) is not greater than 400 mm, the length S4 of the lower bottom of the trapezoidal hollowing (102) is not greater than 500 mm, the angle between the hypotenuse of the trapezoidal hollowing (102) and the horizontal line is not less than 60 degrees, and the minimum spacing S2 between the trapezoidal hollowings (102) is not less than 100 mm; the diameter of the transverse steel bars (2021) of the steel mesh is between 8 mm and 12 mm, and the diameter of the longitudinal steel bars of the steel mesh is between 16 mm and 22 mm.

3. The design method of a steel-concrete composite orthotropic bridge deck according to claim 1 is characterized in that: The step 3 comprises: Step 3.1: Calculate the maximum shear force borne by a single bridge deck element using the comparative orthotropic bridge deck method V u ; Step 3.2: Calculate the shear force shared by the steel fibers in the concrete layer of a single deck unit V f ; ； Where, d f is the steel fiber diameter, ρ f Steel fiber volume ratio, l f is the fiber length, τ f is the average bond strength, , γ is the fiber effective action coefficient, λ is the shear span ratio, is the rib width of a single bridge deck unit, that is, the minimum spacing of the trapezoidal excavation space S 2; Step 3.3: Calculate the concrete shear contribution in the shear compression zone of a single deck element V c ； Where, ρ s is the cross-section steel content, only the bottom steel plate is included. f c is the cubic strength of ultra-high performance concrete, f c ≤140MPa; Step 3.4: Calculate the shear capacity of the bridge deck V Shear strength ； Step 3.5: If V ≥ V u , the shear bearing capacity meets the requirements, if V < V u , increase S 2. Repeat 3.2~3.4 until V ≥ V u 。 4. The design method of a steel-concrete composite orthotropic bridge deck according to claim 1 is characterized in that: The step 5 comprises: Determine whether the neutral axis is within the bottom steel plate and then perform corresponding calculations; If the following equation is satisfied, the neutral axis is in the bottom steel plate, otherwise the neutral axis is in the concrete; ； Where, f sb is the design strength of the longitudinal reinforcement, A sb is the area of ​​longitudinal reinforcement, is the stress non-uniformity coefficient of ultra-high performance concrete in the tension zone, f t The tensile design strength of ultra-high performance concrete, A c is the concrete area, f s is the design strength of the bottom steel plate material, A s is the bottom steel plate area of ​​a single calculation plate unit.

5. The design method of a steel-concrete composite orthotropic bridge deck according to claim 4 is characterized in that: If the neutral axis is within the bottom plate, the calculation process includes: Step 5.11: Calculate the neutral axis position x ； Where, b is the full width of the bridge deck, x is the height of the bottom steel plate compression zone, h s is the thickness of the bottom steel plate; Step 5.12: Calculate the flexural capacity M u 。 6. The design method of a steel-concrete composite orthotropic bridge deck according to claim 4 is characterized in that: If the central axis is in the concrete, the calculation process includes: Step 5.21: Calculate the neutral axis position ； Where, b is the full width of the bridge deck, f c is the cubic strength of ultra-high performance concrete, f c ≤140MPa, x c is the height of the concrete compression zone; the neutral axis position is calculated from this formula x c ; Step 5.22: Calculate the flexural capacity M u ； Will Substitute into the above formula and calculate to get M u .

Images