A steel-concrete composite hollow bridge deck and a preparation method thereof

Abstract

The application 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 of the bridge deck slab in the prior art, such as heavy self weight, insufficient material utilization, high steel content and economic improvement to be promoted, and the like; the application comprises a steel structure assembly, a steel bar mesh and a concrete layer, the concrete layer covers the steel structure assembly and the steel bar mesh, the steel bar mesh is arranged above the steel structure assembly, the steel structure assembly comprises a bottom steel plate, semicircular hollow pieces and shear connectors which are fixedly connected at intervals on the top surface of the bottom steel plate, the steel bar mesh is connected with the top of the semicircular hollow pieces, and the semicircular hollow pieces comprise a hollow piece body, and shear keys are arranged on the outer surface of the hollow piece body; the application hollows out the concrete which may quit work in the tension zone, and the main area of the concrete is located in the compression zone, so that the low tensile property of the concrete is avoided, the high compression property of the concrete is reasonably utilized, and the advantages of the concrete structure are fully exerted.

Description

TECHNICAL FIELD

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

[0002] In the steel-concrete composite beam, the bridge deck is generally in three forms of solid reinforced concrete slab, steel-concrete composite orthotropic slab and steel-concrete composite solid slab.

[0003] The solid reinforced concrete slab is composed of upper and lower steel mesh and concrete, and has the advantages of simple structure and convenient fabrication. However, the concrete in the tensile zone has low strength, and the concrete near the neutral axis has low participation in the bending resistance due to the solid section, so that the material utilization is not sufficient, and thus the self weight is large, which is the main reason for the long-term stagnation of the steel-concrete composite beam cable-stayed bridge at a span of 600-650 m.

[0004] The steel-concrete composite orthotropic slab pours an ordinary concrete layer or an ultra-high performance concrete layer on the steel orthotropic bridge deck, which can obviously improve the stiffness of the steel orthotropic bridge deck, greatly alleviate the fatigue problem of the steel orthotropic bridge deck, and reduce the self weight of the bridge deck due to the thin concrete layer, compared with the solid slab. In recent years, the steel-concrete composite orthotropic slab has developed rapidly. However, due to the high steel ratio, the bridge deck is essentially a "super-reinforced structure" with high steel ratio in the tensile zone, and the steel cannot yield in use, so that the steel cannot fully play a role, and the economy is greatly discounted, and the application range is mainly limited to large-span bridges with strict self weight limit of the bridge deck.

[0005] The steel-concrete composite solid slab has large stiffness and driving comfort, solves the fatigue problem of the orthotropic steel bridge deck and the easy damage of the bridge deck pavement, and is widely used in large-span bridges and small-span bridges. However, in more than ten years of engineering practice, some problems have been exposed. Firstly, the traditional steel-concrete composite bridge deck is a solid slab, the concrete layer has a thickness of 150 mm-25 cm, the structure has a large self weight, the excessive structure self weight increases the primary dead load, which 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. Secondly, the material utilization rate needs to be improved, the concrete in the tensile zone near the bottom steel plate is out of work once the concrete cracks, becomes "dead weight" without contribution to the bending resistance, and the role of the concrete structure cannot be fully played. Thirdly, in the design of the steel-concrete composite bridge deck, the thickness of the bottom steel plate is mainly determined by experience, and the thickness of the bottom steel plate changes greatly between 10 mm and 16 mm, and the design of the bottom steel plate lacks a quantitative method, so that the tensile resistance of the bottom steel plate cannot be fully played. SUMMARY

[0006] In order to solve the problems existing in the prior art, the present application provides a steel-concrete composite hollow bridge deck and a preparation method thereof, which solve the technical problems of the prior art, such as heavy bridge deck, insufficient material utilization, high steel content and poor economy.

[0007] The steel-concrete composite hollow bridge deck comprises a steel structure assembly, a steel mesh and a concrete layer, the concrete layer covers the steel structure assembly and the steel mesh, the steel mesh is arranged above the steel structure assembly, and the steel structure assembly comprises a bottom steel plate, semicircular hollow pieces and shear connectors which are fixedly connected to the top surface of the bottom steel plate at intervals.

[0008] The semicircular hollow pieces comprise a hollow piece body, and a shear key is arranged on the outer surface of the hollow piece body.

[0009] Further, the concrete layer is cast concrete, the bottom steel plate is cast with concrete, the concrete is integrally connected with the steel structure assembly through the shear connectors on the top surface of the bottom steel plate and the shear keys on the outer surface of the semicircular hollow pieces, and the steel-concrete composite hollow bridge deck is formed, when the concrete layer is ordinary concrete, the total thickness h of the concrete layer is 180mm-220mm, and when the concrete layer is fiber concrete or ultra-high performance concrete, the total thickness h of the concrete layer is 150mm-180mm.

[0010] Further, the steel mesh comprises horizontal steel bars and vertical steel bars arranged in upper and lower layers, the horizontal steel bars are arranged to support the top of the semicircular hollow pieces in the lower layer, and the vertical steel bars are arranged in the upper layer.

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

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

[0013] Further, the shear connectors can be perforated plate connectors, shear nails or shear dowels.

[0014] The preparation method of the steel-concrete composite hollow bridge deck comprises the following steps:

[0015] Step 1, determining the maximum and minimum thicknesses 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, shear calculation of oblique section;

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

[0020] Step 6, manufacture the steel structure assembly according to the calculation results of steps 1-5.

[0021] Further, 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 compression zone to the height of the concrete layer when the flexural limit failure occurs, ξ = 0.64, and the value of ordinary concrete is taken according to the “Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts”; ξh is the height of the compression zone at the limit failure; l is the arc length of the part above ξh, C is the chord length at ξh, b = D C + D, D C is the spacing of the semicircular hollow member;

[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] Further, the step 2 comprises:

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

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

[0031] Step 2.2: Calculate the position of the neutral axis

[0032]

[0033] Solve x, Ac, y by simultaneously solving the above (3), (4), (5) formulas b ; in the formula, l1 is the arc length above x, C1 is the chord length at x, x is the height of the neutral axis to the top of the semicircular hollow member, i.e. the height of region A, the width of region A is the width of the bridge deck unit, Ac is the concrete area of region A, y b is the height of the concrete centroid axis of region A to the bottom of the semicircular hollow member, and the meanings of the remaining symbols are the same as before;

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

[0035]

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

[0037] If t < t min , it indicates that t is too small, and t = t min is taken; if t > t max , it indicates that the section height is too small, and the thickness h of the concrete plate should be increased, and t is recalculated by repeating steps B2 to B4.

[0038] Further, the step 3 includes:

[0039] When a spiral steel shear key is used, the diameter d1 of the spiral steel is not less than 10 mm, and the pitch s of the shear key, i.e. the spiral pitch, is calculated according to the following formula

[0040]

[0041] In the formula, is the shear friction coefficient, in which f c1 is the concrete grade; f c is the compressive strength of concrete, f t w is the strength of the fillet weld between the steel bar and the steel plate, β t is the end weld strength increase coefficient, l cThe arc length of the semicircular hollow member is circular. The semicircular hollow member and the concrete are laminated into one body through the shear key, and the semicircular hollow member is integrated with the bottom steel plate, so as to realize the fastening connection of the bottom steel plate and the concrete layer and ensure the shear capacity of the steel-concrete interface.

[0042] The step 4 comprises that the interval D of the semicircular hollow member C When the wall thickness is not less than 4 mm and the shear key interval s meets the requirement of formula (7), the inclined section shear calculation can be not performed.

[0043] Further, the step 5 comprises:

[0044] Step 5.1: Calculate the interface shear 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 is the height from the top of the semicircular hollow member to the top of the upper surface of the concrete slab, i.e. the area B, A 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: Calculate the bearing capacity of a single shear connector.

[0048] When the shear connector is a shear stud and the concrete is ultra-high performance concrete, the bearing capacity of a single shear connector is calculated as V 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 diameter of the shear stud; L s is the length of the shear stud; and δ max is the allowable slip of the shear stud, which is 1 mm.

[0051] When the concrete is ordinary concrete and the shear connector is a shear stud or a perforated plate connector, V u is calculated according to the Design and Construction Specification for Highway Steel-concrete Composite Bridges.

[0052] Further, the step 6 comprises:

[0053] Step 6.1: winding the steel bar with a diameter of d1 as a shear key at the interval s of the shear key on the steel pipe with a diameter of D, and reliably welding the steel bar with the steel pipe;

[0054] Step 6.2: cutting the steel pipe welded with the spiral steel bar into 2 half circles to form a half circle hollow member;

[0055] Step 6.3: welding the shear connecting member and the half circle hollow member on the bottom steel plate with a thickness of t to complete the steel structure assembly;

[0056] Step 6.4: binding the steel mesh and pouring the concrete.

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

[0058] (1) The excavated concrete in the tensile zone is removed, the main area of the concrete is located in the compression zone, the disadvantage of low tensile performance of the concrete is avoided, the advantage of high compression performance of the concrete is reasonably utilized, and the advantages of the concrete structure are fully utilized. At the same time, the area of the 180mm thick hollow concrete layer is only equivalent to the area of the 11.4mm thick solid concrete, which can reduce the weight of the concrete by 36%, significantly reduce the self weight of the structure, and solve the problem of large self weight of the steel-concrete composite solid plate and the solid reinforced concrete plate structure.

[0059] (2) The design method and threshold value of the bottom steel plate are proposed, when the steel-concrete composite plate is damaged, the concrete can reach its designed compression strength, and the bottom steel plate can be tensioned and yielded, the tensile capacity of the bottom steel plate is fully utilized, and the problem of large steel ratio and poor economy of the steel-concrete composite orthotropic bridge deck is solved.

[0060] (3) The steel half circle hollow member is provided with a shear connecting member, which cooperates with the concrete to bear the load, strengthens the concrete layer in the transverse direction, and participates in the shear in the longitudinal direction; at the same time, the steel half circle hollow member plays the role of the stiffening rib of the bottom steel plate, improves the construction period stiffness of the bottom steel plate, and can directly pour the concrete layer on the bottom steel plate, inherits the advantage of convenient construction of the steel-concrete composite orthotropic bridge deck, and the steel half circle hollow member also plays the role of the hollow formwork of the concrete layer, which is fully utilized.

[0061] (4) The transverse steel half circle hollow member forms a shear connecting member with great stiffness, which can bear the interfacial shear between the transverse concrete layer and the bottom steel plate, so that the hollow bridge deck also constitutes a steel-concrete composite plate in the transverse direction, which has great stiffness. When the thickness of the concrete layer is 180mm and the diameter of the steel half circle hollow member is 250mm, the stress of the weld between the steel half circle hollow member and the bottom steel plate is less than 50MPa, and there is no fatigue problem. Inherit the advantage 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 the concrete is proposed, so as to ensure that the concrete does not appear shrinkage cracks. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 A structural schematic diagram of a steel-concrete composite hollow bridge deck panel of the present application.

[0064] Figure 2 A structural schematic diagram of a semi-circular hollow member of the present application.

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

[0066] Figure 4 A schematic diagram of a bridge deck panel unit, i.e. a calculation unit, for determining the thickness of the bottom steel plate.

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

[0068] Figure 6 A three-dimensional structural schematic diagram of a steel-concrete composite hollow bridge deck panel.

[0069] REFERENCE NUMERALS

[0070] 101 - bottom steel plate, 102 - semi-circular 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 solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. 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 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 those skilled in the art without creative work fall within the scope of the present application.

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

[0073] As shown in the figure, Figure 2 The semicircular hollow member 102 includes a hollow member body 1021, and a shear key 1022 is arranged on the outer surface of the hollow member body 1021. In this embodiment, the shear key 1022 is a spiral steel bar.

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

[0075] In another embodiment, the concrete layer 201 is cast concrete; the concrete is cast on the bottom steel plate 101, and the concrete is integrally connected with the steel structure assembly 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, and a steel-concrete combined hollow bridge deck is formed; when the concrete layer 201 is ordinary concrete, the total thickness h is between 180mm and 220mm; when the concrete layer 201 is fiber concrete or ultra-high performance concrete, the total thickness h is between 150mm and 180mm.

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

[0077] In another embodiment, the spacing of the semicircular hollow members 102 is not less than 0.1m, the wall thickness of the semicircular hollow members 102 is not greater than 6mm, 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 55mm; when the total thickness of the concrete layer 201 is 150mm, the concrete shrinkage is not greater than 130με, when the total thickness of the concrete layer 201 is 180mm, the concrete shrinkage is not greater than 150με, when the total thickness of the concrete layer 201 is 220mm, the concrete shrinkage is not greater than 120με, and 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 can also be a perforated plate connector or a shear dowel.

[0080] In another embodiment, a method for manufacturing a steel-concrete composite hollow bridge deck panel 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, calculating the spacing s of the shear keys 1022 on the semicircular hollow member 102:

[0084] Step 4, shear calculation of the oblique section;

[0085] Step 5, shear design of the steel-concrete interface of the bottom steel plate 101 and the concrete 201 plate;

[0086] Step 6, manufacturing the steel structure assembly according to the calculation results of steps 1-5.

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

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

[0089]

[0090] In the formula, f c is the compressive strength of the 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 plate; h is the height of the concrete plate; b is the width of a single bridge deck panel unit; D is the diameter of the semicircular hollow member; ξ is the ratio of the height of the compression zone of the section to the height of the concrete layer when the limit of flexural failure occurs, ξ = 0.64, and the value of ordinary concrete is taken according to the “Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts”; ξh is the height of the compression zone of the section at the limit of failure; l is the arc length of the part above ξh, C is the chord length at ξh, b = D C + D, D C is the spacing of the semicircular hollow member; as shown in Figure 3 B T is the limit height of the neutral axis to the top of the semicircular hollow member, specifically, ξh = D T + B T .

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

[0092]

[0093] In the formula, f ctW = 0.18fct c E = 0.18fct

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

[0095] Step 2.1: Calculate the bending moment of each unit of the bridge deck slab;

[0096] The steel-concrete composite hollow bridge deck slab is divided into n units of the bridge deck slab, as shown in the following figure, each unit of the bridge deck slab specifically comprising the bridge deck between the vertices of two adjacent semicircular hollow members, and the transverse distribution coefficient γ under the lane load is calculated by using the modified orthotropic plate method; the maximum bending moment M Figure 4 of each unit is M ut = γM, and M is the total bending moment of the bridge deck slab.

[0097] Step 2.2: Calculate the position of the neutral axis

[0098]

[0099] Solve x, Ac, y b by using the above formulas (3), (4), and (5); in the formulas, l1 is the arc length above x, C1 is the chord length at x, x is the height of the neutral axis to the top of the semicircular hollow member, i.e. the height of the area A, x≤B T , the width of the area A is the width of the unit of the bridge deck slab, Ac is the concrete area of the area A, y b is the height of the centroid of the concrete of the area A to the bottom of the semicircular hollow member, and the remaining symbols have the same meanings as above; specifically as shown in the following figure. Figure 5

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

[0101]

[0102] Step 2.4: Reasonable judgment of the thickness of the bottom steel plate;

[0103] If t < t min , it indicates that t is too small, and t = t min is taken; if t > t max , it indicates that the section height is too small, the thickness h of the concrete slab should be increased, and t is recalculated by repeating steps 2.2 to 2.4.

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

[0105] When the spiral steel shear key is used, the diameter d1 of the steel bar is not less than 10 mm, and the pitch s of the shear key, i.e. the pitch of the spiral, is calculated by using the following formula ​

[0106]

[0107] wherein, is the shear friction coefficient, wherein f c1 is the concrete grade; f c is the compressive strength of concrete, f t w is the strength of the fillet weld between the steel bar and the steel plate, β t is the strength increase coefficient of the end weld, l c is the arc circumference of the semicircular hollow member, and d1 is the diameter of the spiral steel bar. The semicircular hollow member and the concrete are laminated into one body by the shear key, and the semicircular hollow member is integrated with the bottom steel plate, so as to realize the fastening connection between the bottom steel plate and the concrete layer and ensure the shear resistance of the steel-concrete interface.

[0108] The step 4 comprises: the spacing D C of the semicircular hollow members is not less than 0.1 m, the wall thickness is not less than 4 mm, and when the spacing s of the shear keys meets the requirement of formula (7), the inclined section shear calculation can be omitted.

[0109] In another embodiment, the step 5 comprises:

[0110] Step 5.1: calculating the interface shear 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 is the height from the top of the semicircular hollow member to the top of the upper surface of the concrete plate, i.e. the region B, f 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: calculating the bearing capacity of a single shear connector;

[0114] When the shear connector is a shear stud and the concrete is ultra-high performance concrete, the bearing capacity of a single shear connector is calculated according to the following formula V u

[0115]

[0116] wherein, 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, and As A is the shear area of single shear stud; d s A is the diameter of shear stud; L s A is the length of shear stud; δ max A is the allowable slip of shear stud, 1mm.

[0117] When the concrete is ordinary concrete, and the shear connector is shear stud or perforated plate connector, V u According to the Design and Construction Specification of Highway Steel-concrete Composite Bridge.

[0118] In another embodiment, the step 6 comprises:

[0119] Step 6.1: winding the steel bar with diameter d1 as shear key according to the shear key spacing (pitch) s on the steel pipe with diameter D, and reliably welding the steel bar with the steel pipe;

[0120] Step 6.2: cutting the steel pipe with spiral steel bar into 2 half circles to form a half circle hollow member;

[0121] Step 6.3: welding the shear connector and the half circle hollow member on the bottom steel plate with thickness t to complete the steel structure assembly;

[0122] Step 6.4: binding the steel mesh and pouring the concrete.

[0123] The above-described embodiments only express the specific implementation of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the protection scope of the present application. It should be noted that for ordinary skilled in the art, without departing from the technical concept of the present application, a number of variations and improvements can be made, which are all within the protection scope of the present application.

Claims

1. A method of manufacturing a steel-concrete composite hollow bridge deck panel, characterized in that, The steel-concrete combined hollow bridge deck slab comprises a steel structure assembly, a steel mesh and a concrete layer (201), the steel mesh is arranged above the steel structure assembly, the concrete layer (201) covers the steel structure assembly and the steel mesh, the steel mesh is arranged above the steel structure assembly, the steel structure assembly comprises a bottom steel plate (101), and semicircular hollow pieces (102) and shear connectors (103) which are fixedly arranged on the top surface of the bottom steel plate (101) at intervals, the bottom of the steel mesh is connected with the top of the semicircular hollow pieces (102), and the semicircular hollow pieces (102) comprise a hollow piece body (1021), and the outer surface of the hollow piece body (1021) is provided with shear keys (1022); The method comprises the following steps: 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, calculating the interval s of the shear keys (1022) on the semicircular hollow pieces (102): Step 4, judging the shear strength of the oblique section; Step 5, designing the shear resistance of the steel-concrete interface of the bottom steel plate (101) and the concrete slab; Step 6, manufacturing the steel structure assembly according to the calculation results of steps 1-5; The step 1 comprises: Step 1.1: Determining the maximum thickness t max ； wherein 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 semi-circular 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 slab unit; D is the diameter of the semi-circular hollow member; ξ is the ratio of the height of the compression zone of the cross section to the height of the concrete layer when the limit of flexural failure occurs; ξh is the height of the compression zone of the cross section when the limit of failure occurs; l is the length of the circular arc above ξh, , ; C is the chord length at ξh, ; b = D C + D, D C is the spacing of the semi-circular hollow members; Step 1.2: Determining the minimum thickness t min ； where f ct is the tensile strength of the concrete, W c is the flexural modulus of the hollow concrete slab.

2. The method of claim 1, wherein the steel-concrete composite hollow bridge deck slab is prepared by the steps of: The interval of 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 method for preparing a steel-concrete composite hollow bridge deck according to claim 1, characterized in that, The distance between the top of the semicircular hollow pieces (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, and the allowable shrinkage of the concrete can be determined by linear interpolation when the thickness h is between the above thicknesses.

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

5. The method for preparing a steel-concrete composite hollow bridge deck according to claim 1, characterized in that, The step 2 comprises: Step 2.1, calculating the bending moment borne by a single bridge deck slab unit; The steel-concrete combined hollow bridge deck is divided into n bridge deck units, each of which includes the bridge deck between the vertices of two adjacent semicircular hollow members; a modified orthotropic plate method is used to calculate the transverse distribution coefficient γ under the action of lane load; the maximum bending moment M borne by a single unit is M ut =γM, M is the total bending moment borne by the bridge deck. Step 2.2, calculating the position of the neutral axis ； Solving the above (3), (4), (5) formula, solve x, Ac, y b ; In the formula, l1 is the arc length of x, , , C1 is the chord length of x, , x is the height of the neutral axis to the top of the half-circle hollow member, that is, the height of region A, the width of region A is the width of the bridge deck unit, Ac is the concrete area of region A, y b is the height of the center axis of the concrete of region A to the bottom of the half-circle hollow member, and the meanings of the remaining symbols are the same as before; Step 2.3, calculating the thickness t of the bottom steel plate ； Step 2.4, judging the rationality of the thickness of the bottom steel plate; If t < t min , it indicates that t is too small, take t = t min ; if t > t max , it indicates that the cross-section height is too small, the thickness h of the concrete slab should be increased, and steps 2.2 to 2.4 are repeated to recalculate t.

6. The method for preparing a steel-concrete composite hollow bridge deck according to claim 1, characterized in that, The step 3 comprises: when a spiral steel shear key is adopted, the diameter d1 of the spiral steel is not less than 10 mm, and the interval s of the shear keys, i.e. the pitch s, is calculated according to the following formula ； wherein 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 strength of the fillet weld between the steel bar and the steel plate, is the end weld strength increase coefficient, l c is the circumference of the semicircular hollow member arc The step 4 includes: the half-circle hollow member spacing D C When the shear key spacing s meets the requirement of formula (7), the oblique section of the bridge deck slab meets the oblique section shear strength requirement, and the oblique section shear calculation is not performed.

7. The method for preparing a steel-concrete composite hollow bridge deck according to claim 6, characterized in that, The step 5 comprises: Step 5.1, calculating the interface shear Q ； f c f T A c f y b Step 5.2, calculating the bearing capacity of a single shear connector; When the shear connector is a shear stud and the concrete is ultra-high performance concrete, the load bearing capacity of a single shear connector is calculated by the following formula V u ； wherein f is the compressive strength of the concrete; f s f is the yield strength of the shear stud; E s f is the modulus of elasticity of the shear stud, A s f is the shear area of a single shear stud, d s f is the diameter of the shear stud; L s f is the length of the shear stud; δ max f is the allowable slip of the shear stud.

8. The method for preparing a steel-concrete composite hollow bridge deck according to claim 1, characterized in that, The step 6 comprises: Step 6.1, winding a steel pipe with a diameter of D with a steel bar with a diameter of d1 as a shear key according to the interval s of the shear keys, and reliably welding the steel bar and the steel pipe; Step 6.2, cutting the steel pipe with the spiral steel bar welded into two semicircles to form a semicircular hollow piece; Step 6.3, welding the shear connector and the semicircular hollow piece on the bottom steel plate with a thickness of t to complete the manufacturing of the steel structure assembly; Step 6.4, binding the steel mesh and pouring the concrete.

Images