A concrete reinforced grid deck bridge deck panel and method of designing the same

Abstract

The application discloses a concrete reinforced grid plate bridge deck and a design method thereof, and relates to the technical field of bridge construction. The design method of the concrete reinforced grid plate bridge deck comprises the concrete reinforced grid plate bridge deck, and the specific operation is as follows: the local stress mode of the bridge deck is changed from a large-span one-way plate mode to a two-way plate or a small-span one-way plate mode by using the grid structure formed by the transverse and longitudinal reinforcements with certain bending stiffness, so as to adapt to the local stress demand of the bridge deck. The concrete reinforced grid plate bridge deck and the design method thereof define the concrete reinforced grid plate bridge deck structure, independently make the reinforced grid plate bridge deck into an integral component from the previous bridge deck, reinforcement, transverse diaphragm plate and support structure, and meet the prefabricated assembly modular mode.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, specifically to a reinforced concrete grating bridge deck and its design method. Background Technology

[0002] With the increasing demands of transportation development, the number of lanes and the width of bridge decks on highways and urban roads are constantly increasing. To meet these demands, in recent decades, the following methods have often been adopted for wide-span concrete bridges (including steel-concrete composite beams):

[0003] 1. Increase the number of lateral supports (webs) to control the lateral span of the bridge deck:

[0004] To meet the stress requirements of the bridge deck, the wide-span bridge still adopts the same maximum box girder width B as the narrow-span bridge, and the transverse calculated span of the bridge deck is controlled by increasing the number of longitudinal continuous webs of the transverse supports.

[0005] Clearly, this design scheme cannot increase the cantilever length of the two side flanges. The increased web (lateral support) far exceeds the shear resistance requirements of the section, resulting in unnecessary growth in the main beam section. This further increases the overall construction scale, including the self-weight load effect of the main beam and the foundation requirements. This unnecessary material increase becomes more pronounced as the bridge span, beam height, and web height increase.

[0006] Increase the thickness of the bridge deck to accommodate localized stress requirements:

[0007] To accommodate the increased transverse span of the bridge deck with its wide and large box girder cross-section, a design scheme that enlarges the bridge deck / bottom plate was adopted to meet the local stress requirements of the bridge deck.

[0008] Clearly, this design scheme also makes it difficult to increase the already excessive cantilever length of the two side flanges. In actual engineering projects, the thickness of the top and bottom plates often increases from the previous 180-250mm to 280-350mm. Such a long, thick plate structure, with its increased thickness exceeding the overall stress requirements of the cross-section, will also lead to unnecessary increases in the main beam cross-section and the overall construction scale. Furthermore, in past engineering statistics, there have been numerous reports and literature documenting longitudinal cracks caused by lateral stress in box girders with box girder widths exceeding 7.5m-8.5m.

[0009] 2. Add transverse diaphragms and cantilever stiffeners to enhance the lateral bending stiffness of the bridge deck.

[0010] To meet the lateral stress requirements of the bridge deck, the lateral bending stiffness of the bridge deck is enhanced by adding diaphragms and cantilever stiffeners, without increasing the thickness of the bridge deck by much or no increase.

[0011] Transverse diaphragms and cantilever stiffening can directly increase the lateral bending stiffness of the bridge deck. However, in actual engineering design, for the convenience of segmental construction, transverse diaphragms are often installed one per construction segment, or one every 6-8 meters. Only when the longitudinal spacing L of the transverse diaphragms is less than the width B of the box girder does the local stress on the bridge deck be calculated based on the smaller longitudinal span, resulting in a significant improvement in stress distribution. However, the self-weight of the transverse diaphragms and stiffening is also substantial, and overly dense diaphragm installation further increases the self-weight of the main girder, increasing the overall longitudinal stress load on the bridge. Meanwhile, sparser diaphragms are still limited by the effective width of the structural supports, failing to significantly improve the stress pattern of the bridge deck, and some bridges still report localized cracking and other defects.

[0012] Among the similar patent applications that can be found, most of them are related to the optimization of the shape of long-span transverse stiffening cantilever and diaphragm, but no new structural or design theories have been found that substantially improve the stress on the bridge deck. Summary of the Invention

[0013] (a) Technical problems to be solved

[0014] To address the shortcomings of existing technologies, this invention provides a reinforced concrete grating bridge deck and its design method. This solves the problem that traditional wide bridge decks, in order to meet local bending moment requirements, often involve increasing the number of longitudinal webs, increasing the bridge deck thickness, and adding transverse diaphragms. This results in a significant increase in the self-weight of the superstructure of the main beam, further increasing the overall longitudinal load and construction scale of the structure, which is detrimental to the lightweight development of bridge design.

[0015] (II) Technical Solution

[0016] To achieve the above objectives, the present invention provides the following technical solution: a reinforced concrete grating bridge deck, comprising a reinforced concrete bridge deck top slab, concrete longitudinal ribs, and concrete transverse ribs. The reinforced concrete longitudinal ribs and reinforced concrete transverse ribs below the bridge deck form a grating stiffening rib / slab. The reinforced concrete longitudinal ribs can be beam or slab structures of any suitable shape. The reinforced concrete grating bridge deck is typically assembled as an integral component with one or more components such as web, hangers, columns, bottom slab, and chords, either cast in place or precast, to form the main beam structure.

[0017] A design method for a reinforced concrete grating bridge deck, comprising the aforementioned reinforced concrete grating bridge deck, is described in the following steps:

[0018] By utilizing a grid structure composed of transverse and longitudinal stiffeners with a certain bending stiffness, the local stress pattern of the bridge deck is transformed from a large-span one-way slab mode to a two-way slab or a small-span one-way slab mode to adapt to the local stress requirements of the bridge deck. This design method typically reduces the local stress span of conventional solid slab bridge decks from over 6-8 meters to 3-4 meters, thereby reducing the bridge deck thickness to a reasonable 18-25 cm.

[0019] The overall design steps for using reinforced concrete grating as the core of the bridge deck are as follows:

[0020] S1. Based on the overall bridge calculation, the optimized bridge deck thickness c is obtained after adjusting the main beam section height h0. The reasonable range of this thickness c is often between 18 and 25 cm.

[0021] S2. Based on the main beam section height h0 obtained from the overall bridge calculation, set the spacing of the transverse support / longitudinal ribs (solid web or truss web) B of the main beam section bridge deck. The reasonable range of this spacing B is often 2h0 to 2.5h0.

[0022] S3. If the calculated overall span of the bridge L0 > 20c, and the spacing of the transverse supports B on the bridge deck > 20c, transverse ribs should be provided on the bridge deck to form a grid plate with the transverse supports / longitudinal ribs. The reasonable spacing L of the transverse ribs is often 12c to 20c, the reasonable height h of the transverse and longitudinal ribs / plates is often 1 / 6B to 1 / 8B, and the width b is often 1c to 2c. The reasonable range of the cantilever length B' of the transverse flange plates is 0 to 1.2B. If B' > 0.5B and B' > 8c (where c is the thickness at the root of the cantilever), transverse prestressed steel strands or transverse stiffening ribs / plates of the cantilever need to be provided. If 1.2B > B' > 0.8B, it is advisable to provide outer longitudinal ribs. Finally, the span of the bridge deck local stress calculation can be controlled within 5m.

[0023] S4. The grid bridge deck designed according to the above principles can be set as a cast-in-place or precast structure depending on the project implementation conditions and technology. The transverse support / longitudinal rib (solid web or truss web) of the main beam bridge deck section outside the grid bridge deck height h0 range can be set as a reinforced concrete beam, prestressed concrete beam, steel plate beam composite beam and steel box composite beam, etc., depending on the specific main beam section form.

[0024] S5. Verify the structural stress state by using simulation analysis or superposition of primary and secondary bridge systems to ensure structural safety and reliability and complete the calculations based on the design.

[0025] Preferably, the concrete longitudinal ribs include concrete central longitudinal ribs and may also include concrete edge longitudinal ribs; the concrete transverse ribs include concrete central transverse ribs and may also include concrete edge transverse ribs / bridge deck cantilever transverse ribs; the connection between the concrete bridge deck and the underlying transverse and longitudinal ribs / slabs may or may not have a chamfered transition.

[0026] Preferably, the parameters may be adjusted due to changes in material properties or regional construction techniques, levels of expertise, and design practices. However, these adjustments do not change the core idea of ​​reducing the locally calculated span of the bridge deck from the spacing of the web, diaphragms, and end supports to the minimum value of the bridge deck's transverse and longitudinal ribs / slab spacing through grid-like design.

[0027] Preferably, the concrete is reinforced concrete of grade C30 or above or prestressed concrete of grade C40 or above. The concrete can be ordinary silicate concrete or high-performance concrete with other material proportions. The reinforced concrete longitudinal ribs can be beam or slab structures of any suitable shape. The connection between the concrete bridge deck and the underlying transverse and longitudinal ribs / slabs can have a chamfered transition or not.

[0028] (III) Beneficial Effects

[0029] This invention provides a reinforced concrete grating bridge deck and its design method. It has the following beneficial effects:

[0030] This reinforced concrete grating bridge deck and its design method, through the definition of the reinforced concrete grating bridge deck structure, transform the reinforced grating bridge deck from the traditional bridge deck and its stiffeners, diaphragms, and supporting structures into an independent integral component, meeting the requirements of prefabricated modular assembly. Furthermore, by using a grating structure composed of concrete longitudinal and transverse ribs with a certain flexural stiffness, and by setting support conditions according to the grating dimensions, the local stress calculation span of the bridge deck is reduced, thereby reducing the bridge deck thickness, and consequently reducing the bridge's self-weight and construction scale. This satisfies the increasing demand for bridge deck width in transportation development, meeting the requirements for lightweight and modular bridge design and construction. Attached Figure Description

[0031] Figure 1 This is a typical schematic diagram of a single-box double-cell bridge deck structure combined with a concrete web and bottom plate of the present invention.

[0032] Figure 2 This is a bottom view schematic diagram of the bridge deck structure of the present invention.

[0033] Figure 3 This is a schematic diagram of the cross-section of the small cantilever main beam using the bridge deck structure of this invention.

[0034] Figure 4 This is a schematic longitudinal section of a small cantilever main beam bridge deck using the bridge deck structure of this invention.

[0035] Figure 5 This is a schematic diagram of the main beam section of the steel-concrete composite beam using the bridge deck structure of this invention.

[0036] Figure 6 This is a schematic longitudinal section of the main beam of the steel-concrete composite beam using the bridge deck structure of this invention.

[0037] Figure 7 This is a schematic diagram of the cross-section of the main beam of a cable-stayed bridge using the bridge deck structure of this invention.

[0038] Figure 8 This is a schematic longitudinal section of the main beam of a cable-stayed bridge using the bridge deck structure of this invention.

[0039] Among them: 1. Reinforced concrete bridge deck top slab, 2. Concrete longitudinal ribs, 201. Concrete central longitudinal ribs, 202. Concrete side longitudinal ribs, 3. Concrete transverse ribs, 301. Concrete central transverse ribs, 302. Concrete side transverse ribs / bridge deck cantilever transverse ribs, 4. Main beam web, 5. Main beam bottom slab, c. Bridge deck thickness, B. Spacing of concrete central longitudinal ribs, B'. Spacing of concrete side longitudinal ribs / bridge deck cantilever length, h. Height of grid-reinforced bridge deck. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Please see Figure 1-8 The present invention provides a technical solution: a reinforced concrete grating bridge deck, comprising a reinforced concrete bridge deck top plate 1, reinforced concrete longitudinal ribs 2, and reinforced concrete transverse ribs 3. The reinforced concrete longitudinal ribs 2 and reinforced concrete transverse ribs 3 below the bridge deck form a grating stiffening rib / plate. The reinforced concrete longitudinal ribs can be any suitable beam or plate structure. The reinforced concrete grating bridge deck is usually assembled as an integral component with one or more components in the structure such as web, hangers, columns, bottom plate, and chords, either cast in place or precast, to form the main beam structure.

[0042] The concrete longitudinal rib 2 includes the concrete central longitudinal rib 201 and may also include the concrete edge longitudinal rib 202. The concrete transverse rib 3 includes the concrete central transverse rib 301 and may also include the concrete edge transverse rib / bridge deck cantilever transverse rib 302. The connection between the concrete bridge deck and the lower transverse and longitudinal ribs / slabs may or may not have a chamfer transition.

[0043] The concrete is reinforced concrete of grade C30 or above or prestressed concrete of grade C40 or above. The concrete can be ordinary silicate concrete or high-performance concrete with other material proportions. The reinforced concrete longitudinal ribs can be beam or slab structures of any suitable shape. The connection between the concrete bridge deck and the transverse and longitudinal ribs / slabs below can have a chamfered transition or not.

[0044] A design method for a reinforced concrete grating bridge deck, comprising the aforementioned reinforced concrete grating bridge deck, is described below:

[0045] By utilizing a grid structure composed of transverse and longitudinal stiffeners with a certain bending stiffness, the local stress pattern of the bridge deck is transformed from a large-span one-way slab mode to a two-way slab or a small-span one-way slab mode to adapt to the local stress requirements of the bridge deck. The design method typically reduces the local stress span of conventional solid slab bridge decks from over 6-8 meters to 3-4 meters, thereby reducing the bridge deck thickness to a reasonable 18-25 cm.

[0046] The overall design steps for using reinforced concrete grating as the core of the bridge deck are as follows:

[0047] S1. Based on the overall bridge calculation, the optimized bridge deck thickness c is obtained after adjusting the main beam section height h0. The reasonable range of this thickness c is often between 18 and 25 cm.

[0048] S2. Based on the main beam section height h0 obtained from the overall bridge calculation, set the spacing B of the bridge deck transverse support / longitudinal rib spacing, solid web or truss web spacing of the main beam section. The reasonable range of this spacing B is often 2h0 to 2.5h0.

[0049] S3. If the overall span of the bridge is calculated to be L0 > 20c, and the spacing of the transverse supports on the bridge deck is B > 20c, the bridge deck should be equipped with transverse ribs to form a grid plate with the transverse supports / longitudinal ribs. The reasonable spacing of the transverse ribs L is often 12c to 20c, the reasonable height h of the transverse and longitudinal ribs / plates is often 1 / 6B to 1 / 8B, and the width b is often 1c to 2c. The reasonable range of the cantilever length B' of the transverse flange plates is 0 to 1.2B. If B' > 0.5B and B' > 8c, where c is the thickness at the root of the cantilever, then transverse prestressed steel strands or transverse stiffening ribs / plates of the cantilever need to be installed. If 1.2B > B' > 0.8B, then outer longitudinal ribs should be installed. Finally, the span of the bridge deck local stress calculation can be controlled within 5m.

[0050] S4. The grid bridge deck set according to the above principles can be set as a cast-in-place or precast structure depending on the project implementation conditions and technology. The transverse support / longitudinal rib solid web or truss web of the main beam bridge deck section outside the grid bridge deck height h0 range can be set as a reinforced concrete beam, prestressed concrete beam, steel plate beam composite beam and steel box composite beam, etc., depending on the specific main beam section form.

[0051] S5. Verify the structural stress state by using simulation analysis or superposition of primary and secondary bridge systems to ensure structural safety and reliability and complete the calculations based on the design.

[0052] The parameters may be adjusted due to changes in material properties or regional construction techniques, levels of expertise, and design practices. However, these adjustments do not change the core idea of ​​reducing the locally calculated span of the bridge deck from the spacing of the web, diaphragms, and end supports to the minimum value of the bridge deck's transverse and longitudinal ribs / slab spacing through grid-like design.

[0053] Example:

[0054] Example 1

[0055] like Figure 2 The concrete stiffened grating bridge deck shown includes a reinforced concrete bridge deck top slab 1, concrete longitudinal ribs 2, and concrete transverse ribs 3. The reinforced concrete longitudinal ribs 2 and reinforced concrete transverse ribs 3 below the bridge deck form a grating stiffening rib / slab. The concrete longitudinal ribs 2 include a concrete central longitudinal rib 201 and a concrete edge longitudinal rib 202. The concrete transverse ribs 3 include a concrete central transverse rib 301 and a concrete edge transverse rib / bridge deck cantilever transverse rib 302. The connection between the concrete bridge deck and the underlying longitudinal and transverse ribs / slabs may or may not have a chamfered transition.

[0056] like Figure 1 The structure shown is Figure 2 The concrete stiffened grating bridge deck shown, combined with the typical main beam web 4 and main beam bottom plate 5, forms a schematic diagram of the main beam segment after forming a typical main beam cross-section.

[0057] Figures 1-2 A schematic diagram illustrating a typical structural arrangement of the present invention is provided.

[0058] Example 2

[0059] like Figure 3 The cross-section of the main beam of a large-span landscape bridge shown includes a reinforced concrete bridge deck top plate 1, concrete longitudinal ribs 2, concrete transverse ribs 3, main beam web 4, and main beam bottom plate 5. The reinforced concrete bridge deck top plate 1 and main beam bottom plate 5 have only a small cantilever on the outer side of the outer web, forming an exterior decorative groove.

[0060] The main beam has a cross-sectional width of 29.65m and a height h0 of 3m.

[0061] Furthermore, according to step 1 of the design concept of this invention, the thickness c of the reinforced concrete bridge deck is 22cm based on the longitudinal overall stress analysis.

[0062] According to step 2 of the design concept of the present invention, the reasonable range of the web spacing B of the main beam section is often 2h0 to 2.5h0. Furthermore, in this example section, the web B support spacing is 705cm, the web thickness is 45cm, and the net web B spacing is 660cm.

[0063] According to step 3 of the design concept of this invention, since (net spacing B = 660cm) > (20c = 440cm), transverse stiffening ribs need to be set. The reasonable spacing L of the transverse ribs is 12c to 20c, that is, 264cm to 440cm, the thickness b is 1c to 2c, that is, 22cm to 44cm, and the height h is 1 / 6B to 1 / 8B, that is, 82.5cm to 110cm.

[0064] like Figure 4 As shown, in this example section, the horizontal ribs are evenly spaced at a distance L of 400cm, have a thickness of 30cm, and a height of 100cm.

[0065] The web will be configured with longitudinal prestressed steel strands, which are not shown, according to the overall stress requirements.

[0066] According to calculations, in Example 2 of the single-box four-cell section scheme with the concrete stiffened grating bridge deck of the present invention, the weight and size of the main beam are reduced by 6% and 16.3% respectively compared with the scheme with the top plate thickened to 1 / 20B=33cm and the single-box eight-cell scheme.

[0067] Example 3

[0068] like Figure 5 The cross-section of a large-span steel-concrete composite beam shown includes a reinforced concrete bridge deck top plate 1, concrete longitudinal ribs 2, concrete transverse ribs 3, main beam web 4, and main beam bottom plate 5. The main beam web 4 adopts a welded stiffening steel plate structure, including an outer inclined web and a middle vertical web. The main beam web 4 and the concrete longitudinal ribs 2 are connected by shear keys. The main beam bottom plate 5 adopts an orthotropic welded steel bottom plate. Transverse diaphragms are arranged at certain intervals along the longitudinal direction of the steel structure main beam web 4 and main beam bottom plate 5.

[0069] The main beam of the steel-concrete composite beam has a cross-sectional width of 21m and a height h0 of 3m.

[0070] Furthermore, according to step 1 of the design concept of this invention, the thickness c of the reinforced concrete bridge deck is 22cm based on the longitudinal overall stress analysis.

[0071] According to step 2 of the design concept of the present invention, the reasonable range of the web spacing B of the main beam section is often 2h0 to 2.5h0. Furthermore, in this example section, the net spacing of the web B is 630cm, and the net cantilever length B' of the two side flanges is 3.45m.

[0072] According to step 3 of the design concept of this invention, since (net spacing B = 630cm) > (20c = 440cm), transverse stiffening ribs need to be set. The reasonable spacing L of the transverse ribs is 12c~20c, that is, 264cm~440cm, the thickness b is 1c~2c, that is, 22cm~44cm, and the height h is 1 / 6B~1 / 8B, that is, 78.75cm~105cm. Transverse stiffening ribs are also required for the B' value, but edge longitudinal ribs are still not required.

[0073] like Figure 6 As shown, further, in this example section, the spacing of the lower steel structure diaphragms is 6m, while the uniform spacing L of the transverse ribs of the reinforced concrete grating bridge deck is 300cm. The transverse ribs connected by shear keys at the corresponding positions of the steel structure diaphragms have a thickness of 50cm according to structural requirements. The thickness of the transverse ribs in the middle without shear key connection requirements is 30cm. The height of the middle transverse ribs is 80cm, and the height of the side transverse ribs varies linearly from 80cm to 40cm to adapt to stress and landscape requirements.

[0074] Furthermore, when the main beam section is used under the constraint conditions of a long-span continuous beam, the main beam bridge deck that continuously supports the overall longitudinal negative bending moment region will be equipped with longitudinal prestressed steel strands, which are not shown, according to the overall stress requirements.

[0075] Furthermore, in this example, when the concrete stiffened grating bridge deck structure, together with the lower steel structure web and bottom plate shown in the figure, forms a steel-concrete composite box girder, it can be connected by pouring after the shear key wet joint holes / seams are inserted into the core, or the shear key can be pre-embedded in the precast concrete stiffened grating bridge deck structure and then welded to the steel web, so as to realize the standardized implementation process of precast assembly of the main beam structure.

[0076] Clearly, the reinforced concrete grating bridge deck structure in Example 3, in addition to saving some main beam material and weight, similar to Example 2, also lowers the steel-concrete connection position of the composite section to the neutral axis region, further improving the utilization rate of the various material properties of the steel-concrete composite beam. At the same time, the lightweight grating bridge deck further increases the overall integrity and local bending resistance of the precast bridge deck, providing conditions and possibilities for the standardized precast assembly of the bridge deck structure.

[0077] Example 4

[0078] like Figure 7The cross-section of the main beam of a large-span concrete truss cable-stayed bridge shown includes a reinforced concrete bridge deck top plate 1, concrete longitudinal ribs 2, concrete transverse ribs 3, main beam web 4, and main beam bottom plate 5. The main beam web 4 adopts a spatial prestressed concrete truss rod structure, and the main beam bottom plate 5 adopts a concrete bottom plate with transverse stiffening. The spatial prestressed concrete truss web rod structure can be a pre-stressed precast component or a post-tensioned precast component.

[0079] The main beam of the steel-concrete composite beam has a cross-sectional width of 27.8m and a standard beam height h0 of 4.5m.

[0080] Furthermore, according to step 1 of the design concept of this invention, the thickness c of the reinforced concrete bridge deck is 25cm based on the longitudinal overall stress analysis.

[0081] According to step 2 of the design concept of the present invention, the reasonable range of the web spacing B for the main beam section is often 2h0 to 2.5h0. Furthermore, in this example section, the net web spacing B is 580cm, and the net cantilever length B' of the two side flanges is 580cm. The cable is anchored at the position of the middle longitudinal rib / central anchorage zone.

[0082] According to step 3 of the design concept of this invention, since (net spacing B = 580cm) > (20c = 500cm), transverse stiffening ribs need to be set. The reasonable spacing L of the transverse ribs is 12c to 20c, that is, 300cm to 500cm; the thickness b is 1c to 2c, that is, 25cm to 50cm; and the height h is 1 / 6B to 1 / 8B, that is, 72.5cm to 96.7cm. Furthermore, transverse stiffening ribs and edge longitudinal ribs also need to be set for the B' value.

[0083] like Figure 8 As shown, further, in this example section, the transverse ribs of the reinforced concrete grating bridge deck are evenly spaced at a distance L of 400cm, and the corresponding vertical web member spacing is also 400cm. The longitudinal spacing of the stay cables adopts a double truss segment spacing of 800cm. The thickness of all transverse ribs in the bridge deck is 30cm, the height of the middle transverse rib is 100cm, and the height of the side transverse ribs varies linearly from 80cm to 70cm to adapt to stress and landscape requirements.

[0084] Furthermore, when this main beam section is used in long-span cable-stayed bridges, in addition to the prestressing of the web / web members, the main beam bridge deck and bottom plate will also be equipped with corresponding prestressed steel strands according to the stress requirements. Since they are not related to the scope of this invention, they are not shown.

[0085] Furthermore, in this example, the main beam section can be implemented using a standardized prefabrication and assembly method for the concrete stiffened grating bridge deck, web members, and bottom plate.

[0086] Furthermore, in this example, the web structure of the main beam section can also be replaced with a solid web structure instead of the web structure of the spatial prestressed concrete truss.

[0087] According to engineering estimates, the material and weight of the superstructure main girder of the 178+320+178m central single-cable-plane double-tower three-span prestressed concrete cable-stayed bridge using this lightweight main girder section (solid web) is only 58% of that of the superstructure main girder of a traditional single-box multi-cell cable-stayed bridge of the same span.

[0088] The reinforced concrete grid bridge deck structure and its design method proposed in this invention, on the one hand, define the reinforced concrete grid bridge deck structure, transforming it from a traditional bridge deck with its stiffeners, diaphragms, and support structures into an independent integral component, thus meeting the requirements of prefabricated modular assembly. On the other hand, through the grid structure composed of concrete longitudinal ribs 2 and concrete transverse ribs 3 with a certain bending stiffness, and by setting full or partial supports according to the grid size, the local stress span of conventional solid slab bridge decks is reduced from over 6-8 meters to about 3-4 meters, thereby reducing the bridge deck thickness to a reasonable 18-25 cm, and further reducing the bridge's self-weight and construction scale. This meets the design and construction requirements for lightweight and modular bridges in response to the ever-increasing demand for bridge deck width in transportation development.

[0089] In summary, this reinforced concrete grating bridge deck and its design method, through the definition of the reinforced concrete grating bridge deck structure, transform the reinforced grating bridge deck from the traditional bridge deck and its stiffeners, diaphragms, and support structures into an independent integral component, satisfying the prefabrication and modular assembly mode. Furthermore, by using a grating structure composed of concrete longitudinal and transverse ribs with a certain flexural stiffness in the bridge deck, and by setting support conditions according to the grating dimensions, the local stress calculation span of the bridge deck is reduced, thereby reducing the bridge deck thickness, and consequently reducing the bridge's self-weight and construction scale. Thus, under the ever-increasing demand for bridge deck width in transportation development, it meets the design and construction requirements for lightweight and modular bridges.

[0090] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0091] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A design method for reinforced concrete grating bridge deck panels, characterized in that: The present invention includes a reinforced concrete grating bridge deck, which comprises a reinforced concrete bridge deck top slab (1), reinforced concrete longitudinal ribs (2), and reinforced concrete transverse ribs (3). The reinforced concrete longitudinal ribs (2) and reinforced concrete transverse ribs (3) below the bridge deck form grating stiffeners. The reinforced concrete longitudinal ribs are beam or slab structures of any suitable shape. The reinforced concrete grating bridge deck, as an integral component, is cast-in-place or precast and assembled with one or more components of the web, hangers, columns, bottom plate, and chords to form the main beam structure. The specific steps for designing reinforced grating bridge deck panels are as follows: By utilizing a grid structure composed of transverse and longitudinal stiffeners with bending stiffness, the local stress mode of the bridge deck is transformed from a large-span one-way slab mode to a two-way slab or a small-span one-way slab mode to adapt to the local stress requirements of the bridge deck. The design method reduces the local stress span of conventional solid slab bridge decks from more than 6 meters to 3-4 meters, thereby reducing the bridge deck thickness to a reasonable 18-25 cm. The overall design steps for using reinforced concrete grating as the core of the bridge deck are as follows: S1. Based on the overall bridge calculation, after adjusting the main beam section height h0, the optimized bridge deck thickness c is obtained. The reasonable range of thickness c is between 18 and 25 cm. S2. Based on the main beam section height h0 obtained from the overall bridge calculation, set the transverse support spacing B of the bridge deck of the main beam section. The reasonable range of this spacing B is 2h0~2.5h0. S3. When the calculated overall span of the bridge is L0 > 20c and the spacing of the transverse supports of the bridge deck is B > 20c, the bridge deck should be equipped with transverse ribs to form a grid plate with the transverse supports. The reasonable spacing of the transverse ribs is 12c~20c, the reasonable height h of the transverse and longitudinal ribs is 1 / 6 B ~ 1 / 8B, and the width b is 1c~2c. The reasonable range of the cantilever length B' of the transverse bridge flanges on both sides is 0~1.2B. When B' > 0.5B and B' > 8c, where c is the thickness at the root of the cantilever, transverse prestressed steel strands or transverse stiffening ribs of the cantilever need to be set. When 1.2B > B' > 0.8B, outer longitudinal ribs are set. Finally, the span of the bridge deck local stress calculation is controlled within 5m. S4. The grid bridge deck, as set according to the above principles, shall be set as a cast-in-place or precast structure according to the project implementation conditions and process. The transverse support of the main beam bridge deck section outside the grid bridge deck height h0 within the main beam height h0 shall be set as a reinforced concrete beam, prestressed concrete beam, steel plate beam composite beam and steel box composite beam structure according to the specific main beam section form. S5. Verify the structural stress state by using simulation analysis or superimposing the primary and secondary systems of the bridge to ensure structural safety and reliability and complete the calculations based on the design.

2. The design method for a reinforced concrete grating bridge deck according to claim 1, characterized in that: The concrete longitudinal rib (2) includes a concrete central longitudinal rib (201) and a concrete side longitudinal rib (202). The concrete transverse rib (3) includes a concrete central transverse rib (301) and a concrete side transverse rib (302). The connection between the reinforced concrete bridge deck top plate (1) and the lower transverse and longitudinal ribs has a chamfered transition but no chamfered transition.

3. The design method for a reinforced concrete grating bridge deck according to claim 1, characterized in that: The concrete is reinforced concrete of grade C30 or above or prestressed concrete of grade C40 or above. The concrete is ordinary silicate concrete or high-performance concrete with other material proportions. The reinforced concrete longitudinal ribs are beam or slab structures of any suitable shape. The connection between the top plate (1) of the reinforced concrete bridge deck and the transverse and longitudinal ribs below has a chamfered transition but no chamfered transition.

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