Steel-concrete combined hollow bridge deck slab and preparation method thereof

Abstract

The invention discloses a steel-concrete combined hollow bridge deck slab and a preparation method thereof, relates to the technical field of civil engineering, and solves the technical problems that a bridge deck slab in the prior art is large in dead weight, insufficient in material utilization, high in steel content and to-be-improved in economical efficiency. The device comprises a steel structure assembly, a reinforcing mesh and a concrete layer, the steel structure assembly and the reinforcing mesh are covered with the concrete layer, the reinforcing mesh is arranged above the steel structure assembly, and the steel structure assembly comprises a bottom steel plate, semicircular hollow pieces and shearing force connecting pieces, the reinforcing mesh is connected with the top of the semicircular hollow part, the semicircular hollow part comprises a hollow part body, and shear keys are arranged on the outer surface of the hollow part body; the concrete which may quit working in the tensile area is hollowed out, the main area of the concrete is located in the compression area, the defect of low tensile property of the concrete is avoided, the advantage of high compression resistance of the concrete is reasonably utilized, and the structural advantages of the concrete are fully played.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a steel-concrete composite hollow bridge deck and a preparation method thereof. Background Art

[0002] In steel-concrete composite beams, the bridge deck generally adopts three forms: solid reinforced concrete slab, steel-concrete composite orthotropic slab and steel-concrete composite solid slab.

[0003] Solid reinforced concrete slabs are composed of upper and lower layers of steel mesh and concrete. Their advantages are simple structure and easy production. However, due to the low strength of concrete in the tension zone and the solid cross-section, the concrete near the neutral axis has a low degree of participation in bending resistance and insufficient material utilization, so their self-weight is relatively large. This has become the main reason why the span of steel-concrete composite beam cable-stayed bridges has long hovered between 600 and 650 meters.

[0004] The steel-concrete composite orthotropic slab is cast with a normal concrete layer or an ultra-high performance concrete layer on the steel orthotropic bridge deck, which can significantly improve the stiffness of the steel orthotropic bridge deck and greatly alleviate the fatigue problem of the steel orthotropic bridge deck. In addition, due to the thin concrete layer and lighter self-weight than the solid slab, it is a type of bridge deck that has developed rapidly in recent years. However, due to the high steel content, the bridge deck essentially becomes an "over-reinforced structure" with excessive steel content in the tensile zone. During use, the steel cannot yield and its role cannot be fully exerted, which greatly reduces its economic efficiency. The scope of application is mainly limited to extra-large span bridges with strict self-weight restrictions on the bridge deck.

[0005] The steel-concrete composite solid slab has high rigidity and comfortable driving. It solves the fatigue problem of orthotropic steel bridge deck and the problem of fragile bridge deck pavement. It has been widely used in large-span bridges and small- and medium-span bridges. However, in more than 10 years of engineering practice, several problems have been exposed: First, the traditional steel-concrete composite bridge deck is a solid slab with a concrete layer thickness of 150mm to 25cm. The structure is heavy. The excessive structural deadweight increases the first-stage dead load, restricts the span capacity of the main beam, and becomes the main reason for the long-term difficulty in breaking through the span of the steel-concrete composite structure bridge; second, the material utilization rate needs to be improved. Once the concrete in the tensile zone near the bottom steel plate cracks, it will withdraw from work and become a "dead weight" that does not contribute to bending resistance and only increases the weight of the structure. The role of the concrete structure has not been fully utilized; third, when designing the steel-concrete composite bridge deck, the determination of the thickness of the bottom steel plate mainly relies on experience. Its thickness varies greatly between 10mm and 16mm. The design of the bottom steel plate lacks a quantitative method, which also makes the tensile effect of the bottom steel plate not fully utilized. Summary of the invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a steel-concrete composite hollow bridge deck and a preparation method thereof, which solves the technical problems in the prior art that the bridge deck has a large weight, insufficient material utilization, high steel content, and economic efficiency needs to be improved.

[0007] A steel-concrete composite hollow bridge deck comprises a steel structure component, a steel mesh and a concrete layer, wherein the concrete layer covers the steel structure component and the steel mesh, the steel mesh is arranged above the steel structure component, the steel structure component comprises a bottom steel plate, and semicircular hollow members and shear connectors fixedly connected to the top surface of the bottom steel plate at intervals, and the bottom of the steel mesh is connected to the top of the semicircular hollow member.

[0008] The semicircular hollow member comprises a hollow member body, and a shear key is arranged on the outer surface of the hollow member body. The shear key can be a spiral steel bar, a herringbone pattern, or a wave pattern shear key.

[0009] Furthermore, the concrete layer is poured concrete; concrete is poured on the bottom steel plate, and the concrete is integrally connected to the steel structure components through the shear connector on the top surface of the bottom steel plate and the shear key on the outer surface of the semicircular hollow member to form a steel-concrete composite hollow bridge deck; when the concrete layer adopts ordinary concrete, its total thickness h is between 180mm and 220mm; when the concrete layer adopts fiber concrete and ultra-high performance concrete, its total thickness h is between 150mm and 180mm.

[0010] Furthermore, the steel mesh is a steel mesh, including transverse steel bars and longitudinal steel bars arranged in upper and lower layers, the transverse steel bars are arranged on the top of the lower layer supporting semicircular hollow members, and the longitudinal steel bars are arranged on the upper layer.

[0011] Furthermore, the spacing between the semicircular hollow members is not less than 0.1 m, the wall thickness of the semicircular hollow members is not greater than 6 mm, and the steel material is of the same grade as the bottom steel plate.

[0012] Furthermore, the distance between the top of the semicircular hollow member and the top of the concrete layer is not less than 55 mm; when the total thickness of the concrete layer is 150 mm, the concrete shrinkage is not more than 130 με; when the total thickness of the concrete layer is 180 mm, the concrete shrinkage is not more than 150 με; when the total thickness of the concrete layer is 220 mm, the concrete shrinkage is not more than 120 με. When the thickness h is between the above thicknesses, the allowable shrinkage of the concrete can be determined by linear interpolation.

[0013] Furthermore, the shear connector can be a perforated plate connector, a shear nail, or a shear tenon.

[0014] A method for preparing a steel-concrete composite hollow bridge deck comprises the following steps:

[0015] Step 1: Determine the maximum and minimum thickness of the bottom steel plate;

[0016] Step 2: Determine the thickness of the bottom steel plate;

[0017] Step 3: Calculate the shear key spacing s on the semicircular hollow member:

[0018] Step 4: Calculation of shear resistance of inclined sections;

[0019] Step 5: Shear design of the steel-concrete interface between the bottom steel plate and the concrete slab;

[0020] Step 6: Make steel structure components according to the calculation results of steps 1-5.

[0021] Furthermore, the step 1 comprises:

[0022] Step 1.1: Determine the maximum thickness t max

[0023]

[0024] In the formula, f c is the compressive strength of concrete, f y is the yield strength of the bottom steel plate; D T is the distance from the top of the semicircular hollow member to the upper surface of the concrete slab; h is the height of the concrete slab; b is the width of a single bridge deck unit; D is the diameter of the semicircular hollow member; ξ is the ratio of the height of the cross-section compression zone to the height of the concrete layer when the bending limit failure occurs, ξ=0.64, and the value of ordinary concrete is determined according to the "Design Code for Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts"; ξh is the height of the cross-section compression zone when the limit failure occurs; l is the arc length of the part above ξh, C is the length of the chord at ξh, b=D C +D,D C is the spacing between semicircular hollow parts;

[0025] Step 1.2: Determine the minimum thickness t min

[0026]

[0027] In the formula, f ct is the tensile strength of concrete, W c is the flexural modulus of the hollow concrete slab.

[0028] Furthermore, the step 2 comprises:

[0029] Step 2.1: Calculate the bending moment borne by a single bridge deck element;

[0030] The steel-concrete composite hollow bridge deck is divided into n bridge deck units. Specifically, each bridge deck unit includes the bridge deck between the vertices of two adjacent semicircular hollow members. The modified orthotropic plate method is used to calculate the lateral distribution coefficient γ under the lane load. The maximum bending moment M shared by a single unit is ut =γM, M is the total bending moment borne by the bridge deck.

[0031] Step 2.2: Calculate the neutral axis position

[0032]

[0033] Combining equations (3), (4), and (5), we can solve for x, Ac, and y. b Where l 1 is the length of the arc above x, C 1 is the length of the chord at x, x is the height from the neutral axis to the top of the semicircular hollow member, i.e., the height of area A. The width of area A is the width of the bridge deck unit. Ac is the concrete area of ​​area A. b It is the height from the concrete centroid axis of area A to the bottom of the semicircular hollow part. The other symbols have the same meanings as before.

[0034] Step 2.3: Calculate the bottom steel plate thickness t

[0035]

[0036] Step 2.4: Reasonable judgment of bottom steel plate thickness

[0037] If t <t min , indicating that t is too small, take t = t min ; if t>t max , indicating that the section height is too small. The thickness h of the concrete slab should be increased, and steps B2 to B4 should be repeated to recalculate t.

[0038] Furthermore, the step 3 comprises:

[0039] When spiral reinforcement shear keys are used, the diameter of the spiral reinforcement d 1 Not less than 10mm, the shear key spacing, i.e. the pitch s, is calculated as follows

[0040]

[0041] In the formula, is the shear friction coefficient, where f c1 is the concrete grade; f c is the compressive strength of concrete, f t w is the fillet weld strength between steel bar and steel plate, β tis the end weld strength enhancement factor, l c The semicircular hollow part and the concrete layer are integrated into one by the shear key, and the semicircular hollow part and the bottom steel plate are integrated into one, so that the bottom steel plate and the concrete layer are firmly connected, ensuring the shear resistance of the steel-concrete interface.

[0042] The step 4 comprises: the semicircular hollow piece spacing D C When the wall thickness is not less than 0.1m, the wall thickness is not less than 4mm, and the shear key spacing s meets the requirements of formula (7), the shear resistance calculation of the inclined section does not need to be performed.

[0043] Furthermore, the step 5 comprises:

[0044] Step 5.1: Calculate the interface shear force Q

[0045] Q=min[(f c b.D T +f c A c ),f y bt ] (8)

[0046] f c is the compressive strength of concrete, D T A is the height from the top of the semicircular hollow member to the top of the concrete slab surface, i.e., area B. c is the compressive strength of concrete, f y is the yield strength of the bottom steel plate, b is the width of the bridge deck unit, and t is the thickness of the bottom steel plate;

[0047] Step 5.2: Calculation of bearing capacity of a single shear connector;

[0048] When shear connectors are shear studs and ultra-high performance concrete is used, the bearing capacity of a single shear connector is calculated as follows: u

[0049]

[0050] In the formula, f c is the compressive strength of concrete; f s is the yield strength of the shear stud; E s is the elastic modulus of the shear stud, A s is the shear area of ​​a single shear stud; d s is the shear stud diameter; L s is the shear stud length; δ max The allowable slippage of the shear nail is 1mm.

[0051] When ordinary concrete is used as concrete and shear connectors are shear nails or perforated plate connectors, V uCalculated according to "Specifications for Design and Construction of Highway Steel-Concrete Composite Bridges".

[0052] Furthermore, the step 6 comprises:

[0053] Step 6.1: On a steel pipe with a diameter of D, wind a shear key with a diameter of d according to the spacing s of the shear key. 1 The steel bars are used as shear keys, and the steel bars and steel pipes are reliably welded;

[0054] Step 6.2: Cut the steel pipe welded with spiral reinforcement into two semicircles to form a semicircular hollow part;

[0055] Step 6.3: Weld the shear connector and the semicircular hollow member on the bottom steel plate with a thickness of t to complete the steel structure assembly;

[0056] Step 6.4: Tie the steel mesh and pour concrete.

[0057] The beneficial effects of the present invention include:

[0058] (1) The concrete that may be removed from the tensile zone is hollowed out, and the main area of ​​concrete is located in the compressive zone, which avoids the disadvantage of low tensile strength of concrete, reasonably utilizes the advantage of high compressive strength of concrete, and gives full play to the advantages of concrete structure. At the same time, the area of ​​180mm thick hollow concrete layer is only equivalent to the area of ​​11.4mm thick solid concrete, which can reduce the weight of concrete by 36%, significantly reducing the deadweight of the structure, and solving the problem of heavy deadweight of steel-concrete composite solid slab and solid reinforced concrete slab structure.

[0059] (2) A design method and threshold value of the bottom steel plate are proposed. When the steel-concrete composite slab is damaged, the concrete can reach its designed compressive strength and the bottom steel plate can yield in tension, thus making full use of the tensile capacity of the bottom steel plate and solving the problem of excessive steel content and poor economic efficiency of the steel-concrete composite orthotropic bridge deck.

[0060] (3) The steel semicircular hollow members are equipped with shear connectors, which work together with the concrete to bear the force, strengthen the concrete layer in the horizontal direction, and participate in the shear resistance of the section in the vertical direction. At the same time, the steel semicircular hollow members play the role of stiffening ribs of the bottom steel plate, which improves the stiffness of the bottom steel plate during construction. The concrete layer can be poured directly on the bottom steel plate, inheriting the advantages of convenient construction of steel-concrete composite orthotropic bridge decks. In addition, the steel semicircular hollow members also play the role of hollowing out the template for the concrete layer, which is fully utilized.

[0061] (4) The semicircular steel hollow members in the transverse direction form a shear connector with great rigidity, which can withstand the interface shear force between the concrete layer and the bottom steel plate in the transverse direction of the bridge, so that the hollow bridge deck also forms a steel-concrete composite deck in the transverse direction, with great rigidity. When the thickness of the concrete layer is 180mm and the diameter of the semicircular steel hollow member is 250mm, the stress of the weld between the semicircular steel hollow member and the bottom steel plate is less than 50MPa, and there is no fatigue problem. It inherits the advantages of good fatigue resistance of the steel-concrete composite orthotropic bridge deck.

[0062] (5) The relationship between the concrete layer and the allowable shrinkage strain of concrete is proposed to ensure that shrinkage cracks do not occur in the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a structural schematic diagram of the steel-concrete composite hollow bridge deck of the present invention.

[0064] Figure 2 It is a structural schematic diagram of the semicircular hollow member of the present invention.

[0065] Figure 3 Schematic diagram of the calculation section for determining the maximum thickness of the bottom steel plate.

[0066] Figure 4 Schematic diagram of the bridge deck unit, i.e., the calculation unit, used to determine the bottom steel plate thickness.

[0067] Figure 5 Schematic diagram of the calculation section for determining the bottom steel plate thickness.

[0068] Figure 6 Schematic diagram of the three-dimensional structure of the steel-concrete composite hollow bridge deck.

[0069] Reference numerals

[0070] 101-bottom steel plate, 102-semicircular hollow member, 1021-hollow member body, 1022-shear key, 103-shear connector, 201-concrete layer, 202-longitudinal reinforcement, 203-transverse reinforcement. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0072] A steel-concrete composite hollow bridge deck, such as Figure 1 , Figure 6 As shown, it includes a steel structure component, a steel mesh and a concrete layer 201, wherein the concrete layer 201 covers the steel structure component and the steel mesh, the steel mesh is arranged above the steel structure component, the steel structure component includes a bottom steel plate 101 and a semicircular hollow member 102 and a shear connector 103 fixedly connected to the top surface of the bottom steel plate 101 at intervals, the bottom of the steel mesh is connected to the top of the semicircular hollow member 102, and the shear connector 103 is a shear nail.

[0073] like Figure 2 As shown, the semicircular hollow member 102 includes a hollow member body 1021 , and a shear key 1022 is provided on the outer surface of the hollow member body 1021 . In this embodiment, the shear key 1022 is made of spiral steel bars.

[0074] In another embodiment, the shear key 1022 is a herringbone or wave-shaped shear key.

[0075] In another embodiment, the concrete layer 201 is poured concrete; concrete is poured on the bottom steel plate 101, and the concrete is integrally connected to the steel structure component through the shear connector 103 on the top surface of the bottom steel plate 101 and the shear key 1022 on the outer surface of the semicircular hollow member 102 to form a steel-concrete composite hollow bridge deck; when the concrete layer 201 adopts ordinary concrete, its total thickness h is between 180 mm and 220 mm; when the concrete layer 201 adopts fiber concrete and ultra-high performance concrete, its total thickness h is between 150 mm and 180 mm.

[0076] In another embodiment, the steel mesh is a steel mesh, including transverse steel bars 203 and longitudinal steel bars 202 arranged in upper and lower layers, wherein the transverse steel bars 203 are arranged on the top of the lower supporting semicircular hollow member 102, and the longitudinal steel bars 202 are arranged on the upper layer.

[0077] In another embodiment, the spacing between the semicircular hollow members 102 is not less than 0.1 m, the wall thickness of the semicircular hollow members 102 is not greater than 6 mm, and the steel material is the same grade as the bottom steel plate 101;

[0078] In another embodiment, the distance between the top of the semicircular hollow member 102 and the top of the concrete layer 201 is not less than 55 mm; when the total thickness of the concrete layer 201 is 150 mm, the concrete shrinkage is not greater than 130 με; when the total thickness of the concrete layer 201 is 180 mm, the concrete shrinkage is not greater than 150 με; when the total thickness of the concrete layer 201 is 220 mm, the concrete shrinkage is not greater than 120 με; when the thickness h is between the above thicknesses, the allowable shrinkage of the concrete can be determined by linear interpolation.

[0079] In another embodiment, the shear connector 103 may also be a perforated plate connector or a shear tenon.

[0080] In another embodiment, a method for preparing a steel-concrete composite hollow bridge deck is provided, comprising the following steps:

[0081] Step 1, determining the maximum and minimum thickness of the bottom steel plate 101;

[0082] Step 2, determining the thickness of the bottom steel plate 101;

[0083] Step 3: Calculate the spacing s between the shear keys 1022 on the semicircular hollow member 102:

[0084] Step 4: Calculation of shear resistance of inclined sections;

[0085] Step 5: Shear design of the steel-concrete interface between the bottom steel plate 101 and the concrete plate 201;

[0086] Step 6: Make steel structure components according to the calculation results of steps 1-5.

[0087] In another embodiment, the step 1 comprises:

[0088] Step 1.1: Determine the maximum thickness t max

[0089]

[0090] In the formula, f c is the compressive strength of concrete, f y is the yield strength of the bottom steel plate; D T is the distance from the top of the semicircular hollow member to the upper surface of the concrete slab; h is the height of the concrete slab; b is the width of a single bridge deck unit; D is the diameter of the semicircular hollow member; ξ is the ratio of the height of the cross-section compression zone to the height of the concrete layer when the bending limit failure occurs, ξ=0.64, and the value of ordinary concrete is determined according to the "Design Code for Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts"; ξh is the height of the cross-section compression zone when the limit failure occurs; l is the arc length of the part above ξh, C is the length of the chord at ξh, b=D C +D,D C is the spacing between semicircular hollow parts; Figure 3 As shown in Figure B T is the limit height from the neutral axis to the top of the semicircular hollow member, specifically, ξh=D T +B T .

[0091] Step 1.2: Determine the minimum thickness t min

[0092]

[0093] In the formula, f ct is the tensile strength of concrete, W c is the flexural modulus of the hollow concrete slab.

[0094] In another embodiment, the step 2 comprises:

[0095] Step 2.1: Calculate the bending moment borne by a single bridge deck element;

[0096] The steel-concrete composite hollow bridge deck is divided into n bridge deck units, such as Figure 4 As shown, each bridge deck unit includes the bridge deck between the vertices of two adjacent semicircular hollow members, and the modified orthotropic plate method is used to calculate the lateral distribution coefficient γ under the lane load; the maximum bending moment M shared by a single unit ut =γM, M is the total bending moment borne by the bridge deck.

[0097] Step 2.2: Calculate the neutral axis position

[0098]

[0099] Combining equations (3), (4), and (5), we can solve for x, Ac, and y. b Where l 1 is the length of the arc above x, C 1 is the length of the chord at x, x is the height from the neutral axis to the top of the semicircular hollow part, that is, the height of area A, x≤B T , the width of area A is the width of the bridge deck unit, Ac is the concrete area of ​​area A, y b is the height from the concrete centroid axis of area A to the bottom of the semicircular hollow member, and the other symbols have the same meanings as before; Figure 5 shown.

[0100] Step 2.3: Calculate the bottom steel plate thickness t:

[0101]

[0102] Step 2.4: Determine the rationality of the bottom steel plate thickness;

[0103] If t <t min , indicating that t is too small, take t = t min ; if t>t max , indicating that the section height is too small. The concrete slab thickness h should be increased, and steps 2.2 to 2.4 should be repeated to recalculate t.

[0104] In another embodiment, the step 3 comprises:

[0105] When spiral steel bar shear keys are used, the steel bar diameter d 1 Not less than 10mm, the shear key spacing, i.e. the pitch s, is calculated as follows

[0106]

[0107] In the formula, is the shear friction coefficient, where f c1 is the concrete grade; f c is the compressive strength of concrete, f t w is the fillet weld strength between steel bar and steel plate, β t is the end weld strength enhancement factor, l c is the arc circumference of the semicircular hollow part, d 1 The semicircular hollow member and the concrete layer are integrated through the shear key, and the semicircular hollow member and the bottom steel plate are integrated, so that the bottom steel plate and the concrete layer are tightly connected to ensure the shear resistance of the steel-concrete interface.

[0108] The step 4 comprises: the semicircular hollow piece spacing D C When the wall thickness is not less than 0.1m, the wall thickness is not less than 4mm, and the shear key spacing s meets the requirements of formula (7), the shear resistance calculation of the inclined section does not need to be performed.

[0109] In another embodiment, step 5 comprises:

[0110] Step 5.1: Calculate the interface shear force Q

[0111] Q=min[(f c b.D T +f c A c ),f y bt] (8)

[0112] f c is the compressive strength of concrete, D T f is the height from the top of the semicircular hollow member to the top of the upper surface of the concrete slab, i.e., area B. c is the compressive strength of concrete, f y is the yield strength of the bottom steel plate, b is the unit width of the bottom steel plate, and t is the thickness of the bottom steel plate;

[0113] Step 5.2: Calculation of bearing capacity of a single shear connector;

[0114] When shear connectors are shear studs and ultra-high performance concrete is used, the bearing capacity of a single shear connector is calculated as follows: u

[0115]

[0116] In the formula, f c is the compressive strength of concrete; f s is the yield strength of the shear stud; E s is the elastic modulus of the shear stud, A s is the shear area of ​​a single shear stud; d s is the shear stud diameter; L s is the shear stud length; δ max The allowable slippage of the shear nail is 1mm.

[0117] When ordinary concrete is used as concrete and shear connectors are shear nails or perforated plate connectors, V u Calculated according to "Specifications for Design and Construction of Highway Steel-Concrete Composite Bridges".

[0118] In another embodiment, step 6 comprises:

[0119] Step 6.1: On a steel pipe with a diameter of D, wind a thread with a diameter of d according to the shear key spacing (pitch) s. 1 The steel bars are used as shear keys, and the steel bars and steel pipes are reliably welded;

[0120] Step 6.2: Cut the steel pipe welded with spiral reinforcement into two semicircles to form a semicircular hollow part;

[0121] Step 6.3: Weld the shear connector and the semicircular hollow member on the bottom steel plate with a thickness of t to complete the steel structure assembly;

[0122] Step 6.4: Tie the steel mesh and pour concrete.

[0123] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A steel-concrete composite hollow bridge deck, characterized in that: The invention comprises a steel structure component, a steel mesh and a concrete layer (201), wherein the steel mesh is arranged above the steel structure component, and the concrete layer (201) covers the steel structure component and the steel mesh. The steel mesh is arranged above the steel structure component, and the steel structure component comprises a bottom steel plate (101) and a semicircular hollow member (102) and a shear connector (103) fixed at intervals on the top surface of the bottom steel plate (101). The bottom of the steel mesh is connected to the top of the semicircular hollow member (102), and the semicircular hollow member (102) comprises a hollow member body (1021), and a shear key (1022) is provided on the outer surface of the hollow member body (1021).

2. The steel-concrete composite hollow bridge deck according to claim 1, characterized in that: The spacing between the semicircular hollow pieces (102) is not less than 0.1 m, and the wall thickness of the semicircular hollow pieces (102) is not greater than 6 mm.

3. The steel-concrete composite hollow bridge deck according to claim 1, characterized in that: The distance between the top of the semicircular hollow member (102) and the top of the concrete layer (201) is not less than 55 mm; when the total thickness of the concrete layer (201) is 150 mm, the concrete shrinkage is not greater than 150 με; when the total thickness of the concrete layer (201) is 180 mm, the concrete shrinkage is not greater than 130 με; when the total thickness of the concrete layer (201) is 220 mm, the concrete shrinkage is not greater than 120 με; when the thickness h is between the above thicknesses, the allowable shrinkage of the concrete can be determined by linear interpolation.

4. The steel-concrete composite hollow bridge deck according to claim 1, characterized in that: When the concrete layer (201) is made of ordinary concrete, its total thickness h is between 180 mm and 220 mm; when the concrete layer (201) is made of fiber concrete and ultra-high performance concrete, its total thickness h is between 150 mm and 180 mm.

5. A method for preparing a steel-concrete composite hollow bridge deck, used for preparing a steel-concrete composite hollow bridge deck as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1, determining the maximum and minimum thickness of the bottom steel plate (101); Step 2, determining the thickness of the bottom steel plate (101); Step 3: Calculate the spacing s between the shear keys (1022) on the semicircular hollow member (102): Step 4: Determine the shear strength of the oblique section; Step 5, shear resistance design of the steel-concrete interface between the bottom steel plate (101) and the concrete (201); Step 6: Make steel structure components according to the calculation results of steps 1-5.

6. The method for preparing a steel-concrete composite hollow bridge deck according to claim 5, characterized in that: The step 1 comprises: Step 1.1: Determine the maximum thickness t max In the formula, f c is the compressive strength of concrete, f y is the yield strength of the bottom steel plate; D T is the distance from the top of the semicircular hollow member to the upper surface of the concrete slab; h is the height of the concrete slab; b is the width of a single bridge deck unit; D is the diameter of the semicircular hollow member; ξ is the ratio of the height of the cross-section compression zone to the height of the concrete layer when the bending limit failure occurs; ξh is the height of the cross-section compression zone when the limit failure occurs; l is the length of the arc above ξh, C is the length of the chord at ξh, b=D C +D,D C is the spacing between semicircular hollow parts; Step 1.2: Determine the minimum thickness t min In the formula, f ct is the tensile strength of concrete, W c is the flexural modulus of the hollow concrete slab.

7. The method for preparing a steel-concrete composite hollow bridge deck according to claim 6, characterized in that: The step 2 comprises: Step 2.1: Calculate the bending moment borne by a single bridge deck element; The steel-concrete composite hollow bridge deck is divided into n bridge deck units. Specifically, each bridge deck unit includes the bridge deck between the vertices of two adjacent semicircular hollow members. The modified orthotropic plate method is used to calculate the lateral distribution coefficient γ under the lane load. The maximum bending moment M shared by a single unit ut =γM, M is the total bending moment borne by the bridge deck; Step 2.2: Calculate the neutral axis position Combining equations (3), (4), and (5), we can solve for x, Ac, and y. b ; where l1 is the length of the arc above x, C1 is the length of the chord at x, x is the height from the neutral axis to the top of the semicircular hollow member, i.e., the height of area A. The width of area A is the width of the bridge deck unit. Ac is the concrete area of ​​area A. b It is the height from the concrete centroid axis of area A to the bottom of the semicircular hollow part. The other symbols have the same meanings as before. Step 2.3: Calculate the bottom steel plate thickness t Step 2.4: Determine the rationality of the bottom steel plate thickness; If <t min , indicating that t is too small, take t = t min ; if t>t max , indicating that the section height is too small. The concrete slab thickness h should be increased, and steps 2.2 to 2.4 should be repeated to recalculate t.

8. The method for preparing a steel-concrete composite hollow bridge deck according to claim 6, characterized in that: The step 3 includes: when a spiral steel bar shear key is used, the diameter d1 of the spiral steel bar is not less than 10 mm, and the shear key spacing, i.e., the pitch s, is calculated as follows: In the formula, is the shear friction coefficient, where f c1 is the concrete grade; f c is the compressive strength of concrete, f t w is the fillet weld strength between the steel bar and the steel plate, β t is the end weld strength enhancement factor, l c is the arc circumference of the semicircular hollow part; The step 4 comprises: the semicircular hollow piece spacing D C When the wall thickness is not less than 0.1m, the wall thickness is not less than 4mm, and the shear key spacing s meets the requirements of formula (7), the inclined section of the bridge deck meets the shear strength requirements of the inclined section and the shear strength verification of the inclined section is not required.

9. The method for preparing a steel-concrete composite hollow bridge deck according to claim 8, characterized in that: The step 5 comprises: Step 5.1: Calculate the interface shear force Q Q=min[(f c b·D T +f c A c ),f y bt] (8) f c is the compressive strength of concrete, D T A is the height from the top of the semicircular hollow member to the top of the concrete slab surface, i.e., area B. c is the compressive strength of concrete, f y is the yield strength of the bottom steel plate, b is the width of the bridge deck unit, and t is the thickness of the bottom steel plate; Step 5.2: Calculation of bearing capacity of a single shear connector; When shear connectors are shear studs and ultra-high performance concrete is used, the bearing capacity of a single shear connector is calculated as follows: u In the formula, f c is the compressive strength of concrete; f s is the yield strength of the shear stud; E s is the elastic modulus of the shear stud, A s is the shear area of ​​a single shear stud, d s is the shear stud diameter; L s is the shear stud length; δ max is the allowable slippage of the shear stud.

10. The method for preparing a steel-concrete composite hollow bridge deck according to claim 6, characterized in that: The step 6 comprises: Step 6.1: On the steel pipe with a diameter of D, wind a steel bar with a diameter of d1 as a shear key according to the shear key spacing s, and weld the steel bar to the steel pipe reliably; Step 6.2: Cut the steel pipe welded with spiral reinforcement into two semicircles to form a semicircular hollow part; Step 6.3: Weld the shear connector and the semicircular hollow member on the bottom steel plate with a thickness of t to complete the steel structure assembly; Step 6.4: Tie the steel mesh and pour concrete.

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